914 
FXUS63 KMPX 241816 AAB
AFDMPX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
116 PM CDT SUN MAR 24 2013

.UPDATE...

UPDATED FOR 18Z AVIATION DISCUSSION BELOW.

&&

.PREV DISCUSSION.../ISSUED 304 AM CDT SUN MAR 24 2013/

NEAR TERM FORECAST CONCERN REMAINS CHANCE OF LIGHT SNOW OVER MUCH
OF THE REGION TODAY AND ENDING TO THE WEST LATER TONIGHT. 00Z
DETERMINISTIC MODELS CONTINUE TREND OF DEVELOPING SOME LIGHT SNOW
AS UPPER LOW EJECTS SOUTHERN WAVE TO THE EAST THIS
MORNING...THEREBY LETTING MID LEVEL TROUGH TO DROP SOUTHEAST OVER
THE EASTERN DAKOTAS/WESTERN MN THIS AFTERNOON AND OVERNIGHT. THIS
ENHANCES FORCING ALONG THE SURFACE INVERTED TROUGH WHICH APPEARS
TO BE DEVELOPING OVER EASTERN MN THIS MORNING. VARIOUS MODEL
DERIVED RADAR REFLECTIVITY FORECAST SHOWS BAND OVER CENTRAL MN
WILL DEVELOP FURTHER AND WILL BE THE MAIN FOCUS OF SNOW AS MID
LEVEL TROUGH MOVES SOUTHEAST. AT THIS TIME...IT APPEARS TO BE A
HIGH POPS LOW QPF TYPE EVENT...WITH PERHAPS AROUND AN INCH
ACCUMULATION IN THE MORE FAVORED SOUTHWEST TO SOUTH CENTRAL INTO
TONIGHT. WITH ABUNDANT CLOUD COVER EXPECTED TEMPERATURES SHOULD BE
HELD IN THE UPPER 20S TO MID 30S MOST AREAS AS LIGHT SNOW
DEVELOPS.  

THIS SYSTEM EXITS TO THE SOUTH TONIGHT AND THE SNOW SHOULD END
FROM EAST TO WEST. MAYBE SOME RESIDUAL FLURRIES INTO THE MORNING IN
THE SOUTHWEST. CLOUDS ARE EXPECTED TO REMAIN MOST OF THE DAY...AND
ONLY SLOW CLEARING EXPECTED INTO TUESDAY. CU RULES REMAIN HIGHLY
NEGATIVE AND MODEL LOW LEVEL RELATIVE HUMIDITY REMAINS HIGH DURING
THE PERIOD. 

SOME WEAK COOLING REMAINS INTO MIDWEEK...THEN SUNSHINE EXPECTED TO
RETURN. EASTERN CONUS TROUGH MOVES EAST ALLOWING FOR SOME RIDGING
TO DEVELOP ALOFT. THIS SHOULD HELP DRAW SOME WARMER PACIFIC AIR TO
THE EAST FOR LATER IN THE WEEK...SHOULD SEE SOME HIGHS IN THE 40S
THEN. LONGER TERM MODEL TRENDS CONTINUE TO BRING IN ANOTHER SHORT
WAVE SATURDAY/SATURDAY NIGHT PERIOD. THIS IS EXPECTED TO BE
ANOTHER MIXED TYPE PRECIPITATION EVENT...RAIN/SNOW TO THE
WEST...AND MAINLY SNOW TO THE EAST. WILL HAVE TO MONITOR TRENDS
THROUGH EARLY THIS WEEK...THOUGH IT APPEARS TO BY FAST MOVING CLIPPER
TYPE SYSTEM.

&&

.AVIATION.../18Z TAF ISSUANCE/ 

MVFR CONDITIONS ARE IN PLACE ACROSS MOST OF THE AREA AT TAF
ISSUANCE TIME...EXCEPT FOR A SMALL HOLE OF VFR CONDITIONS HEADED
WEST INTO CENTRAL AND SOUTH CENTRAL MN. IFR VSBYS HAVE
OCCASIONALLY BEEN REPORTED WITH A BAND OF LIGHT SNOW ACROSS WRN
MN. THE MAIN CONCERN/UNCERTAINTY FOR THIS ISSUANCE IS TIMING THE 
VFR AREA ACROSS WRN MN AND WHETHER ADDITIONAL SNOW SHOWERS WILL
DEVELOP THIS AFTERNOON. THERE HAVE BEEN ECHOES ON RADAR ACROSS
WRN WI...BUT THEY HAVE NOT BEEN REACHING THE GROUND. LOW LEVEL
MOISTENING AND INSTABILITY SHOULD ALLOW FOR ADDITIONAL
DEVELOPMENT...BUT IT WILL REMAIN LIGHT AND MORE SCATTERED THAN
THIS MORNING WITH MINIMAL IMPACT EXPECTED. ANY SNOW SHOWERS WOULD
DIMINISH THIS EVENING. CLOUD COVER IS RATHER EXPANSIVE AND THERE
ARE ALSO QUESTIONS WHETHER CIGS WILL RETURN TO VFR TOWARD THE END
OF THE PERIOD. WITH THE LOSS OF SOME LOW LEVEL MOISTURE THIS
EVENING...DID NOT FEEL CONFIDENT TO CHANGE WHAT THE LAST FORECAST
HAD GOING...BUT GUIDANCE REMAINS PESSIMISTIC THROUGH MONDAY
MORNING.

KMSP...MVFR CIGS EXPECTED TO PERSIST AT LEAST THROUGH MID EVENING.
CONFIDENCE IS LOW WITH THE REDEVELOPMENT OF SNOW SHOWERS/FLURRIES
THIS AFTERNOON. SINCE THEY SHOULD BE MORE SCATTERED...SIDED
AGAINST A PREVAILING MENTION AND WENT WITH VCSH FROM MID AFTERNOON
THROUGH MID EVENING. DRIER AIR IN THE LOWER LEVELS COULD ARRIVE
THEREAFTER...ALLOWING FOR MODEST IMPROVEMENT IN CIGS LATE BUT
CONFIDENCE IS LOW.

/OUTLOOK FOR KMSP/
MON...MVFR CIGS POSSIBLE. NW WIND 10G20 KT.
TUE...MVFR CIGS POSSIBLE EARLY. NW 5-10 KT. 
WED...VFR. WINDS LGT AND VRB.

&&

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

$$

DWE/BORGHOFF