Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 270928
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
328 AM CST SAT DEC 27 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CST SAT DEC 27 2014

AFTER TAKING MOST OF DECEMBER OFF...THE SHORT TERM PERIOD MARKS THE
BEGINNING OF THE RETURN OF WEATHER THAT IS MORE TYPICAL OF WHAT WE
WOULD EXPECT IN THE HEART OF WINTER...AT LEAST FOR TEMPERATURES.
FEATURE DRIVING SNOW ACROSS THE AREA THIS MORNING SHOWS UP WELL ON
SATELLITE WITH A NICE SWIRL MOVING INTO THE SIOUX FALLS AREA...WITH
A NICE DRY SLOT NOSING INTO SE MN. THIS DRY SLOT IS ASSOCIATED WITH
A TROWAL...WHICH HAS HELPED FORCE A NICE DEFORMATION BAND OF PRECIP
TO THE NW OF IT. MODELS GOING BACK TO THE 00Z RUNS LAST NIGHT HAVE
ACTUALLY DONE A GOOD JOB HANDLING THIS SNOW AND PRETTY MUCH FOLLOWED
THE HOPWRF AND HRRR FOR ENDING SNOW ACROSS THE AREA THIS MORNING.
EVERYTHING APPEARS ON TRACK FOR A HEALTHY SWATH OF 3 TO 5 INCHES.

BACK TO THE WEST OF THIS LOW...THERE IS A RIDGE AXIS EXTENDING FROM
ERN COLORADO UP INTO THE ERN DAKOTAS. TEMPS AND DEWPS FALL OFF TO
WITHIN 10 DEGS OF EITHER SIDE OF ZERO WITHIN THE RIDGE AXIS...THOUGH
THIS RIDGE AXIS ALSO HAS WHAT HAS BEEN A RARITY THIS MONTH...MOSTLY
CLEAR SKIES. ITS LOOKING LIKE GOOD BET FOR SEEING SOME SUN TODAY
WEST OF I-35. EAST OF I-35...THE CLEARING WILL BE RACING
SUNSET...THOUGH BY THE TIME YOU GET TO EAU CLAIRE...IT`S A PRETTY
GOOD BET THAT SKIES WILL REMAIN OVERCAST THROUGH THE DURATION OF
DAYLIGHT HOURS. THESE MAINLY CLEAR SKIES MAY CAUSE TEMPERATURES TO
BE A BIT COOLER THAN WHAT IS CURRENTLY FORECAST TONIGHT...ESPECIALLY
WHERE WE ARE SEEING SNOW RIGHT NOW FROM SOUTHERN MN INTO WRN WI. OF
COURSE OUR TIME WITH CLEARISH SKIES WILL BE SHORT LIVED...AS BY 12Z
SUNDAY...THE ARCTIC BOUNDARY WILL BE SLIPPING INTO CENTRAL MN...WITH
CLOUD COVER INCREASING AHEAD OF THE FRONT AS IT DROPS SOUTH ACROSS
NRN MN THROUGH THE NIGHT.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CST SAT DEC 27 2014

THE MAIN HIGHLIGHT OF THE LONG TERM FORECAST PERIOD WILL BE THE
RETURN TO BELOW NORMAL TEMPERATURES BEFORE WE RING IN THE NEW
YEAR. OTHER THAN A SLIM CHANCE FOR SNOWFALL ON SUNDAY NIGHT INTO
MONDAY AS THE ARCTIC BOUNDARY RESPONSIBLE FOR THE AFOREMENTIONED
COOL DOWN IN TEMPERATURES MOVES THROUGH...DRY WEATHER IS EXPECTED
UNTIL POSSIBLY NEXT FRIDAY.

SUNDAY WILL LIKELY BE THE ONE AND ONLY MILD DAY THROUGH MOST OF
THE UPCOMING WEEK IN ADVANCE OF THE COLD FRONT. MODEL AGREEMENT WITH
THIS FEATURE HAS NOT REALLY SHOWN MUCH IMPROVEMENT OVER THE LAST
24 HOURS. THE ECMWF HAS BEEN FAIRLY INSISTENT THAT THE FORECAST
AREA WILL MISS OUT ON SNOWFALL WITH THIS FEATURE...WHILE THE
SREF...NAM...AND NOW 27.00 GFS THINK SOUTHERN MN WILL SEE A 1-3
INCH SNOWFALL ON SUNDAY NIGHT AND MONDAY MORNING. SINCE THE ECMWF
IS A BIT OF AN OUTLIER FROM THE OVERALL MODEL CONSENSUS SOLUTION...WHICH
HAS SHOWN UP FOR MULTIPLE RUNS...HAVE INCLUDED 30 POPS FOR 00Z-18Z
MONDAY GENERALLY SOUTH OF INTERSTATE 94. HAVE HOWEVER KEPT SNOWFALL
ACCUMULATIONS AROUND ONE INCH OR LESS WITH THE THOUGHT THE
FORCING/MOISTURE MIGHT BE WEAKER/LOWER THAN PROGGED BY THE
CONSENSUS.

