167  
FXUS63 KAPX 210825  
AFDAPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GAYLORD MI  
325 AM EST TUE FEB 21 2017  
   
NEAR TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 326 AM EST TUE FEB 21 2017  
   
..RAIN EXITING THEN WARM
 
 
HIGH IMPACT WEATHER POTENTIAL...NONE.  
 
OCCLUDED-TYPE FRONT MOVING EAST ACROSS WESTERN UPPER MI AND CENTRAL  
WI. A BAND OF RAIN IS AHEAD OF FRONT, PRESENTLY CROSSING PARTS OF NW  
LOWER AND EASTERN UPPER MI. HELPED IN PART BY EVAP COOLING, TEMPS  
ARE HOVERING NEAR FREEZING IN THE MID/UPPER ST MARYS VALLEY, AND  
FREEZING RAIN HAS BEEN REPORTED AT TIMES AT SAULT CANADA. HOWEVER,  
EVAP COOLING POTENTIAL HAS BEEN USED UP, AND FURTHER WARM ADVECTION  
AND MIXING DOWN OF WARMER AIR FROM ALOFT WILL END ANY FZRA CONCERNS.  
TIMING THE RAIN BAND ACROSS THE AREA IS CONCERN #1. CONCERN #2: JUST  
HOW WARM WILL WE GET TODAY?  
 
TODAY...FRONT CROSSES NORTHERN MI IN THE 1ST HALF OF THE DAY,  
REPLACING ONE PACIFIC AIRMASS WITH ANOTHER. SHOWERS WILL MARCH  
STEADILY NE-WARD ACROSS NORTHERN MI THIS MORNING, EXITING SE  
SECTIONS BY NOON-1PM. RAINFALL TOTALS FROM THIS POINT WILL BE ON THE  
LIGHT SIDE.  
 
BRIEF PERIOD OF WNW LOW-LEVEL WINDS WILL BE SEEN POST-FRONTAL, BUT  
BACKING TOWARD THE SW WILL ALREADY BE IMPINGING ON NORTHERN LAKE MI  
BY DUSK. THERE IS A HEALTHY AMOUNT OF STRATUS BEHIND THE FRONT, WITH  
A BACK EDGE NEARING FAR WESTERN WI. HOWEVER, THE SUN WILL GO TO WORK  
ON THIS AS THE DAY PROCEEDS, AND MOST MODEL GUIDANCE IS BULLISH ON  
BREAKING OUT INTO SUNSHINE THIS AFTERNOON, WITH EASTERN UPPER A  
PARTIAL EXCEPTION. WILL SLOW THE MODEL-BLEND CLEARING TREND DOWN A  
TOUCH. THAT WOULD STILL BE ENOUGH SUN TO POP TEMPS INTO THE 40S IN  
THE STRAITS REGION AND EASTERN UPPER MI, AND THE 50S IN MOST OF  
NORTHERN LOWER.  
 
SOME RECORD HIGHS ARE IN SERIOUS JEOPARDY:  
SAULT STE MARIE 42  
GAYLORD 52  
ALPENA 50  
TRAVERSE CITY 57  
HOUGHTON LAKE 57  
WE SHOULD BE WITHIN A FEW DEGREES OF ALL OF THESE.  
 
