Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 271158
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
558 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 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 542 AM CST SAT DEC 27 2014

ONLY REAL CHANGE MADE TO SNOW WITH 12Z TAFS WAS TO DELAY
IMPROVEMENTS BY ABOUT AN HOUR AS IFR VSBYS STILL EXTENDED BACK TO
THE WRN EDGE OF THE MN/IA BORDER. SNOW WILL RAPIDLY PULL OUT THIS
MORNING...AND DRIER AIR COMING IN FROM THE DAKOTAS WILL ALSO CLEAR
OUT THE STRATUS...FOLLOWED A RAP TIMING FOR THOSE IMPROVEMENTS.
OTHERWISE...WINDS WILL VEER OVER TO THE WSW THIS AFTERNOON AS A
COLD FRONT DROPS INTO NRN MN. THIS FRONT WILL MOVE INTO CENTRAL MN
AFTER 9Z AND MAY BRING A RENEWED THREAT OF MVFR CIGS...BUT NO SNOW
IS EXPECTED WITH THIS BOUNDARY. REALLY...ONLY PART OF FORECAST
THAT HAS LOWER CONFIDENCE IS TIMING OF CIG IMPROVEMENTS TO VFR.

KMSP...BASED ON THE RAP/HRRR...EXPECT IFR VIS SNOW TO END BETWEEN
14Z AND 15Z...WITH ALL SNOW DONE BY 17Z. KEPT THE CIG IMPROVEMENT
AT 20Z...THOUGH THE RAP/HRRR WOULD SAY THAT COULD TAKE TO AS LONG
AS 00Z TO GET HERE. ARCTIC FRONT WILL WORK ACROSS THE FIELD LATE
SUNDAY MORNING. THOUGH NO PRECIP IS EXPECTED...WE MAY SEE CIGS
COME BACK DOWN TO MVFR FOR A BIT IN ITS WAKE.

/OUTLOOK FOR KMSP/
SUN...VFR...CHC MVFR CIGS. WINDS BCMG NE 5-10 KTS.
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...MPG






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