FXUS63 KMPX 061751
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1151 AM CST SUN DEC 6 2009

.AVIATION... /18Z TAF ISSUANCE/ 

ARCTIC HIGH PRESSURE STRETCHES FROM ND TO WI AND WILL MOVE LITTLE
THROUGH THE FORECAST PERIOD AS A WEAK AREA OF LOW PRESSURE PASSES
SOUTH OF THE REGION OVERNIGHT. MVFR STRATUS COVERS THE NORTHERN
TWO-THIRDS OF MN WITH CLR-SCT CONDITIONS TO THE SOUTH AND EAST.
LITTLE CHANGE EXPECTED WITH THE STRATUS TRAPPED UNDER THE
RIDGE...WHILE SLOW FILLING IN THE LOW CLOUDS OCCURS ACROSS
SOUTHERN MN THIS AFTERNOON AND ACROSS WEST CENTRAL WI THIS
EVENING. FLURRIES WILL BE COMMON WITH THE STRATUS WITH
VISIBILITIES FROM 3 TO 5 MILES FROM TIME TO TIME. NORTH WINDS IN
THE 6 TO 10 KNOT RANGE TONIGHT BACKING NW ON MONDAY.

KAXN...CEILINGS IN THE 010-020 FOOT RANGE THROUGH THE PERIOD WITH
OCCASIONAL FLURRIES PRODUCING 3-5 MILE VISIBILITIES.

KSTC...CEILINGS IN THE 020-025 FOOT RANGE THIS AFTERNOON LOWERING
INTO THE 010-020 FOOT RANGE TONIGHT AND CONTINUING MONDAY MORNING.
OCCASIONAL FLURRIES PRODUCING 3-5 MILE VISIBILITIES. 

KRWF...CEILINGS IN THE 015-02O FOOT RANGE DEVELOPING EARLY THIS
AFTERNOON AND THEN CONTINUING THROUGH THE REST OF THE TAF PERIOD.
OCCASIONAL FLURRIES OCCURRING WITH THE CEILINGS PRODUCING 3-5 MILE
VISIBILITIES.

KMSP...BKN CONDITIONS AROUND 025 DEVELOPING EARLY THIS AFTERNOON
ALONG WITH A FEW FLURRIES. SOME INDICATIONS THAT THE CEILING MAY
SCT BY EVENING WITH THE LOSS OF HEATING. HOWEVER...AS THE EVENING
PROGRESSES THE STRATUS TO THE NORTH AND WEST PROGGED TO FILL IN 
WITH CEILINGS IN THE 015-020 RANGE BY 07/06Z AND NEAR 010 BY
DAYBREAK MONDAY. OCCASIONAL MVFR VISIBILITIES IN FLURRIES
OVERNIGHT AND MONDAY MORNING AS WELL. 

KRNH...VFR CONDITIONS THIS AFTERNOON WITH BKN MVFR CEILINGS
AROUND 020 FORECAST TO DEVELOP THIS EVENING AND CONTINUE
OVERNIGHT. OCCASIONAL MVFR VISIBILITIES IN FLURRIES
OVERNIGHT AND MONDAY MORNING WILL ACCOMPANY THE CEILINGS.

KEAU...VFR CONDITIONS THIS AFTERNOON AND EARLY TONIGHT. BKN MVFR
CEILINGS AROUND 020 FORECAST TO DEVELOP DURING THE 07/06Z-09Z
TIME FRAME AND CONTINUING THROUGH THE END OF THE TAF PERIOD. 
OCCASIONAL MVFR VISIBILITIES IN FLURRIES EXPECTED MONDAY MORNING.