TONIGHT...LOW PRESSURE WILL CONTINUE TO SPIN AWAY ON HUDSON BAY. AN  
ASSOCIATED, STRUNG-OUT COLD FRONT IN THE NORTHERN PLAINS WILL SLOWLY  
OOZE EAST TOWARD SUPERIOR. IT DOESN'T GET HERE, BUT THE PRESSURE  
TIGHTENS JUST IN ADVANCE OF THIS FEATURE, PRODUCING AN UPTICK IN LOW-  
AND MID-LEVEL 1000-850MB SW FLOW AND THETA-E ADVECTION. 700-500MB  
LAPSE RATES GET A LITTLE STEEP (NEARING 7.5 C/KM), WHICH WILL AT  
LEAST PROMOTE SOME CLOUD COVER. THIS WILL BE ESPECIALLY THE CASE AT  
THE NOSE OF THE STRONGER FLOW, OVER EASTERN UPPER AND NE LOWER MI.  
NOT COMPLETELY OUT OF THE QUESTION WE COULD SQUEEZE SOME SPRINKLES  
OUT OF THIS, THOUGH DRY AIR BELOW 750MB WILL BE A SHARP LIMITING  
FACTOR. NO MENTION OF PRECIP TONIGHT FOR NOW, THOUGH CLOUDS WILL BE  
ON THE INCREASE IN THE EVENING, BEFORE DIMINISHING SOME TOWARD DAWN.  
MIN TEMPS WILL BE NEAR 30F (THE SAULT) TO THE UPPER 30S (NW LOWER MI  
COAST).  
 

 
   
SHORT TERM
 
(WEDNESDAY THROUGH THURSDAY)  
ISSUED AT 326 AM EST TUE FEB 21 2017  
   
..WARM WEDNESDAY WITH SHOWERS LATE ACROSS THE NORTH
 
 
HIGH IMPACT WEATHER POTENTIAL...MINIMAL  
 
PATTERN SYNOPSIS/FORECAST...SOUTHWESTERLY FLOW WILL LEAD TO STRONG  
WAA THROUGH THE DAY ON WEDNESDAY. WITH A GOOD AMOUNT OF SUNSHINE  
EXPECTED ACROSS NORTHERN LOWER DURING THE DAY, COMING OFF MILD  
(ABOVE FREEZING) LOW TEMPERATURES TUESDAY NIGHT, THERE ARE SIGNALS  
WEDNESDAY WILL SHAPE UP TO BE A VERY WARM DAY AT LEAST ACROSS  
NORTHERN LOWER. TEMPERATURE ANOMALIES FROM 925MB TO 700MB (2 TO 3  
STANDARD DEVIATIONS ABOVE THE MEAN) LEND FURTHER SUPPORT TO AN  
UNSEASONABLY WARM WEDNESDAY. AS PREVIOUS SHIFT MENTIONED, SOME  
RECORD HIGH TEMPERATURES COULD BE IN JEOPARDY ACROSS NORTHERN LOWER  
AS TEMPERATURES PUSH WELL INTO THE 50S...EVEN LOW 60S ACROSS  
SOUTHEAST PARTS OF OUR FORECAST AREA. MORE CLOUD COVER OVER EASTERN  
UPPER WILL KEEP TEMPERATURES THERE LOCKED IN THE 40S.  
 
AN AMPLIFYING SHORTWAVE WILL CROSS THE UPPER GREAT LAKES REGION  
WEDNESDAY NIGHT AS A COLD FRONT DROPS SOUTHEAST FROM OVER LAKE  
SUPERIOR. IMPRESSIVE FGEN FORCING DEVELOPS ALONG THE FRONT WHILE  
OVER LAKE SUPERIOR AND EASTERN UPPER, BUT IT WEAKENS CONSIDERABLY AS  
THE FRONT PROGRESSES INTO NORTHERN LOWER. HIGHEST POPS ARE THEREFORE  
ACROSS EASTERN UPPER, WITH JUST A SLIGHT CHANCE ACROSS FAR NORTHERN  
LOWER TO ACCOUNT FOR THE PROXIMITY OF THE SYSTEM. TEMPERATURES WILL  
BE WARM ENOUGH FOR JUST RAIN WITH THIS SYSTEM. THE COLD FRONT WILL  
USHER IN DRIER WEATHER FOR THE REST OF THE DAY THURSDAY, BUT IT WILL  
ALSO MARK THE BEGINNING OF A COOLING TREND FOR THE REST OF THE WEEK.  
 
