FXUS63 KMPX 152305
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
505 PM CST TUE DEC 15 2009

.DISCUSSION...
ARCTIC HIGH WILL MOVE EAST OVER THE AREA DURING THE NIGHT. THIS
SHOULD GRADUALLY DIMINISH WINDS THIS EVENING...AND PROVIDE A
RATHER QUICK TEMPERATURE DROP THROUGH ABOUT MIDNIGHT IN THE WEST.
THEN SOME HIGH/MID LEVEL CLOUDS OVER THE CWA OVERNIGHT INTO WED
MORNING. WILL TRY AND SLOW DROP TO NEAR STEADY/SLOWLY RISE OVER
THE WESTERN CWA OVERNIGHT. SLOW MODERATION IN TEMPERATURES TO THE
TEENS OVER MUCH OF THE AREA AS THE HIGH EXITS TO THE EAST.  

NEXT SHORT WAVE COMING DOWN IN THE NORTHWEST FLOW BRUSHING THE
NORTHERN CWA DURING THE DAY THURSDAY INTO THURSDAY NIGHT. 12Z
NAM_WRF A BIT MORE AGGRESSIVE WITH THE WAVE AS IT MOVES EAST...WITH
THE GFS WEAKER. WILL CONTINUE THIS TREND WITH A LOW POP OVER THE
NORTHEAST CWA. MAY HAVE TO INTRODUCE FLURRIES THURSDAY NIGHT IF
ENOUGH LIFT IS GENERATED WITH WEAK TROUGH MOVING THROUGH.

NEXT SHORT WAVE TROUGH DIGS A BIT MORE TO THE SOUTHEAST ON FRIDAY.
12Z ECMWF IN BETTER AGREEMENT WITH THE GFS NOW...AS THIS SYSTEM
MOVES THROUGH. WILL CONTINUE SLGT CHC POPS FOR NOW. 

SOME DISCREPANCY IN EARLIER MODEL RUNS IN DEVELOPMENT OF UPPER LOW
OVER THE GREAT LAKES REGION. THE 12Z GFS CONTINUED ITS TREND OF
DIVING A WAVE SOUTHEAST OVER THE AREA LATER SATURDAY NIGHT INTO
MONDAY AS IT CARVED OUT THE UPPER LOW OVER THE AREA. THE 12Z ECMWF
COME IN WITH SOMETHING SIMILAR...DRAGGING A CLIPPER TYPE SYSTEM
SOUTHEAST ROUGHLY IN THE SAME TIME PERIOD. WILL MENTION SOME LOW
POPS DURING THIS PERIOD FOR NOW..AND SEE IF MODEL TRENDS CONTINUE
IN THE LONGER TERM. OVERALL..EXPECT SOME MODERATION IN
TEMPERATURES THROUGH THE END OF THE WORK WEEK...THEN COOL BACK
BELOW NORMAL INTO NEXT WEEK AS THE CLIPPER EXITS THE REGION. 

&&

.AVIATION.../00Z TAF ISSUANCE/ 

ARCTIC HIGH PRESSURE RIDGE WILL BE OVER THE AREA TONIGHT. AN
IMPINGING WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE SOME HIGH TO
MID LEVEL CLOUDS TONIGHT...WITH SOME 4 TO 6 KFT CIGS POSSIBLE IN
CENTRAL MN LATE INTO WED MORNING. THE MODEL GUIDANCE HAS TRENDED
MORE POSITIVELY AGAINST LOW CLOUDS AND AGREE WITH THIS TREND WHICH
WAS FOLLOWED IN PREVIOUS TAF ISSUANCE. SO KEEP THINGS VFR. BEHIND
THIS DISTURBANCE ON WEDNESDAY WILL BE SOME TEMPORARY DRYING BEFORE
ANOTHER SLIGHTLY STRONGER DISTURBANCE APPROACHES NORTHERN AND
CENTRAL MN WED NIGHT. INCREASING BOUNDARY LAYER MOISTURE DUE TO
SOUTHERLY WINDS AND SNOW MELT TO OUR FAR SOUTH MAY LEAD TO SOME
LIGHT FOG OR STRATUS LATE WED NIGHT AND THU MORNING...IN THE 12
HOURS BEYOND CURRENT TAF PERIOD. WINDS TO BACK LATER THIS EVE AND
REMAIN FROM THE SE TO ESE DIRECTION DURING THE DAY TOMORROW.
GENERALLY LIGHT WINDS EXPECTED AT ALL SITES.

KMSP...WINDS TO BE FROM THE WSW FOR A COUPLE HOURS BEFORE BACKING
SOMEWHAT ABRUPTLY. AGAIN THEY SHOULD BE LIGHT. VFR CIGS EXPECTED
WITH HIGH CONFIDENCE THROUGH THE DAY WEDS.

&&

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

$$

DWE/MTF