000
FXUS63 KMPX 032341
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
541 PM CST WED DEC 3 2008
.AVIATION.../00Z TAF ISSUANCE/
PERIOD OF DRY AIR AND SINKING BETWEEN SYSTEMS WILL CONTINUE FOR A
SHORT TIME THIS EVENING...YIELDING GENERALLY SKC CONDITIONS.
COMPACT SHORT WAVE TROUGH OVER ND WILL THEN MOVE INTO FORECAST
AREA OVERNIGHT INTO THURSDAY MORNING. GENERALLY LOW VFR CATEGORY
CIGS ARE EXPECTED WITH THIS WAVE...BUT BRIEF IFR VSBYS AS LOW AS
1SM ARE POSSIBLE VCNTY KRWF. ELSEWHERE...MVFR CIGS AND VSBYS
POSSIBLE FROM 04Z-13Z WEST TO EAST. LOCAL SINKING AND DRYING
BEHIND THIS WAVE MAY BREAK UP CIGS FOR SHORT TIME THURSDAY
MORNING. BUT LOW VFR CIGS EXPECTED AGAIN DURING THE AFTERNOON WITH
SCT SNOW SHOWERS OR FLURRIES. WILL KEEP VSBYS P6SM FOR NOW...BUT
LATER FORECASTS MAY CONSIDER 4-5SM.
&&
.PREV DISCUSSION.../ISSUED 325 PM CST WED DEC 3 2008/
THE FORECAST AHEAD IS RATHER ACTIVE DURING THE NEXT SEVEN DAYS WITH
FOUR LOW PRESSURE SYSTEMS PROGGED TO IMPACT THE FA. THE FIRST IS
TONIGHT...THE SECOND FRIDAY NIGHT INTO SATURDAY...THE THIRD SUNDAY
NIGHT INTO MONDAY AND THE FOURTH ON WEDNESDAY. FAIR AGREEMENT
EXISTS WITH THE FIRST THREE WITH SIGNIFICANT DIVERGENCE SETTING IN BY
NEXT WEDNESDAY AS ONE WOULD EXPECT SEVEN DAYS OUT.
CONCERN TONIGHT IS A VORT MAX CURRENTLY OVER NORTH CENTRAL ND.
THE 18Z NAM HAS BECOME MORE BULLISH ON LIGHT PRECIP LATE TONIGHT
AND EARLY THURSDAY ACROSS THE MN CWA. THIS IS A TREND SEEN AS WELL
WITH THE 48HR 13KM RUC...WHICH SHOWS SOME 20 DBZ ECHOES JUST
SOUTH OF THE TWIN CITIES TOMORROW MORNING. THIS SEEMS TO BE A
REFLECTION OF THE VORT WITH A TWISTY BEING DEPICTED IN THE RH
FIELD. ALTHOUGH THE MAIN EMPHASIS OVERNIGHT AND EARLY THURSDAY
FOR SOME LIGHT SNOW IS ACROSS EASTERN SD AND FAR SW MN...HAVE
KEPT SMALL POPS IN PLAY ACROSS MUCH OF THE CWA UNTIL WE ARE IN THE
WAKE OF THE UPPER TROUGH THURSDAY AFTERNOON.
A RATHER STRONG AREA OF HIGH PRESSURE WILL PASS SOUTH OF THE
REGION THURSDAY NIGHT AND FRIDAY WITH THE LOW LEVEL FLOW BACKING
FROM NW TO SW. A CLIPPER WILL DIVE SE ACROSS MN AND WI FRIDAY
NIGHT AND SATURDAY WITH 1 TO 2 INCH SNOW AMOUNTS LIKELY ACROSS
EASTERN MN AND WEST CENTRAL WI. BRISK NORTHWEST WINDS TO OCCUR
SATURDAY IN THE WAKE OF THIS SYSTEM ALONG WITH STEADY OR SLOWING
FALLING TEMPERATURES.
HIGH PRESSURE WILL SETTLE SOUTH OVER THE UPPER MISSISSIPPI VALLEY
REGION SATURDAY NIGHT WITH A COLD NIGHT AND LOW TEMPERATURES NEAR
ZERO. THE HIGH WILL EXIT SE ON SUNDAY WITH ANOTHER LOW PRESSURE
SYSTEM APPROACHING FROM SOUTHERN SASKATCHEWAN BY EVENING. EXPECT
SNOW TO DEVELOP RATHER QUICKLY SUNDAY EVENING IN STRONG LOW LEVEL
WAA AND CONTINUE INTO MONDAY WITH ANOTHER COUPLE OF INCHES
POSSIBLE. ONCE AGAIN...HIGH PRESSURE WILL FOLLOW IN FOR MONDAY
NIGHT AND TUESDAY WITH LOWS AND HIGHS WELL BELOW NORMAL.
THE SYSTEM FOR WEDNESDAY HAS THE MOST DISAGREEMENT BETWEEN THE
GFS AND ECMWF. THE GFS WOULD BRING A LOW SE ACROSS THE SD AND NE
WHILE THE ECMWF WOULD TAKE THE LOW FROM ND TO LSUP. EITHER
WAY...THEY BOTH AGREE ON A SYSTEM PASSING ACROSS THE REGION AND
LOW CHANCE POPS INSERTED FOR WEDNESDAY.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/JPR
