Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 231012
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
412 AM CST MON FEB 23 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CST MON FEB 23 2015

THE PRIMARY CONCERN IN THE SHORT TERM WILL BE WIND CHILLS EARLY THIS
MORNING...AND THEN ATTENTION SHIFTS TO THE CHANCE FOR LIGHT SNOW
LATE TONIGHT.

CLEAR SKIES AND SURFACE HIGH PRESSURE HAVE CONTRIBUTED TO QUITE A
COLD NIGHT ACROSS THE AREA...WITH WIDESPREAD TEMPERATURES RANGING
FROM 10 BELOW TO 20 BELOW ACROSS THE FORECAST AREA. THE COMBINATION
OF THESE FRIGID TEMPERATURES WITH A 5-7 MPH WIND HAS YIELDED WIND
CHILL READINGS FROM 25 BELOW TO 35 BELOW ACROSS THE MAJORITY OF THE
FORECAST AREA. THE ONE EXCEPTION IS ALONG THE MN RIVER
VALLEY...WHERE LIGHTER WINDS IN CLOSER PROXIMITY TO THE HIGH
PRESSURE RIDGE AXIS HAVE MADE FOR SLIGHTLY WARMER WIND CHILLS IN THE
15 TO 20 BELOW RANGE. WINDS ARE FORECAST TO INCREASE A COUPLE KNOTS
AROUND DAYBREAK HOWEVER...WHICH WOULD PUSH APPARENT TEMPERATURES TO
AROUND THE 25 BELOW MARK WHERE THEY ARE NOT CURRENTLY MEETING
ADVISORY CRITERIA. WILL THEREFORE KEEP THE CURRENT ADVISORY THAT
ENCOMPASSES THE ENTIRE CWA IN TACT THROUGH 10 AM CST.

THE AFOREMENTIONED INCREASE IN WINDS WILL ENSUE THROUGH THE MORNING
HOURS...WITH THE SOUTHWESTERLY DIRECTIONAL COMPONENT YIELDING A
MODERATION IN TEMPERATURES FOR WEST CENTRAL AND SOUTHWEST MN. HIGHS
THERE WILL CLIMB WELL INTO THE 20S...WHILE CENTRAL MN AND WEST
CENTRAL WI EXPERIENCE COOLER HIGHS IN THE 10 TO 20 DEGREE RANGE.

HIGH CLOUDS INCREASE THIS AFTERNOON AS A SHORTWAVE APPROACHES FROM
CANADA. DEEPER SATURATION AND WEAK LIFT ARRIVE BETWEEN 06Z AND 09Z
TUESDAY INTO CENTRAL MN/WI. HAVE INCLUDED 20-30 POPS GENERALLY ALONG
AND NORTH OF THE INTERSTATE 94 CORRIDOR...WHERE A COUPLE TENTHS TO A
HALF INCH NEW SNOW ON THE GROUND APPEARS POSSIBLE BY DAYBREAK
TUESDAY.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 412 AM CST MON FEB 23 2015

DURING THE EXTENDED...WE WILL CONTINUE TO ADD ON TO OUR TEMPERATURE
DEPARTURE FOR THE MONTH...WHICH SAW ANOTHER 9 TENTHS OF A DEGREE
ADDED ON TO THE DEPARTURE FROM NORMAL AFTER YESTERDAYS
AVERAGE TEMPERATURE DEPARTURE OF 27 DEGREES BELOW NORMAL. ON THE
MONTH...MSP NOW SITS AT 8.1 DEGREES BELOW NORMAL AND WILL LIKELY
FINISH CLOSE TO 10 DEGREES BELOW NORMAL AFTER WE GET 3 MORE DAYS
WEDNESDAY...THURSDAY...AND FRIDAY WHERE THE AVERAGE TEMPERATURE
DEPARTURE SHOULD BE NEAR OR GREATER THAN 20 DEGREES BELOW NORMAL.

THE REASON THE COLD LOOKS TO STAY...IS THE LARGE SCALE WEATHER
PATTERN DOES NOT LOOK TO CHANGE ALL THAT MUCH...WITH NOTHING MORE
THAN A WESTWARD SHIFT IN THE RIDGE/TROUGH/RIDGE PATTERN THAT HAS
BEEN IN PLACE PRETTY MUCH ALL OF FEBRUARY. WITHIN THIS PATTERN...WE
WILL BE SCRAPPED BY A STRONG CLIPPER GOING INTO THE WRN GREAT LAKES
TUESDAY AND ANOTHER DIVING SOUTH ACROSS THE DAKOTAS ON WEDNESDAY.
THE BEST SHOT AT SEEING ANY MEANINGFUL SNOW LOOKS TO COME THIS
WEEKEND AS SOUTHERN STREAM ENERGY GETS PULLED INTO THE NORTHERN
STREAM.

