237
FXUS61 KILN 181711
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
111 PM EDT SAT OCT 18 2025
SYNOPSIS
SHOWERS AND BREEZY CONDITIONS ARE EXPECTED THROUGH THE
DAYTIME SUNDAY BEFORE DRIER AND COOLER AIR RETURNS FOR THE FIRST
HALF OF THE UPCOMING WEEK. EVEN COOLER AIR WILL SETTLE INTO THE
REGION BY MIDWEEK AND BEYOND, WITH SLIGHTLY BELOW NORMAL
TEMPERATURES PERSISTING THROUGH MUCH OF THE UPCOMING WEEK. SOME
SHOWERS WILL ALSO BE POSSIBLE MIDWEEK WITH THE ARRIVAL OF THE
CHILLIER AIRMASS.
NEAR TERM /THROUGH TONIGHT/
FOR THIS AFTERNOON, A MIX OF SUN AND CLOUDS AMIDST WAA WILL HELP
TEMPS CLIMB INTO THE LOWER 80S JUST ABOUT EVERYWHERE. THE STANDING
DAILY RECORD HIGH OF 83F MAY BE CHALLENGED AT KCMH IF SUNSHINE CAN
PERSIST FOR LONG ENOUGH. SW WINDS OF 10-15KTS WILL GUST TO AROUND
20KTS AT TIMES MID/LATE AFTERNOON BEFORE BRIEFLY SUBSIDING TOWARD
SUNSET.
THE FIRST STRONG/DEEP SYSTEM OF THE SEASON FOR THE REGION WILL
IMPACT THE OH VLY TONIGHT THROUGH THE DAY SUNDAY, WITH SHOWERS AND
VERY BREEZY CONDITIONS EVOLVING DURING THIS TIME PERIOD.
AN EXPANSIVE TROUGH DIGGING INTO THE UPPER MIDWEST HAS ALLOWED FOR
DEEP-LAYER SW FLOW TO BECOME ESTABLISHED FROM THE MID MS RVR VLY NE
INTO THE OH VLY, PROMOTING A STRENGTHENING OF THE DEEP-LAYER WINDS
AS WELL WITH THE RIDGE AXIS POSITIONED ALONG THE EASTERN SEABOARD.
DIGGING S/W ENERGY AROUND THE BASE OF THIS SHARPENING TROUGH WILL
PROMOTE RAPID CYCLOGENESIS IN THE MID MS RVR VLY LATE THIS EVENING,
WITH THE SFC LOW TRANSLATING TO THE NE FROM NEAR ST. LOUIS AROUND
00Z TO NEAR DETROIT BY 12Z. LL WIND FIELDS WILL RESPOND ACCORDINGLY,
WITH AN ENHANCED LLJ DEVELOPING TONIGHT ON THE ERN SIDE OF THE
TROUGH, WITH H8 WINDS ON THE ORDER OF 50-55KTS NOSING NE INTO THE
LOCAL AREA AFTER MIDNIGHT. 925MB WINDS WILL APPROACH 45KTS BETWEEN
MIDNIGHT AND DAYBREAK AS THE STRENGTHENING LL WIND FIELD IMPINGES TO
THE N INTO THE LOCAL AREA, WITH STRONGEST SUSTAINED SFC WINDS
EVOLVING BY/PAST 08Z. THE DYNAMICS AT PLAY HERE ARE CERTAINLY
IMPRESSIVE AND ARE FAIRLY TYPICAL OF A STRONG MID LATITUDE CYCLONE
THIS TIME OF THE YEAR.
STRONG/DEEP FORCING AND ENHANCED DEEP-LAYER AND LL WIND FIELDS WILL
SPREAD TO THE E INTO THE ILN FA LATE TONIGHT INTO THE PREDAWN HOURS
SUNDAY, WITH MOST OF THE LOCAL RAIN ASSOCIATED WITH THIS SYSTEM
HOLDING OFF UNTIL AFTER 06Z, WITH THE MOST WIDESPREAD PRE-FRONTAL
RAIN EXPECTED BETWEEN 08Z-16Z FROM W TO E, RESPECTIVELY.