PRIMARY FORECAST CONCERNS...STILL CONSIDERABLE VARIANCE BETWEEN  
MODELS IN TERMS OF THE LATE WEDNESDAY SYSTEM'S TIMING AND INTENSITY.  
SOME RECENT NAM AND ECMWF RUNS HAD DEVELOPED A RATHER WOUND-UP  
SYSTEM WITH A POTENT SURFACE LOW, BUT THE LATEST TREND AMONG  
DETERMINISTIC MODELS SEEMS TO BE MORE OF AN OPEN WAVE ALOFT WITH A  
WEAKER SURFACE LOW. HAVE DISCOUNTED THE CANADIAN AS ITS LAST SEVERAL  
RUNS HAVE HANDLED THIS SYSTEM RATHER ERRATICALLY. PINNING DOWN  
TIMING REMAINS SOMEWHAT OF A CHALLENGE, BUT CONSENSUS WOULD POINT  
TOWARDS A LATE AFTERNOON ARRIVAL, WITH THE RAIN DEPARTING BY  
DAYBREAK THURSDAY.  
 

 
   
LONG TERM
 
(THURSDAY NIGHT THROUGH MONDAY)  
ISSUED AT 326 AM EST TUE FEB 21 2017  
 
HIGH IMPACT WEATHER POTENTIAL...STRONG SYSTEM WILL BRING GUSTY  
WINDS, ACCUMULATING SNOW, AND POSSIBLY A WINTRY MIX TO NORTHERN  
MICHIGAN FOR THE END OF THE WEEK.  
 
INTENSIFYING SYSTEM OVER THE CENTRAL PLAINS THURSDAY NIGHT WILL  
BECOME VERTICALLY STACKED AND OCCLUDED AS IT LIFTS NORTHEAST TOWARDS  
THE GREAT LAKES ON FRIDAY. THOUGH THERE IS DECENT GENERAL AGREEMENT  
AMONG THE VARIOUS DETERMINISTIC MODELS THIS MANY DAYS OUT, THEY ARE  
STILL (NOT SURPRISINGLY) STRUGGLING TO SOME EXTENT WITH PINNING DOWN  
SOME IMPORTANT DETAILS SUCH AS TIMING, INTENSITY, AND TRACK OF THE  
SYSTEM. AT THIS TIME, WAA-INDUCED PRECIPITATION SHIELD LOOKS TO LIFT  
INTO NORTHERN LOWER THURSDAY EVENING, OVERSPREADING NORTHERN  
MICHIGAN BY FRIDAY MORNING. MORE OR LESS STEADY PRECIP LOOKS TO BE  
THE RULE DURING THE DAY FRIDAY, AND THEN PARTS OF THE AREA WILL BE  
DRY-SLOTTED FRIDAY EVENING/NIGHT BEFORE WRAP-AROUND PRECIP WORKS ITS  
WAY INTO NORTHERN MICHIGAN FOR SATURDAY. LAST FEW GFS AND ECMWF RUNS  
HAVE REMAINED CONSISTENT WITH SHOWING A FEW HUNDRED J/KG OF MUCAPE  
EXTENDING INTO NORTHERN LOWER FRIDAY AFTERNOON/EVENING, SO HAVE  
INTRODUCED A CHANCE OF THUNDER FOR SOUTHEAST PORTION OF THE FORECAST  
AREA DURING THAT TIMEFRAME. IN TERMS OF PTYPE, EXPECTING PRIMARILY  
SNOW THURSDAY NIGHT WITH A TRANSITION OVER TO RAIN ACROSS NORTHERN  
LOWER DURING THE DAY FRIDAY, THEN BACK TO ALL SNOW FRIDAY NIGHT INTO  
SATURDAY. CERTAINLY CAN'T RULE OUT A WINTRY MIX DURING THE  
TRANSITIONS, BUT HAVE NOT INCLUDED THIS IN THE FORECAST DUE TO LOW  
CONFIDENCE THIS MANY DAYS OUT. MOST OF THE AREA COULD SEE UP TO AN  
INCH OF SNOW THURSDAY NIGHT WITH AN ADDITIONAL 1 TO 2 INCHES  
POSSIBLE ACROSS EASTERN UPPER AND TIP OF THE MITT BY FRIDAY  
AFTERNOON. AMOUNTS ARE SUBJECT TO CHANGE OVER THE COMING DAYS,  
HOWEVER. BETTER ACCUMULATING SNOW POTENTIAL WILL COME IN THE WRAP  
AROUND PRECIP ON SATURDAY, AND BLOWING SNOW WILL LIKELY BECOME AN  
ISSUE AS WINDS RAMP UP OUT OF THE NW DURING THE DAY, BECOMING QUITE  
GUSTY BY MIDDAY AS THE LOW DEPARTS.  
 
