000
FXUS63 KBIS 020852
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
353 AM CDT THU SEP 2 2010

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...

FORECAST HIGHLIGHTS TODAY INCLUDE...EXPANDING THE WIND ADVISORY
TO ENCOMPASS ALL OF WESTERN AND CENTRAL NORTH DAKOTA TODAY THROUGH
EARLY EVENING. ISOLATED THUNDERSTORMS TODAY BUT SHOULD REMAIN NON-
SEVERE. A COUPLE THUNDERSTORMS MAY YIELD SMALL HAIL THIS AFTERNOON
AND ALSO MAY ENHANCE THE ALREADY GUSTY SURFACE WINDS.

VERY HIGH RANGELAND FIRE DANGER INDICES ACROSS THE FAR SOUTHWEST
AND WILL HIGHLIGHT THIS IN THE HWO AND NOAA WEATHER RADIO...BUT
RELATIVE HUMIDITIES A BIT TOO HIGH FOR ANY RED FLAG HIGHLIGHTS AT
THIS TIME.

LATEST WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING INTO
NORTHEASTERN MONTANA THIS MORNING AS THE UPPER TROUGH CONTINUES TO
SHARPEN UP. THIS IS DUE TO A 100KT H3 JET STREAK MOVING INTO THE
BASE OF THE TROUGH AT THIS MOMENT. ALTHOUGH THE BEST FORCING IS
NOW EAST OF WESTERN AND CENTRAL NORTH DAKOTA...INSTABILITY SHOWERS
WILL TAKE OVER THROUGH THE DAY AS SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOP AND TRANSLATE THROUGH. LATEST REGIONAL RADAR
SHOWING SCATTERED SHOWERS OVER NORTHEAST MONTANA AND ALSO ACROSS
NORTHERN AND PORTIONS OF CENTRAL NORTH DAKOTA. TQ INDICES OF 16C
TO 18C ESPECIALLY OVER CENTRAL NORTH DAKOTA BY AROUND 18Z WARRANTS
AT LEAST AN ISOLATED MENTION OF LOW TOP THUNDERSTORMS. SOUNDINGS
SHOW GENERALLY UNIDIRECTIONAL FLOW THROUGH THE COLUMN AND WEAK
CAPE. CANNOT RULE OUT SOME PEA SIZE HAIL TODAY BUT NOTHING SEVERE.
GUSTY WINDS DUE TO A TIGHT PRESSURE GRADIENT BETWEEN SURFACE LOW
PRESSURE OVER SOUTHERN MANITOBA AND HIGH PRESSURE OVER CENTRAL
MONTANA WILL PRODUCE SUSTAINED NORTHWEST WINDS OF 25 TO 35 MPH
WITH GUSTS TO 40 AND 45 MPH THROUGH EARLY EVENING. HENCE HAVE
EXPANDED THE WIND ADVISORY GRADUALLY ACROSS THE FORECAST AREA
THROUGH THE DAY AS A LOW-END WIND ADVISORY TAKES SHAPE. SHOWERS
MAY ALSO MIX DOWN STRONGER WINDS ALOFT HELPING TO INCREASE THE
WINDS AT TIMES. THE SCATTERED SHOWERS WILL DWINDLE ACROSS THE WEST
BY EARLY AFTERNOON AND THIS TREND WILL PROGRESS EAST THROUGH
SUNSET. SKIES WILL TREND CLEAR OVERNIGHT WITH MUCH COOLER AIR
SETTLING IN ACROSS WESTERN AND CENTRAL NORTH DAKOTA.

THE COLDEST MORNING ACROSS THE WEST AND SOUTHWEST WILL BE FRIDAY
MORNING...WITH THE CENTRAL ZONES COLDEST SATURDAY MORNING AS HIGH
PRESSURE SLIDES JUST TO OUR EAST. EXPECT OVERNIGHT LOWS IN THE
UPPER 30S TO AROUND 40F ACROSS WESTERN AND SOUTHWESTERN NORTH
DAKOTA FRIDAY MORNING. THE REST OF CENTRAL NORTH DAKOTA WILL
EXPERIENCE LOWS IN THE 40S. SATURDAY MORNING WILL SEE A PLETHORA
OF TEMPERATURES AROUND 40F ACROSS CENTRAL NORTH. THE FAR WEST
SHOULD BE A BIT WARMER WITH LOWER TO MID 40S SATURDAY MORNING. ALL
LOCALES REMAIN ABOVE 36F BOTH MORNINGS SO NO FROST HIGHLIGHTS AT
THIS TIME. HETTINGER GETS CLOSE FRIDAY MORNING WITH A LOW AROUND
38F. WILL CONTINUE TO MONITOR AND PASS THIS ALONG TO THE NEXT
SHIFT FOR FURTHER INTERROGATION.

FRIDAY AND SATURDAY...RIDGE OF HIGH PRESSURE OFF TO OUR WEST WILL
BRING CLEAR CONDITIONS WITH A SLOW MODERATING TREND. CLOUDS WILL
INCREASE IN THE WEST SATURDAY NIGHT AS THE H7 RIDGE AXIS MOVES
INTO CENTRAL NORTH DAKOTA. MODELS INDICATE A LEE SIDE TROUGH IN
EASTERN MONTANA WILL GENERATE A COUPLE OF SHOWERS CLOSE TO THE
WESTERN BORDER LATE SATURDAY NIGHT. KEPT THE FORECAST DRY FOR NOW.

.LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT...

THE 00 UTC ECMWF AND GFS ARE BEGINNING TO COME INTO BETTER AGREEMENT
THROUGH THE LONG TERM BUT DIFFERENCES STILL EXIST BETWEEN THE
MODELS.  THE LONG TERM PERIOD BEGINS AS UPPER LEVEL RIDING IS MOVING
EASTWARD THROUGH THE NORTHERN PLAINS WITH THE RIDGE AXIS PASSING
THROUGH THE REGION ON SUNDAY. A STRONG 500 HPA TROUGH IS MOVING FROM
BRITISH COLUMBIA INTO THE SOUTHERN CANADIAN PRAIRIE. BOTH MODELS
DEPICT SHORTWAVES EMANATING FROM THE TROUGH PUSHING UP AGAINST THE
UPPER LEVEL RIDGE AXIS AS IT EXITS EASTWARD ON SUNDAY. HOWEVER THE
LOWER ATMOSPHERE APPEARS DRY SO CHANCES OF PRECIPITATION MAY BE
LIMITED INTO SUNDAY EVENING. WE DID ADD A SLIGHT CHANCE OF
PRECIPITATION IN THE FAR NORTHWEST DURING THE DAY SUNDAY. BY
MONDAY...THE MAIN UPPER LEVEL ENERGY MOVES INTO THE NORTHERN PLAINS
AND PUSHES AN OCCLUDED FRONT THROUGH THE REGION WITH MODELS
DEPICTING WIDESPREAD PRECIPITATION OVER THE STATE MONDAY THROUGH
MONDAY NIGHT. THEREFORE WE RAISED POPS INTO THE CHANCE CATEGORY
ACROSS THE ENTIRE CWA ON MONDAY...WITH GOOD CHANCE POPS ACROSS THE
NORTH. KEPT CHANCE POPS FOR ALL BUT THE FAR SOUTHWEST MONDAY NIGHT.
AS THE UPPER LEVEL LOW LIFTS INTO SOUTHWESTERN ONTARIO ON TUESDAY
THE GFS AND ECMWF DEVELOP SOUTHWEST FLOW ALOFT OVER THE REGION. LATE
TUESDAY INTO WEDNESDAY A SHORTWAVE RIDGE IS FORECAST TO BUILD OVER
NORTHERN PLAINS...BRINGING A QUIETER END TO THE LONG TERM PERIOD.

NEAR NORMAL TEMPERATURES ON SUNDAY BEFORE COOLER AIR SPILLS
SOUTHWARD EARLY NEXT WEEK BRINGING BELOW NORMAL TEMPERATURES TO THE
LOCAL AREA.

&&

.AVIATION...

A STRONG UPPER LEVEL LOW REMAINS OVER THE NORTHERN PLAINS EARLY THIS
MORNING AND CONTINUES TO SLOWLY SHIFT EASTWARD OVER THE NEXT 24
HOURS. A TIGHTENING PRESSURE GRADIENT AND COLD AIR FLOWING INTO THE
REGION WILL LEAD TO INCREASING WINDS FROM EARLY THIS MORNING INTO
LATE THIS AFTERNOON. GENERALLY WEST TO NORTHWEST WINDS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA OF 20 TO 30 KNOTS. GUSTS TO AROUND
35 KNOTS ARE POSSIBLE THIS AFTERNOON. WINDS ARE FORECAST TO SUBSIDE
AFTER 00 UTC FRIDAY IN THE WEST BUT MAY HOLD UP A BIT LONGER IN THE
FAR EASTERN CWA.

CURRENTLY...SCATTERED SHOWERS CONTINUE ACROSS MAINLY CENTRAL NORTH
DAKOTA WITH ANOTHER ROUND IN NORTHEAST MONTANA. SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS CAN BE EXPECTED THROUGH LATE THIS
AFTERNOON. PRECIPITATION BEGINS ENDING FROM WEST TO EAST IN THE
AFTERNOON. EXPECT MAINLY VFR CEILINGS TODAY WITH SOME MVFR CEILINGS
POSSIBLE IN AREAS OF SHOWERS...ESPECIALLY THROUGH THIS MORNING. BY
THIS AFTERNOON...MODEL FORECAST SOUNDINGS INDICATE CEILINGS SHOULD
LIFT ABOVE MVFR WITH THE POSSIBLE EXCEPTION OF JAMESTOWN.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON CDT /11 AM MDT/ TODAY TO 7 PM CDT /6 PM
MDT/ THIS EVENING FOR NDZ001>003-009>011-017>021-034-035-042-045-
046.

WIND ADVISORY FROM 6 AM THIS MORNING TO 6 PM MDT THIS EVENING
FOR NDZ031>033-040-041-043-044.

WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING
FOR NDZ004-005-012-013-022-023-025-036-037-047-048-050-051.

&&

$$
KS/DC/TWH

000
FXUS63 KFGF 020812
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
312 AM CDT THU SEP 2 2010

.DISCUSSION...

THE MAIN CHALLENGE WILL BE WINDS TODAY AND PRECIP CHANCES...AND
TEMPS THROUGH THE FORECAST. MODELS CONTINUE IN RELATIVELY GOOD
AGREEMENT...WITH THE GFS PERFORMING BETTER OF LATE AND
INITIALIZING WELL ON CURRENT WEATHER TRENDS...SO WILL UTILIZE THIS
MORNING.

