718  
FXUS61 KCLE 020915  
AFDCLE  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CLEVELAND OH  
415 AM EST MON DEC 2 2024  
   
SYNOPSIS  
 
A SURFACE TROUGH WILL CONTINUE TO LINGER ACROSS THE AREA INTO  
TUESDAY BEFORE A BRIEF HIGH PRESSURE BUILDS EAST TUESDAY AFTERNOON.  
ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE EAST ACROSS THE REGION  
WEDNESDAY THROUGH THURSDAY BEFORE HIGH PRESSURE RETURNS ON  
FRIDAY.  
 
 
   
NEAR TERM /THROUGH TUESDAY/  
 
THE LAKE EFFECT MACHINE CONTINUES TO PRODUCE SNOW SQUALLS ACROSS THE  
SNOWBELT REGION, ALTHOUGH THE MESOSCALE FACTORS ARE SLOWLY BEGINNING  
TO WEAKEN. THE BIG SHIFT WITH LAKE EFFECT TODAY WILL BE DUE TO A  
PREDOMINANTLY NORTHWEST STEERING FLOW RESULTING IN MORE OF A MULTI-  
BAND SYSTEM PUSHING INLAND AS FAR EAST AS CUYAHOGA COUNTY AND  
REACHING FURTHER SOUTH INTO GEAUGA/TRUMBULL COUNTIES ALONG THE  
HIGHER TERRAIN. THIS SHIFT IN DIRECTION WILL DIMINISH THE FETCH  
ACROSS LAKE ERIE, WITH THE EXCEPTION ACROSS NWPA WHERE A CONNECTION  
TO LAKE HURON HAS DEVELOPED. DEFINED BANDS WILL BE HARD TO DETERMINE  
AHEAD OF TIME AS INCREASED SHEAR IS RESULTING IN THE SNOW SHOWERS  
FANNING OUT A BIT AND MAKING THE EXACT LOCATION A BIT MORE DIFFICULT  
COMPARED TO PREVIOUS DAYS. THERE REMAINS A CONVERGENT BOUNDARY  
ACROSS THE SNOWBELT REGION WITH MODEL SOUNDINGS SUGGESTING AN  
INCREASING EQL TO 15+KFT TODAY. THIS COUPLED WITH PERSISTENT 850MB  
TEMPERATURES OF -10 TO -12C AND GOOD OMEGA LIFT WITHIN THE DGZ WILL  
MAINTAIN AN ENVIRONMENT CONDUCIVE TO SNOWBANDS CONTINUING TO FORM  
FOR MUCH OF THIS PERIOD. IF THERE IS A SILVER LINING IN THESE  
CONDITIONS IT IS THAT THE OVERALL SNOWFALL RATES SHOULD BE LESS  
TODAY WITH THE STRONGEST RATES NEAR 1"/HR.  
 
ONE OF THE BIGGEST CHANGES WITH THE UPDATE THIS MORNING IS THAT SOME  
HI-RES MODELS TRY TO PUSH A DRIER AIRMASS FURTHER EAST TODAY,  
ULTIMATELY LOWERING QPF TOTALS. THIS IS RELATIVE AS AREAS ACROSS THE  
SNOWBELT ARE STILL MAINTAINING TOTAL QPF VALUES OF 0.25-0.5". GIVEN  
EXPECTED SNOW RATIOS AVERAGING 15:1, THIS WILL RESULT IN ADDITIONAL  
SNOWFALL TOTALS OF 4-10" ACROSS PORTIONS OF THE OHIO SNOWBELT, WITH  
AN ADDITIONAL 10-20" POSSIBLE ACROSS NWPA. AREAS INLAND, INCLUDING  
TRUMBULL AND PORTAGE COUNTIES, COULD SEE 1-3" OF SNOW THROUGH THIS  
PERIOD.  
 
THROUGHOUT THIS ENTIRE PERIOD, TEMPERATURES WILL BE SLIGHTLY WARMER  
THAN THE LAST COUPLE DAYS WITH HIGHS CLIMBING TO NEAR FREEZING BOTH  
DAYS. OVERNIGHT LOWS WILL REMAIN COLD, DROPPING INTO THE LOW TO MID  
20S WITH APPARENT TEMPERATURES FALLING INTO THE LOW TEENS INLAND  
FROM THE LAKE.  
 
