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000
FXUS63 KMPX 050942
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
342 AM CST THU DEC 5 2013

.UPDATE...
ISSUED AT 329 AM CST THU DEC 5 2013

UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CST THU DEC 5 2013

AFTER A VERY BUSY FEW DAYS THINGS WILL BE SETTLING DOWN ACROSS THE
AREA IN MOST RESPECTS... ALTHOUGH VERY COLD TEMPERATURES AND LOW
WIND CHILLS WILL BE WITH US THROUGH THE NEXT FEW DAYS. COLD
ADVECTION AND SUBSIDENCE WILL PREVAIL OVER THE AREA TODAY... WITH
CYCLONIC BOUNDARY LAYER FLOW LOOKING TO LAST INTO THIS EVENING.
WOULD GENERALLY EXPECT TO SEE PERSISTENT STRATOCU WITH THIS
SCENARIO... AND WILL GO WITH A MOSTLY CLOUDY FORECAST TODAY INTO
TONIGHT WITH THAT IN MIND. HOWEVER... THE FORECAST TEMPERATURES
BENEATH THE FAIRLY SHALLOW SUBSIDENCE INVERSION DURING THIS TIME
PERIOD IS CAUSE FOR SOME CONCERN... AS WE COULD WIND UP WITH MAINLY
ICE CRYSTAL CLOUDS BY THIS AFTERNOON. THAT WOULD LEAD TO MORE IN THE
WAY OF MILKY SUNSHINE THROUGH WHAT WOULD ESSENTIALLY BE LOW-LEVEL
CIRRUS CLOUDS RATHER THAN THE MORE TYPICAL POST-FRONTAL STRATOCU.
THE 11-3.9 MICRON SORT OF SUGGESTS THAT MAY ALREADY BE THE CASE OVER
THE EASTERN DAKOTAS INTO SOUTHWEST MINNESOTA... BUT WE/LL NEED TO
WAIT AND SEE HOW THINGS LOOK THIS MORNING WHEN WE GET SOME VISIBLE
IMAGES. SO... AS MENTIONED... WILL STICK WITH A MOSTLY CLOUDY
FORECAST FOR TODAY INTO TONIGHT... BEFORE ALLOWING THINGS TO SCATTER
OUT AS RIDGING STARTS TO WORK INTO THE AREA. BUT... COULD WIND UP
WITH A BIT OF A SURPRISE DURING THE DAY WITH CEILOMETERS SHOWING
CLOUDS WHILE EYEBALLS SEE MORE OF A MILKY SUNSHINE OVER A GOOD
PORTION OF THE AREA. TEMPERATURES WILL HARDLY BUDGE TODAY... AND
WILL THEN PLUMMET TONIGHT WITH WIND CHILLS DROPPING INTO THE
ADVISORY RANGE FROM WEST TO EAST DURING THE EVENING HOURS. WITH WIND
SPEEDS STAYING UP FOR MUCH OF THE DAY... INCLUDED THE MENTION OF
SOME BLOWING SNOW FOR MOST AREAS THAT SAW SNOW ON WEDNESDAY.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 300 AM CST THU DEC 5 2013

BY 12Z FRIDAY...THE -20C 850MB ISOTHERM IS FORECAST TO BE
BISECTING THE FORECAST AREA...AS WINDS STAY UP IN THE 7-10 MPH RANGE.
DANGEROUSLY COLD WIND CHILL VALUES WILL RESULT...WITH WIDESPREAD
20 BELOW TO 30 BELOW READINGS. THEREFORE PLAN ON ISSUING A WIND
CHILL ADVISORY. CONDITIONS WILL ONLY BRIEFLY MODERATE ABOVE
ADVISORY CRITERIA ON FRIDAY AFTERNOON /25 BELOW/ ACROSS WEST
CENTRAL MN...AND THEN DROP TO EVEN COLDER VALUES ON FRIDAY
EVENING/NIGHT /30 TO 35 BELOW/...SO A PROLONGED ADVISORY FROM
THURSDAY EVENING THROUGH SATURDAY MORNING WAS WARRANTED THERE.
ELSEWHERE...ACROSS CENTRAL AND SOUTH CENTRAL MN AND WEST CENTRAL
WI...WIND CHILLS WILL SNEAK ABOVE ADVISORY CRITERIA AFTER ABOUT 15Z ON
FRIDAY THROUGH THE AFTERNOON...AND THEN FALL BELOW AGAIN AFTER 00Z
SATURDAY. DUE TO THE LONGER BREAK BETWEEN PERIODS OF ADVISORY-
CRITERIA WIND CHILLS ACROSS CENTRAL/SOUTH CENTRAL MN AND WEST
CENTRAL WI...HAVE DECIDED TO ISSUE TWO SEPARATE ADVISORIES TO
HIGHLIGHT THE TIME FRAMES WHEN THE MOST DANGEROUS WIND CHILLS WILL
EXIST.