FOR TODAY/TONIGHT...SFC AND UPPER LEVEL LOW PRESSURE WILL CLOSE OFF
AROUND THE ARROWHEAD OF MN THIS EVENING. THIS WILL CAUSE A STRONG
PRESSURE GRADIENT AND PLENTY OF WRAPAROUND SHOWERS AND A FEW
LIGHTNING STRIKES FOR THE REGION. INSTABILITY PARAMETERS ARE
STRONGEST FROM 18Z-21Z...WITH SFC CAPE AROUND 1000 J/KG AND LI/S
TO -4C. THEREFORE...EXPECT A SMALL WINDOW OF A FEW STORMS
PRODUCING MARGINALLY SEVERE HAIL THIS AFTERNOON. THE BIGGER STORY
WILL BE INCREASING WINDS...WITH 850MB WINDS INCREASING TO AROUND
50KT BY 00Z THIS EVENING. SOUNDINGS INDICATE AN ADIABATIC LAYER TO
NEAR 850MB WILL DEVELOP ALONG WITH A PRESSURE RISE SURGE COMING
DOWN THE VALLEY. THEREFORE...EXPECT ADVISORY LEVEL WINDS WITH
GUSTS OVER 40 MPH IN THE VALLEY AND POINTS WEST FROM 21Z-03Z...AND
A WIND ADVISORY WILL BE ISSUED. THERE COULD ALSO BE SOME MIXING OF
STRONG WINDS TO THE SFC NEAR ANY SHOWERS OR THUNDERSTORMS THIS
AFTERNOON INTO THE EVENING AS WELL. WINDS MAY REMAIN IN OR NEAR
ADVISORY LEVELS AFTER 03Z...BUT AT LEAST SOME DECOUPLING IS
EXPECTED. LATER SHIFTS WILL NEED TO EVALUATE THIS POTENTIAL. TEMPS
WILL BE WELL BELOW NORMAL WITH PLENTY OF CLOUDS AND COLD ADVECTION
TODAY AND TONIGHT.

ON FRIDAY...IT WILL REMAIN WINDY FOR A GOOD PORTION OF THE DAY
ALONG AND EAST OF THE VALLEY. SOME LINGERING SHOWERS WILL BE
POSSIBLE EARLY IN THE MORNING IN THE FAR EAST...WITH MOST AREAS
DRY. TEMPS WILL REMAIN BELOW NORMAL ONCE AGAIN.

FOR SAT/SUN...EXPECT A DRY PERIOD WITH PLENTY OF SUNSHINE DURING
THE DAY AND MOSTLY CLEAR NIGHTS. DAYTIME HIGHS SHOULD BE IN THE
60S FOR THE MOST PART...PERHAPS WARMING INTO THE LOW/MID 70S ON
SUNDAY. EACH MODEL RUN FOR THE PAST SEVERAL DAYS HAS CONTINUE TO
BE COOLER IN THIS TIME PERIOD...SO HAVE LOWERED TEMPS A BIT.
OVERNIGHT LOWS WILL ALSO GET CHILLY WITH SOME MID/UPPER 30S
POSSIBLE NEAR THE SFC HIGH PRESSURE RIDGE.

ON MONDAY/MON. NIGHT...A STRONG SYSTEM WILL MOVE IN FROM THE SW...AND
SPREAD SHOWERS AND STORMS BACK INTO THE REGION. THERE WILL BE
ELEVATED INSTABILITY AND PWATS RISING OVER AN INCH...SO HAVE
INCREASED POPS A BIT FOR THIS PERIOD. TEMPS WILL HINGE ON
INSOLATION...AND WITH EXPECTED CLOUDS AND PRECIP EXPECT TEMPS TO
LIKELY REMAIN BELOW NORMAL.

&&

.AVIATION...

EXPECT MAINLY VFR CIGS THIS MORNING...FALLING INTO THE MVFR
CATEGORY LATER THIS AFTERNOON AND EVENING. NW WINDS WILL ALSO
INCREASE AND GUST OVER 30KT LATE THIS AFTERNOON AND EVENING.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING
     FOR NDZ006>008-014>016-024-026>030-038-039-049-052>054.

MN...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING
     FOR MNZ001>004-007-029.

&&

$$
DK

000
FXUS63 KFGF 020133
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
830 PM CDT WED SEP 1 2010

.DISCUSSION...FORECAST CHALLENGE FOR UPDATE CONCERNS CONTINUED PCPN
CHANCES AND TEMPERATURES. MAIN BAND OF PCPN PUSHING ACROSS VALLEY
REGION IN ZONE OF WARM ADVECTION AHEAD OF LEAD IMPULSE IN MID LEVEL
TROUGH. T CONTINUES ACROSS NORTHERN DVL BASIN AND NE SD ASSOCIATED
WITH STRONGER FORCING WITH TWO SURFACE LOW CENTERS ONE ALONG ND/SD
BORDER NW OF ABR AND ANOTHER WEAKER CIRCULATION BETWEEN MOT AND
DVL.  MSAS SURFACE PRESSURE FALLS INDICATE TWIN LOWS SHOULD
GENERALLY PROPAGATE EAST. FAVORED CONVECTIVE PARAMETERS REMAIN IN SD
ALTHOUGH CONVECTION HAS MAINTAINED THIS EVENING ALONG CANADIAN
BORDER. EXPECT THIS WHOLE AREA TO CONTINUE TO SHIFT EAST ACROSS MN
AHEAD OF WAVE. ONCE MAIN BAND MOVES THROUGH WILL LIKELY SEE A BREAK
IN PCPN UNTIL LATE TONIGHT/THURSDAY WHEN WRAP AROUND PCPN AFFECTS
PARTS OF FA. WILL ADJUST POPS ACCORDINGLY HOWEVER CURRENT FORECAST
HAS GENERAL IDEA OF PCPN TRENDS. CLOUDS...LACK OF COLD ADVECTION
UNTIL LATE ACROSS NW AND AND LOW LEVEL MOISTURE SHOULD HOLD
TEMPERATURES UP OVERNIGHT.

&&

.AVIATION...
EXPECT VFR CONDITIONS THROUGH THIS EVENING. INCREASING CHANCES OF
RAIN SHOWERS/ISOLD T WILL SHIFT FROM VALLEY REGION INTO MN DURING
THE OVERNIGHT. BEHIND MAIN BAND PCPN WILL BE MORE SPOTTY. MVFR CIGS
WILL DEVELOP OVERNIGHT AS UPPER TROUGH GETS CLOSER. ANTICIPATE
MVFR/VFR OVC/BKN CIGS CONTINUING THROUGH TOMORROW MORNING WITH A
POSSIBILITY OF -SHRA LATE IN THE MORNING.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

VOELKER

000
FXUS63 KFGF 012011
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
311 PM CDT WED SEP 1 2010

.SHORT TERM...
THE MAIN CHALLENGE FOR THIS PACKAGE IS TIMING OF LOW PRESSURE SYSTEM
TRACKING ACROSS THE FA. MODELS IN GOOD AGREEMENT ON PROGRESSION OF
SYSTEM AND WENT WITH A BLENDED SOLN ATTM.

TONIGHT-THURSDAY...SFC ANALYSIS SHOWS AREA OF LOW PRESSURE IN SW ND
WITH SRLY WINDS BRINGING WARM ADVECTION TO THE AREA. TEMPS HAVE
INCREASED A BIT OVER PREVIOUS FCST AND HAVE ADJUSTED ACCORDINGLY.
OTHERWISE...SAT SHOWS CIRCULATION IN SW ND WITH BAROCLINIC LEAF
SPREADING OVER ERN ND...AND IS EXPECTED TO PUSH INTO WRN MINNESOTA
THRU THE LATE AFTERNOON AND EVENING HOURS. NOT LOOKING FOR STRONG
ASCENT AS LIFTED INDICIES RANGE FROM 0 TO -2 AND CAPE VALUES ARE
ONLY EXPECTED TO BE AROUND 400 J/KG. THUS...LOOKING MAINLY AT -SHRA
WITH ISOLD TSTMS. PCPN LOOKS TO CONTINUE THRU THE AFTERNOON THURSDAY
WITH MOISTURE WRAPPING BEHIND THE LOW AS IT TRACKS E.

FOR FRIDAY AND SATURDAY...COLD ADVECTION AND FAIRLY TIGHT GRADIENT
WILL HELP DRIVE WINDS ON FRI SO LOOKING AT POSSIBILITY OF ADVISORY
CRITERIA. OTHERWISE...COOLER AIR FILTERING SOUTH OUT OF CANADA WILL
USHER IN DRIER AIR AND HELP DROP MIN TEMPS...MAKING IT FEEL MORE
LIKE FALL.

.LONG TERM (SUN-WED)...
THE MAIN CHALLENGE IN THE LONG TERM IS DETERMINING THE PCPN
POTENTIAL ASSOCIATED WITH A LOW PRESSURE SYSTEM THAT COULD AFFECT
THE NORTHERN PLAINS LATE THIS WEEKEND AND INTO EARLY NEXT WEEK.
HOWEVER...THE MODELS ARE IN POOR AGREEMENT WITH SIGNIFICANT
DIFFERENCES IN TIMING AND TRACKING OF THE LOW PRESSURE.
THEREFORE...LEANED ON THE PREVIOUS FORECAST UNTIL A MODEL CONSENSUS
OCCURS.

SUNDAY SHOULD OFFER A WARMER END TO THE WEEKEND AFTER A COOL
SATURDAY. CLOUD COVER WILL INCREASE SUNDAY NIGHT AS A LOW PRESSURE
SYSTEM APPROACHES THE NORTHERN PLAINS...WITH CHANCES OF SHOWERS AND
STORMS THROUGH EARLY NEXT WEEK AS THE SYSTEM PASSES THROUGH THE
REGION. KEPT CHANCES LOW DUE THE MODEL DIFFERENCES. COOLED
TEMPERATURES A BIT MONDAY AND TUESDAY...AND THIS MAY NEED TO COME
DOWN EVEN MORE IF THE MODELS PINPOINT THE BEST TIMING OF CLOUD COVER
AND PCPN WITH THE SYSTEM.

&&

.AVIATION...
EXPECT VFR CONDITIONS THROUGH THIS EVENING. THERE WILL INCREASING
CHANCES OF RAIN SHOWERS THROUGH THE EVENING. THERE COULD BE SOME
ISOLATED THUNDER...SO INCLUDED CB IN THE TAFS. THE SOUTHERLY WINDS
AROUND 10 KNOTS WILL WEAKEN A BIT THIS EVENING. MVFR CIGS WILL
DEVELOP OVERNIGHT...AND -SHRA SHOULD CONTINUE THROUGH MOST OF THE
NIGHT. THE WINDS WILL BECOME WESTERLY TO NORTHWESTERLY TOMORROW
MORNING WITH THE PASSING SYSTEM. ANTICIPATE MVFR/VFR OVC/BKN CIGS
CONTINUING THROUGH TOMORROW MORNING WITH A POSSIBILITY OF -SHRA LATE
IN THE MORNING.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

HOPKINS/GROCHOCINSKI

000
FXUS63 KBIS 012000
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
300 PM CDT WED SEP 1 2010

.SHORT TERM...