WRAPPING THINGS UP, IT IS IMPORTANT TO NOTE THAT EVEN WITH A  
SLIGHTLY MORE 'OPTIMISTIC' FORECAST THIS MORNING, THE WIDESPREAD  
IMPACTS FROM THIS SYSTEM AS A WHOLE WILL CONTINUE TO BE FELT AND  
PEOPLE SHOULD ADHERE TO ALL GUIDANCE FROM LOCAL OFFICIALS. ACROSS  
AREAS OF THE SNOWBELT THAT CONTINUE TO BE IMPACTED, INCLUDING AREAS  
ALONG AND NORTH OF I-90, PEOPLE SHOULD NOT TRAVEL UNLESS ABSOLUTELY  
NECESSARY AND IF REQUIRED TO VENTURE OUT BE SURE TO HAVE A  
PREPAREDNESS CAR KIT WITH YOU. CLEAN-UP FROM THIS EVENT WILL TAKE  
DAYS SO LINGERING IMPACTS WILL BE FELT EVEN IF IT IS NOT ACTIVELY  
SNOWING.  
 
 
   
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/  
 
THE SHORT TERM FORECAST PERIOD REMAINS VERY ACTIVE FOR THE FORECAST  
AREA WITH A TRANSITION FROM JUST LAKE EFFECT SNOW TO A WEATHER  
SYSTEM THAT COULD HAVE IMPACTS ACROSS THE ENTIRE FORECAST AREA. FOR  
TUESDAY NIGHT, HIGH PRESSURE WILL BE INCHING UP THE OHIO AND  
TENNESSEE RIVER VALLEYS AS IT ADVANCES SOUTHEAST. THE MEAN LOW LEVEL  
RIDGE AXIS SHOULD BE OVER THE MIDDLE OF THE FORECAST AREA AT THE  
START OF THE SHORT TERM FORECAST PERIOD AND SHOULD ALLOW FOR BACKING  
AND WARMING FLOW ACROSS THE REGION. THIS SHOULD START TO WIND DOWN  
THE LAKE EFFECT EVENT AND PUSH ANY REMAINING BANDS NORTH OVER LAKE  
ERIE AND THROUGH NEW YORK AND EVENTUALLY TO CANADA. THERE COULD BE  
AN INCH OF SNOW OR SO OUT OF SCATTERED LAKE EFFECT SHOWERS IN ERIE  
COUNTY PA, BUT NOTHING COMPARED TO THE LAST SEVERAL DAYS.  
 
FOR WEDNESDAY, A STRONG LOW PRESSURE SYSTEM WILL ARRIVE NEAR LAKE  
SUPERIOR. THE LOCAL FORECAST AREA WILL REMAIN BETWEEN THIS STRONG  
LOW AND A DEPARTING HIGH PRESSURE SYSTEM TO THE SOUTHEAST.  
ACCORDINGLY, BETWEEN THESE TWO SYSTEMS A STRONG LOW LEVEL JET OF 55  
KT AT 850 MB WILL BE PRESENT ACROSS THE REGION AND SHOULD MIX DOWN  
TO THE SURFACE IN SOME CAPACITY WEDNESDAY AFTERNOON AND BEYOND. WIND  
GUSTS OF 40 MPH OR GREATER ARE POSSIBLE. THE STRONGEST WINDS WILL BE  
WITH THE ASSOCIATED COLD FRONT ON WEDNESDAY EVENING AS THIS FEATURE  
WILL BRING SNOW AND PERHAPS SOME BRIEF MIX TO RAIN ACROSS THE  
REGION. A WIND ADVISORY MAY BE NEEDED FOR THE MIDDLE OF THE WEEK TO  
ACCOUNT FOR THE ELEVATED WINDS.  
 
FOR WEDNESDAY NIGHT AND BEYOND, THE COLD FRONT WILL PASS TO THE EAST  
AND ALLOW AN OPPORTUNITY FOR THE LAKE EFFECT SNOW MACHINE TO GET  
GOING AGAIN. FOR THIS EVENT, THE AIR ALOFT WILL ACTUALLY BE COLDER  
THAN IT WAS FOR THE CURRENT EVENT WITH -13 TO -14 C AT 850 MB AND A  
FRIGID -23 TO -25C AT 700 MB, WHICH WOULD SUPPORT AMPLE LAKE INDUCED  
INSTABILITY WITH LAKE SURFACE TEMPERATURES LIKELY STILL RESIDING IN  
THE 5-7C RANGE. UNLIKE THE CURRENT LAKE EFFECT EVENT, THERE WILL BE  
SOME FACTORS GOING AGAINST PROLIFIC LAKE EFFECT SNOW AMOUNTS. THERE  
ARE MUCH STRONGER WINDS IN PLACE WITH THE MEAN FLOW IN THE BOUNDARY  
LAYER AT ABOUT 30 KTS, IF NOT SLIGHTLY HIGHER. THIS WILL REDUCE  
RESIDENCE TIME FOR PARCELS OVER THE LAKE, ESPECIALLY IN THE SHORTER  
NORTHWEST FETCH ACROSS LAKE ERIE. THE OTHER LIMITING FACTOR WILL BE  
MOISTURE, THERE SHOULD BE SUFFICIENT MOISTURE FOR SNOW DEVELOPMENT  
DURING THE ONSET OF THE EVENT ON WEDNESDAY NIGHT INTO THURSDAY.  
HOWEVER, DRIER, CONTINENTAL AIR WILL BE WRAPPING IN BEHIND THE  
LARGER LOW PRESSURE SYSTEM AND PRECIPITATION EFFICIENCY MAY BE  
HINDERED QUICKLY, LEAVING SNOW BANDS LIMITED TO WHERE THERE WILL BE  
HELP FROM UPSTREAM LAKE CONNECTIONS. OVERALL, EXPECT MOST OF THE  
SNOW BELT TO AT LEAST SEE SOME ACCUMULATING SNOW AMOUNTS WEDNESDAY  
NIGHT THROUGH THURSDAY NIGHT, BUT DETAILS WILL NEED TO BE REFINED  
BEFORE THINKING ABOUT HEADLINE NEEDS. THE SECONDARY SHOULD AT LEAST  
GET SOMEWHAT MORE INVOLVED WITH SNOW WITH THE STRONG NORTHWEST FLOW.  
TEMPERATURES THROUGH THE PERIOD REMAIN BELOW NORMAL WITH HIGHS IN  
THE 20S AND PERHAPS SOME UPPER 20S ON THURSDAY.  
 
