048
FXUS63 KLOT 142010
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
310 PM CDT WED OCT 14 2026
KEY MESSAGES
- A FALL STORM SYSTEM WILL MOVE THROUGH THE AREA THURSDAY AND
FRIDAY, BRINGING PERIODS OF RAIN SHOWERS AND GUSTY
NORTHWESTERLY WINDS (THE LATTER PRIMARILY ON FRIDAY).
- FROSTY AND NEAR-FREEZING CONDITIONS ARE FAVORED AWAY FROM
LAKE MICHIGAN FRIDAY NIGHT INTO SATURDAY.
- AFTER THE BRIEF PERIOD OF CHILLY WEATHER, THERE WILL BE A
WARMING TREND THIS WEEKEND INTO EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 310 PM CDT WED OCT 14 2026
THROUGH THURSDAY NIGHT:
OTHER THAN A FEW SPITS OF DRIZZLE NEAR LAKE MICHIGAN, MOST OF
THE AREA HAS SINCE DRIED OUT FROM THE OVERNIGHT AND EARLY
MORNING SHOWERS AND THUNDERSTORMS. THE COMBINATION OF OVERCAST
SKIES AND PERSISTENT ONSHORE NORTHEASTERLY WINDS HAVE HELD
TEMPERATURES IN THE LOW TO MID 60S NEAR/NORTH OF I-80. FARTHER
SOUTH, A THINNING OF THE STRATUS LAYER WITH OCCASIONAL PEEKS OF
SUNSHINE HAS ALLOWED TEMPERATURES TO WARM INTO THE UPPER 60S
AND LOWER 70S. GENERALLY EXPECT THE CLOUD COVER TO FILL BACK IN
THROUGH THIS EVENING AND OVERNIGHT WITH TEMPERATURES ONLY
DROPPING INTO THE 50S.
A FALL STORM SYSTEM REMAINS ON TRACK TO LIFT ACROSS THE REGION
ON THURSDAY WHICH WILL BRING WIDESPREAD SHOWERS AND A FEW
RUMBLES OF THUNDER TO THE AREA. THE GREATEST SHOWER COVERAGE IS
CURRENTLY FAVORED LATE MORNING THROUGH THE AFTERNOON. HI-RES
GUIDANCE CONTINUES TO DEPICT A RELATIVE MINIMUM IN PRECIPITATION
DEVELOPING ON THE SOUTHWEST SIDE OF THE SURFACE LOW DURING THE
LATE AFTERNOON AND EARLY EVENING. DEPENDING ON HOW FAR NORTH THE
LOW TRACKS, INCREASING INSTABILITY SOUTHEAST OF THIS DRY WEDGE
MAY LIFT INTO THE FAR SOUTHERN FORECAST AREA, SOUTH OF A PONTIAC
TO RENSSELAER LINE. WHILE THE BETTER INSTABILITY REMAINS
FARTHER SOUTH INTO CENTRAL AND SOUTHERN ILLINOIS, AN ISOLATED
STRONGER STORM CAN'T BE RULED OUT. ANY MORE ROBUST SHOWERS AND
EMBEDDED THUNDERSTORMS WILL BE CAPABLE OF EFFICIENT RAINFALL
RATES FOR THIS TIME OF YEAR IN THE PRESENCE OF PWATS
POTENTIALLY UPWARDS OF 1.5-2". THE LIMITED COVERAGE OF STRONGER
SHOWERS/STORMS SHOULD KEEP ANY FLOODING POTENTIAL TIED MAINLY TO
PONDING ON ROADWAYS AND POOR DRAINAGE SPOTS.
FRIDAY:
IN THE WAKE OF THE DEPARTING STORM SYSTEM AND ASSOCIATED STRONG
COLD FRONT, THE SURFACE PRESSURE GRADIENT INCREASES MARKEDLY
ACROSS THE AREA ON FRIDAY. THIS WILL LEAD TO BLUSTERY NORTHWEST
WINDS GUSTING UP TO 30-40+ MPH, HIGHEST ALONG THE NORTHWEST
INDIANA LAKESHORE. IN ADDITION, MODEL GUIDANCE HAS TRENDED
SLIGHTLY MORE SATURATED WITHIN THE LOW-CLOUD LAYER WHICH MAY
SUPPORT THE REDEVELOPMENT OF GUSTY DIURNAL SHOWERS. WEAK
INSTABILITY WITHIN THE LAYER AND COLDER CLOUD TOPS MAY SUPPORT
SOME GRAUPEL AS WELL. TEMPERATURES ON FRIDAY WILL LIKELY
STRUGGLE TO WARM OUT OF THE LOW TO MID 50S, MAKING FOR THE
COLDEST DAY OF THE SEASON SO FAR.
AS THE NORTHWESTERLY WINDS BEGIN TO TURN MORE NORTHERLY OVER
LAKE MICHIGAN, A BROKEN BAND (OR BANDS) OF LAKE EFFECT RAIN
SHOWERS WILL FOCUS INTO NORTHWEST INDIANA LATE FRIDAY AFTERNOON
THROUGH THE EVENING. WAVES ARE ALSO EXPECTED TO INCREASE AND MAY
LEAD TO MINOR LAKESHORE FLOODING OR EROSION, PARTICULARLY ALONG
THE PORTER COUNTY SHORE.