CLOUD COVER LIMITING INSOLATION AND WEAK MOISTURE LEVELS HAS LEAD TO
THE DEVELOPMENT OF ONLY WEAK INSTABILITY THIS AFTERNOON ACROSS THE
EASTERN PORTIONS OF THE CWA. SPC HAS KEPT THE JAMES RIVER VALLEY IN
THE 2 PERCENT TORNADO CONTOUR FOR THIS AFTERNOON AND EVENING...PER
STRONG LEVEL SHEAR. HOWEVER...THE AFOREMENTIONED WEAK INSTABILITY
SHOULD PRECLUDE ANY THREAT OF SEVERE WEATHER. THAT SAID...SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ARE FORECAST TONIGHT ACROSS MUCH
OF THE CWA IN ASSOCIATION WITH THE UPPER LEVEL LOW. A ZONE OF WARM
AIR ADVECTION ACROSS THE JAMES RIVER VALLEY AHEAD OF A SURFACE
TROUGH WILL BE THE FOCUS FOR THE MOST ORGANIZED PRECIPITATION ON
WEDNESDAY EVENING. A DRY SLOT SHOULD THEN OVERTAKE THIS AREA AFTER
MIDNIGHT TONIGHT...WITH A RESULTING POSSIBLE LULL IN PRECIPITATION
ACROSS THE JAMES RIVER VALLEY.

THE CENTER OF THE UPPER LEVEL LOW IS FORECAST TO BE POSITIONED
ACROSS THE RED RIVER VALLEY BY 18 UTC FRIDAY...WITH A WEAK TROWAL
ARCHING INTO THE FAR SOUTHWEST PORTIONS OF THE CWA. A COOL POCKET
ALOFT...WITH 500 MB TEMPERATURES NEAR -20 C...POINTS TO SCATTERED
SHOWERS AND ISOLATED THUNDER ACTIVITY ACROSS THE CWA ON THURSDAY.
THE THREAT FOR SHOWERS SHOULD DECREASE ACROSS THE WEST IN THE MID TO
LATE AFTERNOON AS THE BEST FORCING AND MOISTURE SHIFTS EAST AS THE
UPPER LEVEL LOW PROPAGATES TOWARDS FAR WESTERN LAKE SUPERIOR.
DIURNALLY DRIVEN CLOUDS AND ANY REMAINING SHOWERS WILL DISSIPATE
WITH SUNSET ACROSS THE AREA THURSDAY NIGHT.

IN ADDITION TO PRECIPITATION....WIND WILL ALSO BE A HIGHLIGHT ON
THURSDAY. MAIN QUESTION IS WHETHER OR NOT ADVISORY CRITERIA GUSTS
WILL BE REACHED. THE BEST DEEP LAYER UNIDIRECTIONAL FLOW AND
SUBSIDENCE ON THE BACKSIDE OF THE UPPER LEVEL LOW IS FORECAST TO BE
LOCATED ACROSS THE FAR SOUTHWEST THURSDAY MORNING...WITH THE
STRONGEST WINDS SPREADING EAST INTO THE CENTRAL PORTIONS OF THE CWA
BY 15 TO 18 UTC AND THE JAMES RIVER VALLEY BY 18 TO 21 UTC. BEST
ISALLOBARIC PUSH ASSOCIATED WITH A 6 TO 8 MB SIX HOUR PRESSURE RISE
APPEARS TO BE BETWEEN 16 AND 00 UTC...ENHANCING GRADIENT WIND
SPEEDS AND GUSTS FROM MOMENTUM TRANSFER. 12 UTC GFS BUFR SOUNDINGS
INDICATE GREATER MIXING DEPTH THAN THE NAM...WHILE THE NAM BUFR
SOUNDINGS INDICATE 40+ KTS TO MIX...COMPARED TO 30 TO 35 KTS ON
THE GFS. AT THIS TIME...HIGHEST CONFIDENCE FOR REACHING 40 MPH
GUSTS OR HIGHER IS TOMORROW MORNING INTO MID DAY IN THE
SOUTHWEST...AND WILL ISSUE A WIND ADVISORY FOR THIS AREA.
CERTAINLY IT WILL BE WINDY ACROSS THE REST OF THE CWA.
HOWEVER...DIFFERENCES IN THE GFS AND NAM EVOLUTIONS OF THE WIND
FIELD LEAD TO HIGH ENOUGH UNCERTAINTY TO HOLD OFF FOR NOW ON A
WIND ADVISORY FURTHER EAST. WILL LET THE MID NIGHT SHIFT TAKE
ANOTHER LOOK AND SEE HOW WINDS ARE DEVELOPING FURTHER WEST LATE
TONIGHT INTO TOMORROW MORNING.

ON THURSDAY NIGHT...HIGH PRESSURE IS FORECAST TO BUILD INTO WESTERN
AND CENTRAL NORTH DAKOTA. DRIER AIR ASSOCIATED WITH THIS
SYSTEM...LIGHT WINDS AND CLEAR SKIES SUGGEST A FAIRLY COOL NIGHT
ACROSS THE AREA. THE FAVORED COOL SPOTS OF THE SOUTHWEST WILL HAVE
TO BE MONITORED FOR FROST...WITH ITS POTENTIAL DEPENDENT UPON HOW
LOW OF DEW POINTS CAN BE ADVECTED INTO THE SOUTHWEST BEHIND THE
DEPARTING LOW.

CYCLONIC FLOW REMAINING ALOFT OVER THE CENTRAL PORTIONS OF THE
CWA...AND WEAK MIXING WITH HIGH PRESSURE AT THE SURFACE SHOULD LEAD
TO ANOTHER COOL DAY WITH TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL
ON FRIDAY. AN UPPER LEVEL RIDGE IS FORECAST TO BUILD INTO THE
NORTHERN PLAINS ON SATURDAY...WITH LEE SURFACE TROUGHING ACROSS
EASTERN MONTANA....RESULTING IN SOUTHEASTERLY SURFACE FLOW NORTH OF
A CENTRAL PLAINS WARM FRONT. SUCH A SURFACE FLOW PATTERN ON SATURDAY
SUGGEST A INCREASE IN TEMPERATURES ON SATURDAY COMPARED TO
FRIDAY...ALBEIT RELATIVELY SMALL...AROUND 5 DEGREES.

.LONG TERM...

FORECAST CHALLENGE IN THE EXTENDED PERIOD WILL BE THE EVENTUAL
EVOLUTION OF A CLOSED MID/UPPER LEVEL LOW WHICH IS FORECAST TO
SLOWLY PUSH EAST ACROSS THE NORTHWEST AND NORTH CENTRAL CONUS
SUNDAY-TUESDAY. MODELS ARE TRENDING TOWARDS A CONSENSUS...BUT FOR
NOW WILL KEEP CHANGES FROM THE INHERITED FORECAST MINIMAL.

AN UPPER LEVEL RIDGE AXIS WILL PUSH EAST ACROSS THE NORTHERN PLAINS
REGION SUNDAY DAYTIME...THEN INTO THE EASTERN DAKOTAS/UPPER
MISSISSIPPI VALLEY BY MONDAY MORNING AS THE UPPER LOW MIGRATES EAST
INTO THE NORTHERN ROCKIES. THE ECMWF IS FASTER IN TRANSITIONING OUR
FLOW ALOFT TO SOUTHWESTERLY SUNDAY AFTERNOON...IN ADDITION WITH
BRINGING LEAD S/WV IMPULSES INTO THE LOCAL AREA. THE GFS IS SLOWER
AND REMAINS DRY. WILL MAINTAIN A DRY FORECAST SUNDAY DAYTIME FOR
NOW...BUT WILL LIKELY NEED TO INCREASE PRECIP CHANCES IF THE GFS
TRENDS MORE TOWARDS THE EC.

THE UPPER LEVEL LOW AND ITS ASSOCIATED SFC LOW PUSH ACROSS THE
NORTHERN PLAINS MONDAY AND MONDAY NIGHT. WILL MAINTAIN CHANCE POPS
AS EVEN THOUGH THE LAST COUPLE OF EC RUNS ARE SIMILAR WITH PRECIP
LIKELY...THIS IS ONLY TWO CONSECUTIVE RUNS WITH PREVIOUS VERSIONS
VASTLY DIFFERENT. IF TRENDS CONTINUE...WILL NEED TO INCREASE POPS
SUBSTANTIALLY FOR MON/MON NIGHT OVER THE NEXT FEW FORECAST ISSUANCES
AS WELL AS LOWER MONDAYS MAX TEMPS.

MODELS EJECT THE UPPER LOW NORTH INTO SOUTH CENTRAL CANADA
TUES-WED...SO WILL GO DRY. WE MAY NEED TO RE-INTRODUCE PRECIP
CHANCES FOR ANY LINGER SHOWERS OR THUNDERSTORMS FOR TUESDAY
DEPENDING ON HOW FAST THIS STORM SYSTEM MOVES OUT OF OUR AREA OF
INTEREST.

TEMPERATURES WILL AVERAGE NORMAL ON SUNDAY...THEN TREND COOLER
MON-WED.

&&

.AVIATION...

A POTENT UPPER LEVEL TROUGH WILL CONTINUE TO SLIDE EAST ACROSS THE
NORTHERN PLAINS REGION TODAY INTO TOMORROW...BRINGING A CONTINUED
THREAT FOR SHOWERS AND THUNDERSTORMS TO MOST LOCATIONS. WINDS WILL
INCREASE BEHIND THE TROUGH PASSAGE THURSDAY DAYTIME...WITH GUSTS
APPROACHING 40 KTS OVER SOME AREAS. FLIGHT CONDITIONS OVERALL SHOULD
REMAIN MOSTLY VFR...WITH MVFR AND LOWER CIGS/VIS NEAR HEAVIER AREAS
OF PRECIPITATION AND POSSIBLE LOW LEVEL CAA STRATUS.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 AM TO 6 PM MDT THURSDAY FOR NDZ031>033-040-
041-043-044.