 
   
LONG TERM /FRIDAY THROUGH SUNDAY/  
 
WHILE IT IS UNLIKELY TO SAY THAT THE LONG TERM FORECAST PERIOD WILL  
BE QUIET, IT APPEARS THAT THERE WILL BE AT LEAST SOME REPRIEVE TO  
ACTIVE WEATHER ACROSS THE LOCAL AREA FOR FRIDAY AND PERHAPS INTO THE  
WEEKEND. HIGH PRESSURE WILL BUILD FROM THE WEST FOR FRIDAY. THIS  
SHOULD BACK FLOW ACROSS THE LAKE AND PUSH ANY LAKE EFFECT SNOW  
NORTHEAST AND OUT OF THE AREA. FOR SATURDAY, A CLIPPER SYSTEM WILL  
TARGET THE GREAT LAKES REGION. HOWEVER, THIS SYSTEM IS TRENDING BOTH  
NORTH AND WEAKER AND IT IS UNCERTAIN HOW MUCH OF AN IMPACT WITH  
PRECIPITATION AND TEMPERATURES THAT IT WILL HAVE FOR THE LOCAL AREA.  
WILL HAVE SOME LOWER END POPS FOR THE BULK OF THE AREA, BUT CAN SEE  
THIS GETTING LOWERED WITH TIME. FOR SUNDAY, A RIDGE WILL BUILD FROM  
THE SOUTHWEST AND SHOULD AT LEAST ALLOW FOR A WINDOW OF DRY WEATHER  
WITH MODERATING TEMPERATURES BEFORE ANOTHER LOW PRESSURE SYSTEM  
ENTERS NEXT WEEK. TEMPERATURES ON SUNDAY COULD BE NEAR NORMAL FOR  
THE FIRST TIME IN A WEEK AND A HALF.  
 
 
   
AVIATION /06Z MONDAY THROUGH FRIDAY/  
 
THERE IS EXPECTED TO BE QUITE A SPREAD IN AVIATION CONDITIONS  
ACROSS THE AREA TODAY AS LAKE EFFECT SNOW CONTINUES TO IMPACT  
THE REGION. STARTING OFF WITH WESTERN TERMINALS (KFDY, KTOL,  
KMFD)THERE IS CURRENTLY A SWATH OF MVFR CEILINGS STREAMING OFF  
OF LAKE MICHIGAN AND IMPACTING AREAS THROUGH SOUTHEASTERN OHIO.  
KTOL IS POSITIONED ON THE NORTHERN FRINGE OF THESE CLOUDS AND  
WILL LIKELY IMPROVE TO VFR FIRST TONIGHT AS THE CLOUD DECK  
BEGINS TO ERODE NORTH TO SOUTH. THE OTHER TWO TERMINALS WILL  
LIKELY BE SOCKED IN WITH MVFR CEILINGS THROUGH THIS AFTERNOON.  
IN ADDITION, THERE IS A POTENTIAL FOR LIGHT SNOW SHOWERS TO  
IMPACT THESE TERMINALS, ALTHOUGH OVERALL IMPACT TO VISIBILITIES  
SHOULD REMAIN LOW.  
 
