431 FXUS63 KMQT 192340 AFDMQT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 640 PM EST TUE FEB 19 2013 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 430 PM EST TUE FEB 19 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A NEG-TILT MID/UPPER LEVEL TROUGH FROM HUDSON BAY THROUGH NW ONTARIO INTO WI/LOWER MI BEING PROPELLED SLOWLY EAST BY A 110-120 KT 300-250 JET MOVG THROUGH THE OHIO VALLEY TOWARD THE EASTERN LAKES IN THE BASE OF THE TROUGH. THE BACK EDGE OF A WELL-DEFINED WARM CONVEYOR SHIELD EXTENDS BACK INTO ERN LAKE SUPERIOR. MODERATE Q-VECT CONV COMBINED WITH NNW FLOW ACROSS ERN LAKE SUPERIOR SUPPORTING WIND-PARALLEL LES BANDS OF MODERATE TO HEAVY IN INTENSITY EAST OF MQT. TIGHT PRES GRADIENT ON BACKSIDE OF 992 MB SFC LOW EAST OF LAKE SUPERIOR STILL MAINTAINING HIGH GALE TO STORM FORCE WINDS OVER ERN HALF OF LAKE SUPERIOR. STRONG WINDS AND MODERATE SNOW RESULTING IN BLIZZARD CONDITIONS OVER THE KEWEENAW PENINSULA AND OVER ALGER COUNTY. STATE POLICE HAS CLOSED M-28 BETWEEN HARVEY AND WETMORE DUE TO BLIZZARD CONDITIONS AND IMPASSABLE ROAD CONDITIONS. THE MODERATE 700-300 QVECTOR CONV AND DEEPER MOISTURE WILL LIFT SLOWLY EAST WITH THE MOVEMENT OF SFC LOW TONIGHT. AS A RESULT LAKE ENHANCED SNOW SHOWERS OVER ERN COUNTIES SHOULD SLOWLY DIMINISH...ESPECIALLY OVERNIGHT INTO WEDNESDAY. DRIER AIR WORKING IN OVER THE WRN PORTION OF LAKE SUPERIOR AS NOTED ON VIS SATELLITE HAS GREATLY DIMINISHED LES OVER FAR WRN COUNTIES LATE THIS AFTERNOON. THUS...HAVE DOWNGRADED WARNINGS TO WINTER WX ADVISORIES THIS EVENING OVER GOGEBIC...ONTONAGON...BARAGA AND SRN HOUGHTON COUNTIES. WILL CONTINUE BLIZZARD WARNINGS INTO THIS EVENING OVER THE KEWEENAW PENINSULA AS WINDS GUSTING AOA 35 MPH WILL STILL CAUSE LOW VISIBILITY AND TRAVEL DIFFICULTIES THERE. MARQUETTE COUNTY HAS SEEN SNOW DIMINISH ACROSS MUCH OF THE AREA BUT LIGHT TO MODERATE LES BANDS AND BLOWING SNOW...ESPECIALLY EAST OF MQT...WILL CONTINUE TO CAUSE TRAVEL DIFFICULTIES INTO THE EVENING HRS SO KEPT WARNING GOING FOR MQT COUNTY. CONTINUED DRYING FROM THE WEST SHOULD LEAD TO IMPROVED CONDITIONS FOR MARQUETTE COUNTY WESTWARD LATE TONIGHT INTO WEDNESDAY. MOST PROLONGED HAZARDOUS CONDITIONS WILL BE FOR COUNTIES EAST OF MQT WHERE WINDS GUSTING OVER 40 MPH AND MODERATE LES BANDS WILL CONTINUE THE BLIZZARD TO NEAR BLIZZARD CONDITIONS THROUGH TONIGHT AND POSSIBLY INTO WED MORNING. CONTINUED THE BLIZZARD WARNING FOR ALGER COUNTY THROUGH MUCH OF WEDNESDAY DUE TO OCCASIONAL MODERATE SNOW AND EXTREME BLOWING SNOW WITH STRONG NNW WINDS TO 35-40 MPH. AS NOTED EARLIER...M-28 CLOSED BTWN HARVEY AND WETMORE DUE TO BLIZZARD CONDITIONS. FAVORABLE SNOW GROWTH WITH DGZ WITHIN AREA OF BEST MODEL OMEGA WILL ADD TO POOR VISIBILITY AND POTENTIAL FOR GREATER SNOWFALL AMOUNTS TONIGHT INTO WED MORNING. MODEL AVG QPF ALONG WITH SLR FM 20-25/1 SHOULD YIELD 3-6 INCH SNOW AMOUNTS TONIGHT OVER ALGER AND NRN SCHOOLCRAFT AND 2-5 INCHES OVER LUCE COUNTY AND SRN SCHOOLCRAFT. DEEPER MOISTURE LEAVING THE AREA AND WEAKENING CYCLONIC NNW FLOW WILL ALLOW LES TO GRADUALLY TAPER OFF BY WED AFTERNOON OVER ERN COUNTIES WITH GENERALLY ADDITIONAL ACCUMS ON WED OF 2-4 INCHES. