655  
FXUS61 KILN 181729  
AFDILN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WILMINGTON OH  
1229 PM EST WED DEC 18 2024  
   
SYNOPSIS
 
 
WIDESPREAD PRECIPITATION IS EXPECTED THROUGH THE FIRST HALF OF  
TODAY BEFORE DRIER AND COOLER CONDITIONS RETURN TONIGHT THROUGH  
THURSDAY. CHANCES FOR SOME LIGHT SNOW WILL RETURN ON FRIDAY,  
WITH BELOW NORMAL TEMPERATURES EXPECTED THROUGH THE UPCOMING  
WEEKEND. WARMER AIR WILL SLOWLY BUILD BACK INTO THE OHIO VALLEY  
THROUGH THE FIRST HALF OF NEXT WEEK, WITH RAIN CHANCES RETURNING  
BY CHRISTMAS EVE.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
THE HEAVIEST OF THE STEADY PRECIPITATION WILL BE MOVING OUT OF  
THE ILN FORECAST AREA BY 11AM, WITH SOME LIGHTER PRECIPITATION  
EXPECTED TO CONTINUE INTO THE AFTERNOON -- PARTICULARLY FOR THE  
SOUTHEASTERN HALF OF THE CWA. THE TEMPERATURE TREND HAS BEEN FOR  
A SLOW RISE EARLY THIS MORNING, WITH THE COLDEST SITE (KDLZ)  
REPORTING 32 DEGREES THROUGH ABOUT 12Z, BUT THIS HAS NOW  
INCREASED TO 34 DEGREES AS OF 13Z. STILL COULD SEE A VERY SMALL  
AMOUNT OF MIXED PRECIPITATION IN THE NORTHERN CWA AS THE LIGHTER  
AND PATCHIER RADAR ECHOES PROGRESS EASTWARD OVER THE NEXT COUPLE  
HOURS, BUT THE TEMPERATURE TREND (INCLUDING ROAD TEMPERATURES)  
WOULD SUGGEST LITTLE TO NO IMPACT.  
 
PREVIOUS DISCUSSION >  
WIDESPREAD PRECIPITATION IS OVERSPREADING THE ILN FA FROM THE  
SW, WITH A WET MORNING COMMUTE EXPECTED FOR MOST LOCAL SPOTS  
THIS MORNING. EARLIER IN THE EVENING/NIGHTTIME, AMIDST MOSTLY  
CLEAR SKIES AND LIGHT/CALM WINDS, GOOD RADIATIONAL COOLING  
CONDITIONS HAD ALLOWED FOR SFC AIR TEMPS TO DIP INTO THE UPPER  
20S/LOWER 30S FOR A FEW LOCALES, ESPECIALLY RURAL/SHELTERED  
AREAS. HOWEVER, WITH THE ARRIVAL OF THICKER CLOUD COVER  
ASSOCIATED WITH THE PCPN, AIR TEMPS ARE RISING ABOVE FREEZING  
PROGRESSIVELY FROM SW TO NE, MEANING THE PREDOMINANT PTYPE WILL  
BE RAIN FOR MOST AREAS. THIS BEING SAID, AIR TEMPS WILL BE  
SLOWEST TO RISE WITHIN A CORRIDOR FROM WC THROUGH CENTRAL OH  
THROUGH MID-MORNING, MEANING THAT THESE AREAS WILL HAVE THE  
GREATEST POTENTIAL FOR A RA/SN MIX, POSSIBLY MIXED WITH SOME  
SLEET. ADDITIONALLY, EVEN IF AIR TEMPS RISE TO 33F OR 34F PRIOR  
TO THE ONSET OF PCPN, ELEVATED SURFACES (INCLUDING BRIDGES,  
TREES, RAILINGS, CARS, ETC.) MAY REMAIN NEAR/BELOW FREEZING FOR  
A BRIEF PERIOD. THEREFORE, THERE MAY BE A FEW INSTANCES OF  
FREEZING OF RAIN ON-CONTACT WITH SUBFREEZING/ELEVATED SURFACES,  
EVEN IF AIR TEMPS ARE JUST ABOVE 32F. WHILE THIS SHOULDN'T LEAD  
TO WIDESPREAD TRAVEL ISSUES (EXCEPT ON BRIDGES), IF STEADY  
SLEET OR SNOW IS ABLE TO MIX IN EVEN BRIEFLY, THERE COULD BE  
ISOLATED SLICK SPOTS TO CONTEND WITH IN WC/CENTRAL OH THROUGH  
THE MORNING COMMUTE. THE CORRIDOR MOST LIKELY TO SEE MORE SNOW  
THAN RAIN (AND THUS, THE POTENTIAL FOR LIGHT SNOW ACCUMULATIONS  
OF A FEW TENTHS OF AN INCH ON UNTREATED SURFACES) THROUGH 16Z  
IS WITHIN A ZONE FROM SHELBY/AUGLAIZE COS TO DELAWARE/LICKING  
COS OH. THIS POTENTIAL HAS BEEN INCLUDED IN THE HWO FOR  
AWARENESS PURPOSES.  
 
