000 FXUS63 KAPX 100312 AFDAPX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1012 PM EST THU FEB 9 2012 .SYNOPSIS.../ISSUED AT 319 PM/ A COLD FRONT STRETCHING ACROSS CANADA...WILL CONTINUE TO SAG SOUTHWARD INTO THE GREAT LAKES TONIGHT. LIGHT SNOW WILL ACCOMPANY THE FRONTAL PASSAGE TONIGHT INTO FRIDAY...ALONG WITH AN ARCTIC AIR MASS THAT WILL SPILL INTO THE REGION. THE COLDER AIR MOVING OVER THE RELATIVELY WARMER AND ICE-FREE GREAT LAKES WILL BRING LAKE EFFECT SNOWS TO THE REGION THIS WEEKEND...WITH SEVERAL INCHES OF SNOW POSSIBLE FOR PARTS OF EASTERN UPPER AND NORTHERN LOWER BY SUNDAY NIGHT. THE COLD SPELL WILL BE SHORT LIVED...WITH TEMPERATURES RECOVERING TO NEAR OR SLIGHTLY ABOVE NORMAL BY LATE THIS WEEKEND INTO EARLY NEXT WEEK. NTS && .SHORT TERM.../ISSUED AT 1012 PM/...OVERNIGHT APPROACHING ARCTIC FRONT HAS MADE ITS WAY THRU MUCH OF LAKE SUPERIOR AND NOW EXTENDS FROM JUST NORTH OF ERN UPR MICHIGAN THRU WRN UPR MICHIGAN INTO NW WISCONSIN AND SRN MINNESOTA. LATEST NAM FINALLY APPEARS TO HAVE A DECENT HANDLE ON THE TIMING OF THIS FRONT... MATCHING QUITE WELL WITH REALITY PER LATEST SURFACE ANALYSIS AND SURFACE OBS. REGIONAL US/CANADIAN MOSAIC RADAR SHOWS A WELL DEFINED NARROW BAND OF SNOW DEVELOPING ALONG AND JUST NORTH OF THE FRONT... DRIVEN BY RELATIVELY STRONG 700-500 MB DIV-Q...AS WELL AS A MODEST AREA OF OMEGA VERTICALLY ALIGNED WITH THE DGZ AND A NARROW BAND OF DEEP MOISTURE. HOWEVER...SINCE THE BAND OF DEEP MOISTURE IS NARROW...AND RESULTING BAND OF SNOW IS NARROW AS WELL...SNOWFALL ALIGNED WITH THE FRONT WILL BE RELATIVELY BRIEF AND GENERALLY LIGHT. BAND OF SNOW WILL FINALLY ARRIVE ACROSS ERN UPR MICHIGAN AFTER MIDNIGHT...AND PROGRESS S/SE LATE TONIGHT INTO EARLY FRIDAY MORNING ALONG AND JUST BEHIND THE FRONT. AROUND AN INCH OR LESS OF NEW SNOW IS STILL A GOOD BET GIVEN THE BRIEF DURATION OF THE SNOW AND WITH THE EXPECTATION THAT INTENSITY WILL GENERALLY BE LIGHT. TEMPS WILL DROP INTO THE 20S OVERNIGHT...AND INTO THE TEENS BY MORNING ACROSS ERN UPR MICHIGAN AS CAA KICKS IN IMMEDIATELY BEHIND THE ARCTIC FRONT. BRISK SW WINDS WILL SHIFT TO THE NW AND THEN NORTH BEHIND THE FRONT. && .LONG TERM.../ISSUED AT 319 PM/...FRIDAY AND BEYOND FRIDAY...HELLO WINTER! BRISK NORTH WINDS KICK IN BEHIND THE DEPARTING FRONT...WITH TEMPERATURES DROPPING THROUGH THE DAY. FRONTAL SNOWS WILL LIKELY BE ONGOING CENTRAL AND SOUTHERN PORTIONS OF THE FORECAST AREA DURING THE MORNING...WITH SYSTEM SNOW DEPARTING BY AFTERNOON. BIGGER STORY WILL BE THE TEMPERATURES...WITH PROGGED NEGATIVE HIGH TEENS 850MB TEMPERATURES AND CURRENT CENTRAL ONTARIO CONDITIONS SUPPORTING TEMPERATURES FALLING INTO THE SINGLE DIGITS AND TEENS