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 430 PM EST TUE FEB 19 2013 COMPARED TO WHAT WAS OCCURRING OUTSIDE TODAY...THE LONG TERM IS GENERALLY QUIET THROUGH MUCH OF THE PERIOD. LAKE EFFECT SNOW WILL BE SLOWLY DIMINISHING ON WEDNESDAY NIGHT AS 1040MB HIGH PRESSURE OVER NORTHERN ONTARIO CONTINUES TO PUSH A SURFACE RIDGE OVER LAKE SUPERIOR. SUBSIDENCE ALOFT FROM THIS HIGH WILL SLOWLY DROP THE INVERSION HEIGHTS OVER THE EASTERN LAKE FROM AROUND 4KFT AT 00Z THURSDAY TO 2KFT AT 12Z. BUT...THERE LOOKS TO BE ENOUGH MOISTURE SUB 900MB TO LEAD TO SOME LAKE EFFECT SNOW IN THE NORTHERLY WIND LOCATIONS OF NORTH CENTRAL UPPER MICHIGAN. NOT OVERLY IMPRESSED WITH THE THICKNESS OF THE CLOUD LAYER...ONLY ABOUT 1-2KFT THICK...SO THERE MIGHT NOT BE MORE THAN VERY LIGHT SNOW OR FLURRIES LATE WEDNESDAY NIGHT INTO THURSDAY MORNING /MORE NORTHEAST WINDS THEN/ BEFORE THE DRIER AIR LOWERS THE INVERSION AND SHOVES THE LINGERING CLOUDS TOWARDS THE SURFACE. AT THAT POINT...IT WOULD LIKELY BE EITHER LOW CLOUDS OR MIX OUT FROM DIURNAL MIXING INLAND. THIS HIGH WILL REMAIN IN PLACE INTO THURSDAY NIGHT...AS A LOW PRESSURE SYSTEM BEGINS TO EXIT THE CENTRAL PLAINS. MODELS NOT SHOWING MUCH IN THE WAY OF STRENGTHENING OR WEAKENING AS THIS LOW MOVES INTO THE GREAT LAKES ON FRIDAY AND THE UPPER GREAT LAKES ON SATURDAY DUE TO IT BECOMING DETACHED FROM THE STRONGER SOUTHERN STREAM JET. WITH IT PRECIPITATING ON IT/S WAY UP INTO THIS AREA...BEING CUT OFF FROM THE GULF MOISTURE...AND RUNNING INTO DRY AIR FROM THE CANADIAN HIGH...THE IDEA THE MODELS HAVE SHOWN FOR SEVERAL DAYS OF THE SNOW DIMINISHING AS IT MOVES INTO THE GREAT LAKES AREA SEEMS REASONABLE. WOULD EXPECT THE LIGHT SNOW TO MOVE INTO THE AREA ON FRIDAY MORNING AND CONTINUE INTO THE DAY ON SATURDAY. TOTAL QPF THROUGH THE 36 HOUR PERIOD LOOKS TO BE AROUND 0.25-0.4 INCH. ESTIMATED SNOW RATIOS AROUND 15 TO 1 AT THIS POINT WOULD LEAD TO 4-6 INCHES OF SNOW OVER MUCH OF THE AREA DURING THAT PERIOD. THIS WOULD LIKELY BE BELOW ADVISORY CRITERIA...ALTHOUGH SOME LOCATIONS COULD NEAR THE 3 INCH IN 12 HOUR MARK DURING THE DAY ON FRIDAY...ESPECIALLY TOWARDS THE WISCONSIN BORDER. ONCE THIS SYSTEM DEPARTS TO THE EAST ON SATURDAY NIGHT...HIGH PRESSURE AND UPPER RIDGING WILL MOVE INTO THE AREA AND LEAD TO A QUIET AND DRY END TO THE WEEKEND AND LIKELY INTO MONDAY. 