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000
FXUS63 KMPX 041740
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1140 AM CST TUE MAR 4 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CST TUE MAR 4 2014

POCKETS OF LIGHT SNOW ARE SPRINKLED ACROSS EAST CENTRAL MINNESOTA
AND WEST CENTRAL WISCONSIN EARLY THIS MORNING AS A SHORT WAVE EXITS
THE EASTERN CWA. EXPECT ALL BUT A FEW FLURRIES TO BE OVER BY 12Z.
THE NEXT WAVE FOR THIS AFTERNOON AND EARLY TONIGHT IS APPROACHING
THE WESTERN DAKOTAS AT THIS TIME. THIS FEATURE WILL BRING SEVERAL
INCHES OF SNOW TO SOUTHERN MINNESOTA LATE THIS AFTERNOON AND
EVENING. THE QPF PATTERNS FROM THE DETERMINISTIC MODELS SEEM WAY TO
BROAD WHEN COMPARED TO THE MID LEVEL FORCING. THE WRF SOLUTIONS ON
THE OTHER HAND HAVE A NICE COMPACT SYSTEM PASSING ALONG AND SOUTH OF
THE MINNESOTA RIVER LATER THIS AFTERNOON AND EARLY TONIGHT. QPF
VALUES ARE PRETTY SIMILAR AND IN THE QUARTER INCH RANGE ALONG
INTERSTATE 90 ON SOUTHWARD INTO NORTHERN IOWA. THIS WOULD MATCH
QUITE WELL WITH THE 06Z NAM MID LEVEL FRONTOGENESIS WITH THE
CORRESPONDING -FN VECTORS FROM I-90 ON SOUTHWARD. WE HIT THE SNOW
ACCUMULATION PRETTY HARD FOR THIS EVENING WITH 3 TO 3.5 INCHES NEAR
THE IOWA BORDER. IF TRENDS REMAIN THIS MORNING WITH THE WRF
SOLUTIONS AN ADVISORY MAY BE NEED FOR THIS EVENING WHEN THE BULK OF
THE SNOW PUSHES THROUGH. BROUGHT THE SNOW TO AN END BY DAYBREAK
WEDNESDAY.

HIGH AND LOW TEMPERATURES ARE A CONCERN TODAY AND TONIGHT. WE WERE A
LITTLE AGGRESSIVE WITH HIGHS ON MONDAY BUT WE ARE STARTING OFF MUCH
WARMER THIS MORNING WITH 7 TO 12 DEGREES COMMON. SO...KEPT TEENS TO
NEAR 20 DEGREE READING IN PLAY TODAY EVEN THOUGH WE WILL HAVE
EXTENSIVE CLOUDINESS. FOR LOWS TONIGHT...THE CONCERN IS THAT AS THE
SNOW ENDS THERE SHOULD BE SOME CLEARING OVER CENTRAL MINNESOTA AND
ADJOINING AREAS OF WEST CENTRAL WISCONSIN AS STRONG HIGH PRESSURE
OVER ONTARIO BUILDS SOUTH. LOWERED LOWS FOR THESE AREAS INTO THE
SINGLE DIGITS BELOW ZERO RANGE FOR WEDNESDAY MORNING.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 329 AM CST TUE MAR 4 2014

DESPITE THE NUMBER OF SLIGHT CHANCE AND CHANCE POPS IN THE
FORECAST FOR THE LONG TERM...THIS PERIOD WILL BE MOSTLY DRY WITH
THE MAIN AREAS OF PRECIPITATION STAYING WITH THE NORTHERN STREAM
IN SOUTHERN CANADA...AND THE SOUTHERN STREAM FROM THE SOUTHWEST
THROUGH THE GULF COAST. TWO CHANCES OF PRECIPITATION PRESENT
THEMSELVES WITH THE FIRST ON THURSDAY...AND THE SECOND ON FRIDAY.
BOTH THE NAM AND GFS REALLY BROAD BRUSH THE FA WITH LIGHT QPF
DURING THESE PERIODS...WHILE THE EC SHOWS WHAT APPEARS TO BE A
MORE REALISTIC OUTPUT...KEEPING THE PRECIPITATION IN NORTH CENTRAL
MN AND AREAS NORTHWARD WHERE THE DEEPEST SATURATION OCCURS AND
BEST FORCING /ALBEIT WEAK/ IS PRESENT. BEHIND THESE TWO WAVES...A
MODIFIED ARCTIC HIGH WILL PUSH SOUTHEAST THROUGH ALBERTA AND
SASKATCHEWAN INTO THE UPPER MIDWEST INTO SATURDAY. THE POSITION OF
THE SURFACE HIGH SATURDAY MORNING WILL BE KEY IN THE MIN TEMPS.
DID LOWER MIN TEMPERATURES FOR SATURDAY MORNING SLIGHTLY FOR
NOW...AND WE DO HAVE A SHOT OF SEEING BELOW ZERO TEMPERATURES
SATURDAY MORNING DEPENDING ON THE EFFICIENCY OF RADIATIONAL
COOLING.

