118  
FXUS63 KAPX 220909  
AFDAPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GAYLORD MI  
509 AM EDT SUN OCT 22 2017  
   
NEAR TERM
 
(TODAY THROUGH TONIGHT)  
ISSUED AT 325 AM EDT SUN OCT 22 2017  
   
..ONE MORE SUMMER-LIKE DAY
 
THEN TURNING WET AND PROGRESSIVELY  
COOLER...  
 
HIGH IMPACT WEATHER POTENTIAL...ELEVATED FIRE DANGER ACROSS NE  
LOWER MICHIGAN BEFORE FROPA.  
 
PATTERN SYNOPSIS/FORECAST...OVERNIGHT WATER VAPOR/UPPER AIR  
ANALYSIS REVEALS A PROGRESSIVE SHORT WAVE TROUGH AXIS ADVANCING  
THROUGH THE CENTRAL CONUS WITH ONE PIECE OF SHORT WAVE ENERGY  
LIFTING NORTHWARD THROUGH THE UPPER MIDWEST...AND SECOND PIECE OF  
ENERGY PUSHING ACROSS THE TEXAS/OKLAHOMA AREA. THESE TWO WAVES  
ARE EXPECTED TO SPLIT OVER THE NEXT 24 HOURS WITH THE NORTHERN  
PIECE HEADING INTO CANADA AND SECOND PIECE SLIDING INTO THE GULF  
STATES (ONLY TO PHASE AGAIN OVER THE GREAT LAKES AROUND TUESDAY).  
AT THE SURFACE...LOW PRESSURE IS OVER MANITOBA WITH A STRETCHED  
OUT COLD FRONT EXTENDING DOWN THROUGH THE MIDWEST AND INTO TEXAS.  
LONG BUT NARROW AXIS OF SHOWERS/STORMS HAVE DEVELOPED AHEAD OF THE  
SURFACE FRONT AND ADVANCING SHORT WAVE TROUGH...WITH THE NORTHERN  
EXTENT OF THAT ACTIVITY ADVANCING ACROSS WISCONSIN/WESTERN U.P.  
 
UPSTREAM COLD FRONT EXPECTED TO GRADUALLY SLOW IT'S EASTWARD  
ADVANCE TODAY/TONIGHT AS IT CROSSES THE CWA...OUTRUNNING THE  
BETTER HEIGHT FALLS/SHORT WAVE FORCING PUSHING UP INTO ONTARIO AND  
BECOMING A BIT MORE PARALLEL TO THE FLOW ALOFT. QG-FORCING FOR  
ASCENT ALSO WEAKENS IN TIME...ESPECIALLY THIS AFTERNOON AS  
STRONGER FORCING PUSHES UP INTO CANADA. BUT STILL EXPECT A MORE-  
OR-LESS CATEGORICAL AXIS OF SHOWERS TO WORK EASTWARD THROUGH THE  
CWA THIS AFTERNOON THROUGH TONIGHT. LATEST GUIDANCE TIMING (AND  
TRENDS) CONTINUE TO SUGGEST A SLOWER PROGRESSION OF RAIN INTO THE  
REGION...AND MOST OF THE CWA MAY END UP DRY THROUGH THE MORNING  
HOURS (SAVE FOR SOME SPOTTY WARM ADVECTION SHOWERS WELL AHEAD OF  
THE MAIN PRECIP BAND). SO...HAVE SLOWED ARRIVAL OF LIKELY-  
CATEGORICAL POPS THROUGH THE AFTERNOON/EVENING AND HELD ONTO  
HIGH POPS THROUGH THE OVERNIGHT HOURS OVER THE EASTERN HALF OF THE  
CWA.  
 
THUNDER THREAT STILL APPEARS LOW...UPSTREAM LIGHTNING OVER  
WISCONSIN HAS DIMINISHED RAPIDLY IN THE LAST FEW HOURS. THERE WILL  
BE A NARROW CORRIDOR OF MODEST MUCAPE SLIPPING THROUGH THE REGION  
AHEAD OF THE FRONT...AND CAN'T COMPLETELY RULE OUT ISOLATED  
THUNDER. BUT...HAVE DECIDED TO NOT INTRODUCE THUNDER AT THIS  
POINT.  
 
FIRE WEATHER CONCERNS...SLOWER ARRIVAL OF COLD FRONT AND RAINFALL  
WILL ALLOW A WINDOW OF OPPORTUNITY FOR TEMPS WARM INTO THE MIDDLE  
70S ACROSS NE LOWER MICHIGAN. COUPLED WITH GUSTIER SW WINDS AND  
RECENT DRY WEATHER...ELEVATED FIRE DANGER ANTICIPATED ONCE AGAIN.  
 