850MB TEMPS SHOULD BE WARMER THAN -10C AND THUS WOULDN/T EXPECT ANY CONCERN FOR LIGHT LAKE EFFECT ON SUNDAY...ESPECIALLY SINCE WINDS WILL BE BACKING TO THE SOUTH AND PULLING WARMER AIR OVER THE AREA FOR SUNDAY NIGHT. ATTENTION THEN TURNS TO THE NEXT WAVE EXITING THE FOUR CORNERS REGION ON SUNDAY NIGHT AND MOVING TOWARDS THE GREAT LAKES ON MONDAY INTO TUESDAY. AS IS TRADITIONALLY THE CASE...THE GFS IS ON THE FAST SIDE WITH THE SYSTEM AND HAVING IT ARRIVE ON MONDAY...WHILE THE ECMWF IS MORE TOWARDS TUESDAY/WEDNESDAY. THERE ARE ALSO DIFFERENCES IN THE EXACT TRACK...SO WILL JUST MENTION CHANCE/SLIGHT POPS AT THIS POINT. AS FOR TEMPERATURES...EXPECT TO SEE A GRADUAL WARMING TREND FOR THE SECOND HALF OF THE WORK WEEK...WITH HIGHS THIS WEEKEND AND INTO THE FIRST PART OF NEXT WEEK AT OR SLIGHTLY ABOVE NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 639 PM EST TUE FEB 19 2013 CMX...EXPECT PREDOMINANT LIFR WITH OCNL VLIFR CONDITIONS THIS EVNG TO MODERATE TO IFR OVERNGT AS THE STRONG NNW WIND DIMINISHES/BLSN SUBSIDES A BIT FOLLOWING SLOW EXIT OF DEEP LO PRES TO THE E. THE ARRIVAL OF DRIER AIR/CONTINUED WEAKENING WINDS ON WED WL ALLOW CONDITIONS TO IMPROVE TO MVFR. IWD...EXPECT LIFR CONDITIONS WITH SN/BLSN TO IMPROVE A BIT TO IFR BY MIDNGT WITH ARRIVAL OF DRIER AIR/SLOWLY WEAKENING WINDS/SUBSIDING BLSN. CONTINUED DRYING/WEAKENING WINDS ON WED WL ALLOW CONDITIONS TO IMPROVE TO MVFR. SAW...EXPECT PREDOMINANT IFR/OCNL MVFR CONDITIONS THRU TNGT TO GIVE WAY TO MVFR CONDITIONS ON WED WITH ARRIVAL OF DRIER AIR/SLOWLY WEAKENING WINDS/DIMINISHED BLSN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 430 PM EST TUE FEB 19 2013 STRONG WRAPPED UP SFC LOW EAST OF LAKE SUPERIOR WILL HEAD TOWARD WESTERN QUEBEC TONIGHT WHILE BEGINNING TO WEAKEN. VERY TIGHT PRESSURE GRADIENT PRESENT THROUGH THIS EVENING COMBINED WITH COLD AIR ADVECTION AND STRONG WINDS ALOFT WILL MAINTAIN STRONG GALES WITH FREQUENT STORM FORCE GUSTS OVER THE EASTERN HALF OF LK SUPERIOR THROUGH THIS EVENING. EXTENDED STORM WARNINGS FOR LSZ266 THROUGH THIS EVENING. WINDS WILL BE SLOW TO DIMINISH WITH GALES PERSISTING OVER CENTRAL AND ERN LK SUPERIOR THROUGH WED. HEAVY FREEZING SPRAY WILL CONTINUE THROUGH THURSDAY MORNING. HIGH PRESSURE CROSSING ON THURSDAY WILL ALLOW WINDS TO RELAX AND HEAVY FREEZING SPRAY TO SUBSIDE. EXPECT EAST WINDS 20-30 KTS ON FRIDAY INTO FRIDAY NIGHT AS LOW PRESSURE MOVES IN FROM THE CENTRAL PLAINS. WINDS FOR THE UPCOMING WEEKEND NO MORE THAN 20 KTS AS WEAK PRESSURE GRADIENT PREVAILS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST /11 PM CST/ TONIGHT FOR MIZ002-004-009-013-084. WINTER STORM WARNING UNTIL 5 PM EST WEDNESDAY FOR MIZ007-014-085. BLIZZARD WARNING UNTIL 1 AM EST WEDNESDAY FOR MIZ001-003. BLIZZARD WARNING UNTIL 5 PM EST WEDNESDAY FOR MIZ006. WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MIZ005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY FOR LSZ162-240>251-263-265-267. GALE WARNING UNTIL 7 PM EST WEDNESDAY FOR LSZ245>251-265-267. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ264- 266. STORM WARNING UNTIL 11 PM EST THIS EVENING FOR LSZ266. GALE WARNING UNTIL 1 PM EST WEDNESDAY FOR LSZ243-244-264. GALE WARNING UNTIL 5 AM EST /4 AM CST/ WEDNESDAY FOR LSZ240>242- 263. LAKE MICHIGAN... GALE WARNING UNTIL 7 AM EST WEDNESDAY FOR LMZ248-250. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...KC MARINE...VOSS