&&

.DISCUSSION... /ISSUED 350 AM CST SUN DEC 6 2009/

RELATIVELY QUIET WEATHER THE NEXT 12 HOURS. SOME WEAK CAA
STRATUS/FLURRIES WORKING SOUTH OVER THE NORTHERN MN THIS MORNING.
MAY WORK INTO ROUGHLY THE NORTHWEST HALF OF THE CWA DURING THE
DAY. WEAK TROUGH EXITING TO THE EAST THIS MORNING LEAVING LITTLE
IN THE WAY OF CLOUDS. SHOULD SEE CLOUDS INCREASE OVER THE SOUTH
DURING THE DAY AHEAD OF THE NEXT SHORT WAVE PROGGED TO LIFT
NORTHEAST OVER IA AND MN SRN MN OVERNIGHT. FLOW ALOFT BECOMES A BIT
MORE CONFLUENT TO THE NORTHEAST OF THE AREA...SO SNOW AREA SHOULD
BE RELATIVELY NARROW. STILL LOOKS LIKE FAR SOUTH CENTRAL MN MAY
PICK UP A FLUFFY INCH OF SNOW OVERNIGHT. ELSEWHERE...DRY MID LEVEL
SHOULD PROHIBIT ANY ACCUMULATING SNOW...BUT MAY GENERATE A FEW
FLURRIES AS TROUGH EXITS TOT HE EAST. THIS HINTED AT IN THE NAM
BUFKIT PROFILES. COLD SFC RDG OVER THE OVER THE DAKOTAS INTO
WESTERN MN THIS MORNING DID PROVIDE ANOTHER NIGHT OF SINGLE DIGITS
WITH A FEW BELOW ZERO READINGS IN THE LOW SPOTS OF THE FAR WEST.
TEMPS WILL STRUGGLE DURING THE DAY OVER THE WEST AND SHOULD WARM 
CLOSE TO MAV GUIDANCE VALUES IN THE EAST. WILL COLD A BIT COLDER 
WEST.

NEXT SYSTEM IS PRETTY MUCH ON SCHEDULE BUT THERE ARE A FEW MINOR
FLUCTUATIONS IN SFC LOW TRACK. 00Z GFS AND THE 00Z ECMWF ARE
SIMILAR WITH TRACK NOW...FROM CO/OKLAHOMA PANHANDLE AREA TUE
EVENING TO NEAR CHICAGO BY 12Z WED. THIS TRACK IS FAVORABLE FOR
SOME SIGNIFICANT SNOWS OVER THE SOUTH AND EAST PORTION OF THE CWA.
CONTEMPLATED ISSUING 5TH PERIOD WATCH...BUT COLLABORATION YIELDED
STRONGLY WORDED HWO FOR NOW. SNOW SHOULD LIFT INTO MUCH OF THE CWA
DURING THE DAY TUESDAY AS ISENTROPIC LIFT INCREASES AND
SATURATION OCCURS. MAY TAK AWHILE OVER THE NORTHEAST CWA AS
ATMOSPHERE WILL BY RATHER DRY TO START OUT. SOLID 2-3 G/KG MIXING
RATIOS OVER THE SOUTHEAST CWA SHOULD GENERATE SOME 6 INCH
VALUES. ONLY QUESTION IS THE SLR FOR THE STORM. MAY BY AVERAGE
MORE CLOSE TO 20:1 IN THE NORTHWEST AND AT LEAST 16:1 IN THE
SOUTHEAST. MODELS INCREASE THE WINDS TUE NIGHT AS LOW LIFTS
NORTHEAST ACROSS IOWA. ANY SNOW WILL BE BLOWN AROUND DURING THE
NIGHT AND INTO WED. QUESTION IS HOW QUICKLY STORM WILL EXIT TOT EH
EAST WED. LEFT THE CURRENT TREND IN THE GRIDS NOW...WITH
IMPROVEMENT OVER THE WEST AND CENTRAL CWA DURING THE DAY. 

COLDER AIR WILL DROP IN BEHIND THE SYSTEM. DEPENDING ON CLOUD
COVER...SHOULD BE ABLE TO GET SOME BELOW ZERO READINGS OVER THE
FRESH SNOW COVER. THIS WILL KEEP TEMPERATURE BELOW NORMAL THEN
THROUGH NEXT WEEKEND.

&&

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

$$

RAH/DWE