 
   
SHORT TERM
 
(MONDAY THROUGH TUESDAY)  
ISSUED AT 325 AM EDT SUN OCT 22 2017  
   
..WARM TEMPS A THING OF THE PAST
 
 
THE SURFACE COLD FRONT STALLS OUT JUST OFF TO OUR EAST WHILE LOW  
PRESSURE MOVES UP ALONG IT. MEANWHILE, AN UPPER TROUGH DROPS DOWN  
FROM THE NORTHWEST. IT'S STILL A DEBATE AS TO WHETHER THESE TWO  
SYSTEMS WILL BE ABLE TO JOIN FORCES (PHASE) WHICH WILL DETERMINE THE  
EXTENT OF DEEPENING BY THE SURFACE LOW. MODELS ARE SQUARELY IN  
DIFFERENT CAMPS HERE WITH THE NAM/GFS STILL ON THE CLOSE BUT NOT  
QUITE PHASING SIDE WHILE THE ECMWF/CANADIAN GO ALL IN ON PHASING.  
WISH I COULD TELL YOU WHAT THE ANSWER IS BUT HONESTLY I CAN'T AS  
THIS IS AN EXTREMELY COMPLEX SITUATION. SO WILL KIND OF PLAY IT IN  
BETWEEN FOR NOW. THE BEST CHANCES FOR SHOWERS MONDAY WILL BE ACROSS  
EASTERN ZONES OUT AHEAD OF THE TROUGH AND MOST LIKELY CLOSER TO THE  
DEVELOPING SURFACE LOW. SHOWERS SHOULD THEN SPREAD INTO ALL AREAS  
MONDAY NIGHT AND CONTINUE INTO TUESDAY. WINDS WILL PICK UP AS WELL,  
POSSIBLY EVEN TO GALE FORCE ON THE GREAT LAKES. AS COLDER AIR  
ADVECTS IN, ENHANCEMENT OFF OF LAKES MICHIGAN AND SUPERIOR SHOULD  
KICK IN AS WELL POSSIBLY LEADING TO THE RAIN FALLING HEAVY AT TIMES.  
HIGHS IN THE UPPER 50S TO LOWER 60S MONDAY WITH LOWS IN THE MIDDLE  
TO UPPER 40S AT NIGHT. TEMPERATURES TUESDAY WILL BE NEARLY STEADY  
OR PERHAPS EVEN FALL OFF DEPENDING UPON HOW THINGS SET UP.  
   
LONG TERM
 
(TUESDAY NIGHT THROUGH SATURDAY)  
ISSUED AT 325 AM EDT SUN OCT 22 2017  
 
LINGERING WRAP AROUND MOISTURE IN COMBINATION WITH LAKE ENHANCEMENT  
AS COLDER AIR CONTINUES TO ADVECT IN FROM THE NORTHWEST TUESDAY  
NIGHT INTO WEDNESDAY. THIS WILL LEAD TO ADDITIONAL RAIN SHOWERS  
WHICH MAY MIX WITH OR CHANGE OVER TO SNOW SHOWERS TUESDAY NIGHT  
ACROSS PORTIONS OF EASTERN UPPER AND THE HIGHER TERRAIN OF NORTHERN  
LOWER. AFTER A BREAK IN THE ACTION THURSDAY, A NORTHERN PLAINS  
SYSTEM WILL LIKELY BRING ANOTHER COUPLE OF DAYS OF UNSETTLED  
WEATHER. THIS SHOULD BE MAINLY IN THE FORM OF RAIN BUT COLDER AIR  
WRAPPING IN BEHIND THE SYSTEM MAY EVENTUALLY LEAD TO A MIX WITH SNOW  
SHOWERS. CHILLY WITH HIGHS RANGING FROM THE MIDDLE 40S TO THE LOWER  
50S.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)  
ISSUED AT 509 AM EDT SUN OCT 22 2017  
 
VFR CONDITIONS WILL HOLD THROUGH THE DAY AT THE TERMINAL SITES.  
HOWEVER, A COLD FRONT ACROSS WISCONSIN THIS MORNING WILL SLIDE  
THROUGH THE REGION LATER THIS AFTERNOON THROUGH TONIGHT BRINGING  
SHOWERS AND CIGS LOWERING TO MVFR TO TONIGHT.  
 
GUSTIER SW WINDS ONCE AGAIN FOR MUCH OF TODAY...VEERING W/NW  
TONIGHT AND DIMINISHING.  
 

 
   
MARINE
 
 
ISSUED AT 509 AM EDT SUN OCT 22 2017  
 
GUSTY SW WINDS ANTICIPATED ONCE AGAIN ON THE LAKES TODAY...VEERING  
TO THE W/NW LATER THIS AFTERNOON AND TONIGHT AS A COLD FRONT  
SWINGS THROUGH THE REGION. SMALL CRAFT ADVISORY WINDS/WAVES WILL  
PERSIST ON LAKE MICHIGAN AND WHITEFISH BAY TODAY...AND ON THE LAKE  
HURON NEARSHORE AREAS THROUGH TONIGHT.  
 
OTHERWISE...DRY WEATHER WILL HOLD THROUGH THIS MORNING. BUT  
SHOWERS WILL OVERSPREAD THE REGION THIS AFTERNOON AND PERSIST  
THROUGH TONIGHT.  
 
WINDS/WAVES WILL DIMINISH HEADING INTO MONDAY AND MONDAY NIGHT.  
BUT STRONGER WINDS WILL RETURN BY TUESDAY WITH GALE FORCE GUSTS  
POSSIBLE.  
 

 
   
APX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LH...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR LHZ346>349.  
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ323-341-  
342-344>346.  
LS...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LSZ321.  

 
 

 
 
NEAR TERM...BA  
SHORT TERM...AS  
LONG TERM...AS  
AVIATION...BA  
MARINE...BA  
 
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