000
FXUS63 KMPX 030104
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
704 PM CST MON DEC 2 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 349 PM CST MON DEC 2 2013

HEADING THROUGH THIS EVENING... A BAND OF WAA/MODEST ISENTROPIC
ASCENT WILL PUSH A BAND OF PRECIPITATION ACROSS EASTERN MINNESOTA
AND WESTERN WISCONSIN. THE EXPECTATION IS FOR A FEW QUICK INCHES
OF SNOW ALONG AND NORTH OF A LINE FROM MORRIS THROUGH ST CLOUD AND
MORA...WHICH LED TO THE DECISION TO EXPAND THE WINTER WEATHER
ADVISORY A ROW OF COUNTIES TO THE SOUTH. THE PRIMARY CONCERN IN
THE NEAR SHORT TERM IS THE HANDLING THE AFOREMENTIONED BAND OF
PRECIP AS IT MOVES FURTHER EAST INTO WISCONSIN THIS EVENING. MOST
SHORT TERM GUIDANCE IS SHOWING A P-TYPE OF RAIN FROM THE TWIN
CITIES ON SOUTH BUT MAINLY SNOW IS BEING OBSERVED AT THIS TIME.
SNOW WILL BE THE MAIN P-TYPE TO THE NORTH. FORECASTER CONFIDENCE
FOR OVERNIGHT AND TUESDAY IS LOW...GIVEN THE UNCERTAINTY AND
DISAGREEMENT BETWEEN NCEP MODELS AND THE EC/UK/GEM...ALONG WITH A
DISAGREEMENT IN P-TYPE MODELS. FOR TUESDAY...DRY AIR PUSHING IN
FROM THE SOUTHWEST LOOKS TO HELP MINIMIZE PRECIP TO DRIZZLE ACROSS
SOUTHWEST MN. SNOW SHOULD BECOME MORE DOMINATE FROM CENTRAL MN
THROUGH WEST CENTRAL WISCONSIN AS THE DAY PROGRESSES WITH THE EC
HINTING AT A SNOW BURST TUESDAY AFTERNOON... WHICH COULD WREAK
HAVOC ON THE EVENING COMMUTE WITH A QUICK ONE TO TWO INCHES.
OVERALL...A MESSY SITUATION ON HAND WITH SUBSTANTIAL MODEL
DISAGREEMENT. STAY TUNED FOR UPDATES.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 349 PM CST MON DEC 2 2013

TWO MAIN ITEMS OF CONCERN ARE THE ACCUMULATING SNOW EXPECTED AT
THE START OF THE PERIOD...AND THE COLD AIR THAT WILL FOLLOW
THROUGH THE REST OF THE WEEK.

THE UPPER LEVEL WAVE THAT WILL BRING WINTRY PRECIP ACROSS THE
REGION IS CURRENTLY ACROSS THE PACIFIC NORTHWEST...AND MODELS
HAVE BEGAN TO CONVERGE ON A SOLUTION THAT IS BEST DESCRIBED AS AN
ELONGATED STRIP OF VORTICITY...AS OPPOSED TWO CONGEALED VORTICITY
MAXIMA AS WAS EARLIER INDICATED BY SOLUTIONS OF THE GFS/NAM/SREF.
THE GEM/ECMWF HAVE BEEN THE MOST CONSISTENT...WITH THE LATEST RUNS
OF THE NAM/GFS BEGINNING TO FALL IN LINE. THIS WILL LEAD TO A
PROLONGED PERIOD OF LIGHT SNOWFALL ACROSS NORTHERN
MINNESOTA...WITH THE BEST FORCING FORECAST TO MOVE ACROSS THE
REGION LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. A BAND OF 4-6
INCHES OF SNOW SHOULD DEVELOP ACROSS WESTERN AND CENTRAL
MN...EXTENDING INTO FAR NORTHERN WI. AS A RESULT HAVE ISSUED A
WINTER STORM WATCH WHICH WILL TAKE EFFECT TUESDAY EVENING. AT THIS
TIME CONFIDENCE IS TOO LOW TO HAVE A WINTER STORM WARNING...BUT
WANTED TO GET THE WORD OUT THAT THERE IS POTENTIAL FOR SIGNIFICANT
IMPACTS FROM BOTH ACCUMULATING SNOWFALL...AND THEN STRONG
NORTHWEST WINDS AND FALLING TEMPERATURES LATE WEDNESDAY. THIS WILL
CAUSE BLOWING AND DRIFTING WHICH COULD REDUCE VISIBILITIES...BUT
MORE IMPORTANTLY WILL FREEZE AND WET ROADS AND BRING COLD WIND
CHILLS NEAR -20 ACROSS FAR WESTERN MN.

