883
FXUS63 KLOT 030505
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1205 AM CDT FRI OCT 3 2025
KEY MESSAGES
- DRY AND UNSEASONABLY WARM DAYTIME CONDITIONS TO PERSIST
THROUGH THE WEEKEND.
- MONITORING AN INCREASED FIRE DANGER THIS WEEKEND, BUT
PRIMARILY ON SUNDAY.
- A MUCH COOLER AIRMASS ARRIVES MIDDLE TO END OF NEXT WEEK.
DISCUSSION
ISSUED AT 222 PM CDT THU OCT 2 2025
OUR UNSEASONABLY MILD AND DRY STRETCH CONTINUES THROUGH THE
WEEKEND BEFORE A COLD FRONT BRINGS OUR NEXT CHANCE OF
PRECIPITATION EARLY NEXT WEEK, FOLLOWED BY A TRANSITION TO A
PERIOD OF MORE SEASONABLE TEMPERATURES.
SUMMER-LIKE (NEAR RECORD) TEMPERATURES ARE EXPECTED AGAIN ON
FRIDAY, WITH HIGHS IN THE MID TO UPPER 80S. FOR REFERENCE, RECORD
HIGH TEMPERATURES FOR FRIDAY THE 3RD ARE 91 AND 90 AT CHICAGO AND
ROCKFORD, RESPECTIVELY. THE ONLY DIFFERENCE FROM TODAY'S WEATHER
WILL BE THE LIKELIHOOD OF A BIT MORE DIURNAL AFTERNOON CU
DEVELOPMENT AS A SLUG OF SLIGHTLY BETTER LOW-LEVEL MOISTURE
SHIFTS OVERHEAD. ACCORDINGLY, THIS IS EXPECTED TO SET UP A PARTLY
CLOUDY AFTERNOON. ALSO, STILL CANNOT RULE OUT A COUPLE OF ISOLATED
LIGHT SPRINKLES FROM ANY DEEPER CU IN THE AFTERNOON. HOWEVER,
WITH THESE LOOKING TO BE FEW AND FAR BETWEEN WE WILL FORGO ANY
TYPE OF MENTION IN THE GRIDDED FORECAST.
DEEP MIXING AND SUBSIDENCE WARMING ALOFT WILL LEAD TO DRY, AND
BREEZY CONDITIONS WITH NEAR RECORD HIGH TEMPERATURES IN THE 80S
THROUGH THE WEEKEND. THE MAIN FOCUS THIS WEEKEND REMAINS ON
DEWPOINT, RH, AND WIND TRENDS. LATEST GUIDANCE TRENDS CONTINUE TO
SUGGEST THAT DEWPOINTS WILL LIKELY MIX OUT MORE AGGRESSIVELY
COMPARED TO FRIDAY, WITH SUNDAY CURRENTLY LOOKING LIKE THE DRIEST
OF THE TWO DAYS. AFTERNOON RH VALUES IN THE 30-40 PERCENT RANGE ON
SATURDAY AND THEN 25-35 PERCENT RANGE ON SUNDAY LOOK PRETTY
REASONABLE AT THIS RANGE, WITH SOME POTENTIAL FOR THESE TO COME
DOWN A BIT FURTHER DEPENDING ON THE DEGREE OF MIXING. SOUTHERLY
WIND GUSTS UP TO 25 MPH ARE POSSIBLE SATURDAY AND THEN ABOUT 30 TO
PERHAPS 35 MPH ON SUNDAY, STRONGEST NORTH AND WEST OF I-55 AND
ACROSS NORTHWEST ILLINOIS WITHIN A BELT OF STRONGER BL FLOW. WILL
CONTINUE TO HIGHLIGHT AN ELEVATED FIRE DANGER BOTH DAYS AS A
RESULT, BUT SUNDAY OBVIOUSLY IS THE GREATER CONCERN AT THIS TIME.
AT THIS POINT, IT LOOKS LIKE WE'LL PROBABLY STAY SHY OF RED FLAG
CONDITIONS.
A STRONG COLD FRONT IS STILL SLATTED TO PUSH THROUGH THE REGION
DURING THE MONDAY-TUESDAY TIMEFRAME. AN INITIAL BOUNDARY/PRE-
FRONTAL TROUGH/COMPOSITE OUTFLOW WILL APPROACH THE REGION ON
MONDAY, POSSIBLY WITH AN INITIAL BATCH OF SHOWERS. MOST GUIDANCE
INDICATES TEMPERATURES WILL WARM BACK INTO THE 80S ACROSS MOST OF
THE AREA MONDAY AFTERNOON BEFORE THE MAIN FRONTAL ZONE SLIPS
THROUGH LATER ON TUESDAY. WHILE MID-LEVEL LAPSE RATES AND
ASSOCIATED INSTABILITY LOOKS UNIMPRESSIVE AHEAD OF THE FRONT
TUESDAY AFTERNOON, STRONGER DEEP-LAYER FLOW WILL ARRIVE THROUGH
THE DAY, AND IF SOME MUTED INSOLATION IS REALIZED, IT WOULDN'T BE
TOTALLY OUT OF THE QUESTION FOR A FEW STRONGER THUNDERSTORMS AHEAD
OF THE SURGING COLD FRONT. A FASTER FROPA WOULD TEND TO DIMINISH
THIS POTENTIAL. ASCENT WILL CONTINUE ATOP THE FRONTAL INVERSION
INTO TUESDAY NIGHT, LEADING TO A CHANCE FOR LINGERING ANAFRONTAL
SHOWERS AND PERHAPS A FEW THUNDERSTORMS BEFORE THINGS DRY OUT ON
WEDNESDAY.
A MUCH COOLER AIRMASS WILL REMAIN IN PLACE THROUGH THE END OF
NEXT WEEK. LOW TEMPERATURES THURSDAY MORNING GENERALLY IN THE
40S ARE EXPECTED, WITH A CHANCE FOR A FEW UPPER 30S IN TYPICAL
COOL/SHELTERED SPOTS.
CARLAW/KJB
AVIATION /06Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 1205 AM CDT FRI OCT 3 2025
VFR WITH NO SIGNIFICANT CONCERNS THROUGH THE PERIOD.
LIGHT SOUTHERLY TO CALM/VRB WINDS THROUGH EARLY THIS MORNING
WILL BECOME SOUTHWESTERLY NEAR 10 KT BY THE MID TO LATE MORNING
AT NORTHERN IL TERMINALS. A LAKE BREEZE MAY APPROACH MDW AND
PERHAPS ORD AFTER SUNSET. GIVEN THAT TIMING, THE BOUNDARY WILL
PROBABLY WASH OUT, WITH WINDS RETURNING TO LIGHT SOUTHERLY
THROUGH FRIDAY NIGHT. EVEN IF THE LAKE BREEZE REACHES MDW AND
ORD, (UNLESS IT WERE TO PUSH INLAND QUICKER AND REACH THE
TERMINALS PRIOR TO SUNSET), SPEEDS FROM THE SOUTHEAST OR EAST-
SOUTHEAST WILL LIKELY BE SAFELY BELOW 10 KT. ANY VERY SPOTTY
SHRA ON FRIDAY SHOULD BE SOUTH OF THE TERMINALS.
CASTRO
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
VISIT US AT WEATHER.GOV/CHICAGO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page