807 FXUS63 KMQT 131128 AFDMQT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 728 AM EDT WED APR 13 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 428 AM EDT WED APR 13 2016 WV LOOP AND 00Z RAOBS SHOW NW FLOW ALOFT OVER UPPER GREAT LAKES BTWN TROUGH OVER EASTERN CANADA AND BUILDING RIDGE FM CENTRAL US PLAINS TO THE NW TERRITORIES OF CANADA. COUPLE OF SHORTWAVES AND H85-H7/H7- H5 Q-VECTOR CONVERGENCE/H85-H7 FRONTOGENESIS IN LEFT EXIT REGION OF 100KT H25 JET IS SUPPORTING LGT SNOW EASING ACROSS MAINLY SW UPR MICHIGAN ATTM. THUS FAR...SNOW HAS STRUGGLED TO MAKE IT ACROSS KEWEENAW TO EASTERN CWA DUE TO H85-H7 DRY LAYER SEEN ON 00Z RAOBS FM GRB AND APX. STRONGER SHORTWAVE OVER MN ARROWHEAD CROSSES WESTERN UPR MICHIGAN THROUGH DAYBREAK AND WILL COMBINE WITH INCREASING H85 FRONTOGENESIS AS H85 TEMP GRADIENT INCREASES FM CNTRL MN TO CNTRL UPR MICHIGAN. DUE TO THIS FORCING AND NEGATIVE EPV ATOP THE FGEN LAYER COULD SEE SNOW INCREASE BRIEFLY THIS MORNING. ALREADY SEEING SIGNS OF THIS ON LAST HR OF RADAR LOOP WITH INCREASING ECHOES OVER WESTERN CWA. WEB CAMS IN THESE AREAS HINT AT STEADY SNOW COMING DOWN. PER MDOT RWIS DATA ROAD TEMPS STILL WELL INTO THE 30S SO MAIN ROADS ARE LIKELY JUST WET. BASED ON INCREASING FORCING AND EXPANSION OF ECHOES ON RADAR OVER WEST...EXPANDED LIKELY POPS BRIEFLY INTO NCNTRL TOWARD DAYBREAK...BUT BY ALL ACCOUNTS SNOW OVER ALL BUT FAR SCNTRL CWA SHOULD THEN DIMINISH LATE THIS MORNING AS STRONG SUBSIDENCE TAKES OVER AFTER SHORTWAVE CROSSES AREA. LINGERED POPS A BIT LONGER THAN THAT OVER FAR SCNTRL... BUT HAVE ALL AREAS DRY BY EARLY AFTN. ENOUGH BLYR WARMING OCCURS TO POSSIBLY HAVE SNOW TO END AS MIX OF RAIN/SNOW OR JUST RAIN. MOST OF PRECIP WILL FALL AS SNOW THOUGH. SNOW ACCUMS BOOSTED BY SLR/S AROUND 15:1...MAY REACH 2 INCHES OVER INTERIOR WEST CWA AND CLOSER TO WI BORDER. WEAK WARM AIR ADVECTION CONTINUING INTO THE AFTN SETS UP INVERSION AND MAY HELP TRAP LOW-LEVEL MOISTURE...ESPECIALLY CNTRL WITH UPSLOPE FLOW OFF LK MICHIGAN. S WINDS PROVIDE DOWNSLOPE OVER WEST AND COULD SEE MORE BREAKS DEVELOP IN THE CLOUDS THERE. TEMPS WILL BE COOLEST NEAR 40 OVER CNTRL BUT WILL PUSH TO AROUND 50 WEST WITH GREATER CHANCES FOR SUNSHINE. WEAK BUT STEADY SOUTH WINDS CONTINUE TONIGHT BTWN HIGH PRESSURE OVER QUEBEC AND LOW PRESSURE TROUGH OVER HIGH PLAINS. MODELS HINT THAT ONGOING WARM AIR ADVECTION MAY SPUR ON SCT- BKN LOWER MID CLOUDS /5-8KFT/. LOWEST TEMPS INTO UPPER 20S OVER PARTS OF EAST HALF CLOSER TO RIDGE/DRIER AIR. MEANWHILE...TEMPS STAY ABOVE FREEZING OVER FAR WEST DUE TO SOUTH WINDS AND POTENTIAL FOR MORE CLOUDS. IF MID CLOUDS ARE NOT AROUND...COULD SEE PATCHY SHALLOW FOG OVER EAST WITH STRONGER RADIATIONAL COOLING AND ADDITIONAL MOISTURE FLOWING IN OFF NORTHERN LK MICHIGAN. TOO PATCHY TO INCLUDE NOW THOUGH. