000
FXUS63 KBIS 130620
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1220 AM CST FRI DEC 13 2013

.UPDATE...
ISSUED AT 1220 AM CST FRI DEC 13 2013

LATEST KMBX RADAR SHOWS SEVERAL NARROW BANDS OF LIGHT SNOW
CONTINUING ACROSS THE TURTLE MOUNTAINS. THE LATEST SURFACE
ANALYSIS SHOWS CONFIRMS THE SNOW FROM RUGBY TO ROLLA. THE
MEANDERING BAROCLINIC ZONE CONTINUES TO SAG SOUTH WITH SUBZERO
TEMPERATURE READINGS NOW PUSHING INTO ROLLA AND RUGBY. COLD
AIR ADVECTION WILL TAKE CONTROL OVERNIGHT INTO FRIDAY. TREND OF
DEVELOPING FLURRIES AND OR LIGHT SNOW SLOWLY SOUTH OVERNIGHT INTO
FRIDAY REMAINS ON TRACK.

UPDATE ISSUED AT 1004 PM CST THU DEC 12 2013

LIGHT SNOW CONTINUES TO DEVELOP OVER NORTH CENTRAL NORTH DAKOTA IN
AN AREA OF ENHANCED ISENTROPIC ASCENT CO-LOCATED WITH THE RIGHT-
REAR QUAD OF AN UPPER LEVEL JET STREAK. THIS ACTIVITY IS STILL
EXPECTED TO SAG SOUTH THROUGH THE OVERNIGHT HOURS AS THE UPPER
LEVEL JET DIPS SOUTH. THE CURRENT SNOW FORECAST IS ON TRACK WITH
NO UPDATES REQUIRED. FRESHENED UP THE SPS FOR THIS UPDATE.

FURTHERMORE...THE CURRENT WIND CHILL ADVISORY STILL LOOKS GOOD FOR
AREAS ACROSS NORTH CENTRAL NORTH DAKOTA. SENT OUT A FRESHENED UP
WSW TO CLEAN UP THE OVERNIGHT WORDING.

OTHERWISE...NO MAJOR ADJUSTMENTS WERE MADE TO THE ONGOING
FORECAST. THE UPDATED PRODUCTS HAVE BEEN SENT.

UPDATE ISSUED AT 640 PM CST THU DEC 12 2013

THE KMBX WSR-88D IS DETECTING AN AREA OF SNOW OVER NORTH CENTRAL
NORTH DAKOTA THIS EVENING. THE LATEST MODEL PROGS AND FORECAST
CONTINUE TO GRADUALLY SHIFT THIS AREA OF SNOW SOUTHWEST TONIGHT.
HOWEVER...THE BULK OF THE SNOW WILL REMAIN OVER NORTH CENTRAL
NORTH DAKOTA THROUGH THE PERIOD. 2 TO 3 INCHES OF SNOW IS STILL
EXPECTED OVER THE NORTH CENTRAL PART OF THE STATE TONIGHT AND
TOMORROW MORNING. THE CURRENT FORECAST IS ON TRACK WITH NO MAJOR
UPDATES REQUIRED. THE UPDATED PRODUCTS HAVE BEEN SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 259 PM CST THU DEC 12 2013

CONCERNS THIS FORECAST PERIOD INCLUDE ACCUMULATING SNOW ACROSS THE NORTH
CENTRAL FOLLOWED BY WIND CHILLS ACROSS THE NORTH CENTRAL LATE TONIGHT
AND FRIDAY. THIS THURSDAY AFTERNOON SURFACE LOW PRESSURE ACROSS
EASTERN MONTANA WILL TRACK SOUTHEAST. THE FOCUS FOR LIGHT SNOWFALL
WILL BE ACROSS THE NORTH AND EAST TONIGHT AND FRIDAY. SNOW
ACCUMULATIONS OF 1 TO 3 INCHES ARE FORECAST FOR THURSDAY
NIGHT AND FRIDAY. AS THE ARCTIC HIGH PULLS BACK IN ACROSS THE
REGION LATE TONIGHT THE WIND CHILLS ARE AGAIN EXPECTED TO DIP INTO
THE ADVISORY CATEGORY ACROSS THE NORTH CENTRAL THROUGH THE
WESTERN DEVILS LAKE BASIN AFTER 06Z. ALTHOUGH WIND CHILLS RECOVER
TO AROUND 15 BELOW FRIDAY AFTERNOON...THEY AGAIN RETURN TO 25 TO
30 BELOW FRIDAY NIGHT. CONSIDERING THERE WILL BE ONLY A FEW HOURS
WITH OUT WIND CHILL ADVISORY CRITERIA RAN THE WIND CHILL ADVISORY
THROUGH 18Z SATURDAY. WILL CONTINUE TO HANDLE THE SNOWFALL AMOUNTS
OF 1 TO 3 INCHES OVER 24-36 HOURS IN A SPECIAL WEATHER STATEMENT.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 259 PM CST THU DEC 12 2013

