FXUS63 KBIS 261700
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1100 AM CST SAT DEC 26 2009
.UPDATE...
JAMESTOWN AND BISMARCK OBSERVATIONS NO LONGER SUPPORT A BLIZZARD
WARNING. WHILE SOME AREAS ARE LIKELY EXPERIENCING OCCASIONAL
VISIBILITY RESTRICTIONS BELOW ONE QUARTER MILE...THE DURATION OF
SUCH CONDITIONS NO LONGER MEETS BLIZZARD CRITERIA. HWY 2 HAS BEEN
OPENED EAST OF MINOT...AND BLOWING SNOW IS HAVING TROUBLE REDUCING
VISIBILITIES TO LESS THAN 3 MILES WITHOUT FALLING SNOW. THE HEAVY
SNOW IS STILL ONGOING IN MINOT AND WINDS AND SNOW ARE KEEPING ASOS
VISIBILITIES AT OR BELOW ONE HALF MILE IN DICKINSON...HETTINGER
AND BOWMAN. GENERALLY...WHEN ASOS IS EVEN CLOSE TO ONE
QUARTER...A MAJORITY OF THE SURROUNDING AREA IS WORSE BECAUSE OF
OPEN TERRAIN. SO...THE BLIZZARD WARNING IS JUSTIFIED ALONG THAT
STRETCH.
&&
.PREV DISCUSSION... /ISSUED 345 AM CST SAT DEC 26 2009/
SHORT TERM...TODAY THROUGH MONDAY NIGHT...
THE MAIN FORECAST CONCERN REVOLVES AROUND ONGOING BLIZZARD
CONDITIONS ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA THROUGH
TODAY. MODELS ARE IN REALLY GOOD AGREEMENT WITH THIS SYSTEM...SO THE
FORECAST WILL BE A MODEL BLEND.
CURRENTLY...A POWERFUL VERTICALLY STACKED LOW IS SPINNING IN PLACE
OVER IOWA. THE STORM CENTER IS FORECAST TO MOVE NORTHEASTWARD SLOWLY
TODAY AND BE OVER ILLINOIS/WISCONSIN BY SUNDAY MORNING...THEN MOVE
EASTWARD ACROSS THE SOUTHERN GREAT LAKES. WINDY CONDITIONS ARE
EXPECTED TO CONTINUE TODAY...THOUGH NOT AS STRONG AS YESTERDAY. THE
SURFACE PRESSURE GRADIENT IS FORECAST TO RELAX SOMEWHAT.
HOWEVER...MORE SNOWFALL IS ON THE WAY AS A COUPLE OF BANDS OF
ENHANCED/COOLING CLOUD TOPS WERE SEEN ON SATELLITE PICS INDICATIVE
OF THE MID LEVEL TROUGH OF WARM AIR ALOFT (TROWAL) THAT HAS BEEN
ASSOCIATED WITH THE MODERATE TO HEAVY SNOWFALL AMOUNTS RECEIVED IN
THE WRAP AROUND PRECIPITATION ACROSS THE STATE (REPORTS RANGING FROM
5 TO 15 INCHES ACROSS WESTERN AND CENTRAL NORTH DAKOTA SO FAR).
NORTHWEST WINDS OF 20 TO 35 MPH WERE REPORTED THIS MORNING WITH
VISIBILITIES RANGING FROM 1/4 TO 3/4 MILE MOST AREAS...WITH SOME
VISIBILITIES ABOVE A MILE OR 2. MORE SNOWFALL EXPECTED TODAY WILL
KEEP VISIBILITIES BELOW A MILE WITH 1/2 TO 1/4 MILE AT TIMES EVEN
THOUGH WINDS WILL LIKELY NOT BE AS STRONG TODAY AS THEY WERE
YESTERDAY. TRAVEL CONDITIONS REMAIN VERY HAZARDOUS ACROSS THE STATE
AND WILL KEEP THE CURRENT BLIZZARD WARNING GOING THROUGH TODAY WITH
THE WINTER WEATHER ADVISORY FOR THE FAR NORTHWEST CORNER OF THE
STATE. IN OTHER WORDS...ONGOING WINTER WEATHER HEADLINES LOOK GOOD
ACROSS THE AREA AND WILL LEAVE AS IS FOR NOW.
EXPECTING ANOTHER 1 TO 3 INCHES ACCUMULATION TODAY ACROSS THE REGION
WITH SNOW TAPERING OFF BY EVENING. OVERALL WEATHER CONDITIONS SHOULD
BEGIN TO IMPROVE LATER THIS AFTERNOON OR EARLY EVENING WITH
DECREASING WINDS AND IMPROVING VISIBILITIES AS THE UPPER LEVEL LOW
AND ITS ATTENDANT SURFACE LOW BEGIN TO MOVE NORTHEASTWARD.
COLD CANADIAN HIGH PRESSURE SINKS INTO THE REGION TONIGHT THROUGH
MONDAY.
LONG TERM...MONDAY THROUGH SATURDAY NIGHT...
MEDIUM RANGE MODELS IN FAIR AGREEMENT IN EXTENDED WITH USUAL
DISCREPANCIES IN DETAILS. WILL USE A BLEND FOR THE EXTENDED GRIDS.
NORTHERN PLAINS REMAIN IN NORTHWEST FLOW WITH PERIODIC SHORT WAVES
IN FLOW. HOWEVER AT THIS TIME MODELS DO NOT BRING QPF TO PLAINS AND
WILL LEAVE A GENERALLY DRY FORECAST IN PLACE.
TEMPERATURES WILL BE MODERATE AND NEAR NORMAL THROUGH BEGINNING OF
EXTENDED PERIODS. NEXT ARCTIC HIGH MOVES SOUTH AS NEXT WEEKEND
APPROACHES. THIS COLD AIR MASS GIVES GLANCING BLOW TO WESTERN AND
CENTRAL NORTH DAKOTA BEFORE SETTLING LONGER IN UPPER MISSISSIPPI
VALLEY AND GREAT LAKES REGION THIS COMING WEEKEND.
AVIATION...
BANDS OF PRECIPITATION WILL CONTINUE TO SPIRAL OVER TAF SITES AS
SURFACE LOW NOW OVER NORTHERN IOWA MOVES SLOWLY EAST. TEMPO IFR
GROUPS WILL BE CONTINUED IN TAFS THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NDZ003-004-010>012-017>021-031>034-040>045.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ002-
005-009-013-022-023-025-035>037-046>048-050-051.
&&
$$
SHORT TERM...VINING
LONG TERM/AVIATION...WETZEL
UPDATE...SCHECK
