372  
FXUS63 KAPX 212010  
AFDAPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GAYLORD MI  
310 PM EST TUE NOV 21 2017  
   
NEAR TERM
 
(TONIGHT THROUGH WEDNESDAY)  
ISSUED AT 309 PM EST TUE NOV 21 2017  
 
HIGH IMPACT WEATHER POTENTIAL: MINIMAL.  
 
PATTERN SYNOPSIS AND FORECAST:  
 
A MID LEVEL TROUGH AXIS WAS WORKING INTO THE REGION, WITH THE  
ASSOCIATED STRONG COLD FRONT NOW SOUTH AND EAST OF NRN MICHIGAN.  
FORCING WITH THE TROUGH WAS A BIT BETTER THAN EXPECTED WITH DPVA  
WORKING WITH RUC ANALYZED STRONGER UPPER DIVERGENCE. THIS ALLOWED  
FOR SOME FLURRIES TO DEVELOP OVER NRN LOWER AND SOME FRONTALLY  
FORCED PRECIPITATION JUST SCRAPING GLADWIN AND ARENAC COUNTIES.  
OTHERWISE THE MAIN SHOW CONTINUES TO ORGANIZE ITSELF. STRONG COLD  
ADVECTION WAS ALLOWING FOR TEMPERATURES TO FALL THROUGH THIS  
AFTERNOON, WITH NW FLOW LAKE EFFECT SNOWS ALREADY DEVELOPED AND  
PUSHING INTO EASTERN UPPER MICHIGAN. OVER THE NEXT COUPLE HOURS,  
LAKE EFFECT WILL GET GOING OVER NW LOWER AS THE DEEPER, BUT NOT  
IMPRESSIVE MOISTURE ARRIVES. HIGH PRESSURE AND CLEAR SKIES WERE SEEN  
IN THE MIDDLE OF THE COUNTRY.  
 
COLD AIR CONTINUES TO POUR INTO THE REGION TONIGHT, MAXING OUT  
AROUND DAYBREAK WEDNESDAY AT -12C TO -14C WHILE GUSTY NW WINDS TAPER  
DOWN. MOISTURE IS NOT DEEP WITHIN THE CONVECTIVE BL, AND INVERSION  
HEIGHTS VARY AMONGST DIFFERENT DATA SETS. AVERAGE INVERSION HEIGHTS  
ARE AROUND 5KFT OR SO, WITH THE BEST OF THE SNOWS LOOKING TO SET UP  
CLOSER TO EVENING. THIS OUGHT TO BE THE BETTER SNOW INTENSITIES, BUT  
UNIDIRECTIONAL FLOW AND A TAP FROM LAKE SUPERIOR RESULT IN HI-RES DATA  
SUGGESTING A COUPLE OF DOMINANT BANDS AGAIN, WHILE THE REST OF THE  
LES LIKELY BEING QUITE LIGHT AS MOISTURE SHALLOWS SOME. THROUGH  
WEDNESDAY, THE HIGHER PRESSURE WILL WORK INTO THE REGION WITH LOW  
LEVEL WINDS BACKING MORE WEST THEN POSSIBLY A LITTLE SOUTH OF WEST.  
CONTINUED SHALLOWING MOISTURE WILL MAKE THIS MORE OF JUST A NUISANCE  
SNOW/FLURRIES TYPE DEAL WITH MINIMAL ACCUMULATIONS. FOR THE  
REMAINDER OF THIS AFTERNOON THROUGH TONIGHT, 1 TO MAYBE 3 INCHES IN  
THE NW FLOW SNOWBELTS OF NRN LOWER, AND 1 TO 4 INCHES ACROSS EASTERN  
UPPER.  
 

 
   
SHORT TERM
 
(WEDNESDAY NIGHT THROUGH FRIDAY)  
ISSUED AT 306 PM EST TUE NOV 21 2017  
   
..MORE CHANGEABLE WEATHER
 
 
A WEAK SHORT WAVE MOVING THROUGH THE FLOW WILL LEAD TO A CHANCE FOR  
A FEW LIGHT SNOW SHOWERS ON THANKSGIVING DAY, OTHERWISE QUIET BUT  
CHILLY HOLIDAY WEATHER IS EXPECTED. LOW PRESSURE THEN APPROACHES  
FROM THE WEST THURSDAY NIGHT INTO FRIDAY WITH STRONG WARM AIR  
ADVECTION OUT AHEAD OF IT. THIS WILL LEAD TO INCREASING CHANCES FOR  
RAIN SHOWERS (MAINLY FRIDAY AFTERNOON). TEMPERATURES WILL BE NEAR  
NORMAL THROUGH THURSDAY NIGHT THEN RISE TO A FEW DEGREES ABOVE ON  
FRIDAY.  
 