&&

$$

AYD/NH

000
FXUS63 KFGF 011517 AAA
AFDFGF

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAND FORKS ND
1017 AM CDT WED SEP 1 2010

.DISCUSSION...
MODELS IN GOOD AGREEMENT ON TIMING OF SYSTEM EXPECTED TO CROSS THE
FA LATER TODAY AND TONIGHT. SFC ANALYSIS SHOWS HIGH PRESSURE
BEGINNING TO PUSH TOWARD THE GREAT LAKES WITH SRLY FLOW DEVELOPING
OVER THE PLAINS. THIS WILL ALLOW TEMPS TO REBOUND TODAY BEFORE THE
FRONT PUSHES THROUGH LATER TONIGHT. TEMP CURVE REMAINS ON TRACK SO
VERY MINOR CHANGES MADE ATTM. OTHERWISE...REST OF FCST LOOKS
GOOD.

AVIATION...

EXPECT VFR CONDITIONS THROUGH THIS EVENING...WITH MVFR CIGS
DEVELOPING OVERNIGHT WITH INCREASING CHANCES FOR SHOWERS AND A FEW
STORMS.

&&

.PREV DISCUSSION... /ISSUED 253 AM CDT WED SEP 1 2010/

DISCUSSION...

THE MAIN CHALLENGE THIS MORNING WILL BE UPCOMING PRECIP EVENT
LATE WED AFTERNOON THROUGH THURSDAY. WATER VAPOR IMAGERY SHOWS A
STRONG JET STREAM DIGGING INTO TROUGH FORMING NEAR WYOMING. THIS
JET ENERGY WILL EVENTUALLY FORM A TROUGH OVER THE REGION AND AID
LARGE SCALE LIFTING. MODELS ARE IN GOOD OVERALL AGREEMENT WITH
THIS SCENARIO AND ONCE AGAIN LIKE THE COOLER GFS SFC TEMPS THAT
HAVE VERIFIED BETTER THAN THE NAM OF LATE.

FOR TODAY...WARM ADVECTION WILL BEGIN DURING THE AFTERNOON IN THE
MID LEVELS OVER EASTERN ND. SATURATION WILL TAKE SOME TIME
THOUGH...AND EXPECT MOST OF THE SHOWER AND EMBEDDED THUNDER
ACTIVITY TO HOLD OFF UNTIL AFTER 21Z. HAVE MENTION SOME LOW POPS
AFTER 18Z IN THE FAR WEST THOUGH SINCE WAVE IS DIGGING QUICKLY
INTO THE BASE OF THE TROUGH. TEMPS SHOULD BE WARMER THAN YESTERDAY
WITH INCREASING CLOUDS FOR ALL AREAS BY AFTERNOON.

FOR WED NIGHT-THU...VERY STRONG LIFTING PER Q VECTOR CONVERGENCE
AND OMEGA FIELDS WILL MOVE FROM WEST TO EAST THROUGH THE PERIOD.
PRECIPITABLE WATERS WILL CLIMB OVER 1 INCH NEAR A DEVELOPING UPPER
LOW THAT WILL ATTEMPT TO CUT OFF ON THURSDAY. INSTABILITY
PARAMETERS ARE FAIRLY WEAK...WITH SHOWALTERS AROUND -2C IN THE
SOUTH TONIGHT AND LI/S TO ABOUT -2C THU AFTERNOON. NOT EXPECTING
MUCH IF ANY SEVERE WEATHER...WITH THE BEST POTENTIAL FOR AN
ISOLATED HAIL REPORT OVERNIGHT WHEN THE LOW LEVEL JET INCREASES TO
ABOUT 40KT NEAR A SFC INVERTED TROUGH OVER THE VALLEY. EXPECT A COOL
DAY ON THU WITH PLENTY OF WRAPAROUND CLOUDS AND INCREASING WINDS.
THE GFS IS MORE BULLISH ON 850MB WINDS ON THU...AND WOULD PUSH
WINDS INTO ADVISORY LEVELS WITH GUSTS OVER 40 MPH POSSIBLE. THE NAM
IS A BIT SLOWER TO DEVELOP THESE STRONGER WINDS AND WOULDN/T
BRING THE STRONGEST 850MB WINDS IN UNTIL THU NIGHT. WE WILL NEED
TO WATCH THIS TIMEFRAME FOR ADVISORY LEVEL WINDS STARTING THURSDAY
AFTERNOON THROUGH THURSDAY NIGHT.

FOR FRI...EXPECT A DRYING COLUMN AND TEMPS BELOW NORMAL. HIGH
PRESSURE WILL BUILD IN FRI NIGHT AND RESULT IN A COOL MORNING FOR
SAT.

SATURDAY AND SUNDAY SHOULD BE DRY WITH TEMPS REMAINING SLIGHTLY
BELOW NORMAL...WITH A WARMER DAY EXPECTED SUNDAY WITH WARM
ADVECTION IN THE MID LEVELS AND A BUILDING SHORTWAVE RIDGE.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

HOPKINS

000
FXUS63 KBIS 010831
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
331 AM CDT WED SEP 1 2010

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

FORECAST CONCERNS WILL BE DEALING WITH SCATTERED
SHOWERS/THUNDERSTORMS TODAY INTO THURSDAY...AND A POSSIBLE WIND
ADVISORY FOR THURSDAY AFTERNOON. IT APPEARS THE BULK OF SEVERE
WEATHER TODAY INTO EARLY TONIGHT WILL REMAIN JUST SOUTH OF NORTH
DAKOTA...HOWEVER AN ISOLATED SEVERE THUNDERSTORM OR TWO REMAINS A
POSSIBILITY AS WELL.

A COLD UPPER TROUGH DEVELOPING OVER THE FAR PACIFIC NORTHWEST WILL
SLIDE SOUTHEAST AND PRODUCE SCATTERED SHOWERS ALONG WITH ISOLATED
TO SCATTERED THUNDERSTORMS TODAY INTO THURSDAY. SOME THUNDERSTORMS
TODAY COULD PRODUCE SMALL HAIL AND GUSTY WINDS. THE NAM IS SLIGHTLY
SLOWER WITH THE OVERALL PROGRESSION OF THE LOW/TROUGH THAN THE GFS.
HAVE USED A BLEND OF THE NAM AND 4KM WRF-NMM FOR PRECIPITATION
FORECASTING TODAY THROUGH THURSDAY.

THE LATEST WATER VAPOR IMAGERY SHOWS AN ELONGATED 100KT-120KT H3
JET CORE FROM THE GULF OF ALASKA INTO THE PACIFIC NORTHWEST THIS
MORNING. THIS IS DEPICTED WELL BY THE NAM AND GFS. THIS JET WILL
BREAK INTO TWO PIECES AS AN AMPLIFYING RIDGE DEVELOPS OVER THE
NORTHEAST PACIFIC TODAY. THUS WILL HONE IN ON A 120KT JET STREAK
AND A SHORTWAVE TROUGH NOW OVER SOUTHEAST BRITISH COLUMBIA. THIS
JET WILL SLIDE SOUTHEAST INTO THE CENTRAL AND NORTHERN HIGH PLAINS
THROUGH 12Z THURSDAY...BEFORE ROUNDING THE BASE OF THE TROUGH
THURSDAY AFTERNOON AS IT MOVES INTO MINNESOTA. THE SHORTWAVE TROUGH
WILL DEEPEN/SHARPEN UP THROUGH EARLY THURSDAY AS HEIGHT FALLS
CONTINUE OVER CENTRAL SOUTH DAKOTA/SOUTHERN NORTH DAKOTA INTO 12Z
THURSDAY. AS THE THE LEFT FRONT EXIT REGION OF THE JET/UPPER LEVEL
DIVERGENCE AREA APPROACHES TODAY...THE H85-H3 VERTICAL MOTION/OMEGA
FIELD WILL EXPAND AND INCREASE OVER WESTERN AND CENTRAL NORTH
DAKOTA TODAY INTO THIS EVENING. AT THE SURFACE...LOW PRESSURE WILL
DEVELOP OVER SOUTHEASTERN MONTANA/NORTHWESTERN SOUTH DAKOTA THIS
MORNING AND THEN ADVANCE EAST THROUGH THIS EVENING. BY 00Z
THURSDAY...MODELS DEPICT THE LOW LOCATED NEAR MOBRIDGE WITH THE
COLD FRONT/INVERTED TROUGH STRETCHING FROM MOBRIDGE TO LINTON AND
BISMARCK...AND NORTHEAST TO STANLEY TO NEAR REGINA CANADA.

SFC-H85 SOUTHERLY WINDS DEVELOP TODAY BUT SIGNIFICANT MOISTURE
RETURN INTO NORTH DAKOTA APPEARS WEAK AT THIS TIME. THE BEST CAPE
AND INSTABILITY IS ACROSS SOUTH DAKOTA AND AREAS SOUTH. LOW TOP
CONVECTION LOOKS MORE LIKELY ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TODAY AND THURSDAY. TQ INDICES OF 16C TO 18C TODAY THROUGH
THURSDAY CERTAINLY INDICATIVE OF LOW TOP THUNDERSTORM POTENTIAL.
SPC HAS MODIFIED THE SLIGHT RISK AREA AND HAS PUSHED IT FURTHER
SOUTH...INCORPORATING CENTRAL AND EASTERN SOUTH DAKOTA AND AREAS
SOUTH. THE 4KM WRF-NMM COMPOSITE REFLECTIVITY FORECAST SHOWS
MAINLY RAIN SHOWERS THROUGH ABOUT 21Z...THEN DEVELOPS A LINE OF
THUNDERSTORMS ALONG THE LOW PRESSURE AND FRONTAL ZONE MENTIONED
ABOVE BETWEEN 22Z AND 00Z. HENCE WILL MENTION ISOLATED TO
SCATTERED SHOWERS DURING THE MORNING WITH MORE OF A SCATTERED
SHOWER AND THUNDERSTORM THREAT THIS AFTERNOON AND EVENING. SMALL
HAIL AND GUSTY WINDS THE MAIN THREATS BETWEEN 18Z WED AND 06Z THU.
THE BEST INSTABILITY AND OMEGA SHIFTS EAST INTO THE JAMES RIVER
VALLEY BY 06Z...WITH SCATTERED SHOWERS ONCE AGAIN TAKING CONTROL
OVER WESTERN NORTH DAKOTA.