A FEW MINOR CHANGES WERE NEEDED TO THE FORECAST TUESDAY AND
WEDNESDAY. HIGHS WERE KNOCKED BACK A COUPLE OF DEGREES ON TUESDAY AS
WE WILL BE FIRMLY WITHIN STRONG CAA IN THE WAKE OF THE COLD FRONT
COMING THROUGH TONIGHT. THIS WILL LEAD TO GRADUALLY FALLING
TEMPERATURES DURING THE AFTERNOON ON TUESDAY AS NW WINDS LIKELY GUST
TO BETWEEN 30 AND 40 MPH. ALSO REMOVED THE POPS ACROSS SW MN ON
TUESDAY AS THEY WILL BE UNDER THE INFLUENCE OF SUBSIDENCE WITHIN THE
RIGHT EXIT REGION OF A NORTHWESTERLY JET STREAK. RAISED THE CHANCE
POPS A BIT TUESDAY MORNING IN THE EAST WHERE THE SNOW ARRIVING THERE
TONIGHT WILL BE EXITING DURING THE MORNING. LIKE MOST OF THE SYSTEMS
WE HAVE SEEN IN THIS PATTERN...THIS WILL ONLY RESULT IN AROUND A
HALF INCH OF SNOW IN WRN WI. FOR WEDNESDAY...MODELS CONTINUE TO
PAINT A SWATH OF 2-4 INCHES OF SNOW GOING FROM WESTERN NODAK TOWARD
WESTERN IOWA. THE BRUNT OF THIS WAVE STILL LOOKS TO REMAIN SW OF THE
MPX AREA...THOUGH THE ECMWF/SREF/NAM ALL SHOW THE NE EDGE OF THE
SNOW BAND COMING ABOUT AS FAR NE AS THE UPPER MN RIVER VALLEY...SO
ADDED SOME CHANCE POPS SW OF THE MN RIVER TO ACCOUNT FOR THAT. STILL
NOT CONVINCED WE WILL  SEE SNOW IN THE MPX CWA WITH THIS SYSTEM AS
NORTHERLY LOW LEVELS WINDS WILL RESULT IN DRY AIR UNDERCUTTING THIS
PRECIP SHIELD...WHICH IS THE SCENARIO THE 23.00 AND 23.06 GFS SHOWS
PLAYING OUT.

BESIDE THE LIGHT SNOW IN THE SW...THIS HIGH WILL BRING US ANOTHER
STINT IN ARCTIC AIR TUESDAY NIGHT THROUGH THURSDAY NIGHT.
HOWEVER...IT WILL NOT BE QUITE AS COLD AS WHAT WE JUST EXPERIENCED
SUNDAY...AS H85 TEMPS WILL BE ABOUT 5C WARMER THAN THEY WERE OVER
THE WEEKEND. STILL...HIGHS ON THURSDAY WILL BE MOSTLY IN THE SINGLE
DIGITS...WITH DOUBLE DIGIT BELOW ZERO LOWS LIKELY THURSDAY AND
FRIDAY MORNINGS ACROSS CENTRAL MN INTO WISCONSIN. OF COURSE THIS COLD
MEANS WE WILL HAVE TO BE ON THE LOOKOUT FOR MORE WIND CHILL ISSUES
AND WEDNESDAY NIGHT INTO THURSDAY MORNING IS STILL LOOKING TO BRING
US ANOTHER ROUND OF WIND CHILL ADVISORY WORTHY APPARENT TEMPERATURES
ACROSS CENTRAL MN.

