888 FXUS63 KMPX 181211 AFDMPX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 611 AM CST MON FEB 18 2013 .AVIATION... /12Z TAF ISSUANCE/ LOW PRESSURE OVER NORTH CENTRAL MN AT TAF ISSUANCE WITH A COLD FRONT SOUTH THROUGH KAXN TO WEST OF KRWF. MVFR TO IFR CEILINGS IN THE WAKE OF THE FRONT ALONG WITH NW WINDS 20-25 KNOTS GUSTING 30-35 KNOTS. THIS PATTERN WILL BE SPREADING SE THIS MORNING WITH SIGNIFICANT WIND FOR KAXN AND KRWF THIS AFTERNOON AND EVENING. SPEEDS SUSTAINED NEAR 30 KNOTS WITH GUSTS REACHING 40 KNOTS LIKELY. MAIN QUESTION IS HOW MUCH BLOWING SNOW WILL OCCUR. NOT MUCH ACTUAL SNOW IS EXPECTED IN THE WAKE OF THE FRONT. OVERNIGHT... TEMPERATURES HAVE BEEN IN THE MIDDLE 30S ACROSS THE EASTERN DAKOTAS/WEST CENTRAL MN. THIS SHOULD HAVE PUT A CRUST ON THINGS...BUT THE STRONG SUSTAINED WINDS TODAY MAY BREAK THROUGH THIS AND CAUSE BLSN PROBLEMS. HENCE...THE WESTERN TAFS ARE FAIRLY PESSIMISTIC. THE LOW TO OUR NORTH WILL JOIN FORCES WITH A LOW COMING NORTHEAST FROM THE CENTRAL PLAINS...RESULTING IN A DEEPENING LOW PRESSURE SYSTEM OVER THE WESTERN GREAT LAKES BY LATE IN THE AFTERNOON. SHORT TERM GUIDANCE OVERNIGHT HAS SHIFT THE DEEP LAYER MOISTURE AND FORCING WITH THE SOUTHERN WAVE A LITTLE FARTHER EAST WITH SNOW THIS AFTERNOON/EVENING ACROSS WEST CENTRAL WI. THE STRONG NORTHWEST WINDS WILL CONTINUE TONIGHT WITH 15 TO 25 KNOTS STILL LIKELY ON TUESDAY. KMSP...WIND SHIFT FROM SOUTH TO WEST EXPECTED AROUND 14Z. SPEEDS INCREASING TO 23 KNOTS BY LATE IN THE MORNING ALONG WITH A MORE NORTHWEST DIRECTION (290-300). GUSTS AROUND 30 KNOTS WILL ALSO DEVELOP LATE IN THE MORNING AND CONTINUE THROUGH THE AFTERNOON AN EVENING. CONFIDENCE ON SNOW TODAY IS LOWERING WITH BETTER CHANCES OF SNOW DEVELOPING OVER WEST CENTRAL WI THIS AFTERNOON. MVFR CIGS HAVE ALREADY STARTED TO DEVELOP AROUND THE TWIN CITIES. HOWEVER...A SOLID MVFR OVC CEILING IS NOT EXPECTED UNTIL AFTER THE WIND SHIFT OCCURS. CEILINGS LOWERING TO AROUND 015 FOR THE AFTERNOON AND EVENING. /OUTLOOK FOR KMSP/ TUE...MVFR CIGS. WINDS NW AT 15 TO 25 KTS DIMINISHING TO 10 KTS LATE. WED...VFR. WINDS N TO E NEAR 5 KTS. THU...VFR MORNING. IFR OR LOWER WITH SNOW AFTERNOON/NIGHT. WINDS E AT 15 KTS. && .DISCUSSION... /ISSUED 247 AM CST MON FEB 18 2013/ MAIN FORECAST CHALLENGE/CONCERN IS THE LACK OF DEEP MOISTURE ACROSS MOST OF THE FA TODAY...OR AT LEAST UNTIL THIS AFTN...AND MAINLY AFFECTING WC WI. SATELLITE IMAGERY INDICATED THAT THE MAIN SOURCE OF GULF MOISTURE IS STILL ACROSS THE SOUTHERN MISSISSIPPI VALLEY REGION AS OF 2 AM. THIS MOISTURE SOURCE WAS EXPECTED TO BE ACROSS NORTHERN MO AT THIS TIME BASED ON EARLIER MODEL RUNS. ALTHOUGH MOISTURE ACROSS ND HAS INCREASED OVER THE PAST 6 HRS...THIS AREA WILL LIKELY ONLY AFFECT N MN AS THE MAIN SHRTWV MOVES ACROSS WC...INTO NE MN LATER TODAY. EVEN SOME OF THE SHORT TERM MODELS INDICATED VERY LITTLE RADAR RETURNS AS THE MAIN COLD FRONT MOVES THRU THIS MORNING. IT IS NOT UNTIL ARND 18Z THAT ANY TYPE OF SIGNAL TRANSLATES INTO LIGHT PRECIPITATION DEVELOPING ACROSS THE FAR EASTERN FA. BASED ON THESE