FXUS63 KBIS 240329
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
929 PM CST WED DEC 23 2009

.UPDATE...
NO UPDATES TO THE CURRENT HAZARDS. WILL DO SOME ADJUSTING TO POPS
AND TEMPERATURES IN THE WEST. SNOW HAS PRETTY MUCH ENDED IN
EASTERN MONTANA...AND EXPECT IT TO TAPER OFF ACROSS THE WEST THIS
EVENING. ALTHOUGH SNOW WILL END (FOR THE OVERNIGHT PERIOD) WILL
KEEP THE SNOW AND BLOWING SNOW ADVISORY DUE TO THE WINDS PRODUCING
AREAS OF BLOWING SNOW.

IN THE CENTRAL...FAR WESTERN PORTIONS OF THE WINTER STORM WARNING
WILL LIKELY SEE SNOW TAPERING OFF TONIGHT...THE REMAINDER OF THE
WARNING AREA IS NOT SO CLEAR...AS MOISTURE FROM THE EAST GETS
PULLED IN...IT IS TOUGH TO DETERMINE EXACTLY HOW FAR EAST THE BACK
EDGE OF THE SNOW WILL GET. THINK IT'S BEST TO LET THINGS BE FOR
THE OVERNIGHT PERIOD.

WE DROPPED POPS IN THE FAR WEST...AND LOWERED CLOUD COVER.
THEREFORE WE HAD TO DROP TEMPERATURES IN THE FAR WEST AS WELL.
WILL PROBABLY GO AROUND 5 BELOW IN THE NORTHWEST AND FAR WEST
CENTRAL. 

&&

.PREV DISCUSSION... /ISSUED 506 PM CST WED DEC 23 2009/ 

SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
MODELS IN GOOD AGREEMENT ON MERGER OF NORTHERN AND SOUTHERN STREAM
UPPER LOWS...AND PROLONGED SIGNIFICANT WEATHER EVENT ACROSS THE
FORECAST AREA THROUGH SATURDAY. HAVE INCREASED POPS INTO SATURDAY
AND SATURDAY EVENING...WITH TROWAL FEATURE LIKELY KEEPING AT LEAST
MODERATE SNOWS GOING...ALONG WITH CONTINUED WIND IMPACT. EXPECT
LIGHT TO MODERATE SNOW AND WINDS MAINLY 15 TO 25 MPH TONIGHT
THROUGH THURSDAY. MORE SEVERE CONDITIONS ARE EXPECTED LATE
THURSDAY NIGHT...THROUGH CHRISTMAS DAY INTO SATURDAY. LOOK FOR
HEAVIER SNOW...AND VERY STRONG NORTHWEST WINDS...ESPECIALLY ACROSS
THE SOUTHEAST HALF OF THE FORECAST AREA. SUSTAINED SPEEDS OF 25 TO
35 MPH ARE EXPECTED OVER THESE AREAS...WITH GUSTS OF 40 TO 50 MPH.
A BLIZZARD WATCH REMAINS IN EFFECT FOR FRIDAY INTO SATURDAY...AND
WILL LIKELY BE UPGRADED OVER THE FAVORED LOCATIONS OVERNIGHT.
TRAVEL WILL BECOME EXTREMELY DANGEROUS...IF NOT IMPOSSIBLE...LATE
THURSDAY NIGHT INTO SATURDAY. REFER TO WEATHER.GOV/BISMARCK FOR
MORE DETAILS OF SNOWFALL TOTALS THROUGH SATURDAY. HIGHEST AMOUNTS
OF 12 TO 16 INCHES...AND LOCALLY HIGHER...ARE EXPECTED EAST OF A LINE 
FROM ROLETTE...TO BUTTE AND WASHBURN...SOUTH THROUGH BISMARCK TO
SELFRIDGE. LESSER AMOUNTS OF 8 TO 12 ARE EXPECTED FROM
MINOT...SOUTH THROUGH GARRISON AND MANDAN...TO ELGIN. 4 TO 8 INCH
TOTALS WILL BE COMMON THROUGH SATURDAY OVER THE WESTERN COUNTIES. 

LONG TERM...SUNDAY THROUGH WEDNESDAY
THE MODELS ALL ARE IN AGREEMENT INITIALLY AND INDICATE A COMBINATION 
OF SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE COVERING THE HIGH 
PLAINS EAST OF THE ROCKIES.  THIS SHOULD KEEP THE CHANCE OF 
SIGNIFICANT PRECIPITATION LOW. BY WEDNESDAY THE MODELS DIVERGE SO 
FOR NOW WILL STAY WITH THE TREND OF THE PREVIOUS FORECAST WHICH 
KEEPS POPS LOW AND FOLLOWS THE GFS TREND.  OVERALL TEMPS WILL BE 
BELOW NORMAL THROUGH THE PERIOD.  

AVIATION...
EXPECT CENTRAL ND TO CONTINUE TO HAVE INTERMITTENT LIGHT 
SNOW AND VARIABLE LOW CEILINGS THROUGH THURSDAY AFTERNOON AS A LARGE 
LOW PRESSURE SYSTEM DOMINATES THE WEATHER IN THE CENTRAL US.  THIS 
WILL CAUSE WIDESPREAD IFR CONDITIONS DUE TO LOW CEILINGS AND 
VISIBILITIES IN SNOW. THE FAR WEST WILL BE ON THE FRINGE OF THE 
SYSTEM AND COULD SEE IMPROVEMENT AFTER MIDNIGHT.

&&

.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 WATCH FROM FRIDAY MORNING THROUGH SATURDAY AFTERNOON 
FOR NDZ001>005-009>013-017>023-025-031>037-040>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.

&&

$$
TWH