FCST SOUNDINGS FROM A NUMBER OF SOLUTIONS, INCLUDING HI-RES CAMS,
SHOW TWO IMPORTANT ITEMS THAT WILL BE WATCHED CAREFULLY AS WE
PROGRESS THROUGH THE NEXT 12-18 HOURS. THE FIRST OF THESE WILL BE
THE EXPECTED LACK OF INSTBY, WITH A RATHER UNFAVORABLE LL
THERMODYNAMIC ENVIRONMENT WITH EASTWARD EXTENT. THIS WILL LIMIT THE
OVERALL COVERAGE OF THUNDER AND CONVECTIVE INTENSITY, LIKELY
INHIBITING (AT LEAST TO SOME DEGREE) THE POTENTIAL FOR STRONG/SEVERE
STORMS IN THE TRADITIONAL SENSE. THIS BEING SAID, THE SECOND ITEM TO
MONITOR WILL BE THE MAINTENANCE OF A VERY SHALLOW ISOTHERMAL LAYER
BETWEEN 925MB AND THE SFC THAT WILL HELP KEEP SOME OF THE STRONGER
WINDS ALOFT FROM TRANSLATING TO THE GROUND IN THE STEADIER PRECIP.
THIS SMALL STABLE LAYER, HOWEVER, COULD BE OVERCOME IN TWO DIFFERENT
SCENARIOS. THE FIRST (AND MORE LIKELY) SCENARIO WOULD BE ON THE
LEADING EDGE OF THE RAIN WHERE, INITIALLY, STEEPER LL LAPSE RATES
WILL STILL EXIST WITH A FAIRLY DRY SUB-CLOUD LAYER. NEAR THE ONSET
OF THE STEADIER RAIN, RELATIVELY LITTLE PRECIP MAY ACTUALLY REACH
THE GROUND AS THE LL PROFILE SLOWLY SATURATES. AND IF THE PRECIP IS
TOO MINIMAL, LIGHT RAIN FALLING INTO AND EVAPORATING WITHIN THE SUB-
CLOUD LAYER MAY STEEPEN THE LOW-LEVEL LAPSE RATES AND ENHANCE MIXING
FOR A BRIEF PERIOD OF TIME UNTIL RAIN BECOMES STEADY ENOUGH TO
EFFECTIVELY SATURATE/STABILIZE THE BL. THE SECOND (AND LESS LIKELY)
WAY THE SMALL STABLE LAYER COULD BE OVERCOME IS THROUGH TRADITIONAL
CONVECTIVE PROCESSES ALONG A THIN/NARROW LOW-TOPPED CONVECTIVE LINE.
THIS MAY ALLOW FOR CONVECTIVE ENHANCEMENTS TO BECOME REALIZED
ABOVE/BEYOND THE BACKGROUND SYNOPTIC-SCALE FLOW. THE BACKGROUND
SYNOPTIC-SCALE FLOW WILL PROMOTE SOUTHERLY WINDS OF 20-25KTS, WITH
GUSTS TO 30-35KTS, ESPECIALLY BETWEEN 08Z-16Z. THE CONVECTIVE
ENHANCEMENTS CERTAINLY COULD BRING GUSTS ON THE ORDER OF 40-45 KTS,
BUT DO THINK THIS WOULD BE SOMEWHAT BRIEF/ISOLATED IN NATURE AND
THEREFORE IT WOULD BE BEST TO BE HANDLED WITH SHORT-FUSE SPSS AND/OR
WARNINGS (IF NECESSARY). DO THINK THAT MOST SPOTS WILL SEE PEAK WIND
GUSTS AROUND 35KTS LATE TONIGHT THROUGH SUNDAY MORNING, WITH
ISOLATED INSTANCES OF 40-45KTS WHERE EITHER EVAPORATIVE COOLING ON
THE LEADING EDGE OF THE PRECIP OR CONVECTIVE PROCESSES ALONG A LOW-
TOPPED LINEAR STRUCTURE ARE ABLE TO OVERWHELM THE OTHERWISE MARGINAL
NEAR-SFC LAPSE RATES. BOTTOM LINE IS THAT THE SETUP FOR STRONG
SYNOPTIC-SCALE GUSTS OF 40+KTS OR STRONG/SEVERE "STORMS" IS VERY
MARGINAL, BUT COULD BE MATERIALIZE IN VERY BRIEF/LOCALIZED INSTANCES.
SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/
AS WE PROGRESS INTO LATE MORNING, THE PRE-FRONTAL SEMI-LINEAR
SHOWERS/LOW-TOPPED CONVECTION WILL EXIT TO THE E, WITH A RELATIVE
LULL IN BOTH PRECIP AND GUSTINESS EXPECTED FROM ABOUT 16Z-18Z OR SO.
PAST 18Z, THE SHARPENING TROF AXIS WILL APPROACH FROM THE W, WITH AN
ABRUPT INCREASE IN DEEP-LAYER FORCING ONCE AGAIN MID AFTERNOON
THROUGH THE EVENING. THIS WILL OCCUR COINCIDENT WITH THE STEEPENING
OF LL LAPSE RATES AS COOLER AIR ALOFT ADVECTS IN FROM THE NW. THIS
WILL PROMOTE THE DEVELOPMENT OF ADDITIONAL RAIN ON THE "BACKSIDE" OF
THE DEPARTING SFC SYSTEM WITHIN THE CAA REGIME. IN FACT, THUNDER
SEEMS MUCH MORE PLAUSIBLE BY MID/LATE AFTERNOON THAN WILL BE THE
CASE THROUGH THE MORNING AS ENOUGH INSTBY MAY DEVELOP IN THE
BURGEONING CAA REGIME TO ALLOW FOR THUNDERSTORMS MID/LATE DAY. THE
SFC PRESSURE GRADIENT WILL AGAIN TIGHTEN, LEADING TO INCREASED
SYNOPTIC-SCALE SUSTAINED WINDS AND GUSTS BETWEEN 18Z-04Z BEFORE THE
SYSTEM DEPARTS THE ILN FA ALTOGETHER AROUND MIDNIGHT. ADDITIONAL
RAINFALL OF HALF TO THREE QUARTERS OF AN INCH WILL BE POSSIBLE LATE
DAY THROUGH THE EVENING, WITH WNW WINDS OF 15-20KTS, AND GUSTS TO
35KTS, EXPECTED DURING THIS TIME FRAME. TOTAL RAINFALL BY SUNDAY
NIGHT WILL GENERALLY RANGE FROM 0.75" TO 1.25" ACROSS THE BOARD.
TEMPS ON SUNDAY WILL BE NON-DIURNAL IN NATURE WITH CAA EVOLVING AREA-
WIDE BY EARLY AFTERNOON. NEARLY-STEADY TEMPS THROUGH THE MORNING
WILL SLOWLY FALL INTO THE AFTERNOON AS CAA INTENSIFIES. DAYBREAK
TEMPS WILL RANGE FROM THE UPPER 60S IN THE LOWER SCIOTO VALLEY, NE
KY, AND CENTRAL OH TO THE LOWER 60S W OF I-75. BY LATE AFTERNOON,
THE TEMP GRADIENT WILL RANGE FROM THE LOWER 60S IN THE E TO THE MID
50S IN THE W.
EXPANSIVE CLOUD COVER WILL LINGER THROUGH THE FIRST PART OF SUNDAY
NIGHT, BUT EVEN WITH THIS, TEMPS SHOULD DIP INTO THE UPPER 30S TO
LOWER 40S BY SUNRISE MONDAY WITH THE AIRMASS CHANGE AND CLEARING
SKIES.
LONG TERM /MONDAY THROUGH SATURDAY/
HIGH PRESSURE BRIEFLY BUILDS IN FROM SOUTH ACROSS THE OHIO VALLEY ON
MONDAY. SUNNY SKIES AND SOUTHWESTERLY WINDS HELP HIGHS REACH INTO
THE LOWER TO MIDDLE 60S AREAWIDE. FOR TUESDAY NIGHT, DRY CONDITIONS
REMAIN IN PLACE FOR THE FIRST HALF OF THE NIGHT. WINDS STAY ELEVATED
AS THE OHIO VALLEY IS SANDWICHED BETWEEN HIGH PRESSURE TO THE
SOUTHEAST AND A STRONG LOW OVER THE NORTHERN GREAT LAKES. FORECAST
LOWS ONLY DROP INTO THE UPPER 40S AS CLOUDS INCREASE ALONG WITH
RAIN CHANCES.