FRIDAY NIGHT ONWARD:
SKIES WILL QUICKLY CLEAR OUT AFTER MIDNIGHT FRIDAY, WHICH WILL
ALLOW FOR EFFICIENT RADIATIONAL COOLING AMIDST AN ALREADY COOLER
AIRMASS. THIS WILL LIKELY LEAD TO AREAS OF FROST DEVELOPMENT
OUTSIDE OF CHICAGO AND AWAY FROM LAKE MICHIGAN, COVERAGE
DEPENDENT UPON HOW LIGHT WINDS END UP. CAN'T RULE OUT
TEMPERATURES IN PORTIONS OF INTERIOR NORTHERN ILLINOIS DROPPING
INTO THE LOWER 30S. HOWEVER, CONFIDENCE IS NOT HIGH ENOUGH FOR A
FREEZE WATCH WITH THIS UPDATE.
WHILE STILL COOLER ON SATURDAY WITH TEMPERATURES IN THE 50S TO
AROUND 60, A RETURN OF SOUTHWESTERLY LOW-LEVEL FLOW WILL BEGIN A
GRADUAL WARMING TREND THAT CONTINUES THROUGH EARLY NEXT WEEK,
BRINGING A RETURN TO ABOVE NORMAL TEMPERATURES.
PETR
AVIATION /18Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 107 PM CDT WED OCT 14 2026
KEY MESSAGES:
- MVFR CEILINGS WILL CONTINUE THIS AFTERNOON.
- RAIN IS EXPECTED TOMORROW WITH ASSOCIATED LOWERED CEILINGS AND
VISIBILITIES.
MVFR CEILINGS ARE BEING OBSERVED AT ALL OF OUR TAF SITES AT
PRESS TIME EARLY THIS AFTERNOON. SOME LIFTING AND/OR SCATTERING
OF THIS MVFR STRATOCUMULUS WITH TIME SHOULD ALLOW FOR VFR
CONDITIONS TO RETURN TO AT LEAST A FEW OF OUR TAF SITES BY THIS
EVENING, BUT CONFIDENCE IN PRECISE CEILING TRENDS THROUGH
TONIGHT IS NOT VERY HIGH.
REGARDLESS, CEILINGS WILL DETERIORATE TOMORROW AS A SLUG OF RAIN
ASSOCIATED WITH AN INCOMING LOW PRESSURE SYSTEM PUSHES INTO THE
AREA FROM THE SOUTHWEST. A PERIOD OF IFR CEILINGS IS LIKELY
TOMORROW AFTERNOON, AND THERE IS A SIGNAL IN FORECAST GUIDANCE
FOR LIFR CEILINGS TO BE OBSERVED AS WELL. MVFR OR LOWER
VISIBILITIES ARE ALSO LIKELY TO BE OBSERVED AT TIMES TOMORROW
DURING THE STEADIER RAINFALL. COULDN'T RULE OUT SOME ISOLATED
LIGHTNING STRIKES OCCURRING TOMORROW AFTERNOON, PARTICULARLY
NEAR GYY AND MDW, THOUGH THE BETTER THUNDERSTORM POTENTIAL
SHOULD REMAIN SOUTH OF THE TERMINALS.
WINDS THROUGH THE TAF PERIOD ARE EXPECTED TO RETAIN AN EASTERLY
COMPONENT WITH MAGNITUDES AVERAGING OUT NEAR OR JUST UNDER 10
KTS.
OGOREK
MARINE
ISSUED AT 310 PM CDT WED OCT 14 2026
STRONG NORTHWESTERLY GALES TO 40 KT AND VERY HAZARDOUS WAVES
ARE FORECAST TO DEVELOP FRIDAY AFTERNOON IN THE WAKE OF A
DEPARTING FALL STORM SYSTEM, BECOMING MORE NORTHERLY INTO FRIDAY
EVENING. ACCORDINGLY, A GALE WATCH HAS BEEN ISSUED FOR THE
ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS FROM 1 PM FRIDAY
THROUGH 1 AM SATURDAY.
INCREASING LAKE INDUCED INSTABILITY WILL BECOME SUPPORTIVE OF
THE DEVELOPMENT OF A BAND OF LAKE EFFECT SHOWERS OVER LAKE
MICHIGAN FRIDAY AFTERNOON AND EVENING. WATERSPOUTS ALSO CANNOT
BE RULED OUT WITHIN THE STRONGEST SHOWERS.
PETR
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 PM CDT THURSDAY FOR WINTHROP
HARBOR TO WILMETTE HARBOR IL.
GALE WATCH FROM FRIDAY AFTERNOON THROUGH LATE FRIDAY NIGHT FOR
THE IL AND IN NEARSHORE WATERS.
SMALL CRAFT ADVISORY UNTIL 10 AM CDT THURSDAY FOR WILMETTE
HARBOR TO NORTHERLY IS. IL.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT THURSDAY FOR NORTHERLY IS.
IL TO MICHIGAN CITY IN.
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