SHOWERY AND COOL WEATHER CONTINUES INTO THURSDAY WITH THE UPPER
TROUGH MOVING THROUGH AND A DECENT SURFACE PRESSURE GRADIENT
SETTING UP...WHICH AS MENTIONED ABOVE MAY PROMPT A WIND ADVISORY
FOR PORTIONS OF CENTRAL AND WESTERN NORTH DAKOTA THURSDAY
AFTERNOON. HOWEVER THAT CAN BE DEALT WITH LATER TODAY/TONIGHT FOR
A POSSIBLE ISSUANCE. WILL MENTION THE POSSIBILITY OF IT IN THE HWO.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL WANE FROM WEST
TO EAST LATE THURSDAY AFTERNOON AND EARLY EVENING. SKIES WILL
THEN CLEAR FROM WEST TO EAST THURSDAY NIGHT WITH COLDER TEMPERATURES
FILTERING IN VIA THE NORTHWESTERLY FLOW. OVERNIGHT LOWS FOR BOTH
FRIDAY MORNING AND SATURDAY MORNING WILL BE IN THE 40S. ALTHOUGH
WITH INCREASING SUBSIDENCE THURSDAY NIGHT...DEPENDING ON HOW MUCH
MOISTURE REMAINS NEAR THE SURFACE...SOME FOG MAY BE POSSIBLE EARLY
FRIDAY MORNING. OTHERWISE...SUNNY SKIES FRIDAY WITH HIGHS IN THE
UPPER 60S TO LOWER 70S AND CLEAR SKIES FRIDAY NIGHT.

.LONG TERM...SATURDAY THROUGH TUESDAY NIGHT...

THERE IS GOOD AGREEMENT EARLY IN THE LONG TERM BETWEEN THE 00 UTC
GFS AND ECMWF...BUT TIMING DIFFERENCES BEGIN TO DEVELOP BY SUNDAY.
FORECAST CONCERNS REVOLVE AROUND CHANCES OF PRECIPITATION LATE IN
THE PERIOD. MODELS AGREE ON 500 HPA RIDGING OVER THE NORTHERN PLAINS
ON SATURDAY. UPPER LEVEL RIDGE AXIS SHIFTS TO THE EAST ON SATURDAY
NIGHT AND THIS IS WHEN MODELS BEGIN TO DIVERGE. THE GFS DIGS A MUCH
DEEPER AND STRONGER TROUGH OVER THE WESTERN US THAN THE ECMWF. THE
ECMWF PLACES THIS TROUGH FARTHER TO THE NORTH IN SOUTHERN CANADA
WHILE THE GFS IS CENTERED OVER WY/MT. BOTH MODELS DEVELOP
PRECIPITATION OVER THE REGION SUNDAY THROUGH MONDAY NIGHT. THE GFS
LINGERS PRECIPITATION OVER THE REGION ON TUESDAY WITH SOUTHWEST FLOW
ALOFT AND THE UPPER LEVEL LOW CENTERED OVER THE REGION WHILE THE
ECMWF LEAVES A MORE ZONAL PATTERN IN PLACE WITH THE UPPER LEVEL LOW
OVER SOUTHERN ALBERTA AND SASKATCHEWAN. BOTH PATTERNS WOULD POINT TO
A MORE ACTIVE PATTERN EARLY NEXT WEEK.

THE GFS SOLUTION WOULD ALSO BE COOLER THAN THE ECMWF. A SLOW
MODERATING TREND IN THE MODELS THROUGH SUNDAY BEFORE COOLER AIR
FLOWS SOUTHWARD FOR EARLY NEXT WEEK.

&&

.AVIATION...

UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS SINCE THIS WEEKEND IS
SLOWLY PUSHED EASTWARD TODAY AND DRIVES A COLD FRONT THROUGH THE
STATE THIS AFTERNOON INTO TONIGHT. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP THIS AFTERNOON ALONG AND AHEAD OF THE FRONT
AND CONTINUE INTO THE EVENING ENDING FROM WEST TO EAST. WINDS SHIFT
FROM SOUTH TO WEST BEHIND THE COLD FRONT. THE COLD FRONT IS EXPECTED
TO ARRIVE AT KISN AND KDIK AROUND 21 UTC...KMOT AND KBIS BY 00UTC
AND TO KJMS BY 06 UTC. VFR CONDITIONS TODAY WITH CEILINGS LOWERING
TO 4 TO 5KFT IN SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THIS
EVENING.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

KS/DC/TWH

000
FXUS63 KFGF 010753
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
253 AM CDT WED SEP 1 2010

.DISCUSSION...

THE MAIN CHALLENGE THIS MORNING WILL BE UPCOMING PRECIP EVENT
LATE WED AFTERNOON THROUGH THURSDAY. WATER VAPOR IMAGERY SHOWS A
STRONG JET STREAM DIGGING INTO TROUGH FORMING NEAR WYOMING. THIS
JET ENERGY WILL EVENTUALLY FORM A TROUGH OVER THE REGION AND AID
LARGE SCALE LIFTING. MODELS ARE IN GOOD OVERALL AGREEMENT WITH
THIS SCENARIO AND ONCE AGAIN LIKE THE COOLER GFS SFC TEMPS THAT
HAVE VERIFIED BETTER THAN THE NAM OF LATE.

FOR TODAY...WARM ADVECTION WILL BEGIN DURING THE AFTERNOON IN THE
MID LEVELS OVER EASTERN ND. SATURATION WILL TAKE SOME TIME
THOUGH...AND EXPECT MOST OF THE SHOWER AND EMBEDDED THUNDER
ACTIVITY TO HOLD OFF UNTIL AFTER 21Z. HAVE MENTION SOME LOW POPS
AFTER 18Z IN THE FAR WEST THOUGH SINCE WAVE IS DIGGING QUICKLY
INTO THE BASE OF THE TROUGH. TEMPS SHOULD BE WARMER THAN YESTERDAY
WITH INCREASING CLOUDS FOR ALL AREAS BY AFTERNOON.

FOR WED NIGHT-THU...VERY STRONG LIFTING PER Q VECTOR CONVERGENCE
AND OMEGA FIELDS WILL MOVE FROM WEST TO EAST THROUGH THE PERIOD.
PRECIPITABLE WATERS WILL CLIMB OVER 1 INCH NEAR A DEVELOPING UPPER
LOW THAT WILL ATTEMPT TO CUT OFF ON THURSDAY. INSTABILITY
PARAMETERS ARE FAIRLY WEAK...WITH SHOWALTERS AROUND -2C IN THE
SOUTH TONIGHT AND LI/S TO ABOUT -2C THU AFTERNOON. NOT EXPECTING
MUCH IF ANY SEVERE WEATHER...WITH THE BEST POTENTIAL FOR AN
ISOLATED HAIL REPORT OVERNIGHT WHEN THE LOW LEVEL JET INCREASES TO
ABOUT 40KT NEAR A SFC INVERTED TROUGH OVER THE VALLEY. EXPECT A COOL
DAY ON THU WITH PLENTY OF WRAPAROUND CLOUDS AND INCREASING WINDS.
THE GFS IS MORE BULLISH ON 850MB WINDS ON THU...AND WOULD PUSH
WINDS INTO ADVISORY LEVELS WITH GUSTS OVER 40 MPH POSSIBLE. THE NAM
IS A BIT SLOWER TO DEVELOP THESE STRONGER WINDS AND WOULDN/T
BRING THE STRONGEST 850MB WINDS IN UNTIL THU NIGHT. WE WILL NEED
TO WATCH THIS TIMEFRAME FOR ADVISORY LEVEL WINDS STARTING THURSDAY
AFTERNOON THROUGH THURSDAY NIGHT.

FOR FRI...EXPECT A DRYING COLUMN AND TEMPS BELOW NORMAL. HIGH
PRESSURE WILL BUILD IN FRI NIGHT AND RESULT IN A COOL MORNING FOR
SAT.

SATURDAY AND SUNDAY SHOULD BE DRY WITH TEMPS REMAINING SLIGHTLY
BELOW NORMAL...WITH A WARMER DAY EXPECTED SUNDAY WITH WARM
ADVECTION IN THE MID LEVELS AND A BUILDING SHORTWAVE RIDGE.

&&

.AVIATION...

EXPECT VFR CONDITIONS THROUGH THIS EVENING...WITH MVFR CIGS
DEVELOPING OVERNIGHT WITH INCREASING CHANCES FOR SHOWERS AND A FEW
STORMS.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$
DK

000
FXUS63 KFGF 010117 AAA
AFDFGF

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAND FORKS ND
817 PM CDT TUE AUG 31 2010

.UPDATE...
ONLY MINOR UPDATE THIS EVENING...JUST FOR CURRENT TRENDS. AREA OF
CLOUDS FROM NE SOUTH DAKOTA INTO NORTH CENTRAL MINNESOTA AND BAND
OF ALTOCU AND HIGH BASED RADAR RETURNS ASSOC WITH ENTRANCE REGION
OF DEPARTING 110 KT 300 MB JET OVER ERN NORTH DAKOTA INTO
SOUTHEAST MANITOBA AND NORTHWEST MINNESOTA. CUMULUS CLOUDS
DISSIPATING AS EXPECTED ELSEWHERE WITH SUNSET AND LOOK FOR A
MOSTLY CLEAR SKY FOR MOST OF TONIGHT MOST AREAS. EXCEPTION WILL BE
FAR NW FCST AREA WHERE HIGH CLDS IN ADVANCE OF NEXT 500 MB TROUGH
PLOWING INTO SOUTHERN B.C. WILL MOVE INTO BEFORE 12Z. EXPECT AN
INCREASE IN HIGH AND THEN MID LEVEL MOISTURE WEDNESDAY....ESP
NORTHERN AREAS. SHOWER/TSTORM THREAT AFTER 18Z IN ERN ND.

WINDS TONIGHT WILL DIMINISH TO LIGHT/VARIABLE...THEN BECOMIGN
SOUTHERLY 5 KTS OVER ERN ND BY 12Z AS HIGH PRESSURE MOVES THROUGH
SOUTH DAKOTA. LIGHT WINDS AND SEASONABLY COOL AIRMASS WILL ALLOW
LOWS TO DROP INTO THE 45 TO 50 RANGE IN MOST AREAS OVERNIGHT.

&&

.PREV DISCUSSION... /ISSUED 231 PM CDT TUE AUG 31 2010/

SHORT TERM...

TEMPS AND PRECIP CHANCES TOMORROW NIGHT INTO THURSDAY WILL BE THE
MAIN FORECAST CONCERNS.

WV LOOP HAS THE SYSTEM THAT BROUGHT ALL OF YESTERDAY`S RAIN
EXITING OFF TO THE NORTHEAST. A TROUGH CONTINUED OVER THE WESTERN
CONUS...KEEPING THE NORTHERN PLAINS IN SOUTHWESTERLY FLOW ALOFT.
THE WEST TO SOUTHWESTERLY FLOW BETWEEN SYSTEMS WILL CONTINUE INTO
TONIGHT. THE WEST WINDS WILL GO DOWN THIS EVENING AS THE SFC LOW
HEADS OFF AND HIGH PRESSURE BUILDS IN. WITH FAIRLY DRY DEWPOINTS
IN THE UPPER 40S...ALONG WITH LIGHT WINDS...LOWS SHOULD GET FAIRLY
CHILLY TONIGHT...DROPPING INTO THE UPPER 40S TO LOW 50S.

