Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 290039
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
639 PM CST WED JAN 28 2015

.UPDATE...
ISSUED AT 555 PM CST WED JAN 28 2015

UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 342 PM CST WED JAN 28 2015

AN ACTIVE SHORT TERM AHEAD AS A LOW PRESSURE SYSTEM OVER THE
EASTERN DAKOTAS SLIDES SOUTHEAST INTO NORTHERN IL BY THURSDAY
MORNING. LITTLE ICE IS INDICATED ALOFT OVER NORTHERN AND EASTERN
AREAS OF THE FA TONIGHT WITH DEEPENING LOW LEVEL SATURATION. IN
ADDITION...SOUTHERLY LOW LEVEL WINDS INCREASE RATHER DRAMATICALLY
EARLY TONIGHT ACROSS EASTERN IA ON NORTHWARD INTO WEST CENTRAL
WI...WITH A VEERING PROFILE THROUGH 800MB. THIS SHOULD ADD THE
TURBULENCE FACTOR TO ALLOW FREEZING DRIZZLE TO BECOME WIDESPREAD
ACROSS MUCH OF WEST CENTRAL WI FROM AROUND MID EVENING INTO EARLY
THURSDAY MORNING. THIS IS COLLABORATED BY RUNS TODAY OF THE
HOPWRF...HRRR AND RAP SHOWING SOME A FEW HUNDREDTHS OF QPF IN THE
AFOREMENTIONED AREAS. THEREFORE...ISSUED A FREEZING RAIN ADVISORY
FROM 9 PM THROUGH 3 AM FROM RICE LAKE AND LADYSMITH ON SOUTH
THROUGH MENOMONIE AND AUGUSTA. THE EVENING SHIFT WILL NEED TO KEEP
A CLOSE EYE FROM THE TWIN CITIES ON NORTHWARD WHERE CONFIDENCE ON
THE FREEZING DRIZZLE IS LOWER.

IN THE WAKE OF THE LOW PRESSURE SYSTEM...THE SURFACE PRESSURE
GRADIENT INCREASES SIGNIFICANTLY  ACROSS EASTERN SD AND SW MN
AFTER MIDNIGHT (12 MILLIBARS). IN FACT...6 HOUR PRESSURE CHANGES
ARE NEAR 14 MILLIBARS TO OUR WEST. BUFKIT PROFILE DATA SHOWED TWO
THINGS. FIRST...THE NAM PROFILE HAD THE STRONGEST TOP OF THE
CHANNEL WINDS NEARING 50 KNOTS ACROSS THE MN RIVER VALLEY AROUND
09Z WHILE THE GFS PROFILE HAD 32 KNOT WINDS AT 200 FEET AT KFRM.
THE COMBINATION OF CAA AND A UNIDIRECTIONAL FLOW TO THE TOP OF THE
CHANNEL RESULTED IN A WIND ADVISORY BEING ISSUED ALONG AND SOUTH
OF A LINE FROM APPLETON TO ALBERT LEA FROM MIDNIGHT THROUGH 9 AM.

TEMPERATURES TONIGHT AND THURSDAY ARE INTERESTING. BECAUSE OF THE
LOW PRESSURE SYSTEM COMING INTO THE AREA TONIGHT...TEMPERATURES
WILL WARM A LITTLE THIS EVENING AND THEN DROP BACK TO A LITTLE
BELOW WHERE WE ARE NOW. THURSDAY`S HIGHS WILL BE EARLY IN THE MORNING
WITH READINGS FALLING INTO THE TEENS AND LOWER 20S BY THIS TIME
THURSDAY AFTERNOON.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM CST WED JAN 28 2015

BY TOMORROW EVENING...THE PRESSURE GRADIENT WILL BE WEAKENING AND
THOSE STRONG NORTHWESTERLY WINDS WILL START TO SLOWLY DECREASE. A
SURFACE HIGH WILL DRIFT SOUTHEAST THROUGH OUR AREA OVERNIGHT THROUGH
FRIDAY MORNING...WHICH WILL BE ONE OF THE COOLER MORNINGS WE`VE HAD
IN TWO+ WEEKS WITH LOWS RANGING FROM NEAR ZERO NEAR LADYSMITH...TO
ABOUT 10-15 ABOVE TOWARD REDWOOD FALLS. THE CORE OF THE COLD WILL
ESSENTIALLY MISS US TO THE EAST AS IT IS DRAGGED SOUTH BEHIND THE
SYSTEM IMPACTING OUT REGION TONIGHT.

ON FRIDAY...MODEST WARM AIR ADVECTION WILL ENSUE AND ALLOW
TEMPERATURES TO WARM TO VERY NEAR SEASONAL NORMALS. WITH THE COLDER
AIR IN PLACE TO THE EAST OF THE AREA...HIGHS WILL STRUGGLE TO REACH
20 IN WEST CENTRAL WI...BUT WARMER AIR THE FURTHER WEST YOU GO WILL
YIELD HIGHS IN THE MID 20S FOR EASTERN MN AND LOW 30S ACROSS FAR
SOUTHWESTERN MN.

