447  
FXUS61 KCLE 201121  
AFDCLE  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CLEVELAND OH  
721 AM EDT MON OCT 20 2025  
   
SYNOPSIS  
 
A TROUGH OVER THE EASTERN GREAT LAKES WILL DEPART TO NEW ENGLAND  
TODAY ALLOWING A RIDGE TO BUILD OVER THE OHIO VALLEY. THE NEXT LOW  
PRESSURE SYSTEM WILL MOVE INTO THE UPPER GREAT LAKES TONIGHT,  
PULLING A SERIES OF COLD FRONTS EAST ACROSS THE AREA THROUGH  
WEDNESDAY. HIGH PRESSURE WILL BUILD INTO THE OHIO VALLEY ON  
FRIDAY.  
 
 
   
NEAR TERM /THROUGH TONIGHT/  
 
THE UPPER LEVEL TROUGH AXIS PIVOTS EAST THIS MORNING, TAKING WITH IT  
DEEPER MOISTURE FROM 700MB AND ABOVE. STEADY RAIN THAT HAS BEEN  
FALLING OVERNIGHT IN THE EAST WILL DIMINISH TOWARDS 12Z WHILE A FEW  
LIGHT SHOWERS MAY LINGER IN NW PA THIS MORNING. THE AIRMASS BEHIND  
THIS SYSTEM WILL BE NOTICEABLY COOLER WITH HIGHS RUNNING ABOUT 10  
DEGREES LOWER THAN SUNDAY MORNING. WHILE SOME STRATOCU WILL  
HOLD ON IN THE EAST THROUGH MIDDAY, WESTERN PORTIONS OF THE AREA  
WILL SEE MOSTLY SUNNY SKIES AND WINDS BACKING AROUND TO THE  
SOUTH TOWARDS SUNSET. SURFACE RIDGING THAT WILL START THE  
EVENING ALONG THE OHIO/PA STATE LINE, WILL QUICKLY SHIFT EAST  
WITH RETURN FLOW DEVELOPING BEHIND IT. SOME LOCATIONS IN FAR  
EASTERN OHIO AND NW PENNSYLVANIA WILL DIP INTO THE UPPER 30S,  
BUT FROST IS NOT EXPECTED WITH INCREASING SOUTHERLY WINDS AND  
CLOUDS OVERNIGHT. A NARROW RIBBON OF THETA-E ADVECTION IS PULLED  
NORTH AHEAD OF THE FRONT WITH A 45 KNOT LOW LEVEL JET AND COULD  
SEE A FEW SHOWERS BEFORE SUNRISE REACH THE WESTERN HALF OF THE  
AREA. THERE IS SOME DISCREPANCY IN MODELS ABOUT THE AMOUNT OF  
MOISTURE BUT ANY SHOWERS WILL TEND TO BE LIGHT AND MOVE THROUGH  
QUICKLY.  
 
 
   
SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/  
 
BY TUESDAY MORNING, SURFACE LOW PRESSURE WILL BE OVER LAKE SUPERIOR  
WITH AN OCCLUDING COLD FRONT SET TO QUICKLY SWEEP EAST ACROSS THE  
LOCAL AREA. THE UPPER LEVEL TROUGH CLOSES OFF ACROSS WISCONSIN, THEN  
PIVOTS ACROSS THE AREA TUESDAY NIGHT, WITH A BROAD UPPER TROUGH  
ENCOMPASSING THE UPPER MIDWEST AND GREAT LAKES REGION BY  
WEDNESDAY. THIS WILL BE A COLDER SYSTEM AS 850MB TEMPERATURES  
FALL TO AROUND - 2C WITH A COLD POOL AT 500MB OF -28C. INITIALLY  
ON TUESDAY WE WILL SEE A BAND OF SHOWERS SWEEP EAST ACROSS THE  
AREA THROUGH 18Z, FOLLOWED BY A BREAK AS A DEEP LAYER DRY-SLOT  
WRAPS IN. SHOWERS WILL START TO SPREAD BACK INTO THE AREA LATE  
IN THE DAY ON TUESDAY AS MOISTURE AND COLDER AIR ALOFT ARRIVES.  
THIS WILL BE THE COOLEST AIRMASS OF THE SEASON SO FAR AND HIGH  
TEMPERATURES WILL STRUGGLE TO REACH THE LOW 50S.  
 
