Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 250528
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1128 PM CST TUE FEB 24 2015

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM CST TUE FEB 24 2015

FOR THIS EVENING...WE`RE WATCHING A WAVE OF ENERGY APPROACHING THE
REGION FROM THE WEST.  THE EARLY EVENING WILL REMAIN QUIET ACROSS
THE FA...BUT SHORTLY AFTER MIDNIGHT WE`RE EXPECTING SNOWFALL TO
SPREAD EASTWARD INTO EXTREME WESTERN MINNESOTA. A NORTHWEST TO SOUTH
BAND OF DECENT FORCING WILL SET UP THANKS TO STRONG F-GEN IN THAT
AREA.  THE MAIN DIFFERENCE FROM THE PREVIOUS FORECASTS WERE THAT THE
GFS AND NAM SHIFTED NORTHEAST MORE IN LINE WITH THE ECMWF AND GEM.
SO...SIGNIFICANTLY INCREASED POPS ALONG OUR EXTREME WESTERN AND
SOUTHERN FA TO INCLUDE CATEGORICAL LEVELS  WITH 1-3" OF SNOW
EXPECTED ALONG AND SOUTH OF THE MINNESOTA RIVER VALLEY IN WESTERN MN
THROUGH MANKATO...WITH AMOUNTS IN EXCESS OF 3" ALONG FROM WESTERN
YELLOW MEDICINE COUNTY THROUGH MARTIN COUNTY.

THERE WILL BE QUITE A BIT OF DRY AIR TO COMBAT ON THE NORTHERN
FRINGE OF THE F-GEN BAND...SO AMOUNTS WILL BE CUT OFF VERY SHARPLY
ON THE NORTHERN FRINGE...MORE SO THAN CAN BE INDICATED IN A FORECAST
AT THIS STAGE. DID INCREASE POPS TO INCLUDE THE TWIN
CITIES...HOWEVER KEPT POPS LIMITED TO AROUND 20 PERCENT IN THE SOUTH
METRO. ALONG AND NORTH OF THE I-94 CORRIDOR WILL REMAIN DRY.

TEMPERATURES WILL CONTINUE TO FALL THROUGH THE NIGHT AND WITH
ANOTHER ARCTIC PUSHING SOUTH THROUGH TOMORROW AFTERNOON...HIGHS
TOMORROW WILL BE HELD IN THE TEENS /ABOUT 20 DEGREES BELOW
NORMAL/.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM CST TUE FEB 24 2015

CONFIDENCE CONTINUES TO INCREASE IN A COLD REST OF THE
WEEK...FOLLOWED BY LITTLE TO NO SNOW OVER THE WEEKEND. THE MOST
NOTABLE CHANGE TO THE FORECAST WAS TO DROP MIN TEMPS THURSDAY
NIGHT/FRIDAY MORNING TOWARD THE COLD END OF GUIDANCE AS HIGH
PRESSURE BUILDS ACROSS THE REGION SETTING THE STAGE FOR VERY COLD
NIGHT. LASTLY...THE POTENTIAL EXISTS FOR AN EARLY MARCH SNOW STORM
TUESDAY NIGHT INTO WEDNESDAY.

AT THE START OF THE FORECAST PERIOD NORTHWEST FLOW CONTINUES TO
REINFORCE A SURFACE HIGH PRESSURE ACROSS THE HIGH PLAINS...WHICH HAS
BEEN A NEARLY PERMANENT FIXTURE FOR THE LAST SEVERAL WEEKS.
THEREFORE HAVE A DRY PERIOD WITH PLENTY OF SUNSHINE...BUT BELOW
NORMAL TEMPERATURES. OVER THE WEEKEND A TROUGH WILL CARVE OUT ACROSS
SOUTHERN CALIFORNIA SETTING UP SOUTHWEST FLOW ACROSS THE CENTRAL
CONUS. HOWEVER...THE NORTHERN STREAM WILL DRIVE THIS FEATURE TO THE
SOUTH KEEPING ANY LEGITIMATE PRECIP CHANCES CLOSER TO THE I-80
CORRIDOR THAN THE I-90 CORRIDOR. BASED ON THE OVERALL SETUP OF THIS
NORTHERN STREAM JET FEEL FAIRLY CONFIDENT THAT MOST OF THE AREA WILL
BE DRY OVER THE WEEKEND.