WE THEN HEAD INTO A MUCH COLDER LAKE EFFECT SNOW PATTERN SATURDAY  
NIGHT THROUGH EARLY MONDAY AS MUCH COLDER 850MB AIR PLUNGES INTO THE  
UPPER GREAT LAKES (DOWN TO -15 TO -20C PER LATEST GFS). HOWEVER,  
FORECAST SOUNDINGS REVEAL NOT-SO-FAVORABLE LOW LEVEL MOISTURE WILL  
BE IN PLACE DURING THIS TIMEFRAME, SO THAT WILL BE A LIMITING  
FACTOR. WINDS DIRECTION ALSO SHIFTS AROUND A BIT, SO ACCUMULATIONS  
WILL LIKELY BE FANNED OUT ACROSS A LARGER AREA. DESPITE THE LIMITED  
MOISTURE, INCREASING CONFIDENCE IN LAKE EFFECT SNOWS WARRANTED  
BUMPING POPS UP TO LIKELY IN THE SNOWBELTS. HIGHS OVER THE WEEKEND  
INTO MONDAY WILL RANGE FROM THE 20S TO 30S ACROSS NORTHERN  
MICHIGAN...WINTER WILL MOST DEFINITELY MAKE A COMEBACK.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)  
ISSUED AT 1122 PM EST MON FEB 20 2017  
 
VFR CONDITIONS CONTINUE TO HOLD ON ACROSS NORTHERN LOWER MICHIGAN  
FOR THE TIME BEING, WITH GRADUALLY THICKENING AND LOWERING  
CLOUD COVER. UPSTREAM, SURFACE LOW PRESSURE IS OVER SOUTH-  
CENTRAL CANADA WITH A COLD FRONT STRETCHING DOWN THROUGH THE  
CENTRAL PLAINS AND AN ELONGATED AXIS OF RAINFALL AHEAD THE FRONT  
STRETCHING FROM THE WESTERN LAKES TO THE GULF.  
 
RAINFALL WILL SLOWLY SPREAD W-E INTO THE REGION OVERNIGHT AND  
PERSIST THROUGH TUESDAY MORNING. VFR CONDITIONS NOW WILL  
DETERIORATE TO IFR CONDITIONS AT ALL TERMINAL SITES THROUGH  
TUESDAY MORNING. SLOW IMPROVEMENT TUESDAY AFTERNOON AS THE RAIN  
COMES TO AN END AND WEDGE OF DRY AIR SPREADS INTO THE REGION. ALL  
SITES SHOULD RETURN TO VFR BY LATE DAY OR EARLY TUESDAY EVENING.    
..WARM WEDNESDAY WITH SHOWERS LATE ACROSS THE NORTH
 
 
HIGH IMPACT WEATHER POTENTIAL...MINIMAL  
 
PATTERN SYNOPSIS/FORECAST...SOUTHWESTERLY FLOW WILL LEAD TO STRONG  
WAA THROUGH THE DAY ON WEDNESDAY. WITH A GOOD AMOUNT OF SUNSHINE  
EXPECTED ACROSS NORTHERN LOWER DURING THE DAY, COMING OFF MILD  
(ABOVE FREEZING) LOW TEMPERATURES TUESDAY NIGHT, THERE ARE SIGNALS  
WEDNESDAY WILL SHAPE UP TO BE A VERY WARM DAY AT LEAST ACROSS  
NORTHERN LOWER. TEMPERATURE ANOMALIES FROM 925MB TO 700MB (2 TO 3  
STANDARD DEVIATIONS ABOVE THE MEAN) LEND FURTHER SUPPORT TO AN  
UNSEASONABLY WARM WEDNESDAY. AS PREVIOUS SHIFT MENTIONED, SOME  
RECORD HIGH TEMPERATURES COULD BE IN JEOPARDY ACROSS NORTHERN LOWER  
AS TEMPERATURES PUSH WELL INTO THE 50S...EVEN LOW 60S ACROSS  
SOUTHEAST PARTS OF OUR FORECAST AREA. MORE CLOUD COVER OVER EASTERN  
UPPER WILL KEEP TEMPERATURES THERE LOCKED IN THE 40S.  
 