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 414 AM EDT WED APR 13 2016 WITH THE WRN N AMERICA RIDGE/POSITIVE ANOMALY THAT HAS DOMINATED APR SO FAR BREAKING DOWN...THE ERN N AMERICA TROF THAT HAS LED TO AN UNUSUALLY COLD/SNOWY BEGINNING TO APR FOR UPPER MI IS LIFTING OUT/WEAKENING. FOR THE FIRST 12 DAYS OF APR...THE AVG TEMP IS RUNNING AN IMPRESSIVE 12.3F BLO NORMAL HERE AT NWS MQT WITH SNOWFALL 32.2 INCHES ABOVE NORMAL. LIFTING OUT OF THE ERN TROF WILL ALSO BE AIDED BY THE DEMISE OF WHAT IS CURRENTLY A VERY STRONG POSITIVE HEIGHT ANOMALY OVER GREENLAND (3.5 STANDARD DEVIATIONS ABOVE CLIMATOLOGY). IN FACT...RIDGING WILL DEVELOP OVER THE GREAT LAKES BY FRI...AND POSITIVE HEIGHT ANOMALIES WILL REACH 2+ STANDARD DEVIATIONS ABOVE CLIMATOLOGY OVER THE UPPER LAKES ON SAT. HEADING INTO NEXT WEEK...RIDGING/POSITIVE HEIGHT ANOMALIES WILL SHIFT BACK TOWARD WRN CANADA. THIS WILL FORCE REDEVELOPMENT OF MODEST TROFFING IN ERN CANADA...LIKELY ALLOWING FOR PERIODIC SHOTS OF COOLER AIR OUT TO 2 WEEKS. LAST FEW NAEFS 8-14 DAY OUTLOOKS HAVE SHOWN A LARGE AREA OF ABOVE NORMAL TEMPS BEING FAVORED OVER FAR WRN CANADA AND MOST OF THE CONUS AND AN AREA OF NEAR TO BLO NORMAL TEMPS BEING FAVORED IN CNTRL/ERN CANADA INTO THE GREAT LAKES. SO...A GENERAL WRN CANADA RIDGE/ERN CANADA TROF CONFIGURATION. WITH THE RIDGE BUILDING INTO THE GREAT LAKES OVER THE NEXT FEW DAYS...THE LONG ADVERTISED SIGNIFICANT WARMUP IS ON TRACK THRU THE END OF THE WEEK. WITH RIDGING SHIFTING BACK TOWARD WRN CANADA EARLY NEXT WEEK...REDEVELOPMENT OF MODEST ERN CANADA TROFFING WILL SPELL COOLER WEATHER FOR THE AREA...BUT LIKELY STILL ABOVE NORMAL. IN TYPICAL SPRING-TIME FASHION...COOLING WILL BE MOST NOTABLE NEAR LAKE SUPERIOR. AS FOR PCPN...LOOKS LIKE A MOSTLY DRY PERIOD IS SHAPING UP DURING THE LONG TERM AND OUT THRU AT LEAST 10 DAYS AS WELL. FOR A NUMBER OF DAYS...THERE HAS BEEN CONSIDERABLE UNCERTAINTY IN THE PCPN FCST EARLY NEXT WEEK DUE TO THE UNCERTAIN EVOLUTION OF A MID LEVEL LOW THAT WILL BE OVER THE CNTRL/SRN ROCKIES OVER THE WEEKEND. IN RECENT DAYS...THERE WERE INDICATIONS THAT THE SYSTEM WOULD LIFT NE AND BRING A POTENTIALLY WET PERIOD HERE EARLY NEXT WEEK. MORE RECENTLY...MEDIUM RANGE GUIDANCE IS TRENDING TOWARD THE IDEA THAT REDEVELOPMENT OF WRN CANADA RIDGING/ERN CANADA TROFFING EARLY NEXT WEEK WILL SUPPRESS ANY REMNANTS OF THE MID LEVEL LOW FROM AFFECTING UPPER MI. THIS WOULD RESULT IN PCPN CHANCES BEING TIED ONLY TO A COLD FROPA SOMETIME SUN IN ASSOCIATION WITH A SHORTWAVE PASSING THRU NRN ONTARIO. WITH THE UPCOMING WARM WEATHER...SNOWMELT WILL LEAD TO RISING RIVER LEVELS. FORTUNATELY...NO MEANINGFUL RAINFALL WILL OCCUR DURING THE SNOWMELT. A NICE STRETCH OF SPRING WEATHER IS EXPECTED THU THRU SAT. WHILE THERE WILL BE SOME MID CLOUDS AROUND ON THU...FRI AND SAT SHOULD FEATURE ABUNDANT SUNSHINE UNDER A DRY COLUMN. 