FXUS63 KMPX 282048
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
248 PM CST SAT NOV 28 2009
.DISCUSSION...
ACTIVE...THOUGH RATHER UNEVENTFUL EVENING FORTHCOMING TONIGHT AS A
COUPLE OF SHORTWAVES DIG ACROSS THE AREA. THE FIRST WAVE IS
CURRENTLY UP BY LAKE WINNIPEG...WHILE THE SECOND IS BACK OVER
ALBERTA. THE FIRST IS PROGGED TO TRACK ACROSS NRN MN WITH THE SECOND
FORECAST TO HEAD FOR SW MN/NWRN IA BY SUNDAY MORNING. DURING THE DAY
SUNDAY...ALL GUIDANCE WANTS TO MERGE THESE TWO PIECES OF ENERGY AS
THEY MEET UP WITH SFC TROUGH TO THE SE OF CWA. NOTHING REALLY SEEMS
TO LINE UP FOR MUCH IN THE WAY OF PRECIP CHANCES TONIGHT...AS UPPER
FORCING LAGS SFC TROUGH BY QUITE A BIT. ONLY LOOKS TO BE A BRIEF
WINDOW OF A COUPLE OF HOURS ACROSS AREA WHERE FGEN AND MOISTURE LINE
UP ENOUGH TO BRING LIGHT SNOW SHOWERS/FLURRIES TO THE AREA. NOT
UNTIL SUNDAY NIGHT DO MODELS START INTRODUCING SOME TROPICAL
MOISTURE AND BETTER POPS TO THESE FEATURES...WHEN ALL ARE WELL EAST
AND SOUTH OF AREA... SO NOT EXPECTING ANY ACCUMULATIONS
TONIGHT...WITH MAYBE A FEW LOCATIONS BEING ABLE TO SQUEEZE OUT
MEASURABLE LIQUID PRECIP. OF INTEREST...THIS WILL BE THE LAST CHANCE
THIS MONTH FOR MSP TO SEE SNOW...AND IF NONE IS SEEN...THIS WOULD
ONLY BE THE SECOND TIME IN OBSERVED HISTORY WHERE NOT EVEN A TRACE
OF SNOW WAS REPORTED IN THE TWIN CITIES IN NOVEMBER...THE OTHER TIME
THAT HAPPENED WAS IN 1963. FOR TEMPERATURES TONIGHT...MAV/MET
SIMILAR IN VALUE AND NUMBERS LOOKED REASONABLE...SO STAYED CLOSE TO
THOSE FOR LOWS.
GOING FORWARD...WILL SEE STRONG BLAST OF CAA TONIGHT INTO
SUNDAY...WHICH WILL LEAD TO A RATHER COOL AND BLUSTERY DAY SUNDAY...
BUT BY SUNDAY NIGHT UPPER RIDGE WILL BE MOVING BACK IN FROM THE
WEST...SETTING REGION BACK UP INTO WAA MONDAY. AT THE SAME TIME....
12Z GUIDANCE HAS A STRONG SHORTWAVE DIVING SE THROUGH BRITISH
COLUMBIA INTO ALBERTA. THIS WILL SPIN UP A LOW TO THE LEE OF THE
CANADIAN ROCKIES AND SEND A WARM FROM N THROUGH THE PLAINS. H85
TEMPS MONDAY AND ESPECIALLY TUESDAY AGAIN PROGGED TO CLIMB ABOVE 0C.
TEMPERATURES TUESDAY WILL BE THE TRICKIEST...AS STRONG COLD FRONT
WILL BE SWEEPING ACROSS AREA DURING THE DAY...BUT WITH WARM AIR IN
PLACE IN THE MORNING...IF THIS FRONT IS SLOWED UP ENOUGH...THEN
HIGHS MAKING A RUN AT 50 LOOKS VERY PLAUSIBLE ACROSS SRN MN TUESDAY
BEFORE SIGNIFICANT ONSLAUGHT OF COLD AIR MOVES IN TUESDAY
NIGHT...THIS IS WHAT THE ECMWF CONTINUES TO HINT AT. ON TUESDAY
NIGHT...UPPER WAVE/SFC COLD FRONT WILL SWEEP SE ACROSS CWA.