TOMORROW...THE UPPER TROUGH WILL MOVE INTO MT...PUSHING THE SFC
HIGH OFF TO THE EAST AND ALLOWING WINDS TO SHIFT BACK TO THE SOUTH
AS THE LEE SFC TROUGH REDEVELOPS. MUCH OF THE DAY WILL BE FAIRLY
QUIET...WITH SUNSHINE AND SOUTH WINDS HELPING HIGHS GET INTO THE
MID 70S. HOWEVER...MODELS ARE IN PRETTY GOOD AGREEMENT ON BRINGING
A LEAD VORT MAX OUT AHEAD OF THE MAIN WAVE...AND THERE COULD BE
SOME MODERATE INSTABILITY IN OUR SOUTHWESTERN COUNTIES. WILL
CONTINUE TO KEEP 20-30 POPS COMING INTO OUR WEST FOR WEDNESDAY
AFTERNOON. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE
MOVING INTO THE CWA AS THE UPPER TROUGH EJECTS INTO WESTERN ND
WEDNESDAY NIGHT. PUT HIGHEST POPS IN OUR SOUTH WHERE THE NAM AND
GFS BOTH HAVE THE BEST LIFT AND MOISTURE AS THE SYSTEM COMES OUT.
DOUBTFUL HOW MUCH SFC BASED CAPE WILL BE AVAILABLE WEDNESDAY
NIGHT...BUT THERE SHOULD BE ENOUGH ELEVATED CAPE TO INCLUDE A
ISOLATED THUNDER MENTION. LOWS WILL BE A BIT LESS COOL WITH
INCREASING CLOUDS...DEWPOINTS...AND PRECIP.

THURSDAY...THE MAIN UPPER TROUGH WILL HAVE MOVED TO OUR
EAST...WITH THE SFC TROUGH AXIS/COLD FRONT PUSHING THROUGH THE CWA
SOMETIME DURING THE MORNING. THE NAM...GFS...AND ECMWF ALL HAVE A
HEALTHY AMOUNT OF MOISTURE WRAPPING AROUND THE BACKSIDE OF THE SFC
LOW AND INTO OUR EASTERN COUNTIES. THERE COULD ALSO BE SOME
THUNDER DEVELOPING WITH STEEP LAPSE RATES UNDER THE UPPER LOW.
WILL KEEP FAIRLY HIGH POPS MAINLY IN OUR EASTERN COUNTIES THROUGH
MUCH OF THE DAY ON THURSDAY...THEN TAPERING SHOWERS OFF SLOWLY
THURSDAY NIGHT AS THE SYSTEM MOVES FURTHER EAST. TEMPS WILL BE
FAIRLY COOL UNDER A GOOD AMOUNT OF CLOUDS AND SOME PRECIP...WITH
HIGHS STAYING IN THE 60S. DECREASING CLOUDS OVERNIGHT SHOULD ALLOW
THURSDAY NIGHT LOWS TO DROP INTO THE 40S AND LOW 50S.

FOR FRIDAY...THE NORTHERN PLAINS WILL BE UNDER NORTH TO
NORTHWESTERLY FLOW ALOFT. SFC HIGH PRESSURE WILL BE MOVING IN FROM
THE WEST. HIGHS WILL CONTINUE TO BE BELOW AVERAGE...TOPPING OUT IN
THE UPPER 60S TO LOW 70S. THE COLD POOL ALOFT WILL STILL BE
LINGERING OVER THE NORTHEASTERN CWA...SO SOME SHOWER DEVELOPMENT
FRIDAY AFTERNOON IS NOT OUT OF THE QUESTION. INCLUDED SOME 20 POPS
IN THE LAKE OF THE WOODS REGION.

LONG TERM...

LONG TERM (FRI NIGHT-TUE)...
REASONABLE FORECAST CONFIDENCE FOR THE EXTENDED PERIOD WITH GUIDANCE
AGREEING ON HIGH PRESSURE FOR THE WEEKEND WITH A GRADUAL WARMING
TREND SUCCEEDING THE END OF WEEK COOL DOWN. H5 LOW PRESSURE CENTERS
LIKELY TO BE ANCHORED OVER BOTH ATLANTIC AND PACIFIC CANADIAN
MARITIME PROVINCES AS UPPER RIDGE BUILDS INTO CENTRAL CONUS. 12Z
GFS/06Z DGEX SWEEPS THIS PACIFIC UPPER ENERGY PACKET OVER NORTHERN
PLAINS BY LATE LABOR DAY INTO TUESDAY. DEARTH OF INSTABILITY DURING
PORTION OF THIS DAY6/7 TIMEFRAME LED TO RW AS OPPOSED TO STRAIGHT TS
IN GRIDS...AS TRANSITION TO FALL SEASON COMMENCES.

AVIATION...
GUSTY WINDS TO DIMINISH PRIOR TO SUNSET AS HIGH PRESSURE BUILDS IN
FROM WEST RESULTING IN VRB WINDS OVERNIGHT INTO TUES. VFR CONDITIONS
EXPECTED AT ALL LOCATIONS.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$
RIDDLE/JR

000
FXUS63 KBIS 312108
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
408 PM CDT TUE AUG 31 2010

.SYNOPSIS...

A STRONG UPPER LEVEL TROUGH OVER THE NORTHWESTERN U.S. WILL
FINALLY BECOME PROGRESSIVE AS SEVERAL MIDDLE LEVEL IMPULSES
EMBEDDED IN THE MONSTROUS SUPERGRADIENT UPPER LEVEL JET STREAK
OVER THE NORTHERN PACIFIC SWING THROUGH THE BASE OF THE TROUGH AND
EJECT INTO THE NORTHERN PLAINS. THE LEADING SHORTWAVE LOOKS
TO BE HEADED FOR SOUTH DAKOTA...WHICH IS WHY ONLY THE SOUTHERN
COUNTIES OF NORTH DAKOTA ARE FORECAST TO EXPERIENCE SEVERE WEATHER
WEDNESDAY. THEREAFTER...UPPER LEVEL RIDGING WILL PASS THROUGH THE
DAKOTAS AND RESULT IN GENERALLY ABOVE AVERAGE TEMPERATURES FOR
MUCH OF LABOR DAY WEEKEND.

&&

.SHORT TERM...TUESDAY THROUGH WEDNESDAY NIGHT...

THE MAIN FORECAST PROBLEM OF THE DAY IS THE CHANCE OF
PRECIPITATION WITH THE EVENTUAL PROGRESSION OF AN UPPER LEVEL TROUGH
CURRENTLY OVER THE PACIFIC NORTHWEST.

A MUCH COOLER AIRMASS HAS MOVED INTO THE DAKOTAS IN THE WAKE OF
YESTERDAYS FRONTAL PASSAGE. SURFACE HIGH PRESSURE OVER WESTERN
SOUTH DAKOTA WILL SLOWLY SLIDE INTO THE UPPER MISSISSIPPI VALLEY
BY WEDNESDAY MORNING. 12 UTC GFS/ECMWF/GEM GLOBAL/NAM FORECASTS
INDICATE THAT THE NEXT MIDDLE LEVEL SHORTWAVE MOVES ACROSS NORTH
DAKOTA WEDNESDAY AFTERNOON...LIKELY RESULTING IN SCATTERED SHOWERS
AND THUNDERSTORMS BY WEDNESDAY EVENING. THE ABOVE GUIDANCE DOES
LITTLE TO HIGHLIGHT INSTABILITY OVER SOUTHERN NORTH DAKOTA...BUT
THE SYSTEM APPEARS DYNAMICALLY CHARGED ENOUGH TO RESULT IN MORE
INSTABILITY THAN MODELS HAVE FORECAST...SO NCEP/STORM PREDICTION
CENTER HAS OUTLINED SOUTH CENTRAL IN A SLIGHT RISK FOR SEVERE
THUNDERSTORMS. REGARDLESS OF SEVERE POTENTIAL...MODELS HAVE BEEN
HIGHLIGHTING QPF IN THE AREA FOR SEVERAL DAYS.

LOOK FOR A WARMUP WEDNESDAY AS SOUTHWESTERLY FLOW ADVECTS HIGHER
THICKNESSES INTO THE REGION JUST BEFORE ANOTHER AIRMASS
CHARACTERIZED BY COOL TEMPERATURES SLIDES INTO NORTH DAKOTA.

.LONG TERM...THURSDAY THROUGH TUESDAY...

THE MAIN AREA OF UNCERTAINTY WITH THIS PERIOD LIES WITH THE TIMING
OF THE AFOREMENTIONED UPPER LEVEL TROUGH PROGRESSION THROUGH THE
NORTHERN PLAINS.

BELOW AVERAGE TEMPERATURES AT THE BEGINNING OF THE PERIOD SHOULD
SLOWLY MODERATE AND SHIFT TO THE WARM SIDE OF AVERAGE AS BROAD
ANTICYCLONIC FLOW SLOWLY PROGRESSES ACROSS THE NORTHERN TIER OF
CONUS. LOOK FOR SUNDAY TO HAVE THE WARMEST TEMPERATURES AS
SOUTHWESTERLY FLOW AHEAD OF THE NEXT UPPER LEVEL TROUGH MOVES ONCE
AGAIN ADVECTS WARMER TEMPERATURES WHILE ENHANCING DOWNSLOPE FLOW.

EVEN WITH ENSEMBLE SPREAD EXPANDING WITH TIME...THE BEST CHANCE
FOR PRECIPITATION STILL LOOKS TO BE SUNDAY NIGHT INTO MONDAY WHEN
A MAJORITY OF MODELS/ENSEMBLES INSIST THAT THE NEXT UPPER LEVEL
LOW SLIDES INTO THE NORTHERN HIGH PLAINS.

&&

.AVIATION...