PARAMETERS...AND THE LACK OF UPPER LEVEL FORCING...HIGHER POPS WILL BE CONFINED TO WC WI. WILL MONITOR RADAR RETURNS OVER THE NEXT TWO HRS AND SEE ANY SIGNS OF DEVELOPMENT ACROSS IA...TO CHG MY PRESENT SCENARIO OF CHC POPS FOR MOST OF THE FA...WITH THE EXCEPTION OF WC WI. THE OTHER FORECAST CONCERN IS THE STRONG WINDS DEVELOPING IN ON THE BACK SIDE OF THIS COLD FRONT WHICH IS EXPECTED TO MOVE THRU THE FA BY 21Z. SEVERAL LOCAL MODELS HAVE INDICATED A VERY STRONG SIGNAL OF WIND SPDS OF 30 TO 35 MPH...WITH GUSTS OVER 45 MPH ACROSS WC/SW AND SC MN LATER TODAY...AND INTO THIS EVENING. BASED ON THE ALREADY DEEP SNOW COVER IN THE WEST...WILL CONTINUE THE WINTER WX ADVISORY FOR BLOWING SNOW...WITH SOME LIGHT SNOW...BUT NOT EXPECTING ANYTHING ON ADDITIONAL ACCUMULATIONS. AREAS IN SC MN WHERE SNOW COVER IS ALMOST NON-EXISTENT...WILL GO WITH A WIND ADVISORY. THIS SYSTEM QUICKLY DEPARTS THE AREA BY TUESDAY MORNING...WITH A QUIET PERIOD UNTIL LATE WED/EARLY THURSDAY AS THE NEXT WEATHER SYSTEM BEGINS TO AFFECT THE REGION. DURING THIS TIME...TEMPS WILL LIKELY AVERAGE 10 TO 20 DEGREES BELOW NORMAL. FOR THE WEATHER SYSTEM LATE IN THE WEEK...MODELS HAVE BEEN CONSISTENT ON PRECIPITATION DEVELOPING BY LATE WED/EARLY THURSDAY ACROSS SW MN...AND SLOWLY SPREADING N/NE ACROSS THE FA THRU FRIDAY. AS WITH PREVIOUS DISCUSSIONS...THIS SYSTEM WEAKENS AS IT MOVES NORTHEAST ACROSS THE PLAINS...AND INTO THE UPPER MIDWEST. MODELS HAVE ALSO INDICATED THAT THE BULK OF THE GULF MOISTURE WILL TRANSLATE FROM THE CENTRAL PLAINS...INTO THE MID MISSISSIPPI VALLEY BY THU/FRI. THIS WILL LEAD TO MAINLY A LARGE WARM AIR ADVECTION PATTERN ACROSS THE UPPER MIDWEST WITH A WEAKENING TREND AS THE SYSTEM MOVES NE. BASICALLY THIS WILL LEAD TO THE HIGHEST QPF AMTS ACROSS KANSAS/NEBRASKA/IOWA THRU THURSDAY MORNING. AS IT MOVES ACROSS NORTHERN IA...AND INTO SOUTHERN MN...QPF AMTS WILL DECREASE AS PER THE CUT OFF OF THE DEEPER GULF OF MEXICO MOISTURE TO THE EAST. ALTHOUGH THERE WILL BE A PROLONGED PERIOD OF LIGHT SNOW...GENERALLY SNOWFALL TOTALS THRU FRIDAY MORNING AS THE SYSTEM RINGS ITSELF OUT...WILL TRANSLATE TO LOCALLY 6 TO 8 INCHES ALONG THE IOWA BORDER...TO 3 TO 6 INCHES ACROSS THE REST OF THE FA...WITH THE LEAST AMTS ACROSS CENTRAL MN. ALTHOUGH STRONG WINDS WILL ACCOMPANY THE BEGINNING OF THIS SYSTEM...THE WIND SPDS WILL LIKELY DECREASE BY THURSDAY AFTN/EVENING AS THE LOW WEAKENS. PAST FRIDAY...ANOTHER WINTER STORM IS PROGGED TO MOVE INTO THE CENTRAL PLAINS BY LATE IN THE WEEKEND. IT IS TOO EARLY TO TELL IF SIGNIFICANT SNOW WILL FALL ACROSS THE UPPER MIDWEST...BUT WITH THIS ACTIVE PATTERN CONTINUING...THIS FEBRUARY COULD END UP WITH MORE SNOWFALL THAN AVERAGE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT FOR BROWN-CARVER-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE- MCLEOD-MEEKER-NICOLLET-POPE-REDWOOD-RENVILLE-SIBLEY-STEARNS- STEVENS-SWIFT-TODD-WRIGHT-YELLOW MEDICINE. WIND ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT FOR BLUE EARTH-FARIBAULT-FREEBORN-LE SUEUR-MARTIN-STEELE-WASECA- WATONWAN. WI...NONE. && $$ RAH/JLT