850MB TEMPS AT 12Z THU WILL RANGE FROM 0C E TO 5C W. BY 12Z FRI...850MB TEMPS WILL RANGE FROM AROUND 5C E TO 9C W. BASED ON MIXING HEIGHTS ON NAM/GFS FCST SOUNDINGS...MAX TEMPS SHOULD REACH THE MID 50S TO LWR 60S ON THU AND UPPER 50S TO UPPER 60S ON FRI...PERHAPS REACHING 70F AT SOME LOCATIONS OVER THE W. HIGHS SAT SHOULD BE SIMILAR TO FRI. ALL 3 DAYS...HIGHEST TEMPS WILL BE OVER THE W. OBVIOUSLY...WHERE THE WIND HAS A COMPONENT OFF LAKE MICHIGAN OR LAKE SUPERIOR...TEMPS WILL BE CONSIDERABLY COOLER. WITH S TO SE GRADIENT WINDS...THAT COOLING WILL BE MOST NOTABLE NEAR LAKE MI AND ON THE E SIDE OF THE KEWEENAW. MEDIUM RANGE GUIDANCE IS MOVING TOWARD BETTER AGREEMENT ON DROPPING A COLD FRONT ACROSS THE AREA AT SOME POINT SUN AS A SHORTWAVE MOVES ACROSS NRN ONTARIO. AHEAD OF THE FRONT...GFS FCST SOUNDINGS SHOW MOISTURE LACKING...SO INSTABILITY IS ALMOST NONEXISTENT WITH PARCELS NOT ABLE TO GET PASSED A MORE STABLE LAYER ALOFT. AS A RESULT... FROPA WILL LIKELY BE DRY AS SUPPORTED BY THE ECMWF AND GLOBAL CANADIAN MODELS. BETTER CHC OF PCPN WILL OCCUR AFTER FROPA MAINLY SUN NIGHT AS MID LEVEL FRONTOGENESIS AND RIGHT ENTRANCE OF UPPER JET WORK TO GENERATE PCPN. GFS/ECMWF/CANADIAN ALL AGREE ON THIS POINT. SOMEWHAT OF A FASTER TREND IS NOTED WITH THE 00Z MODEL RUNS...SO PCPN CHC MAY MATERIALIZE ON SUN RATHER THAN SUN NIGHT IF NEXT SET OF MODEL RUNS BACK UP THE FASTER TREND. DRY WEATHER RETURNS MON...AND IT WILL BE MUCH COOLER (AT LEAST 10-15F LOWER THAN SUN) AS HIGH PRES BUILDING FROM THE NRN PLAINS INTO NRN ONTARIO RESULTS IN A GRADIENT NRLY WIND ACROSS LAKE SUPERIOR. DRY WEATHER WILL CONTINUE INTO TUE WITH TEMPS MODERATING A BIT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 727 AM EDT WED APR 13 2016 AN UPPER LEVEL DISTURBANCE WILL BRING SNOW TO CENTRAL UPPER MICHIGAN THIS MORNING...INCLUDING KSAW...THEN AS THE SYSTEM MOVES AWAY THIS AFTN AND TONIGHT...THE SNOW WILL END. AT KIWD AND KCMX...CONDITIONS WILL BE VFR THROUGH TONIGHT WITH BKN MID CLOUDS. AT KSAW...IFR CIGS/MVFR VSBY IN LGT SNOW THIS MORNING TRANSITION TO BKN MVFR CIGS THIS AFTN. CLOUDS WILL THEN SCATTER OUT TONIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 428 AM EDT WED APR 13 2016 WEAK PRESSURE GRAIDENT BTWN HIGH EXITING OVER QUEBEC AND LOW PRESSURE TROUGH OVER SCNTRL CANADA WILL KEEP SOUTHERLY WINDS 20 KTS OR LESS INTO TONIGHT. GRADIENT TIGHTENS LATER THU INTO THU NIGHT AND MAY SEE WINDS 25-30 KTS OVER PORTIONS OF NORTH AND EAST LK SUPERIOR. WARMER AIR FLOWING ACROSS LK SUPERIOR WILL SET UP INCREASINGLY STABLE TEMP INVERSION FRI AND SAT...SO EXPECT WINDS TO STAY MAINLY 20 KTS OR LESS. COLD FRONT MOVES FROM NORTHERN ONTARIO ACROSS LK SUPERIOR SUN AFTN INTO SUN EVENING. EXPECT LIGHT SOUTHWEST WINDS AHEAD OF THE FRONT TO SHIFT NORTHERLY UP TO 25 KTS SUN NIGHT INTO MON MORNING BEHIND THE FRONT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...ROLFSON AVIATION...JLA MARINE...JLA