THE BRIEF WARM UP AHEAD OF THE ARCTIC HIGH WILL BRING WARM AIR
ALOFT ON THE POSITIVE SIDE OF 0C INITIALLY...SO SUBSEQUENT SHIFTS
WILL NEED TO SORT OUT ANY P TYPE ISSUES IF THE PRECIPITATION STAYS
IN THE FORECAST. FOR NOW...WENT WITH ALL SNOW FOR THIS PERIOD AS
CONFIDENCE IN PLACEMENT OF THE THERMAL RIDGE ALOFT ALONG WITH QPF
IS LOW. DID NOT FEEL ADDING PRECISION WOULD HELP WITH ACCURACY IN
THIS REGARD...AS THE MODEL SPREAD IN DAYS 3-4 IS TOO WIDE TO NAIL
DOWN TRANSITION AREAS BETWEEN RAIN/SNOW/SLEET. WILL HAVE TO WATCH
FOR DRIZZLE AND POTENTIAL FOG ON FRIDAY...BUT DID NOT MENTION IT
IN THE FORECAST PACKAGE YET. ECMWF KEEPS SOUTHERN MN DRY AND WARM
INTO FRIDAY...WHILE NAM/GFS WANT TO SPREAD LIGHT QPF THROUGH THE
AREA. AGAIN...TEMPERATURES CRASH THIS WEEKEND WITH HIGHS ON
SATURDAY EXPECTED TO BE AROUND 15 DEGREES BELOW NORMAL.
THANKFULLY...BOTH THE GFS AND EC SHOW A DECENT THERMAL RIDGE
WORKING EASTWARD MONDAY AS ZONAL FLOW OFF THE ROCKY MOUNTAINS
DESCENDS DOWN THE HIGHER TERRAIN...AND UNDERGOES COMPRESSION WITH
THE PRESSURE CHANGE AND WARMS NICELY. HENCE...TEMPERATURES NEAR 40
ARE FORECAST MONDAY WITH A SLIGHT CHANCE OF RAIN...DURING THE
AFTERNOON.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1127 AM CST TUE MAR 4 2014

MVFR/IFR CIGS/VSBYS WILL DEVELOP THIS AFTN IN WC/SW MN...AND
CONTINUE THRU MOST OF THE TAF PERIOD BASED ON UPSTREAM OBS IN
ND/SD AS A POTENT SHRTWV MOVES SE ACROSS THE UPPER MIDWEST.
CONFIDENCE IS HIGH ON IFR VSBYS IN -SN DEVELOPING FOR KRWF BY
20-21Z...WITH LESS CONFIDENCE KAXN/KSTC/KRNH FOR THE FIRST 6 HRS
BASED ON DRIER AIR FILTERING SW ACROSS NORTHERN/CENTRAL MN THIS
AFTN/EVENING. BETTER LIFT/SATURATION IS NOTED IN WC/SW/SC MN BY
21-00Z...WITH MARGINAL FOR AREAS NORTH OF I-94. WINDS WILL REMAIN
FROM THE E/NE...BECOME MORE E/ESE BY WEDNESDAY MORNING.

KMSP...

BASED ON LATEST OBS/REGIONAL RADAR IN SD/ND...AM LEANING TOWARD
IFR VSBYS DEVELOPING BY 23Z. CONFIDENCE ON SNOWFALL DEVELOPING IS
HIGH...BUT LOW CONFIDENCE ON HOW LOW THE VSBYS WILL GET FROM DRIER
AIR FILTERING IN FROM THE NE DURING THE LATE AFTN/EVENING TIME
FRAME. BEST TIME FRAME OF IFR VSBYS WILL OCCUR BETWEEN 23-03Z OR
DURING THE WORSE TIME PERIOD FOR AIR TRAFFIC. IN ADDITION...THERE
COULD BE SOME MODERATE SNOWFALL ARND 00-02Z. MAY CONSIDER AN AWW
IF UPSTREAM CONDS WARRANT. WINDS WILL REMAIN FROM THE E/ENE THRU
TONIGHT...AND BECOME MORE SE/ESE BY WEDNESDAY MORNING.

/OUTLOOK FOR KMSP/

WED NGT...VFR. WINDS SE 5-10 KTS.
THU...VFR. CHC MVFR/-SN. WINDS S 10-15 KTS.
FRI...VFR. CHC MVFR/-SN EARLY. WINDS N 10 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...RAH
LONG TERM...SPD
AVIATION...JLT