232  
FXUS63 KLOT 221842  
AFDLOT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL  
1242 PM CST WED NOV 22 2017  
   
SHORT TERM
 
 
1242 PM CST  
 
THROUGH FRIDAY...  
 
HIGH PRESSURE WILL MOVE EAST OF THE AREA TONIGHT WITH LIGHT  
SOUTHERLY WINDS DEVELOPING. THE COMBINATION OF THE LIGHT SOUTH  
WINDS AND MORE SO MID-HIGH LEVEL OVERCAST SHOULD HELP KEEP TEMPS  
MUCH MILDER TONIGHT VS LAST NIGHT. SKIES SHOULD CLEAR OUT  
THANKSGIVING DAY WITH TEMPS MILDER THAN TODAY.  
 
THURSDAY NIGHT INTO FRIDAY, STRONG LOW PRESSURE WILL TRACK EAST  
ACROSS SOUTHERN CANADA LEADING TO INCREASINGLY STRONG SOUTHERLY  
WINDS THURSDAY NIGHT AND ESPECIALLY FRIDAY. GULF OF MEXICO IS SHUT  
DOWN FOR BUSINESS WITH RESPECT TO MOISTURE RETURN, SO WITH THE  
SOUTHERLY WINDS ONLY ADVECTING RECYCLED CONTINENTAL AIR NORTH,  
STRATUS SEEMS UNLIKELY. GIVEN THE EXPECTED SUNSHINE AND STRONG  
LOW LEVEL WINDS ENCOURAGING MECHANICAL MIXING OF THE WARMER AIR  
ALOFT TO THE SURFACE, STRONGLY SUSPECT GUIDANCE TEMPS AREN'T WARM  
ENOUGH FRIDAY. THE FORECAST 925MB TEMPS FRIDAY AFTERNOON IN THE  
ECMWF, GFS, AND NAM ALL SUPPORT HIGHS REACHING THE LOWER 60S.  
WHILE I'M NOT COMFORTABLE GOING THAT WARM YET, DID ADJUST HIGHS UP  
CONSIDERABLY FROM THE BLENDED INITIALIZATION.  
 
- IZZI  
 

 
   
LONG TERM
 
 
1242 PM CST  
 
FRIDAY NIGHT THROUGH WEDNESDAY...  
 
MAIN STORM TRACK THROUGH THE LONG TERM PERIOD WILL REMAIN WELL  
NORTH OF OUR AREA, WHICH SHOULD RESULT IN LITTLE IF ANY PRECIP  
THROUGH THE PERIOD AND A TEMPERATURE ROLLER COASTER. COLD FRONT  
WILL KNOCK TEMPS DOWN SOME OVER THE WEEKEND, GENERALLY IN THE BALL  
PARK OF SEASONAL NORMS, BEFORE THE NEXT POWERFUL CYCLONE DEVELOPS  
AND RESULTS IN MORE STRONG SOUTHERLY WINDS AND UNSEASONABLE WARMTH  
EARLY NEXT WEEK. ONCE AGAIN, FORECAST 925MB TEMPS FROM THE GFS AND  
ECMWF WOULD SUPPORT HIGHS WELL INTO THE 50S TO NEAR 60 MONDAY.  
NUDGED TEMPS UPWARD IN THAT DIRECTION, BUT STILL LIKELY FAR TOO  
COOL IF CURRENT PROGS VERIFY. SOME DIFFERENCES ARISE BETWEEN THE  
ECMWF AND GFS HEADING INTO THE MIDDLE OF NEXT WEEK, BUT GENERALLY  
NEAR TO ABOVE NORMAL TEMPS AND DRY CONDITIONS LOOK TO BE THE RULE  
AT THIS POINT.  
 
- IZZI  
 

 
   
AVIATION
 
 
FOR THE 18Z TAFS...  
 
NO WEATHER CONCERNS THROUGH THE TAF CYCLE WITH VFR CONDITIONS AND  
WINDS LESS THAN 10KT EXPECTED.  
 
- IZZI  
 

 
   
MARINE
 
 
1242 PM CST  
 
ACTIVE PATTERN EXPECTED ON THE LAKE THE NEXT WEEK. FIRST, AS HIGH  
PRESSURE MOVES EAST TONIGHT, SOUTHERLY WINDS WILL DEVELOP AND  
FRESHEN UP OVER NIGHT INTO THURSDAY. GALES LOOK UNLIKELY, BUT  
WINDS COULD PUSH 30KT FOR A TIME THURS MORNING OVER NORTHERN  
PORTIONS OF THE LAKE. SOUTHERLY WINDS WILL REALLY RAMP UP LATER  
THURSDAY NIGHT INTO FRIDAY AS DEEP CYCLONE TRACKS EAST TOWARD THE  
UPPER GREAT LAKES REGION. GUIDANCE CONTINUES TO SUPPORT GALE FORCE  
WINDS AND WILL BE HOISTING A GALE WATCH FOR THE OPEN LAKE FOR THIS  
SOUTHERLY WIND EVENT. COLD FRONT WILL MOVE ACROSS THE LAKE FRIDAY  
NIGHT, BUT WITH ONLY A MODEST PUSH OF COLD AIR IN THE WAKE OF THE  
FRONT, THE NORTHWEST WINDS WILL PROBABLY TOP OUT JUST BELOW GALES  
SATURDAY. ANOTHER PERIOD OF STRONG SOUTHERLY WINDS AND POSSIBLE  
GALES LOOK TO BE ON TAP FOR SUNDAY NIGHT INTO MONDAY.  
 
- IZZI  
 

 
   
LOT WATCHES/WARNINGS/ADVISORIES
 
 
IL...NONE.  
IN...NONE.  
LM...NONE.  

 
 

 
 
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