AN AMPLIFYING SHORTWAVE WILL CROSS THE UPPER GREAT LAKES REGION  
WEDNESDAY NIGHT AS A COLD FRONT DROPS SOUTHEAST FROM OVER LAKE  
SUPERIOR. IMPRESSIVE FGEN FORCING DEVELOPS ALONG THE FRONT WHILE  
OVER LAKE SUPERIOR AND EASTERN UPPER, BUT IT WEAKENS CONSIDERABLY AS  
THE FRONT PROGRESSES INTO NORTHERN LOWER. HIGHEST POPS ARE THEREFORE  
ACROSS EASTERN UPPER, WITH JUST A SLIGHT CHANCE ACROSS FAR NORTHERN  
LOWER TO ACCOUNT FOR THE PROXIMITY OF THE SYSTEM. TEMPERATURES WILL  
BE WARM ENOUGH FOR JUST RAIN WITH THIS SYSTEM. THE COLD FRONT WILL  
USHER IN DRIER WEATHER FOR THE REST OF THE DAY THURSDAY, BUT IT WILL  
ALSO MARK THE BEGINNING OF A COOLING TREND FOR THE REST OF THE WEEK.  
 
PRIMARY FORECAST CONCERNS...STILL CONSIDERABLE VARIANCE BETWEEN  
MODELS IN TERMS OF THE LATE WEDNESDAY SYSTEM'S TIMING AND INTENSITY.  
SOME RECENT NAM AND ECMWF RUNS HAD DEVELOPED A RATHER WOUND-UP  
SYSTEM WITH A POTENT SURFACE LOW, BUT THE LATEST TREND AMONG  
DETERMINISTIC MODELS SEEMS TO BE MORE OF AN OPEN WAVE ALOFT WITH A  
WEAKER SURFACE LOW. HAVE DISCOUNTED THE CANADIAN AS ITS LAST SEVERAL  
RUNS HAVE HANDLED THIS SYSTEM RATHER ERRATICALLY. PINNING DOWN  
TIMING REMAINS SOMEWHAT OF A CHALLENGE, BUT CONSENSUS WOULD POINT  
TOWARDS A LATE AFTERNOON ARRIVAL, WITH THE RAIN DEPARTING BY  
DAYBREAK THURSDAY.  

 
   
MARINE
 
 
ISSUED AT 326 AM EST TUE FEB 21 2017  
 
ONGOING SE TO S FLOW WILL RELENT SOMEWHAT AND VEER SW AS AN  
OCCLUDED FRONT PASSES. STILL, IN SOME AREAS ADVISORY-LEVEL  
WINDS/WAVES COULD LINGER DEEPER IN THE MORNING, AND WILL BE TAKING  
A HARDER LOOK AT THAT SHORTLY. ANOTHER UPTICK IN SOUTHERLY WINDS  
WILL BE SEEN LATE TONIGHT IN WEDNESDAY, THOUGH AT THIS TIME THIS  
DOES NOT APPEAR TO WARRANT ADVISORIES.  
 

 
   
APX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LH...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR LHZ345>349.  
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR LMZ323-341-  
342-344>346.  
LS...NONE.  

 
 

 
 
NEAR TERM...JZ  
SHORT TERM...MEK  
LONG TERM...MEK  
AVIATION...TBA  
MARINE...JZ  
 
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