THE SAME CAN NOT BE SAID FOR THE MIDDLE OF NEXT WEEK. THE
DIFFERENCES LIE IN A WEAKER...MORE ZONAL NORTHERN STREAM UPPER LEVEL
PATTERN...WHILE THE SOUTHERN STREAM TROUGH REMAINS ACROSS THE WEST
COAST. BOTH THE 24.12 GFS AND ECMWF HAVE A WELL DEFINED SHORTWAVE
EJECTING ACROSS THE SOUTHERN HALF OF THE CONUS TUESDAY INTO
WEDNESDAY. WITHOUT THE NORTHWEST FLOW IN THE NORTHERN STREAM...THE
POTENTIAL EXISTS FOR A STORM TO DEVELOP ON THE LEE SIDE OF THE
ROCKIES AND CURL UP ACROSS THE MIDWEST. AT THIS TIME...MODELS KEEP
THE PRECIP TO THE SOUTH ACROSS THE TENNESSEE RIVER VALLEY...BUT
WOULD THIS SYSTEM HAS A MUCH BETTER CHANCE OF SHIFTING TO THE NORTH
THAN THIS WEEKENDS PRECIP.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1128 PM CST TUE FEB 24 2015

WINDS HAVE WEAKENED ACROSS THE AREA AND WILL REMAIN OUT OF THE
NORTHWEST FROM AROUND 5 TO 10 KTS OVERNIGHT.  MID-LEVEL CLOUDS ARE
CURRENTLY MOVING INTO OUR REGION FROM THE WEST...WITH VFR CONDITIONS
PERSISTING DURING THIS TIME. CIGS WILL LOWER BY THE EARLY MORNING
WEDNESDAY...BUT VFR CONDITIONS SHOULD PREVAIL AS RELATIVELY DRY AIR
REMAINS PRESENT AT LOWER LEVELS. FROM WEDNESDAY MORNING THROUGH THE
AFTERNOON...SNOW WILL OCCUR IN SW MN...INCLUDING RWF WHERE IFR/LIFR
VISIBILITY AND MVFR CIGS ARE POSSIBLE. THE REST OF THE TERMINALS
SHOULD REMAIN DRY AND GENERALLY VFR THROUGH THE REMAINDER OF THE
PERIOD...THOUGH MVFR CIGS AND BRIEF PERIODS OF LIGHT SNOW CANNOT BE
RULED OUT AT AXN OR MSP AS LOWER LEVELS BECOME MORE SATURATED.

KMSP...WINDS WILL QUICKLY DECREASE THIS EVENING...AND SHIFT FROM
THE NW TO BECOME MORE NORTHERLY OVERNIGHT. LOW CONFIDENCE REMAINS IN
-SN REACHING MSP ON WEDNESDAY...BUT LATEST MODELS HAVE BROUGHT THE
ACCUMULATING SNOW CLOSER TO MSP...AND THEREFORE LIGHT SNOW CANNOT BE
RULED OUT FROM WEDNESDAY MORNING THROUGH THE EARLY AFTERNOON.

/OUTLOOK FOR KMSP/
THU...VFR. WINDS NW 5-10 KTS.
FRI...VFR. WINDS WSW 5 KTS.
SAT...VFR. WINDS S 10G15 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 3 PM CST WEDNESDAY FOR
     MNZ091.

WI...NONE.
&&

$$

SHORT TERM...SPD
LONG TERM...JRB
AVIATION...ADL



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