LOOKING AHEAD...THE ARCTIC AIR WILL REMAIN ACROSS THE REGION
THROUGH THE END OF THE WEEK...WITH ANOTHER STORM SYSTEM POSSIBLE
EARLY NEXT WEEK. THE THERMAL PROFILE OF THIS SYSTEM WOULD SUPPORT
ONLY SNOW.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 551 PM CST MON DEC 2 2013

MAIN BAND OF PRECIP HAS WORKED THROUGH THE MN TAF SITES AND IS
PROGRESSING EWD THRU THE WI TAF SITES. SHOULD EXIT THE WI TAF
SITES BY 04Z-05Z...THEN LOW CLOUDS WITH PATCHY -DZ/-RA WILL REMAIN
THRU THE OVERNIGHT PERIOD. SINCE THIS BAND WAS ASSOCIATED WITH A
WARM-FRONT-TYPE BOUNDARY MOVG THRU...TEMPS SHOULD SLOWLY RISE
WHICH SHOULD MITIGATE CONCERNS FOR -FZDZ OR FZFG. LOW LEVEL ELY
FLOW WILL KEEP LOW CLOUDS IN PLACE FOR JUST ABOUT THE ENTIRE TAF
PERIOD...CERTAINLY WITHIN IFR LEVELS AND POSSIBLY LOWER...ESP
OVERNIGHT TNGT. THE BREAK IN THE MORE SUSTAINED PRECIP WILL END
DURG THE DAY TMRW WITH -SN MOVING IN FROM THE W MAINLY AFTER
DAYBREAK. THE PUNCH OF WAMRER AIR FROM THE S WILL CHANGE THE
PRECIP OVER TO -RA...OR AT LEAST A MIX OF -RA/-SN...FOR ALL SITES
EXCEPT KAXN-KSTC...WHICH ARE EXPECTED TO REMAIN AS ALL -SN. WINDS
MAY GO LGT/VRBL IN SW AND S-CENTRAL MN AS THE LOW PRES CENTER
MOVES ACRS...WHILE N-CENTRAL MN INTO W-CENTRAL WI REMAIN ELY.
SPEEDS GENERALLY AOB 10 KT.

KMSP...CERTAINLY IFR CONDS TO PREVAIL...AT TIMES DUE TO VSBY AND
OTHERS DUE TO CEILING...WITH VERY LIGHT -RASN OR EVEN -DZ
OVERNIGHT FOLLOWED BY ADDITIONAL -RA CHANGING BACK TO -SN LATER
DURG THE DAY ON TUE. SHOULD BE ABLE TO AVOID -FZDZ OVERNIGHT BUT
THE LOW LEVEL ELY FLOW WITH PLENTY OF MOISTURE AND LESSENING WINDS
WILL KEEP LOW CLOUDS AND REDUCED VSBY IN PLACE. THE PRECIP WILL
RETURN AFTER DAYBREAK TMRW WITH PERIODS OF -RA WHICH WILL
GRADUALLY CHANGE OVER TO -SN BY LATE AFTN INTO EARLY EVE. NOT
LOOKIGN FOR CEILINGS TO RISE ABOVE 008 THROUGHOUT THIS TAF PERIOD
WHIC VSBY LOOK TO STAY AOB 3SM. WINDS REMAIN ELY IN THE 5-10 KT
RANGE THEN BECOME LGT/VRBL TUE EVE AS THE CENTER OF LOW PRES
APPROACHES.

/OUTLOOK FOR KMSP/
TUE...MVFR CIGS/VSBYS. SN LIKELY. ESE WINDS 10 KTS.
WED...MVFR CIGS. CHC SN. WINDS NW 15-25 KTS.
THU...MVFR CIGS POSSIBLE. WINDS WNW 10-15 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 3 AM CST TUESDAY FOR MNZ041>045-
     047>053.

     WINTER STORM WATCH FROM TUESDAY EVENING THROUGH THURSDAY MORNING
     FOR MNZ041>045-047>070-073.

WI...WINTER WEATHER ADVISORY UNTIL 3 AM CST TUESDAY FOR WIZ014>016.

     WINTER STORM WATCH FROM TUESDAY EVENING THROUGH THURSDAY MORNING
     FOR WIZ014>016-023>025-027.

&&

$$

SHORT TERM...SPD
LONG TERM...JRB
AVIATION...JPC