BY TUESDAY MORNING, RAIN CHANCES ARRIVE WHEN ANOTHER COLD FRONT
MOVES THROUGH THE REGION. MOISTURE RETURN APPEARS TO BE FAIRLY WEAK
ALONG WITH FORCING. COOLER, DRIER AIR MOVES IN BEHIND THE FRONT
TUESDAY NIGHT AND INTO THE MIDDLE OF THE WORK WEEK. WEDNESDAY NIGHT
IS LIKELY TO BE THE COLDEST NIGHT THIS WEEK WITH LOWS DROPPING INTO
THE 30S FOR MOST LOCATIONS. FROST POTENTIAL WILL NEED TO BE
MONITORED, BUT WINDS MAY REMAIN STRONG ENOUGH OVERNIGHT TO PREVENT
WIDESPREAD FROST FORMATION. CLOUD COVER COULD ALSO INHIBIT FROST.
A SLOW MODERATING TREND DEVELOPS FOR THE END OF THE WORK WEEK WHEN
HIGH PRESSURE SLOWLY DRIFTS FURTHER SOUTHEAST. RAIN CHANCES ALSO
RETURN TOWARD THE WEEKEND WHEN A WEAK LOW POTENTIALLY MOVES IN FROM
THE MISSISSIPPI RIVER VALLEY.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
A BKN 6-8KFT DECK IS OVERSPREADING THE REGION FROM THE SW, WITH SOME
SPOTTY SPRINKLES POSSIBLE EARLY AT KCVG/KLUK. HOWEVER, CONDITIONS
WILL REMAIN MAINLY DRY AREA-WIDE THROUGH THE EVENING, WITH THE
PRIMARY ITEM OF INTEREST THROUGH 06Z BEING THE ARRIVAL OF SOME SW
LLWS ON THE ORDER OF ABOUT 45KTS BY 06Z, OVERSPREADING THE ENTIRETY
OF THE LOCAL AREA THROUGH ABOUT 12Z. SW WINDS AROUND 10-12KTS WILL
OCCASIONALLY GUST TO 18-20KTS THROUGH SUNSET BEFORE BRIEFLY
SUBSIDING BETWEEN 23Z-06Z.
BY/AFTER 06Z, A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR SOUTHERLY
WINDS TO GRADUALLY STRENGTHEN, WITH A BAND OF RA EXPECTED TO
OVERSPREAD THE AREA W TO E BETWEEN 09Z-15Z. ON THE LEADING EDGE OF
THIS RA, A BRIEF (1-2 HOURS) PERIOD OF GUSTY CONDITIONS IS EXPECTED,
WITH GUSTS OF 35-40+ KTS POSSIBLE DURING THIS TIME. ONCE THE STEADY
RA ARRIVES, THE GUSTINESS SHOULD SUBSIDE A BIT, BUT WITH THE TIGHT
PRESSURE GRADIENT, SSW FLOW OF ABOUT 20KTS, WITH GUSTS TO AROUND
30KTS, WILL PERSIST THROUGH ABOUT 14Z OR SO BEFORE SUBSIDING THROUGH
MID AFTERNOON. WNW WINDS AROUND 20KTS, WITH GUSTS TO AROUND 30-35KTS,
ARE LIKELY AGAIN BY/PAST 21Z.
DID ADD A PROB30 TS FOR SRN SITES OF KCVG/KLUK NEAR THE END OF THE
PERIOD GIVEN THE SLIGHTLY BETTER LAPSE RATES EVOLVING BY SUNDAY
AFTERNOON.
CIGS WILL TRANSITION FROM VFR TO MVFR PROGRESSIVELY FROM W TO E
NEAR/AFTER 12Z SUNDAY.
OUTLOOK...WIND GUSTS AT/ABOVE 30KTS ARE POSSIBLE INTO EARLY SUNDAY
EVENING. MVFR/IFR CIGS AND MVFR VSBY WILL OCCUR INTO SUNDAY EVENING.
MVFR/IFR CIGS WILL PERSIST INTO SUNDAY NIGHT.
ILN WATCHES/WARNINGS/ADVISORIES
OH...NONE.
KY...NONE.
IN...NONE.
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page