 
   
LONG TERM
 
(FRIDAY NIGHT THROUGH TUESDAY)  
ISSUED AT 306 PM EST TUE NOV 21 2017  
   
..A CONTINUED ROLLER COASTER RIDE
 
 
THE UP AND DOWN WEATHER PATTERN IS EXPECTED TO CONTINUE THROUGH AT  
LEAST THE BEGINNING OF NEXT WEEK. COLDER AIR MOVING IN BEHIND LOW  
PRESSURE MOVING BY TO THE NORTH WILL LIKELY CHANGE RAIN OVER TO A  
PERIOD OF SNOW EARLY SATURDAY. THIS WILL BE FOLLOWED BY A SHOT OF  
COLDER AIR AND LAKE EFFECT SNOW SHOWERS SATURDAY INTO EARLY SUNDAY.  
MODEL TRENDS ARE FOR LESS AVAILABLE MOISTURE BUT AM STILL CONCERNED  
THAT WE COULD SEE ICY SPOTS DEVELOPING EARLY SATURDAY AS  
TEMPERATURES DROP TO NEAR FREEZING FOLLOWED BY ACCUMULATING LAKE  
EFFECT SNOW AND BLOWING SNOW SATURDAY INTO SATURDAY NIGHT AS WINDS  
BECOME QUITE GUSTY. LINGERING LAKE EFFECT SHOULD DIMINISH SUNDAY DUE  
TO INCREASING RIDGING ALOFT. TURNING MILDER ONCE AGAIN MONDAY INTO  
TUESDAY WITH ANOTHER CHANCE FOR RAIN TUESDAY.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)  
ISSUED AT 1218 PM EST TUE NOV 21 2017  
 
A COLD FRONT HAS CROSSED ALL NRN LOWER AIRPORTS WITH WINDS NOW  
SHIFTED MORE WESTERLY AND WERE QUITE GUSTY. COLD AIR WAS POURING  
INTO THE REGION AND TEMPERATURES WERE FALLING. THE AIR WILL GET  
COLD ENOUGH THROUGH THE AFTERNOON FOR LAKE EFFECT RAIN AND SNOW  
SHOWERS TO DEVELOP, AND THEN QUICKLY CHANGE TO JUST SNOW. CIGS  
WILL BE LOW END VFR FOR THE MOST PART, MAYBE GOING MVFR AT TIMES.  
THE SNOWS ARE NOT EXPECTED TO BE HEAVY, WITH LOW SNOWFALL RATES  
BEING DOMINANT. VSBYS WILL STILL LIKELY BE ABLE TO FALL TO AROUND  
1-2SM AT TIMES, BRIEFLY SUB 1SM. THE SNOWS WILL LIKELY TREND LESS  
INTENSE GOING THROUGH THE OVERNIGHT HOURS AND INTO WEDNESDAY  
MORNING. TOTAL SNOWFALL AROUND AN INCH, MAYBE TWO IF IN A STRONGER  
SNOW BAND.  
 

 
   
MARINE
 
 
ISSUED AT 306 PM EST TUE NOV 21 2017  
 
AFTER A STRONG COLD FRONT CROSSED THE REGION EARLIER TODAY, WNW  
WINDS DEVELOPED AND REMAINED QUITE GUSTY. FOR MOST AREAS ACROSS  
LAKE MICHIGAN, GALES WERE NOT BEING MET BASED ON AREA OBSERVATIONS,  
SO WILL ALLOW THAT HEADLINE TO EXPIRE. GALES ARE LIKELY TO CONTINUE  
THROUGH EVENING IN WHITEFISH BAY AND IN AND AROUND THE PRESQUE ISLE  
LIGHT AREA. ADVISORIES THROUGH TONIGHT ALL OTHER AREAS. HIGHER  
PRESSURE AND SUB ADVISORY WINDS EXPECTED WITH HIGHER PRESSURE  
WEDNESDAY, BEFORE WINDS RAMP BACK UP WEDNESDAY NIGHT AHEAD OF THE  
NEXT COLD FRONT FOR POTENTIAL NEW ADVISORIES.  
 

 
   
APX WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LH...SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR LHZ345-346-349.  
GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LHZ347-348.  
LM...SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR LMZ323-341-342-  
344>346.  
LS...SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR LSZ322.  
GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LSZ321.  

 
 

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