THE MAIN CHANGE FROM THE PREVIOUS FORECAST WAS TO THE SATURDAY NIGHT
SYSTEM.  BOTH THE GFS AND EC RUNS CAME IN WITH A STRONG SURFACE HIGH
PUSHING SOUTH FROM SASKATCHEWAN INTO THE UPPER MIDWEST AS THE
NORTHERN STREAM JET BUCKLES SOUTHWARD ALLOWING DRY ARCTIC AIR TO
ADVANCE FURTHER SOUTH THAN PREVIOUS RUNS INDICATED. THIS IS A GREAT
HINDRANCE TO THE POTENTIAL FOR SNOW FROM A SYSTEM DEVELOPING IN THE
SOUTHWESTERN CONUS. BUT...THERE IS POTENTIAL FOR LIGHT SNOW FROM A
NORTHERN STREAM SHORTWAVE SATURDAY NIGHT. THIS LINES UP WELL WITH AN
ENHANCED AREA OF PV ADVECTING SOUTHEAST AND IN CONJUNCTION WITH THE
LEFT EXIT REGION OF A 120KT JET STREAK. ANY SNOW THAT DOES FALL
THROUGH WILL BE VERY LIGHT WITH THE PRE-EXISTING LOW LEVEL DRY AIR.

IT LOOKS LIKE WE`LL BEGIN FEBRUARY WITH TEMPERATURES SLIGHTLY BELOW
NORMAL AFTER AN IMPRESSIVE WARM STRETCH FOR THE LAST 3 WEEKS OF
JANUARY.  BOUTS OF ARCTIC AIR WILL DROP SOUTH THROUGH THE
NORTHERN/NORTHEASTERN GREAT LAKES...GIVING US MORE OF A GLANCING
BLOW. ANOTHER POSSIBLE CLIPPER SYSTEM COULD BRING ANOTHER SHOT OF
VERY LIGHT SNOW MONDAY NIGHT/TUESDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 555 PM CST WED JAN 28 2015

LOW STRATUS/FG WILL REMAIN IN PLACE THRU ARND MIDNIGHT...WITH SOME
PASSING -FZDZ/-SHSN ALONG THE WAY AS A CDFNT PUSHES THRU THE AREA.
TAFS MOST SUSCEPTIBLE TO SEEING PRECIP WILL BE THE WI SITES...AND
POSSIBLY AS FAR W AS KMSP-KSTC. ANY SITE THAT DOES SEE PRECIP WILL
LIKELY DROP INTO IFR RANGE...IF NOT THERE ALREADY BY VIRTUE OF LOW
STRATUS. ONCE THE CDFNT MOVES THRU...WINDS WILL QUICKLY SWING ARND
TO NW AND ANY PRECIP WILL COME TO AND END. WIND SPEEDS WILL ALSO
INCRS WHICH WILL HELP SCOUR OUT ANY NEAR-GROUND MOISTURE...THUS
ALLEVIATING VSBY CONCERNS. HOWEVER...THE LOW STRATUS WILL REMAIN
THRU AT LEAST THE FIRST HALF OF THU THOUGH CIGS WILL SLOWLY RISE
FROM IFR INTO THE LOWER-HALF RANGE OF MVFR. BY LATE AFTN...ANY
LINGERING LOW STRATUS WILL SCATTER OUT...RESULTING IN VFR CONDS BY
LATE TMRW AFTN INTO TMRW EVE. THE TIGHT PRES GRADIENT INCOMING
BEHIND THE FROPA WILL RESULT IN STRONG WINDS FOR THE REST OF THE
OVERNIGHT THRU MUCH OF THE DAY TMRW. SUSTAINED SPEEDS WILL
INCREASE TO 15-25 KT WITH HIGHER GUSTS BEFORE SETTLING DOWN THU
EVE.

KMSP...ABLE TO INITIALIZE AS MVFR BUT CONDS ARE EXPECTED TO DROP
TO IFR BY 02Z THEN REMAIN THERE THRU CLOSE TO DAYBREAK. OCNL
PERIODS OF -FZDZ/-SHSN WILL DRIFT ACRS THE FIELD OVERNIGHT BUT NOT
LOOKING FOR ANYTHING HEAVY. COLD FROPA BY 06Z WILL ALLOW PRECIP TO
GRADUALLY CEASE AND STRONG NW WINDS TO DEVELOP. HOWEVER...CIGS ARE
NOT EXPECTED TO RISE ABOVE 1700FT THRU LATE MRNG AND MAY EVEN HOLD
ON LONGER THAN THE 14Z TIME CURRENTLY ADVERTISED. CONDS LIKELY TO
IMPROVE TO VFR BY LATE THU AFTN.

/OUTLOOK FOR KMSP/
FRI...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS. WIND N 10 KT.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST THURSDAY FOR
     MNZ054-056-064-065-073>075-082>084-091>093.

WI...FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO 3 AM CST
     THURSDAY FOR WIZ015-016-025-027-028.

&&

$$

UPDATE...JPC
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...JPC


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