THE PLACEMENT OF THIS BROAD UPPER LEVEL TROUGH WILL RESULT IN NEARLY  
UNI-DIRECTIONAL FLOW ACROSS LAKE ERIE, INITIALLY STARTING AS  
SOUTHWESTERLY ON TUESDAY NIGHT, THEN TRENDING TOWARDS MORE WESTERLY  
LATER WEDNESDAY THROUGH THURSDAY. WITH CONTINUED ABOVE NORMAL WATER  
TEMPERATURES, LAKE INDUCED CAPE VALUES COULD RANGE FROM 800-1500  
J/KG AT TIMES WITH LAKE TO 850MB DELTA T UP TO 20C. THE MID-WEEK  
PERIOD WILL BE WET IN NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA  
WITH LAKE ENHANCED RAINS AND COULD SEE A FEW THUNDERSTORMS OFF  
LAKE ERIE. QPF AMOUNTS WILL NEED TO BE ADJUSTED BASED ON WHEN  
THE FLOW SHIFTS MORE ONSHORE BUT COULD SEE QPF AMOUNTS IN EXCESS  
OF 2 INCHES ALONG PORTIONS OF THE NORTHEAST LAKESHORE. IN  
ADDITION THIS FALL AIRMASS WILL BRING ANOTHER ROUND OF BREEZY  
CONDITIONS WITH WESTERLY WINDS COMMONLY GUSTING BETWEEN 25-35  
MPH.  
 
 
   
LONG TERM /FRIDAY THROUGH SUNDAY/  
 
WHILE THE UPPER LEVEL TROUGH SHIFTS TOWARDS THE EAST COAST AT  
THE START OF THE LONG TERM, IT IS UNCLEAR IF WE SEE ANY  
ADDITIONAL SHORTWAVES MOVING THROUGH THE NORTHWEST FLOW ACROSS  
THE GREAT LAKES REGION. WE ARE EXPECTING TO SEE A SURFACE RIDGE  
BUILD NORTH THROUGH THE OHIO VALLEY ON FRIDAY. LOW CHANCES OF  
RAIN CAN NOT BE RULED OUT BY THE WEEKEND AS WE COULD EITHER  
START TO GET SOME MOISTURE FROM A SYSTEM MOVING OUT OF THE  
SOUTHERN PLAINS AND/OR POSSIBLY COMBINING WITH ANY IMPULSES  
MOVING THROUGH THE NORTHWEST FLOW ALOFT. NORMAL HIGHS ARE  
TRENDING CLOSER TO THE LOW 60S AND WE CAN EXPECT HIGHS TO  
APPROACH THAT BY SUNDAY.  
 
 
   
AVIATION /12Z MONDAY THROUGH FRIDAY/  
 
CONDITIONS HAVE IMPROVED TO VFR THIS MORNING AS A RIDGE OF HIGH  
PRESSURE BUILDS ACROSS TERMINALS. SOME LIGHT RAIN SHOWERS WILL  
LINGER ACROSS TERMINALS IN EXTREME NORTHEAST OHIO AND NORTHWEST  
PENNSYLVANIA FOR THE NEXT FEW HOURS BEFORE THE RIDGE PUSHES THEM  
EAST. WESTERLY TO NORTHWESTERLY WINDS 8-12 KNOTS WILL CONTINUE  
THROUGH THE EVENING HOURS. SOME EASTERN TERMINALS MAY SEE  
OCCASIONAL GUSTS 18-22 KNOTS DURING THE AFTERNOON HOURS TODAY.  
WINDS TURN SOUTHERLY THIS EVENING AND DIMINISH TO 8 KNOTS OR  
LESS.  
 