FOR THE WEEKEND...THE ECMWF AND GFS CONTINUE TO SHOW A PLOWABLE
SNOWFALL HITTING THE SE THIRD OR SO OF THE MPX CWA. THE MAIN
DIFFERENCE BETWEEN THE ECMWF AND GFS IS ONE OF TIMING...WITH THE
ECMWF BEING ABOUT 12 HOURS BEHIND THE GFS. OTHERWISE...THEY BOTH
SHOW A DEEP TROUGH/NEARLY CLOSED UPPER LOW DEVELOPING OVER THE 4
CORNERS REGION BY SATURDAY...WITH A PIECE OF THIS ENERGY GETTING
PULLED NE INTO THE GREAT LAKES BY EARLY NEXT WEEK BY A POSITIVELY
TILTED NORTHERN STREAM TROUGH WORKING ACROSS SRN CANADA. HAVE
INCREASED POPS INTO THE 40S FOR THE SE CWA SATURDAY NIGHT AND
SUNDAY. ALTHOUGH IT IS LOOKING INCREASINGLY LIKELY THAT WE WILL
START MARCH WITH SHOVEL WORTHY SNOW...MODELS TRADITIONALLY STRUGGLE
WITH PHASING SYSTEMS SUCH AS THIS MORE THAN 3 OR 4 DAYS OUT...SO I
WOULD NOT GET YOUR HOPES UP TOO MUCH FOR SEEING MEASURABLE UNTIL THE
FORECAST LOOKS LIKE THIS TUESDAY OR WEDNESDAY AND BEYOND.

ON THE SNOW NOTE...THE REST OF FEBRUARY LOOKS TO GO OFF MOSTLY SNOW
FREE...BRINGING TO AN END ONE OF THE LEAST SNOWIEST METEOROLOGICAL
WINTERS WE HAVE SEEN IN TWO DECADES. FOR DEC/JAN/FEB...THE 15.6" OF
SNOW SO FAR AT MSP AND THE 16.6" AT EAU ARE THE LEAST BOTH LOCATIONS
HAVE SEEN SINCE THE WINTER OF 1994-95...WHILE THE PALTRY 9" OBSERVED
SO FAR THIS METEOROLOGICAL WINTER AT STC IS THE LEAST SINCE 1986-87.
OF COURSE WINTER IN MINNESOTA AND WISCONSIN DOES NOT END WITH
FEBRUARY...BUT IT WILL TAKE QUITE THE SPRING RALLY FOR US TO GET OUR
SEASONAL SNOWFALL TOTALS UP ANYWHERE NEAR OUR NORMAL OF 50 TO 55
INCHES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1052 PM CST SUN FEB 22 2015

HIGH PRESSURE WILL MOVE SOUTH OF THE TAF SITES OVERNIGHT WITH
LIGHT NORTHWEST SURFACE WINDS BACKING TO THE SOUTHWEST. THE
PRESSURE GRADIENT ACROSS MN/WI WILL INCREASE SIGNIFICANTLY DURING
THE DAY ON MONDAY AS A CLIPPER LOW PRESSURE SYSTEM DROPS SOUTH
FROM CENTRAL CANADA. SOUTHWEST WINDS WILL INCREASE TO 12-15 KNOTS
BY MID MORNING AND TO 20-25 KNOTS FOR THE AFTERNOON AND EVENING.
WIND GUSTS DURING THE AFTERNOON WILL BE IN THE 30 TO 35 KNOT RANGE
WITH THE HIGH END GUSTS AROUND KAXN. OTHERWISE...VFR THROUGH THE
PERIOD.

KMSP...WINDS BY 15Z MONDAY EXPECTED TO BE FROM 210-220 DEGREES AT
12-15 KNOTS. WIND SPEEDS INCREASE BY EARLY AFTERNOON TO 15-20
KNOTS WITH GUSTS APPROACHING 30 KNOTS. THESE SPEEDS AND GUSTS ARE
EXPECTED TO PERSIST WELL INTO THE EVENING (03Z). AN ARCTIC COLD
FRONT WILL PASS THE AIRFIELD JUST BEYOND THE END OF THE 30 HOUR
TAF (15Z TUE). WINDS WILL BECOME WESTERLY AHEAD OF THE FRONT
BEFORE DAYBREAK TUESDAY AND THEN SWITCH TO THE NORTHWEST DURING
THE MORNING.

/OUTLOOK
FOR KMSP/

TUE...VFR. SCT FLURRIES IN THE MORNING. WINDS NW 15-20G30 KTS.
WED...VFR. WINDS N 10 KTS.
THU...VFR. WINDS NW 5-10 KTS.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR MNZ041>045-
     047>070-073>078-082>085-091>093.

WI...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR WIZ014>016-
     023>028.

&&

$$

SHORT TERM...LS
LONG TERM...MPG
AVIATION...RAH


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