FXUS63 KBIS 240955
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
355 AM CST THU DEC 24 2009
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...
THE WORST OF THIS PROLONGED WINTER WEATHER EVENT HAS YET TO ARRIVE.
BLIZZARD CONDITIONS WITH HEAVY SNOW WILL DEVELOP LATE TONIGHT AND
CONTINUE INTO SATURDAY FOR CENTRAL NORTH DAKOTA AND PORTIONS OF
WESTERN NORTH DAKOTA.
WILL CONTINUE WITH THE WINTER STORM WARNING FOR CENTRAL NORTH DAKOTA
THROUGH THURSDAY NIGHT...AND HAVE DECIDED TO UPGRADE THE BLIZZARD
WATCH TO A BLIZZARD WARNING BEGINNING 12Z FRIDAY THROUGH SATURDAY.
IN THE WEST...A WINTER WEATHER ADVISORY CONTINUES THROUGH 12Z
FRIDAY DESPITE A LULL IN THE PRECIPIATION TODAY. BLOWING SNOW AND
WIND CHILL ARE THE MAIN THREATS TODAY. THIS WILL SHIFT TO SNOW AND
BLOWING SNOW TONIGHT INTO SATURDAY. A BLIZZARD WATCH REMAINS IN
EFFECT FOR WESTERN NORTH DAKOTA FRIDAY INTO SATURDAY...AND WITH
THE WEST STILL QUESTIONABLE WITH THE STRENGTH OF WINDS AND AMOUNT
OF SNOW FRIDAY INTO SATURDAY...HAVE DECIDED TO DEFER ANY DECISION
ON A BLIZZARD WARNING TO THE DAYSHIFT OR SWING SHIFT FOR FURTHER
EVALUATION.
THE LATEST WATER VAPOR IMAGERY SHOWS A STRONG LONG FETCH OF MOISTURE
FROM THE GULF OF MEXICO BEING TRANSPORTED NORTH AROUND AN UPPER
LOW OVER WEST TEXAS. OUR NORTHERN STREAM UPPER LOW PRESSURE SYSTEM
NOW OVER EASTERN MONTANA WILL MERGE WITH THE ENTIRE SOUTHERN
PLAINS SYSTEM. AS THE NORTHERN STREAM UPPER LOW BECOMES THE MORE
DOMINANT ONE...IT RETROGRADES THE ROBUST MOISTURE...SURFACE LOW
PRESSURE/UPPER DYNAMICS BACK INTO THE MIDWEST AND NORTHERN HIGH
PLAINS. A COUPLE OF TROWALS DEVELOP AS DEPICTED IN THE GFS. THIS
WILL RESULT IN PERSISTANT MODERATE TO HEAVY SNOW BANDS FOR ABOUT
24 HOURS ACROSS CENTRAL NORTH DAKOTA AND INTO PORTIONS OF WESTERN
NORTH DAKOTA. ADDITIONAL SNOWFALL ACCUMULATIONS FROM THIS EVENT
WILL RANGE FROM 6 TO 12 INCHES OVER MOST AREAS...PERHAPS MORE
DEPENDING ON THE EXACT LOCATION AND STRENGTH OF THE TROWAL.
SNOWFALL WILL BE HARD TO MEASURE DURING THE EVENT AS NORTH TO
NORTHWEST WINDS OF 15 TO 25 MPH TODAY WILL INCREASE LATE TONIGHT
TO 25 AND 35 MPH AND CONTINUE INTO SATURDAY. WIND GUSTS WILL RANGE
BETWEEN 40 AND 50 MPH. THE RESULT...BLIZZARD CONDITIONS WILL
DEVELOP BEGINNING LATE THURSDAY NIGHT/EARLY FRIDAY MORNING AND
CONTINUE THROUGH SATURDAY. EXPECTING WHITEOUT CONDITIONS AT TIMES.
STORM TOTAL SNOWFALL THROUGH SATURDAY WILL GENERALLY RANGE FROM
FROM 12 TO 18 INCHES OR POSSIBLY MORE OVER FAR EAST CENTRAL NORTH
DAKOTA...INCLUDING HARVEY...JAMESTOWN AND OAKES. TEN TO 15 INCHES
WILL LIKELY FALL FROM NEAR MINOT TO BISMARCK AND SOUTH TO SELFRIDGE.
SNOWFALL ACCUMULATIONS WILL TAPER FURTHER WEST WITH 6 TO 10 INCH
ACCUMULATION FROM DICKINSON TO GARRISON AND 2 TO 6 INCHES FROM
WILLISTON TO BOWMAN.
MOTORISTS AND HOLIDAY TRAVELERS ARE URGED TO STAY INFORMED WITH
THE LATEST INFORMATION AND FORECASTS AT WEATHER.GOV/BISMARCK.
.LONG TERM...
THE LONG TERM BEGINS WITH THE LAST LINGERING CLOUDS AND SNOW SHOWERS
EXITING THE STATE AS THE LARGE STORM SYSTEM OVER THE CENTRAL CONUS
WORKS ITS WAY EAST. BY MONDAY...THE MODELS DEVELOP A HIGH AMPLITUDE
RIDGE JUST EAST OF THE ROCKIES AND SWIFT NORTHWEST FLOW ALOFT OVER
NORTH DAKOTA. THIS RESULTS IN A DOME OF COLD AIR DESCENDING FROM
NORTHERN CANADA INTO THE NORTHERN PLAINS MONDAY NIGHT AND TUESDAY.
OVERALL...FORECAST REMAINS CLEAR OF ANY PRECIP...WITH TEMPERATURES
REMAINING STEADY AT AROUND SEASONAL NORMALS...WITH THE EXCEPTION OF
LATE MONDAY AND TUESDAY.
&&
.AVIATION...
WIDESPREAD IFR CONDS EXPECTED AS SEVERE WINTER WEATHER CONTINUES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM CST /5 AM MST/ FRIDAY FOR
NDZ003>005-011>013-019>023-025-034>037-042-045>048-050-051.
BLIZZARD WARNING FROM 6 AM CST /5 AM MST/ FRIDAY TO 6 PM CST /5
PM MST/ SATURDAY FOR NDZ003>005-011>013-019>023-025-034>037-042-
045>048-050-051.
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ FRIDAY FOR
NDZ001-002-009-010-017-018-031>033-040-041-043-044.
BLIZZARD WATCH FROM FRIDAY MORNING THROUGH SATURDAY AFTERNOON
FOR NDZ001-002-009-010-017-018-031>033-040-041-043-044.
&&
$$
KS/BPN/HW