THROUGH THE AFTERNOON..WITH WIND CHILL VALUE DROPPING A FEW DEGREES UNDER THE GOOSE EGG. NO DOUBT NORTH TO NORTH-NORTHEAST LAKE INDUCED SNOWS WILL CONTINUE...ALTHOUGH QUICK LOSS OF SYNOPTIC MOISTURE AND TANKING INVERSIONS WILL KEEP INTENSITY LEVELS IN CHECK. ALL IN ALL...WOULD EXPECT NO MORE THAN AN INCH OR TWO WEST AND SOUTHWEST OF TRAVERSE CITY...WITH LESS THAN AN INCH ELSEWHERE. DEEP LAYER DRYING LIKELY TO BRING SOME CLEARING BY LATE MORNING AND EARLY AFTERNOON ACROSS EASTERN UPPER AND INTERIOR SECTIONS OF NORTHERN LOWER MICHIGAN. DON'T LET IT FOOL YOU...ITS GOING TO FEEL DOWNRIGHT COLD AFTER OUR RECENT STRETCH OF MILD CONDITIONS. MSB FRIDAY NIGHT...THE COLD FRONT, HAVING GONE THROUGH THE FORECAST AREA EARLIER IN THE DAY, SPILLS THE COLD AIR INTO THE REGION. WINDS INITIALLY IN THE 1000-850 MB LAYER, TURN RATHER ABRUPTLY TO THE NORTH OR NORTH-NORTHEAST. WITH THE 850 MB TEMPERATURES AROUND -18C AND THE LAKE TEMPERATURES AROUND +3C INSTABILITY IS PRETTY GOOD. MOISTURE BEHIND THE FRONT MAY BRIEFLY DIP, FROM THE SUBSIDENCE, BUT THE 850-700 MB MOISTURE INCREASES TO OVER 80% THROUGH THE NIGHT. THIS WILL START THE LES MACHINE OFF WITH LIGHT SNOW SHOWERS AS THINGS COALESCE. SATURDAY...DURING THE DAY, THE DELTA TS CONTINUE TO BE NEAR 20C WITH THE MOISTURE IN THE 850-700 MB LAYER STILL ABOVE 80%. WIND DIRECTIONS, HOWEVER, CONTINUE TO BACK FROM THE NORTH TO NORTHWEST, AND SETTLING IN THE NW DIRECTION BY 00Z. THIS WILL ALLOW FOR SOME ORGANIZATION OF THE SNOW BANDS, BUT WOULD NOT BE SURPRISED THAT DURING THE DAY THAT THE INSTABILITY OVER THE LAND DURING THE DAY WOULD BREAK THE BANDS INTO CELLS. SATURDAY NIGHT...OVERNIGHT THE DRIER AIR BEGINS TO MOVE INTO THE REGION AND THE 850 MB TEMPERATURES WILL BEGIN TO WARM. TEMPERATURES AT 850 MB WILL STILL BE BELOW -10C, SO WILL EXPECT THAT THERE WILL BE MULTIPLE LAKE SNOW BANDS ORIENTED IN A NW FLOW PATTERN. THERE IS A CONCERN HOWEVER, THAT THERE COULD BE SINGLE DOMINATE BAND THAT FORMS OVERNIGHT. IF THAT HAPPENS, THEN SNOW AMOUNTS UNDER THE BAND, WOULD BE MUCH MORE SIGNIFICANT THAN THE LIGHT TO MODERATE AMOUNTS EXPECTED. HOWEVER, WITH THE DRIER AIR BEGINNING TO FILTER INTO THE REGION, EXPECTING THAT THE AMOUNTS WILL REMAIN LIGHT TO MODERATE, WITH MOST AMOUNTS LIGHT. SUNDAY...850 MB TEMPERATURES BEGIN TO WARM TO NEAR -7C OVER THE LAKES, AND THE WINDS BEGIN TO BACK TO THE WNW. THIS WILL PUT A MAJOR DAMPER ON THE SNOW BANDS, WITH THE SNOW EXPECTED TO PRETTY MUCH BEING DONE BY THE AFTERNOON, WHEN THE TEMPERATURES POP UP ABOVE -10C. COUPLING THE TEMPERATURES WITH THE 25% RH IN THE 850-700 MB LAYER, WOULD EXPECT FLURRIES FOR THE AFTERNOON. OVERNIGHT, AS THE TEMPERATURES WARM TO -6C, SO