SHIFTING GEARS TO THE REMAINDER OF THE TERMINALS ACROSS THE  
EASTERN PORTION OF THE AREA, MORE HAZARDOUS AVIATION CONDITIONS  
ARE EXPECTED FOR AT LEAST A PERIOD OF TIME TODAY AS A RESULT OF  
LAKE EFFECT SNOW SHOWERS STREAMING SOUTHEAST ACROSS THE AREA.  
CURRENTLY, CEILINGS ARE HOVERING IN THE HIGH END MVFR TO LOW END  
VFR HEIGHTS, BUT AM EXPECTING EVERYTHING TO BECOME MVFR IN THE  
HOURS TO COME. THE BIGGER CONCERN WITH THIS TAF PERIOD IS THE  
CONTINUED LAKE EFFECT SNOW SHOWERS EXPECTED TO IMPACT THE AREA.  
CONTRARY TO PREVIOUS DAYS WHERE THE LAKE EFFECT BAND HELD CLOSE  
TO THE LAKESHORE, A NORTHWEST WIND IS NOW PUSHING THIS SNOW  
FURTHER INLAND, IMPACTING TERMINALS INCLUDING KYNG AND EVEN KCAK  
AT TIMES. THERE IS HIGH CONFIDENCE IN PERIODS OF IFR CONDITIONS  
FOR KYNG AND KERI THROUGH THIS PERIOD, ALTHOUGH CANNOT RULE OUT  
THOSE CONDITIONS AT KCLE AND KCAK AS WELL. IT WILL BE HIGHLY  
DEPENDENT ON HOW FAR WEST THE BAND SHIFTS, SO WILL HAVE TO  
CONTINUE TO MONITOR IT. FOR NOW, OPTED TO CAP BOTH OF THOSE  
TERMINALS IN THE MVFR RANGE.  
 
PREDOMINATELY WEST WINDS OF 5-10 KNOTS WILL PERSIST THROUGH THIS  
PERIOD, SLOWLY SHIFTING TO NORTHWEST NEAR THE END. KERI MAY BE  
THE OUTLIER WITH SUSTAINED WINDS A TAD STRONGER IN THE 10-15  
KNOT RANGE GIVEN THE STRONG FLOW OFF OF THE LAKE.  
 
OUTLOOK...NON-VFR LIKELY IN LAKE-EFFECT SNOW BANDS THROUGH  
TUESDAY. THE HEAVIEST AND MOST-PERSISTENT LAKE-EFFECT SNOW IN  
OUR REGION IS EXPECTED TO IMPACT THE PRIMARY SNOWBELT IN FAR  
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA.  
 
 
   
MARINE  
 
TROUGH OVER THE LAKE WILL CONTINUE TODAY AND WILL ALLOW FOR THE 15  
TO 20 KT WESTERLY FLOW TO REMAIN IN PLACE AND WAVES OVER 4 FT FOR  
THE CENTRAL AND EASTERN BASINS. FOR TUESDAY, HIGH PRESSURE WILL  
BUILD SOUTHWEST OF THE LAKE AND INCREASE THE PRESSURE GRADIENT  
ACROSS THE REGION AS THE MAIN TROUGH MOVES OUT. THEREFORE, WEST  
WINDS 15 TO 20 KT WILL CONTINUE WITH WAVES OVER 4 FT AND WILL  
CONTINUE THE SMALL CRAFT ADVISORY THROUGH 7 AM WEDNESDAY. FOR  
WEDNESDAY AND THURSDAY, A STRONG LOW PRESSURE SYSTEM AND ASSOCIATED  
COLD FRONT WILL CROSS THE GREAT LAKES REGION. SOUTHWEST WINDS WILL  
INCREASE GREATLY ON WEDNESDAY AHEAD OF THE SYSTEM WITH THE POTENTIAL  
FOR GALE FORCE WINDS. THE COLD FRONT WILL MOVE THROUGH ON WEDNESDAY  
NIGHT AND WEST TO NORTHWEST FLOW WILL BE STRONG WITH GALE FORCE  
WINDS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY. WILL BEGIN MENTIONING  
IN THE HAZARDOUS WEATHER OUTLOOK, BUT A GALE WATCH MAY BE NEEDED  
WITHIN THE NEXT ONE OR TWO FORECAST CYCLES. HIGH PRESSURE WILL  
RETURN SOUTHWEST OF THE REGION FOR FRIDAY AND BOTH REDUCE AND BACK  
FLOW ACROSS THE LAKE AND THERE COULD BE A BRIEF WINDOW WITHOUT THE  
NEED FOR A MARINE HEADLINE.  
 
 
   
CLE WATCHES/WARNINGS/ADVISORIES  
 
OH...LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR OHZ011>014-  
089.  
PA...LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR PAZ003.  
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST TUESDAY FOR PAZ001-002.  
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST WEDNESDAY FOR LEZ145>149.  
 
 
 
 
 
SYNOPSIS...CAMPBELL  
NEAR TERM...CAMPBELL  
SHORT TERM...SEFCOVIC  
LONG TERM...SEFCOVIC  
AVIATION...CAMPBELL  
MARINE...SEFCOVIC  
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