S OF I-71 IN PARTS OF THE TRI-STATE/N KY, STEADY RAIN IS  
EXPECTED THROUGH MID-AFTERNOON, WITH THE GREATEST RAINFALL ON  
THE ORDER OF AROUND 1/2 OF AN INCH FOCUSING NEAR AN AXIS FROM  
OWEN CO KY TO SCIOTO CO OH AND POINTS FURTHER TO THE S. DRIER  
CONDITIONS WILL RETURN AREA-WIDE FOR LATE AFTERNOON FOLLOWING  
THE FROPA, WITH ONLY A FEW FLURRIES LINGERING THIS EVENING,  
ESPECIALLY IN CENTRAL OH. HOWEVER, MOISTURE AVAILABILITY IN THE  
DGZ WILL BECOME INCREASINGLY MEAGER LATE TONIGHT, SO FLURRY  
ACTIVITY MAY NOT BE TOO WIDESPREAD.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/
 
 
DRIER/COLDER CONDITIONS SETTLE IN THIS EVENING THROUGH THURSDAY,  
WITH A FEW FLURRIES POSSIBLE TONIGHT IN THE CAA REGIME. TEMPS  
TONIGHT DIP INTO THE MID 20S IN THE NW TO THE LOWER 30S IN THE  
SE BEFORE REBOUNDING INTO THE MID 30S TO LOWER 40S,  
RESPECTIVELY, ON THURSDAY AFTERNOON.  
 
SKIES SHOULD REMAIN MOSTLY CLOUDY TO OVC THROUGH THE DAY ON  
THURSDAY, EVEN AS WEAK SFC HIGH PRESSURE TRAVERSES THE REGION.  
LL FLOW WILL BECOME SOUTHERLY ONCE AGAIN LATE IN THE DAY AHEAD  
OF THE NEXT SYSTEM, POISED TO IMPACT THE REGION ON FRIDAY.  
 

 
   
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
 
 
THE START OF THE EXTENDED ARRIVES DRY AND CHILLY, WITH THURSDAY  
OVERNIGHT LOWS FALLING INTO THE UPPER 20S. A CLIPPER SYSTEM WILL BE  
MOVING OUT OF ILLINOIS AND INTO THE GREAT LAKES REGION, WITH ITS  
MAIN IMPACTS FELT FRIDAY DAYTIME HOURS.  
 
DESPITE THE SYSTEM BEING RATHER MOISTURE STARVED, WE'RE STILL  
EXPECTING A LITTLE BIT OF SNOWFALL, PARTICULARLY NORTH OF I-71 AS  
THE LOW PRESSURE SYSTEM ROLLS RIGHT OVER THE AREA. FORECAST  
SOUNDINGS INDICATE PRETTY GOOD SATURATION THROUGH THE SNOW GROWTH  
ZONE AND THE ENTIRE COLUMN LOOKS TO REMAIN BELOW FREEZING. IT SHOULD  
BE NOTED THAT (FOR RIGHT NOW AT LEAST) THE MORE ROBUST FORCING/  
NEGATIVE OMEGA LOOKS TO REMAIN SOUTH OF THE CWA, WHICH MAY INHIBIT  
MORE ENHANCED SNOWFALL. EVEN SO, DECENT MODEL CONSENSUS THAT ABOUT  
AN INCH OF SNOW WILL LIKELY FALL, LIKELY ACCUMULATING ON GRASSY  
AREAS. NOT ANTICIPATING TOO MANY TRAVEL IMPACTS AT THIS TIME GIVEN  
THAT SNOW WILL FALL DURING DAYLIGHT HOURS. HIGH TEMPERATURES ON  
FRIDAY WILL BE RIGHT AROUND FREEZING NORTH OF I-70 WITH AREAS NEARER  
TO THE OHIO RIVER REACHING THE MID/UPPER 30S. UNFORTUNATELY, WITH  
WIND GUSTS FRIDAY AFTERNOON REACHING 20 MPH OR SO, FEELS LIKE TEMPS  
WILL BE IN THE 20S.  
 