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EAST-SOUTHEAST ACROSS
THE LOCAL AREA OVER THE NEXT 12-24 HOURS...AND WILL BE POSITIONED
OVER THE WESTERN GREAT LAKES REGION BY LATE MORNING WEDNESDAY.
WESTERLY WINDS GUSTING TO AROUND 30 MPH WILL GRADUALLY SUBSIDE THIS
AFTERNOON WEST TO EAST...THEN AREA WIDE THIS EVENING AND BECOME MORE
SOUTHERLY AS RETURN FLOW REDEVELOPS ON THE BACKSIDE OF THE SFC HIGH.
CURRENT BKN CU FIELD WILL DISSIPATE WITH SCT CLOUDS OVER MOST
LOCATIONS TONIGHT. A MID LEVEL DISTURBANCE IS FORECAST TO LIFT
EAST-NORTHEAST INTO THE DAKOTAS LATE TONIGHT...BRINGING A SLIGHT
RISK OF RAIN SHOWERS TO WESTERN AND CENTRAL PORTIONS OF NORTH DAKOTA
AROUND AND AFTER 12Z WED MORNING. A CHANCE OF SHOWERS AND
THUNDERSTORMS WILL CONTINUE WED AFTERNOON AND EVENING. OVERALL
FLIGHT CONDITIONS WILL REMAIN VFR.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS/SHORT TERM/LONG TERM...SCHECK
AVIATION...NH

000
FXUS63 KFGF 311931
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
231 PM CDT TUE AUG 31 2010

.SHORT TERM...

TEMPS AND PRECIP CHANCES TOMORROW NIGHT INTO THURSDAY WILL BE THE
MAIN FORECAST CONCERNS.

WV LOOP HAS THE SYSTEM THAT BROUGHT ALL OF YESTERDAY`S RAIN
EXITING OFF TO THE NORTHEAST. A TROUGH CONTINUED OVER THE WESTERN
CONUS...KEEPING THE NORTHERN PLAINS IN SOUTHWESTERLY FLOW ALOFT.
THE WEST TO SOUTHWESTERLY FLOW BETWEEN SYSTEMS WILL CONTINUE INTO
TONIGHT. THE WEST WINDS WILL GO DOWN THIS EVENING AS THE SFC LOW
HEADS OFF AND HIGH PRESSURE BUILDS IN. WITH FAIRLY DRY DEWPOINTS
IN THE UPPER 40S...ALONG WITH LIGHT WINDS...LOWS SHOULD GET FAIRLY
CHILLY TONIGHT...DROPPING INTO THE UPPER 40S TO LOW 50S.

TOMORROW...THE UPPER TROUGH WILL MOVE INTO MT...PUSHING THE SFC
HIGH OFF TO THE EAST AND ALLOWING WINDS TO SHIFT BACK TO THE SOUTH
AS THE LEE SFC TROUGH REDEVELOPS. MUCH OF THE DAY WILL BE FAIRLY
QUIET...WITH SUNSHINE AND SOUTH WINDS HELPING HIGHS GET INTO THE
MID 70S. HOWEVER...MODELS ARE IN PRETTY GOOD AGREEMENT ON BRINGING
A LEAD VORT MAX OUT AHEAD OF THE MAIN WAVE...AND THERE COULD BE
SOME MODERATE INSTABILITY IN OUR SOUTHWESTERN COUNTIES. WILL
CONTINUE TO KEEP 20-30 POPS COMING INTO OUR WEST FOR WEDNESDAY
AFTERNOON. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE
MOVING INTO THE CWA AS THE UPPER TROUGH EJECTS INTO WESTERN ND
WEDNESDAY NIGHT. PUT HIGHEST POPS IN OUR SOUTH WHERE THE NAM AND
GFS BOTH HAVE THE BEST LIFT AND MOISTURE AS THE SYSTEM COMES OUT.
DOUBTFUL HOW MUCH SFC BASED CAPE WILL BE AVAILABLE WEDNESDAY
NIGHT...BUT THERE SHOULD BE ENOUGH ELEVATED CAPE TO INCLUDE A
ISOLATED THUNDER MENTION. LOWS WILL BE A BIT LESS COOL WITH
INCREASING CLOUDS...DEWPOINTS...AND PRECIP.

THURSDAY...THE MAIN UPPER TROUGH WILL HAVE MOVED TO OUR
EAST...WITH THE SFC TROUGH AXIS/COLD FRONT PUSHING THROUGH THE CWA
SOMETIME DURING THE MORNING. THE NAM...GFS...AND ECMWF ALL HAVE A
HEALTHY AMOUNT OF MOISTURE WRAPPING AROUND THE BACKSIDE OF THE SFC
LOW AND INTO OUR EASTERN COUNTIES. THERE COULD ALSO BE SOME
THUNDER DEVELOPING WITH STEEP LAPSE RATES UNDER THE UPPER LOW.
WILL KEEP FAIRLY HIGH POPS MAINLY IN OUR EASTERN COUNTIES THROUGH
MUCH OF THE DAY ON THURSDAY...THEN TAPERING SHOWERS OFF SLOWLY
THURSDAY NIGHT AS THE SYSTEM MOVES FURTHER EAST. TEMPS WILL BE
FAIRLY COOL UNDER A GOOD AMOUNT OF CLOUDS AND SOME PRECIP...WITH
HIGHS STAYING IN THE 60S. DECREASING CLOUDS OVERNIGHT SHOULD ALLOW
THURSDAY NIGHT LOWS TO DROP INTO THE 40S AND LOW 50S.

FOR FRIDAY...THE NORTHERN PLAINS WILL BE UNDER NORTH TO
NORTHWESTERLY FLOW ALOFT. SFC HIGH PRESSURE WILL BE MOVING IN FROM
THE WEST. HIGHS WILL CONTINUE TO BE BELOW AVERAGE...TOPPING OUT IN
THE UPPER 60S TO LOW 70S. THE COLD POOL ALOFT WILL STILL BE
LINGERING OVER THE NORTHEASTERN CWA...SO SOME SHOWER DEVELOPMENT
FRIDAY AFTERNOON IS NOT OUT OF THE QUESTION. INCLUDED SOME 20 POPS
IN THE LAKE OF THE WOODS REGION.

.LONG TERM...

.LONG TERM (FRI NIGHT-TUE)...
REASONABLE FORECAST CONFIDENCE FOR THE EXTENDED PERIOD WITH GUIDANCE
AGREEING ON HIGH PRESSURE FOR THE WEEKEND WITH A GRADUAL WARMING
TREND SUCCEEDING THE END OF WEEK COOL DOWN. H5 LOW PRESSURE CENTERS
LIKELY TO BE ANCHORED OVER BOTH ATLANTIC AND PACIFIC CANADIAN
MARITIME PROVINCES AS UPPER RIDGE BUILDS INTO CENTRAL CONUS. 12Z
GFS/06Z DGEX SWEEPS THIS PACIFIC UPPER ENERGY PACKET OVER NORTHERN
PLAINS BY LATE LABOR DAY INTO TUESDAY. DEARTH OF INSTABILITY DURING
PORTION OF THIS DAY6/7 TIMEFRAME LED TO RW AS OPPOSED TO STRAIGHT TS
IN GRIDS...AS TRANSITION TO FALL SEASON COMMENCES.

&&

.AVIATION...
GUSTY WINDS TO DIMINISH PRIOR TO SUNSET AS HIGH PRESSURE BUILDS IN
FROM WEST RESULTING IN VRB WINDS OVERNIGHT INTO TUES. VFR CONDITIONS
EXPECTED AT ALL LOCATIONS.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

JR/WJB/WJB

000
FXUS63 KBIS 311542
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1042 AM CDT TUE AUG 31 2010

.UPDATE...

WINDS HAVE INCREASED A BIT FASTER THAN ANTICIPATED BY GRIDS FROM
EARLIER THIS MORNING. UPDATES HAVE INCLUDED TWEAKING OF THE WINDS
USING THE 12 UTC RUC...WHICH SEEMS TO HAVE A GOOD HANDLE ON WIND
SPEEDS AS THEY RAMP UP INTO THE UPPER 20S KNOTS.

&&

.PREV DISCUSSION... /ISSUED 340 AM CDT TUE AUG 31 2010/

SHORT TERM...TODAY THROUGH THURSDAY NIGHT...

A BRIEF BREAK BETWEEN SHORTWAVE TROUGHS TODAY. UNSETTLED WEATHER
WILL RETURN WEDNESDAY THROUGH THURSDAY...BUT THE SEVERE POTENTIAL
APPEARS CONFINED TO FAR SOUTH CENTRAL NORTH DAKOTA WEDNESDAY INTO
WEDNESDAY EVENING. THE SHORTWAVE TROUGH WHICH PRODUCED SHOWERS
AND THUNDERSTORMS MONDAY INTO EARLY TUESDAY MORNING IS LOCATED
OVER FAR SOUTHEASTERN SASKATCHEWAN AND LIFTING NORTHEAST. SOME
RESIDUAL ENERGY/VORTICITY STRETCHES BACK INTO SOUTHERN IDAHO PER
LATEST WATER VAPOR IMAGERY...BUT IS FORECAST TO REMAIN FAIRLY
CHANNELED AS IT SLIDES THROUGH LATE THIS MORNING AND INTO THE
AFTERNOON. WEAK SUBSIDENCE ALOFT ALONG WITH A 1013MB SURFACE HIGH
PRESSURE DEVELOPING BEHIND THE MAIN UPPER SHORTWAVE TROUGH
MENTIONED ABOVE SHOULD SUPPRESS ANY RE-DEVELOPMENT OF SHOWERS IN
ALL AREAS EXCEPT OVER THE FAR NORTHWESTERN AND NORTHERN ZONES
WHERE WEAK INSTABILITY RESIDES.

CURRENT FOG/STRATUS LOOP AND SURFACE OBSERVATIONS SHOW A SWATH OF
LOW CLOUDS/MVFR ACROSS WESTERN AND CENTRAL NORTH DAKOTA. LATEST
NAM 925MB MOISTURE PANEL GRADUALLY DECREASES THE HIGH RH ACROSS
THE AREA DURING THE MORNING HOURS WITH INCREASING SUNSHINE BY
AFTERNOON. THUS EXPECT THE STRATUS TO LIFT AND BECOME A BKN/SCT
STRATOCUMULUS DECK BY LATE MORNING THEN DECREASING FURTHER DURING
THE LATE AFTERNOON. GRIDDED FORECAST OF BREEZY WEST TO NORTHWESTERLY
WINDS OF 15 TO 25 MPH TODAY WITH DECREASING CLOUDS LOOK GOOD FOR
TODAY.