THE MAIN FORECAST ISSUE IS TIMING AND COVERAGE OF SEVERAL LIGHT SNOW
EVENTS THROUGH THE PERIOD...AS WELL AS SWINGS IN TEMPERATURES WITH
THE TIMING OF ARCTIC COLD FRONTS AND PACIFIC WARM FRONTS THAT ARE
EXPECTED TO TRAVERSE NORTH DAKOTA DURING THIS TIME PERIOD.

ON FRIDAY NIGHT...AN UPPER LEVEL SHORTWAVE MOVING SOUTHEASTWARD IS
FORECAST TO MOVE ACROSS THE STATE AS A SURFACE ARCTIC HIGH SLIDES
SOUTHEAST AND A PACIFIC WARM FRONT PUSHES EASTWARD ACROSS WESTERN
NORTH DAKOTA. THIS WILL PRODUCE A LARGE AREA OF LIGHT SNOW OR
FLURRIES...BUT WITH LITTLE IN THE WAY OF ACCUMULATION. LOWS FROM 5
TO 15 BELOW ALONG AND EAST OF THE MISSOURI RIVER...WITH THE PACIFIC
AIR MOVING INTO THE SOUTHWEST WITH LOWS OF ZERO TO 5 ABOVE.

A BIT WARMER ON SATURDAY...BUT SHORTLIVED AS ANOTHER ARCTIC COLD
FRONT MOVES SOUTHEAST ACROSS THE STATE. LOOKING AT HIGHS FROM AROUND
ZERO IN THE TURTLE MOUNTAINS TO THE LOW TO MID 20S IN THE FAR
SOUTHWEST.

THE ARCTIC COLD WILL ALSO BE SHORTLIVED...AS ANOTHER PACIFIC FRONT
IS PROGGED TO MOVE EAST ACROSS THE STATE LATE SATURDAY NIGHT INTO
SUNDAY. THIS WARM FRONT WILL BRING A CHANCE OF LIGHT SNOW TO THE
FORECAST AREA SATURDAY NIGHT AND SUNDAY...WITH LITTLE ACCUMULATION
EXPECTED. LOWS SATURDAY NIGHT FROM NEAR 15 BELOW IN THE TURTLE
MOUNTAINS TO 15 ABOVE IN THE FAR SOUTHWEST...BUT SHOULD SEE A VERY
NICE WARM-UP ON SUNDAY WITH HIGHS IN THE SINGLE DIGITS ABOVE ZERO IN
THE DEVILS LAKE AND JAMES RIVER BASINS TO THE LOW TO MID 30S IN THE
SOUTHWEST.

THE RELATIVELY MILD PACIFIC AIR SHOULD REMAIN OVER THE STATE SUNDAY
THROUGH TUESDAY...THEN THE MODELS BEGIN TO DIVERGE - THEY DEVELOP A
LONGWAVE TROUGH OVER THE WEST/ROCKIES WHICH WOULD INDICATE ANOTHER
SURGE OF ARCTIC AIR MOVING SOUTHWARD INTO THE PLAINS...BUT THE
TIMING DIFFERENCES BRING MUCH UNCERTAINTY FOR TEMPERATURES.
HOWEVER...THE MODELS ARE IN AGREEMENT THAT ANOTHER ROUND OF ARCTIC
OUTBREAKS ARE IN THE OFFING BEGINNING THE MIDDLE OR END OF NEXT
WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM CST FRI DEC 13 2013

MVFR CIGS EXPECTED ACROSS THE AERODROMES WITH PERIODS OF IFR CIGS
AT KBIS/KDIK. PERIODS OF LIGHT SNOW WILL ALSO ACCOMPANY THE LOW
CLOUDS WHICH AT TIMES WILL REDUCE VSBYS INTO THE MVFR RANGE. VERY
LITTLE IMPROVEMENT...IF ANY...THROUGH 06Z SATURDAY.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST SATURDAY FOR NDZ002>005-
011>013-022-023-025.

&&

$$

UPDATE...KS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...KS