SATURDAY HIGHS WILL STRUGGLE TO ECLIPSE ZERO DEGREES ACROSS WEST
CENTRAL MN...WHILE HIGHS ELSEWHERE RANGE FROM ZERO TO 5 ABOVE.
SATURDAY NIGHT WILL BRING ANOTHER NIGHT WITH LOWS FROM ZERO TO 15
BELOW...ALTHOUGH LIGHTER WINDS WILL LIKELY KEEP WIND CHILL
READINGS FROM HITTING ADVISORY CRITERIA FOR A THIRD NIGHT IN A
ROW.

THE SATURDAY NIGHT THROUGH SUNDAY NIGHT TIMEFRAME BRINGS THE NEXT
CHANCE FOR MEASURABLE SNOWFALL TO THE AREA...AS A SHORTWAVE TROUGH
EJECTS NORTHEAST FROM THE FOUR CORNERS REGION. STILL LOOKS LIKE A
PORTION OF THE AREA COULD SEE SNOWFALL AMOUNTS IN THE 1-3 INCH
RANGE...WITH SOUTH CENTRAL MN TOWARD EAU CLAIRE THE FAVORED PATH
FOR THE AMOUNTS ON THE HIGHER END OF THAT RANGE.

CONTINUED COLD CONDITIONS PERSIST ON TUESDAY AND WEDNESDAY...WITH
YET ANOTHER CHANCE FOR LIGHT SNOW ON TUESDAY /CENTRAL MN ACROSS WI/...AS
A WEAK SHORTWAVE DIPS SOUTHEAST ACROSS THE AREA IN THE NORTHWEST
FLOW REGIME.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 329 AM CST THU DEC 5 2013

LOW PRESSURE WHICH BROUGHT YESTERDAY/S SNOW WILL CONTINUE TO MOVE
NORTHEAST OF THE REGION TODAY AS ARCTIC HIGH PRESSURE BUILDS
SOUTHEAST FROM CANADA. LINGERING LOW LEVEL MOISTURE AND A
SUBSIDENCE INVERSION WILL TRY TO KEEP CEILINGS IN PLACE ACROSS THE
AREA TODAY... BUT THEY WILL TRY TO ERODE FROM SOUTHWEST TO
NORTHEAST AS RIDGING SLOWLY ENCROACHES ON THE AREA. IN ADDITION...
THE EXCEPTIONALLY COLD AIRMASS MAY LEAD TO MORE IN THE WAY OF ICE
CRYSTAL CLOUDS TODAY... MEANING WE MAY SEE MVFR CEILINGS THAT ARE
ACTUALLY TRANSLUCENT RATHER THAN THE TYPICAL POST-COLD FRONTAL
STRATOCUMULUS. KEPT THE TAFS FAIRLY PESSIMISTIC GIVEN CURRENT
CONDITIONS AND FORECAST SOUNDINGS... BUT IT IS POSSIBLE THINGS
COULD IMPROVE MORE QUICKLY THAN EXPECTED TODAY. DID NOT INCLUDE
ANY LOWERED VISIBILITIES DUE TO BLOWING SNOW... BUT IT IS POSSIBLE
THERE COULD BE SOME OCCASIONAL MVFR VISIBILITIES AS WINDS REMAIN
GUSTY INTO THE AFTERNOON.

KMSP...HAVE SOME CONCERN THAT FORECAST CEILINGS MAY NOT REMAIN IN
PLACE AS LONG AS FORECAST... BUT OPTED TO REMAIN PESSIMISTIC AT
THIS POINT GIVEN TYPICAL EXPECTATIONS IN THE CYCLONIC FLOW COLD
ADVECTION REGIME. HOWEVER... THE EXCEEDINGLY COLD AIRMASS WORKING
INTO THE AREA MAY LEAD TO MORE OF A TRANSLUCENT CEILING
CONDITION... SO THAT WILL NEED TO BE MONITORED.

/OUTLOOK FOR KMSP/
FRIDAY AFTERNOON...VFR. NORTHWEST WIND 5 TO 15 KT.
FRIDAY NIGHT...VFR. WEST WIND LESS THAN 10 KT.
SATURDAY...VFR. VARIABLE WIND 5 KT OR LESS.
SATURDAY NIGHT...VFR. SOUTH WIND 5 KT OR LESS.
SUNDAY AND SUNDAY NIGHT...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH
A CHANCE OF SNOW. IFR CONDITIONS POSSIBLE. SOUTHEAST WIND 5 TO 10
KT SHIFTING WEST.
MONDAY...MVFR CEILINGS POSSIBLE EARLY. WEST WIND 10 TO 20 KT.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST FRIDAY
     FOR MNZ044-045-051>053-059>063-066>070-074>078-082>085-
     091>093.

     WIND CHILL ADVISORY FROM 6 PM FRIDAY TO 9 AM CST SATURDAY FOR
     MNZ044-045-051>053-059>063-066>070-074>078-082>085-091>093.

     WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST SATURDAY
     FOR MNZ041>043-047>050-054>058-064-065-073.

WI...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST FRIDAY
     FOR WIZ014>016-023>028.

     WIND CHILL ADVISORY FROM 6 PM FRIDAY TO 9 AM CST SATURDAY FOR
     WIZ014>016-023>028.

&&

$$

UPDATE...
SHORT TERM...
LONG TERM...LS
AVIATION...