WATER VAPOR IMAGERY SHOWS THE NEXT SHORTWAVE OF INTEREST NOW OVER
WESTERN BRITISH COLUMBIA WITH A 120KT H3 JET CORE STRETCHING FROM
THE GULF OF ALASKA INTO THE NORTHEAST PACIFIC. THIS JET ENERGY
WILL HELP DEVELOP ANOTHER SHARP SHORTWAVE TROUGH ALOFT TONIGHT
THROUGH THURSDAY AS EVERYTHING ADVANCES SOUTHEAST CLOSER TO NORTH
DAKOTA. IN RESPONSE AT THE SURFACE...A LOW PRESSURE AND COLD
FRONT DEVELOP OVER SOUTHEASTERN SASKATCHEWAN THIS AFTERNOON...THEN
TRANSLATING FURTHER INTO SOUTHEAST MONTANA BY 12Z WEDNESDAY. THE
COLD FRONT MARCHES EAST WEDNESDAY PASSING THROUGH WESTERN NORTH
DAKOTA EARLY WEDNESDAY AFTERNOON AND CENTRAL NORTH DAKOTA
WEDNESDAY EVENING. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG
AND AHEAD OF THIS FRONT WEDNESDAY. HENCE EXPECT DRY CONDITIONS
TONIGHT FOLLOWED BY MORE CLOUDS AND A RETURN TO SCATTERED SHOWERS
AND THUNDERSTORMS WEDNESDAY...ESPECIALLY DURING THE AFTERNOON AND
EVENING. SPC HAS OUR FAR SOUTH CENTRAL ZONES INCLUDED IN A SLIGHT
RISK AREA. MODELS SUGGEST THE BEST LARGE SCALE ASCENT AND GREATEST
INSTABILITY RESIDES OVER SOUTH DAKOTA AND AREAS SOUTH...SO FOR
RIGHT NOW WE ARE ON THE NORTHERN FRINGE. ADJUSTMENTS OF THE SEVERE
POTENTIAL FURTHER NORTH OR SOUTH CERTAINLY POSSIBLE AS THIS TROUGH
EVOLVES. WILL MENTION THE POTENTIAL IN THE HWO FOR NOW AND
CONTINUE TO MONITOR AND ADJUST AS NECESSARY. THIS TROUGH WILL HAVE
MUCH COOLER AIR ASSOCIATED WITH IT AS IT MOVES THROUGH LATE
WEDNESDAY NIGHT AND THURSDAY. EXPECT A WINDY/RAW DAY THURSDAY WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. NORTHWEST WINDS OF 20 TO
35 MPH AND HIGHS IN THE 60S ACROSS WESTERN/CENTRAL NORTH DAKOTA.
DATA SUGGESTS THAT WE GET CLOSE TO WIND ADVISORY CRITERIA
THURSDAY...FROM SOUTHWEST TO SOUTH CENTRAL. WILL CONTINUE TO LOOK
AT THIS AS WE GET CLOSER.

THE TROUGH EXITS THURSDAY EVENING WITH CLEARING WITH COLDER
CONDITIONS SETTLING IN THURSDAY NIGHT. LOWS FRIDAY MORNING SOLIDLY
IN THE 40S...WITH SOME LOCALES IN THE LOWER 40S.

LONG TERM...FRIDAY THROUGH MONDAY NIGHT...

THE 00 UTC ECMWF AND GFS CONTINUE TO BE GOOD AGREEMENT THROUGH THE
PERIOD. THE LONG TERM BEGINS WITH THE SHORT TERM TROUGH OVER THE
WESTERN GREAT LAKES WITH RIDGING OVER THE WESTERN US AND A SECOND
TROUGH IN THE  GULF OF ALASKA. THIS PLACES NORTH DAKOTA UNDER
NORTHWEST FLOW ALOFT. UPPER LEVEL RIDGE SLOWLY SHIFTS EASTWARD
THROUGH THE WEEKEND AS THE GULF OF ALASKA TROUGH DIGS INTO BC/WA.
THE RIDGE AXIS MOVES INTO WESTERN MINNESOTA BY SUNDAY NIGHT AS
DISTURBANCES EJECTING OUT OF THE TROUGH MOVES INTO THE REGION. THIS
BRINGS A RISK OF SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH
SUNDAY NIGHT THROUGH MONDAY NIGHT.

TEMPERATURES IN THE MID 70S TO LOWER 80S BY THE WEEKEND WITH THE
WARMEST TEMPERATES OVER THE WESTERN PART OF THE STATE. TEMPERATURES
COOL INTO THE LOWER TO MID 70S FOR MONDAY. OVERNIGHT LOWS GENERALLY
IN THE MID 40S TO LOWER 50S.

AVIATION...

UPPER LEVEL TROUGH REMAINS OVER THE REGION THROUGH THE PERIOD.
SURFACE LOW IS DEPARTING TO THE NORTHEAST WITH A SURFACE HIGH
BUILDING INTO NORTH DAKOTA FROM THE WEST. A TIGHT PRESSURE GRADIENT
ACROSS THE STATE TODAY WITH WESTERLY WINDS OF 15 TO 25 KNOTS
BECOMING GUSTY IN THE AFTERNOON AS WINDS MIX TO THE SURFACE. MVFR
CEILINGS ACROSS WESTERN NORTH DAKOTA WITH CEILINGS VARYING FROM MVFR
TO VFR OVER THE CENTRAL PART OF THE STATE. THERE IS ONE AREA OF IFR
CIGS FROM JUST NORTH OF JMS...NORTH THROUGH DVL...RUGBY AND ROLLA.
AT THIS TIME IT APPEARS THE LOW DECK WILL REMAIN NORTH OF JMS AND
WITH A WESTERLY FLOW...IT SHOULD NOT EXPAND INTO MINOT. EXPECT QUICK
LIFTING OF CEILINGS AFTER 12 UTC. VFR CONDITIONS EXPECTED BY THIS
AFTERNOON ACROSS THE REGION...WITH SKIES BECOMING CLEAR THIS
EVENING. WINDS WILL ALSO DIMINISH QUICKLY AFTER 00 UTC.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...KS
LONG TERM/AVIATION...DC/TWH
UPDATE...SCHECK

000
FXUS63 KFGF 311514
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
1014 AM CDT TUE AUG 31 2010

.DISCUSSION...

WINDS IN THE DEVILS LAKE BASIN TOWARDS GFK HAVE BEEN STRONGER THAN
EXPECTED...SO MORNING UPDATE WILL FOCUS ON THEM. PRESSURE GRADIENT
REMAINS FAIRLY TIGHT ACROSS THE NORTHERN CWA AS THE VIGOROUS LOW
PRESSURE SYSTEM CONTINUES TO MOVE SLOWLY ACROSS ONT. SPEEDS HAVE
BEEN RISING ABOVE 20 KTS IN OUR NORTHERN CWA...AND THIS WILL
CONTINUE THROUGH AROUND 20Z OR SO WHEN HIGH PRESSURE FINALLY
BEGINS TO MOVE IN AND THE GRADIENT RELAXES. DO NOT THINK AT THIS
POINT THAT AN ADVISORY WILL BE NEEDED...BUT WEST WINDS WILL BE
JUST BELOW CRITERIA. WILL ALSO TAKE A LOOK AT WAVE MODEL AND MAY
PUT IN SOMETHING FOR DEVILS LAKE IN THE HWO.

CLOUDS WILL CONTINUE TO HANG ON IN OUR NORTH AND EAST THIS
MORNING...BUT WILL BEGIN TO BREAK UP A BIT THIS AFTERNOON. HIGHS
CONTINUE TO LOOK ON TRACK TO TOP OUT IN THE 70S AND UPPER 60S IN
THE NORTHWEST.

&&

.AVIATION...

MVFR CEILINGS WILL BEGIN TO SCATTER OUT AFTER 17Z TODAY AT
KDVL...LEAVING THE FORECAST AREA WITH VFR CONDITIONS. AT THE
NORTHERN TAF SITES...KDVL AND KGFK...WEST WINDS WILL BE SUSTAINED
AT 20 KTS OR MORE FOR THIS MORNING...WITH SOME GUSTS IN THE 25 TO
30 KT RANGE. WINDS WILL DECREASE AROUND 20Z OR SO AS THE PRESSURE
GRADIENT DECREASES.

&&

.PREV DISCUSSION... /ISSUED 306 AM CDT TUE AUG 31 2010/

DISCUSSION...

THE MAIN CHALLENGE WILL BE TEMPS AND PRECIP CHANCES WED-THU. A
SHORTWAVE TROUGH AND ASSOCIATED INSTABILITY IS MOVING EAST OF THE
VALLEY...WITH JUST A FEW LEFT OVER SHOWERS AND RUMBLES OF THUNDER
IN THE FAR EAST. MODELS ARE IN DECENT AGREEMENT AND PREFER THE NAM
MOISTURE FIELDS BUT LIKE THE GFS LOW LEVEL THERMAL FIELDS...SINCE
THE NAM HAS BEEN TOO WARM OF LATE. THEREFORE A MODEL BLEND IS
PREFERRED THIS MORNING.

FOR TODAY...EXPECT A DRY AND COOL DAY WITH SUBSIDENCE AND HIGH
PRESSURE BUILDING IN. THERE WILL BE SOME LINGERING CYCLONIC FLOW
IN THE NORTH...BUT THE LACK OF ANY FOCUS SHOULD PRECLUDE AND
SHOWER ACTIVITY. THEREFORE HAVE NOT MENTIONED ANY PRECIP TODAY.
TEMPS SHOULD REMAIN BELOW NORMAL WITH WESTERLY WINDS GUSTING TO
AROUND 20-25KT BY LATE MORNING/EARLY AFTERNOON.

ON WEDNESDAY/WED NIGHT...RETURN FLOW WILL QUICKLY DEVELOP BY
AFTERNOON AND TEMPS SHOULD WARM TO NEAR NORMAL. EXPECT AN
INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS INTO EASTERN ND BY
AFTERNOON. THE MAIN CONVECTION IS EXPECTED ON WED NIGHT AS A
SHORTWAVE COMBINES WITH INCREASING MOISTURE AND SOME INSTABILITY.
HAVE INCREASED POPS A BIT INTO THE HIGH CHANCE CATEGORY WITH MOST
AREAS SEEING AT LEAST SOME RAIN.

FOR THU...COLD ADVECTION IS EXPECTED WITH PLENTY OF WRAPAROUND
SHOWERS AND A FEW THUNDERSTORMS MAINLY IN EASTERN ND WHERE
INSTABILITY WILL BE MAXIMIZED WITH CAPES AROUND 1000 J/KG. EXPECT
A COOLER DAY THAN WED...WITH HIGHS BELOW NORMAL ONCE AGAIN.

BY FRIDAY...DRIER AIR SHOULD BUILD INTO THE REGION...ALTHOUGH THE
LAST FEW MODEL RUNS HAVE BEEN SLOWER WITH THIS EVOLUTIO. HAVE LEFT
FRIDAY DRY FOR NOW...BUT MAY NEED TO ADD POPS INTO AT LEAST THE
EASTERN AREAS IF THIS TREND CONTINUES. TEMPS SHOULD REMAIN BELOW
NORMAL WITH COOL 850MB TEMPS FROM +4C TO +8C FROM NE TO SW.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$
JR

      
      

  
    
    
  
  
    
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