WHILE CONFIDENCE IS RATHER LOW WITH RESPECT TO SNOWFALL CHANCES AS
THIS BOUNDARY SURGES ACROSS THE AREA...WHAT IS MORE CERTAIN IS
THAT A BLAST OF COLDER AIR WILL FOLLOW IN ITS WAKE. THERE IS STILL
FINE AGREEMENT THAT H85 TEMPERATURES WILL REDUCE TO -18C TO -20C
BY TUESDAY. SUB-ZERO LOWS FOR TUESDAY AND WEDNESDAY MORNINGS ARE
FAIRLY CERTAIN...ALONG WITH HIGHS IN THE SINGLE DIGITS TO LOW
TEENS. WIND CHILLS WILL SNEAK TO AROUND -20F TO -30F ON MONDAY
NIGHT AND TUESDAY NIGHT...BUT MODERATE A TAD /-10F/ FOR NEW YEARS
EVE AS LOW TEMPERATURES RECOVER TO ABOVE ZERO VALUES.

AT THE END OF THE UPCOMING WEEK...GFS AND ECMWF MODELS FORECAST ANOTHER
WAVE TO DROP SOUTH FROM CANADA...THIS TIME THROUGH THE BASE OF A
HUDSON/JAMES BAY CYCLONE. WHILE TIMING/AMPLITUDE DETAILS ARE A BIT
UP IN THE AIR AT THIS POINT...THE PROGS DO WARRANT INCLUSION OF
20-30 POPS FOR SNOW ON FRIDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1051 PM CST FRI DEC 26 2014

-SN HAS OVERSPREAD MUCH OF THE WFO MPX COVERAGE AREA...INCLUDING
CEILINGS FROM LOWER-END MVFR INTO BARELY IFR RANGE WITH VSBYS AS
LOW AS 1SM IN SOME OF THE HEAVIER SNOW BANDS. THE SNOWFALL WILL
CONTINUE TO FILL IN FROM THE SW OVERNIGHT...AFFECTING ALL BUT KAXN
AND POSSIBLY NOT KSTC...OR AT LEAST NOT AS BAD AT KSTC AS THE
REMAINING TAF SITES. ALL SITES /BUT KAXN/ WILL EXPERIENCE FLIGHT
CATEGORY REDUCTIONS AT TIMES TO IFR DURING THE FIRST HALF OF THIS
TAF PERIOD. HAVE DROPPED CONDS TO AS LOW AS 1SM...BUT GOING LESS
THAN THAT FOR VSBY CERTAINLY CANNOT BE RULED OUT. SAME WITH
CEILINGS...SEEING IFR CONDS WILL BE LIKELY WITH CEILINGS INTO LIFR
NOT UNREASONABLE. CONDS WILL IMPROVE FROM DAYBREAK ON THRU LATE
MRNG AS THE -SN PULLS OUT. VFR CONDS ARE EXPECTED BY LATE SAT
AFTN INTO EARLY SAT EVE.

KMSP...CONDS HAVE IMPROVED AT KMSP...EVEN TO VFR AT TIMES...AFTER
THE INITIAL BAND OF SNOW DEVELOPED OVER THE S/E TWIN CITIES
METRO AT THE START OF THE 27/00Z TAF. MORE WIDESPREAD SNOW IS
EXPECTED DURING THE THE EARLY MRNG HRS. CONDS IMPROVE AROUND
DAYBREAK. VSBY MAY WELL DROP BELOW 1SM FOR A TIME...BUT RATES OF 1
IN/HR ARE NOT EXPECTED BUT WILL CONTINUE TO MONITOR FOR ANY
POTENTIAL OF AN AIRPORT WEATHER WARNING AS THE EVENT UNFOLDS.
AFTER DAYBREAK...CEILINGS WILL INCRS TO MVFR LEVELS AND LIKELY GO
TO VFR SAT AFTN-EVE.

/OUTLOOK FOR KMSP/
SUN...VFR...CHC MVFR CIGS. WINDS S 5 KTS...BCMG E.
MON...VFR. WINDS N 10 KTS.
TUE...VFR. WINDS NW 5-10 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ053-
     060>063-065>070-073>078-082>085-091>093.

WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ014>016-
     023>028.

&&

$$

SHORT TERM...MPG
LONG TERM...LS
AVIATION...JPC





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