000
FXUS63 KBIS 072043
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
243 PM CST SAT DEC 7 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 243 PM CST SAT DEC 7 2013

MAIN FORECAST ISSUES ARE COLD TEMPS/WIND CHILLS AND CHANCE OF
LIGHT SNOW TONIGHT AND SUNDAY. WIND CHILL ADVISORY IS IN EFFECT
FOR MOST OF THE REGION WITH EXCEPTION OF SOUTH CENTRAL AND SOUTH
EAST. WINDS WILL BE GENERALLY LIGHT...BUT ENOUGH FOR WIND CHILL
VALUES TO EASILY REMAIN IN ADVISORY RANGE FOR NORTHERN AREAS.
HOWEVER...CLOUDS CURRENTLY OVER SOUTH DAKOTA THAT ARE MOVING
NORTHWARD WITH NEXT WEAK DISTURBANCE COULD IMPACT TEMPS ESPECIALLY
OVER CENTRAL/SOUTHERN COUNTIES. HAVE CONTINUED TREND OF SPREADING
LOW POPS FROM SOUTHWEST TO EAST OVERNIGHT AND SUNDAY AS LOW
PRESSURE WELL TO OUR SOUTH CROSSES THE CENTRAL PLAINS.
GFS/ECMWF/SREF ALL GENERATE A FEW HUNDREDTHS OF LIQUID EQUIVALENT
MAINLY AFTER 12Z SUNDAY. ALSO KEPT MENTION OF FLURRIES IN ACROSS
THE NORTHWEST ON SUNDAY AS COLD FRONT ENTERS THE STATE DURING THE
AFTERNOON.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 243 PM CST SAT DEC 7 2013

MAIN HIGHLIGHT IN THE LONG TERM WAS THE ISSUANCE OF A SPECIAL
WEATHER STATEMENT FOR MONDAY INTO TUESDAY.

FOR SUNDAY NIGHT THROUGH TUESDAY...TWO ALBERTA CLIPPER SYSTEMS WILL
QUICKLY SWEEP THROUGH...ONE MONDAY AFTERNOON AND EVENING...THE
SECOND NEARLY 24HRS LATER SLATED FOR TUESDAY AFTERNOON. GFS/NAM
SOUNDINGS CONTINUE TO SHOW PERIODS OF GUSTY WINDS WITH EACH
SYSTEM...WITH BOUNDARY LAYER WINDS OF 25KT TO 30KT. WILL LIKELY SEE
SOME GUSTS TO AROUND 40 MPH. PER GFS...THE STRONGEST COLD AIR
ADVECTION IS ASSOCIATED WITH TUESDAYS CLIPPER AS A 10MB PRESSURE
BUBBLE RISE IS FORECAST TO ENVELOP WESTERN AND CENTRAL NORTH DAKOTA
DURING THE AFTERNOON. NEW SNOWFALL ACCUMULATIONS THROUGH TUESDAY
AFTERNOON WILL REMAIN LIGHT...WITH ONE TO TWO INCHES FORECAST ALONG
AND WEST OF HIGHWAY 85...AND LESS THAN ONE INCH ELSEWHERE. THE
COMBINATION OF STRONG WINDS...EXISTING SNOWFALL ON THE GROUND...AND
ADDITIONAL LIGHT SNOWFALL FORECAST INTO TUESDAY...WILL RESULT IN
AREAS OF BLOWING AND DRIFTING SNOW. THIS MAY REDUCE VISIBILITIES AND
IMPACT TRAVEL. WILL HAVE SUBSEQUENT SHIFTS LOOK AT THIS FURTHER AND
ADJUST AS NEEDED THROUGH SUNDAY AND MONDAY.

IN TERMS OF WIND CHILL HEADLINES...A WIND CHILL ADVISORY WILL LIKELY
BE NEEDED SUNDAY NIGHT INTO MONDAY MORNING FOR ALL OF WESTERN AND
CENTRAL NORTH DAKOTA. FOR MONDAY NIGHT...PORTIONS OF THE FAR NORTH
INTO THE TURTLE MOUNTAINS MAY BE NEED AN ADVISORY...AND ALL BUT THE
SOUTHWEST WILL LIKELY NEED A WIND CHILL ADVISORY TUESDAY NIGHT INTO
WEDNESDAY MORNING. AFTER WEDNESDAY MORNING...NOT EXPECTING ANY
FURTHER WIND CHILL HEADLINES FOR THE REST OF THE EXTENDED.

FOR WEDNESDAY...SOME DISCREPANCIES AMONGST THE LONG RANGE MODELS.
PER GFS...ANOTHER QUICK MOVING ALBERTA CLIPPER SYSTEM MOVES MAINLY
THROUGH THE NORTH AND EAST CENTRAL WEDNESDAY...ALTHOUGH THE ECMWF
DOES NOT SHOW THIS. THE GEM IS IN BETWEEN WITH A COUPLE OF AREAS OF
LIGHT SNOW BEING ADVERTISED. THE GFS HAS A SURFACE REFLECTION WHILE
THE GEM DOES NOT. THE ALLBLEND HAS DIMINISHED THE PRECIPITATION THREAT
TO A SLIGHT CHC IN THE FAR NORTH CENTRAL AND EAST AND CONCUR WITH THIS.

FOR THURSDAY INTO SATURDAY...ANOTHER CLIPPER TYPE SYSTEM AS ADVERTISED BY
BOTH THE GFS AND ECMWF DEVELOP A CHANCE OF SNOW VIA WARM AIR
ADVECTION PROCESSES THURSDAY IN THE NORTH AND ACROSS THE TURTLE
MOUNTAINS. A RETURN TO COLD AIR ADVECTION QUICKLY DEVELOPS BEHIND
THIS SYSTEM FOR FRIDAY. FRIDAY INTO SATURDAY SHOWS SOME WEAK
DISTURBANCES SLIDE THROUGH WITH A SLIGHT CHC/CHC OF SNOW.

THE WARMEST HIGH TEMPERATURES WILL BE FELT ON THURSDAY WITH HIGHS
AROUND 10 ABOVE IN THE NORTH TO 25 IN THE SOUTHWEST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 243 PM CST SAT DEC 7 2013

VFR CONDITIONS ARE FORECAST THROUGH 06 UTC TONIGHT ACROSS WESTERN
AND CENTRAL NORTH DAKOTA. THEREAFTER...MVFR CONDITIONS DUE TO LOWER
CEILINGS MAY OCCUR ACROSS SOUTHERN NORTH DAKOTA BY 12 UTC
SUNDAY...POSSIBLY IMPACTING KDIK...KBIS AND KJMS. SOME LIGHT SNOW
IS ALSO POSSIBLE...BUT NOT ENOUGH CONFIDENCE IN TIMING TO WARRANT
INCLUSION IN TAFS. ANY LIGHT SNOW THAT FALLS WOULD OCCUR BETWEEN
12Z SUNDAY AND 00Z MONDAY.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST /11 AM MST/ SUNDAY FOR
NDZ001>005-009>013-017>023-025-031>037-040-043.

&&

$$

SHORT TERM...JNS
LONG TERM...KS
AVIATION...JNS