FXUS63 KBIS 061524
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1024 AM CDT MON OCT 6 2008

.UPDATE...
THE SURFACE TROUGH AND ITS ASSOCIATED PRECIPITATION CONTINUES TO
PUSH EAST THIS MORNING AND IS CURRENTLY LOCATED OVER THE RED RIVER
VALLEY REGION. STILL SOME LIGHT TO MODERATE SHOWERS OVER MY FAR
SOUTHEASTERN COUNTIES SO HAVE KEPT SOME HIGHER POPS HERE.
OTHERWISE SCALED BACK GREATLY TO SLIGHT CHANCES ELSEWHERE AS WE
MAY STILL SEE A SHOWER OR TWO AS THE UPPER LEVEL TROUGH SWINGS
ACROSS THE STATE THIS AFTERNOON. ALSO SCALED BACK ON CLOUD COVER
TONIGHT AS DRY AIR ADVECTS INTO THE STATE. WITH THIS I ALSO NEEDED
TO LOWER OVERNIGHT LOWS (INTO THE LOWER 30S WEST) TO ACCOUNT FOR
THE DRY AIR AND CLEARING SKIES. WILL KEEP FOG WORDING OUT OF THE
FORECAST FOR TONIGHT AS WELL FOR NOW AS DESPITE OUR RECENT
PRECIPITATION...DRY LOW LEVEL WESTERLY FLOW SHOULD BE DETRIMENTAL
TO FOG DEVELOPMENT.



&&

.PREV DISCUSSION... /ISSUED 355 AM CDT MON OCT 6 2008/

SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...

CURRENTLY SURFACE TROUGH EXTENDED NORTH TO SOUTH ACROSS CENTRAL
NORTH DAKOTA. AREA OF SHOWERS WAS MOVING NORTHWARD ALONG AND EAST OF
THE TROUGH. SOUTHEAST WINDS EAST OF THE TROUGH WITH LIGHT FOG AND
LOW CLOUDS ALONG WITH THE SHOWERS. WESTERLY WINDS BEHIND THE TROUGH
WITH DRY AIR MOVING IN WITH CLEAR TO PARTLY CLOUDY SKIES. THIS
TROUGH IS FORECAST TO MOVE EAST INTO THE RED RIVER VALLEY THIS
AFTERNOON WITH DRY AIR PUSHING IN BEHIND IT. AT UPPER LEVELS...THE
MAIN TROUGH REMAINS WELL WEST OF THE SURFACE TROUGH. EXPECTING
CUMULUS TO FORM LATE THIS MORNING AND INTO THE AFTERNOON IN AREAS
WEST OF THE TROUGH...WITH INSTABILITY SHOWERS...SO KEEPING A SLIGHT
CHANCE OF SHOWERS IN THE WEST WITH SCATTERED SHOWERS EASTERN
COUNTIES THIS AFTERNOON.

DRY HIGH PRESSURE CONTINUES TO ADVECT DRY AIR INTO THE STATE TONIGHT
AND TUESDAY. THE NEXT SYSTEM TO MOVE INTO THE REGION IS AN UPPER
LEVEL LOW THAT IS PROGGED TO MOVE ACROSS SOUTH CENTRAL CANADA ON
TUESDAY NIGHT AND WEDNESDAY. PUT A SLIGHT CHANCE OF SHOWERS ACROSS
THE NORTHERN TIER OF COUNTIES THIS PERIOD WITH MOST OF THE VORT
ENERGY NORTH OF THE STATE IN CANADA.

BRACING FOR A WINDY DAY ON WEDNESDAY AS THE UPPER LEVEL CANADIAN LOW
DEVELOPS A STRONG SURFACE LOW OVER CENTRAL CANADA AND THE PRESSURE
GRADIENT TIGHTENS OVER THE NORTHERN PLAINS. AN UPPER LEVEL JET WITH
WESTERLY WINDS OF 120-140 KNOTS AND H850 WINDS OF 25 TO 35 KNOTS
WILL BRING 20 TO 30 MPH WESTERLY SURFACE WINDS.

LONG TERM...THURSDAY THROUGH SUNDAY NIGHT...
BIG DIFFERENCES BETWEEN THE ECMWF AND GFS. THE EC IS DEEPER AND
SLOWER WITH THE UPPER TROUGH ON THURSDAY THROUGH SATURDAY. AS A
CONSEQUENCE IT ALSO PUSHES THE ASSOCIATED PRECIPITATION FURTHER
NORTH INTO NORTH DAKOTA...WHEREAS THE GFS KEEPS US OUT OF THE LINE
OF FIRE FOR THE MOST PART. I HAVE LEFT THE EXISTING POPS IN FOR THE
LONG TERM...BUT IF THE EC IS CORRECT THEY WILL NEED TO BE UPPED AS
WE GET CLOSER TO THE END OF THE WEEK. THE EC ALSO CONTINUES TO
PORTRAY SOME BORDERLINE TEMPERATURES FOR SNOW WITH THIS EVENT.

AVIATION...
I EXPECT SLOW IMPROVEMENT DURING THE MORNING HOURS OVER THE CENTRAL
PART OF THE STATE AS THE SURFACE FRONT PUSHES FURTHER EAST. BY
MIDDAY I EXPECT VFR WEATHER WITH SCATTERED SHOWERS.

FIRE WEATHER...
FIRE WEATHER CONCERNS ON WEDNESDAY WITH WEST WINDS OF 20 TO 30 MPH
AND AFTERNOON RELATIVE HUMIDITIES OF 20 TO 25 PERCENT OVER
SOUTHWESTERN NORTH DAKOTA. RED FLAG CONDITIONS MAY BE MET IN THE
SOUTHWEST WITH MARGINAL RED FLAG CONDITIONS IN THE NORTHWEST - RH OF
30 TO 35 PERCENT EXPECTED IN THE NORTHWEST.

&&

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

$$

JV/RSL/HEINERT

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