UNFORTUNATELY...AS THIS IS OCCURRING CURRENT LOW CUT OFF OVER CA
WILL BE MOVING INTO S TX...WHICH WILL LEAD TO THE FORMATION OF A SFC
LOW IN THE NRN GULF. THIS LOOKS TO UNLEASH QUITE A BIT OF PRECIP
ALONG THE GULF COAST...ROBBING ANY HINT OF A MOISTURE RETURN IN
FRONT OF TUESDAYS COLD FRONT... WHICH MEANS ANOTHER DRY FROPA WITH
NOT MUCH MORE THAN INCREASED MID/UPPER LEVEL CLOUDS IS IN STORE.
GEM/GFS/ECMWF STILL IN AGREEMENT WITH BRINGING SIGNIFICANT BLAST OF
COLD AIR DOWN BY THE MIDDLE OF THE WEEK...WITH H85 TEMPS PROGGED TO
BE DOWN TO -15C BY THURSDAY AFTERNOON. THOUGH THIS SOUNDS LOW...
QUICK LOOK AT ANOMALIES AT THIS LEVEL SHOWS THIS IS BASICALLY WHERE
WE ARE SUPPOSED TO BE THIS TIME OF YEAR...THOUGH AFTER THE NOVEMBER
JUST EXPERIENCED...HIGHS WED/THU NEXT WEEK IN THE 20S WILL FEEL
PRETTY COOL. AS FOR ANY PRECIP CHANCES NEXT WEEK. SYSTEM MOVING
THROUGH TUESDAY IS PROGGED TO DEEPEN EAST OF CWA AS GULF LOW SWEEPS
UP THE EAST COAST...KEEPING ANY SIGNIFICANT PRECIP WELL EAST OF THE
AREA. HOWEVER...WITH CYCLONIC FLOW AND STRONG CAA ENTRENCHED OVER
AREA...WILL LIKELY BE DEALING WITH ON AND OFF FLURRIES WEDNESDAY
THROUGH FRIDAY.
&&
.AVIATION.../18Z TAF ISSUANCE/
SHORT TERM CONCERN IS THE LOW STRATUS LAYER IN THE 003-006 RANGE
IN THE MN RIVER VALLEY AREA...AFFECTING KRWF. INITIAL COLD
ADVECTION IN NW FLOW DOWN THE VALLEY AREA...IS GENERALLY REMAINING
BETWEEN THE HIGHER TERRAIN TO THE EAST AN SW. WILL KEEP AN
OCCASIONAL BKN CONDITION AT KWRF FOR A FEW HOURS. THERE IS ALSO A
NARROW BAND OF IFR CIGS FARTHER TO THE TO THE NORTH WHICH WILL
AFFECT KAXN FOR A COUPLE HOURS. OTHERWISE MOD SFC COLD ADVECTION
WILL CONTINUE THROUGH THE FORECAST PERIOD WITH A BIT STRONGER PUSH
SUNDAY MORNING BEHIND THE APPROACHING MID LEVEL TROUGH. SAID
TROUGH WILL MOVE ACROSS MAINLY CENTRAL MN OVERNIGHT WITH A CHANCE
OF SNOW SHOWERS MAINLY AFFECTING CENTRAL MN INTO PARTS OF WEST
CENTRAL WISCONSIN. OVERALL CIGS WILL LOWER INTO THE 040-060 RANGE
WITH A CHANCE OF BRIEF MVFR VSBYS. THE RENEWED STRONGER LOW LEVEL
COLD ADVECTION WILL BRING MVFR CIGS TO MOST SITES AFTER 08Z-
09Z...BEGINNING FROM THE NW...THROUGH THE REST OF THE FORECAST
PERIOD. INCREASING SINKING AND MID LEVEL DRYING MAY BREAK UP CIGS
WESTERN AREAS NEAR THE END OF THE PERIOD.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JPR