A COLD FRONT WILL APPROACH TERMINALS FROM THE WEST LATE  
TONIGHT/EARLY TUESDAY MORNING WHICH WILL ALLOW FOR SOUTHERLY TO  
SOUTHWESTERLY WINDS TO INCREASE TO 10-15 KNOTS WITH GUSTS 20-25  
KNOTS NEAR THE END OF THE TAF WINDOW (~08Z/TUE AND BEYOND).  
AHEAD OF THE COLD FRONT, A SOUTHWESTERLY LOW-LEVEL JET (LLJ)  
40-50 KNOTS WILL MOVE OVERHEAD WHICH MAY LEAD TO A BRIEF WINDOW  
OF LOW-LEVEL WIND SHEAR (LLWS). FOR NOW, OPTED TO ONLY PUT LLWS  
IN WESTERN TERMINALS FOR NOW WHERE THE LLJ IS THE STRONGEST.  
 
OUTLOOK...NON-VFR EXPECTED IN PERIODS OF RAIN SHOWERS TUESDAY  
THROUGH FRIDAY.  
 
 
   
MARINE  
 
ELEVATED NORTHWESTERLY WINDS REMAIN ACROSS THE CENTRAL AND EASTERN  
BASINS OF LAKE ERIE THROUGH THE BULK OF THE DAY TODAY. ONSHORE FLOW  
WILL ALLOW FOR WAVE HEIGHTS OF 6-8 FEET TO PERSIST. A RIDGE OF HIGH  
PRESSURE WILL BUILD EAST ACROSS THE REGION THROUGH TODAY WHICH WILL  
ALLOW FOR NORTHWESTERLY WINDS TO DIMINISH TO 10-20 KNOTS AND WAVE  
HEIGHTS TO SUBSIDE TO 3 FEET OR LESS LATER THIS AFTERNOON AND  
EVENING. REMAINING SMALL CRAFT ADVISORIES WILL EXPIRE FROM WEST TO  
EAST TODAY.  
 
A BRIEF LULL IN HAZARDOUS MARINE CONDITIONS TONIGHT UNDER THE RIDGE  
BEFORE SOUTHERLY WINDS INCREASE TO 20-30 KNOTS LATE TONIGHT INTO  
TUESDAY AS A COLD FRONT PUSHES EAST ACROSS THE LAKE. GENERALLY  
SOUTHWESTERLY WINDS REMAIN ELEVATED ON TUESDAY BEFORE ANOTHER COLD  
FRONT CROSSES LAKE ERIE AND WINDS VEER WESTERLY BY WEDNESDAY.  
HIGHEST WINDS WILL LIKELY OCCUR IN THE COLD AIR ADVECTION REGIME  
LATE WEDNESDAY AFTERNOON/EARLY WEDNESDAY EVENING BEHIND THE COLD  
FRONT. CAN'T RULE OUT A SHORT WINDOW OF GALE FORCE WINDS ACROSS THE  
CENTRAL AND EASTERN BASINS, THOUGH CONFIDENCE REMAINS LOW (~20-30%)  
WITH THIS FORECAST PACKAGE. ELEVATED WESTERLY WINDS WILL PERSIST  
ACROSS LAKE ERIE THROUGH AT LEAST THURSDAY NIGHT WITH A PERIOD OF  
PROLONGED SMALL CRAFT ADVISORIES EXPECTED. WATER LEVELS MAY DROP  
BELOW THE CRITICAL MARK FOR SAFE NAVIGATION OVER THE WESTERN BASIN  
TUESDAY AND WEDNESDAY GIVEN THE STRONG WESTERLY WINDS.  
 
 
   
CLE WATCHES/WARNINGS/ADVISORIES  
 
OH...NONE.  
PA...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR  
LEZ144>146.  
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR  
LEZ147>149.  
 
 
 
 
 
SYNOPSIS...10  
NEAR TERM...10  
SHORT TERM...10  
LONG TERM...10  
AVIATION...13  
MARINE...13  
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