AFTER THE CLIPPER MOVES EAST, SNOWFALL TAPERS OFF BY SUNSET AND COLD  
AIR ADVECTION IS REINFORCED INTO THE AREA. FRIDAY NIGHT'S LOWS FALL  
INTO THE LOW 20S AND TEENS. ANY MELTED SNOWFALL FROM FRIDAY DAY WILL  
HAVE THE OPPORTUNITY FOR REFREEZE OVERNIGHT.  
 
HIGH PRESSURE MOVES INTO THE NORTHERN GREAT LAKES REGION AND BECOMES  
THE PRIMARY WEATHER INFLUENCER FOR THE WEEKEND. THE AREA REMAINS DRY  
FOR SATURDAY AND SUNDAY, THOUGH COLD, WITH DAYTIME HIGHS IN THE  
UPPER 20S/LOW 30S AND OVERNIGHT LOWS IN THE TEENS, POSSIBLY EVEN  
SINGLE DIGITS NORTH OF I-70.  
 
BY THE START OF THE FOLLOWING WORK WEEK, WE'LL BE ON THE CUSP OF A  
MAJOR PATTERN CHANGE AND SUBSEQUENT WARMING TREND. THE HIGH PRESSURE  
SHIFTS OFF TO THE EAST AND WARM AIR ADVECTION RETURNS TO THE REGION.  
MONDAY AND TUESDAY'S HIGHS WILL BE ABOUT 10-15 DEGREES WARMER THAN  
THE WEEKEND. ADDITIONALLY, THERE IS A SIGNAL FOR A DISTURBANCE TO  
MOVE THROUGH THE OHIO VALLEY SOMETIME AROUND CHRISTMAS EVE (PERHAPS  
DURING AM HOURS?). STILL A BIT TOO FAR OUT TO NAIL DOWN THE  
SPECIFICS. HOWEVER, PRECIPITATION TYPE DOES LOOK TO BE RAIN.  
 
WHILE CONFIDENCE ON PRECIPITATION CHANCES/TIMING IS STILL LOW AT  
THIS TIME, THERE IS GOOD CONFIDENCE ON AN ANOMALOUSLY HIGH RIDGE  
THAT WILL BEGIN BUILDING IN FROM WESTERN CANADA. THIS WILL HERALD IN  
MUCH WARMER TEMPERATURES FOR THE END OF THE WEEK.  
 

 
   
AVIATION /17Z WEDNESDAY THROUGH SUNDAY/
 
 
STEADY RAIN IS MOVING EASTWARD OUT OF THE TAF SITES. WHILE  
PREVAILING CEILINGS SHOULD SETTLE INTO MVFR VALUES, SOME  
PERSISTING IFR CEILINGS AND VISIBILITIES MAY CONTINUE WITH LIGHT  
RAIN THROUGH AROUND 19Z.  
 
GENERALLY DRY CONDITIONS ARE EXPECTED THROUGH THE REST OF THE  
TAF PERIOD, ALTHOUGH SOME LIGHT FLURRIES ARE POSSIBLE AFTER 03Z.  
CEILINGS WILL GENERALLY REMAIN MVFR, THOUGH SOME BREAKS TO IFR  
ARE POSSIBLE THIS AFTERNOON AT KCVG/KLUK/KDAY. MVFR CEILINGS  
WILL THEN PERSIST INTO TOMORROW, WITH VFR CONDITIONS EXPECTED BY  
MID-MORNING.  
 
NORTHERLY WINDS OF AROUND 10 KNOTS ARE EXPECTED THIS AFTERNOON.  
THESE WINDS WILL WEAKEN TONIGHT, AND BECOME LIGHT AND VARIABLE  
THROUGH TOMORROW MORNING.  
 
OUTLOOK... MVFR CEILINGS AND MVFR TO IFR VISIBILITIES LIKELY ON  
FRIDAY WITH SNOW. THE MVFR CEILINGS MAY PERSIST INTO FRIDAY  
NIGHT AND SATURDAY.  
 

 
   
ILN WATCHES/WARNINGS/ADVISORIES
 
 
OH...NONE.  
KY...NONE.  
IN...NONE.  
 

 
 

 
 
SYNOPSIS...KC  
NEAR TERM...KC/HATZOS  
SHORT TERM...KC  
LONG TERM...CA  
AVIATION...HATZOS  
 
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