WOULD EXPECT THAT LIGHT SNOW IS STILL POSSIBLE. EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, THE SFC HIGH BEGINS TO MOVE OFF TO THE EAST. WE STILL HAVE WEST WINDS WITH 850 MB TEMPERATURES AROUND -8C TO -10C, WILL ALLOW FOR THE LES THAT IS GOING FROM SUNDAY NIGHT TO CONTINUE FOR A BIT LONGER. TIMING ON THE NEXT SYSTEM IS OFF BY ABOUT 12 HOURS BETWEEN GFS AND ECMWF. LEANED TOWARD THE ECMWF IDEA AS THE MODELS BACK OFF A BIT ON THE TIMING. TUESDAY, GFS ENDS THE SNOW, THE ECMWF CONTINUES FOR A TIME DURING THE DAY, SO WILL ALLOW THE CHANCE POPS TO CONTINUE AS THE LAST OF THE SYSTEM MOVES OUT OF THE REGION. HIGH PRESSURE BUILDS INTO THE REGION OVERNIGHT SO WILL KEEP THAT DRY. WEDNESDAY, THE NEXT SYSTEM IS GETTING ORGANIZED. THINK THAT THE GFS IS A LITTLE FAST WITH THE SYSTEM AND MAY HAVE THE 500 MB WAVE A LITTLE OVER DEVELOPED. SO KEPT THINGS DRY OVERNIGHT. THURSDAY, THE STORM MOVING OUT OF THE SOUTHERN PLAINS WILL BRING SNOW INTO THE SW PORTION OF THE FORECAST AREA DURING THE DAY, AND THE REST OF THE FORECAST AREA OVERNIGHT. JSL && .MARINE.../ISSUED AT 319 PM/ GUSTY SOUTHWEST WINDS EXPECTED TO INCREASE A TOUCH MORE LATER THIS AFTERNOON AND EVENING AS 35+ KNOT PRE-FRONTAL 925MB JET STREAK CUTS ACROSS NORTHERN LAKE MICHIGAN AND HURON. WHILE APPEARING MARGINAL...CURRENT NORTHERN LAKE MICHIGAN GALE WARNING MORE THAN JUSTIFIED WITH A FEW LOW END GALE GUSTS LIKELY. OTHERWISE... INHERITED SCA/S WILL CONTINUE THROUGH FRIDAY MORNING...WITH FUTURE EXTENSIONS FULLY EXPECTED AS GUSTY NORTH WINDS DEVELOP BEHIND DEPARTING COLD FRONT. BRIEF WINDOW FOR A FEW ADDITIONAL GALES FRIDAY MORNING ACROSS CENTRAL LAKE MICHIGAN AS CAA IS MAXIMIZED. THIS LOOKS LIKE A SHORT WINDOW AND WOULD PREFER TO COVER IT WITH HIGH END SCA/S FEATURING BORDERLINE GALE GUSTS. MSB && .AVIATION.../ISSUED AT 618 PM/...VALID FOR 00Z TAFS PERSISTENT VFR CONDITIONS WILL GIVE WAY TO MVFR/POSSIBLY IFR CONDITIONS AFTER 09Z AS AN AREA OF LIGHT SNOW DEVELOPS ALONG AN ARCTIC FRONT DROPPING SOUTH THRU NRN MICHIGAN VERY LATE TONIGHT/EARLY FRIDAY MORNING. NORTH FLOW LIGHT LAKE EFFECT SNOWS WILL DEVELOP BEHIND THE DEPARTING FRONT BY LATE FRIDAY MORNING... IMPACTING MAINLY TVC AND MBL THRU FRIDAY EVENING. LLWS WILL CONTINUE TO BE AN ISSUE AT ALL TAF SITES UNTIL FROPA. LOW LEVEL WINDS WILL SHIFT TO THE NORTH BEHIND THE FRONT...WITH GUSTS TO 25 KTS EXPECTED THROUGHOUT FRIDAY. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 11 AM EST FRIDAY FOR LHZ346-347. GALE WARNING UNTIL 4 AM EST FRIDAY FOR LHZ345. LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST FRIDAY FOR LMZ323-345-346. GALE WARNING UNTIL 4 AM EST FRIDAY FOR LMZ341-342-344. LS...NONE. && $$