567
FXUS63 KLOT 150507
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1107 PM CST SAT FEB 14 2026
KEY MESSAGES
- RAIN IS EXPECTED ACROSS CENTRAL IL/IN AND MAY EXTEND AS FAR
NORTH AS US-24 THIS EVENING AND OVERNIGHT.
- ABOVE AVERAGE TEMPERATURES CONTINUE THROUGH MIDWEEK THEN TURN
COLDER TOWARD THE END OF THE WEEK.
- PERIODIC PRECIPITATION CHANCES EXIST MID TO LATE NEXT WEEK
(~20-40% CHANCE).
DISCUSSION
ISSUED AT 300 PM CST SAT FEB 14 2026
THROUGH TONIGHT:
EXPANSIVE STRATUS EXTENDING NORTH OF AN APPROACHING DISTURBANCE
SLOWED DIURNAL WARMING ACROSS THE AREA FOR MUCH OF THE DAY.
HOWEVER, A BRIEF SOUTHWARD SHIFT IN THE NORTHERN EDGE OF THE
CLOUDS HAS ALLOWED SUN TO SHINE OVER FAR NORTHERN ILLINOIS
INTERMITTENTLY WHERE TEMPERATURES HAVE SINCE WARMED INTO THE
LOWER 50S. ELSEWHERE TEMPERATURES ARE STILL IN THE MID TO UPPER
40S AND MAY STRUGGLE TO WARM MUCH MORE PRIOR TO SUNSET. A WEAK
LAKE BREEZE HUGGING THE IMMEDIATE LAKESHORE WILL ALSO KEEP
TEMPERATURES IN THE LOWER TO MID 40S THERE.
LOOKING AHEAD TO TONIGHT, DRY CONDITIONS ARE EXPECTED FOR MOST
OF THE AREA. WE ARE MONITORING AN EXPANSIVE AREA OF RAIN
CURRENTLY LIFTING INTO CENTRAL ILLINOIS. BASED ON THE LATEST
HI-RES MODEL TRENDS, HAVE HELD ONTO RAIN CHANCES FOR LOCALES
SOUTH OF US-24 WHERE THE NORTHERN PERIPHERY OF THE RAIN SHIELD
COULD BRIEFLY LIFT ACROSS. RAINFALL AMOUNTS SHOULD REMAIN LIGHT
GIVEN THE LIMITED DURATION, UNDER 0.15". INCREASING LOW-LEVEL
MOISTURE IN THE WAKE OF THE DEPARTING SYSTEM COULD ALLOW FOR
PATCHY FOG DEVELOPMENT (WELL SOUTH OF I-80) AS TEMPERATURES COOL
OVERNIGHT.
SUNDAY:
A WEAK MID-LEVEL SHORT-WAVE WILL DIVE ACROSS THE AREA LATE
TONIGHT INTO EARLY SUNDAY MORNING WITH AN ASSOCIATED SURFACE
TROUGH AXIS TURNING WINDS NORTHWEST. THIS WILL ACTUALLY LEAD TO
WARMER UPSTREAM AIR ADVECTING INTO THE AREA ON SUNDAY. IN
CONTRAST TO TODAY'S TEMPERATURE FORECAST WHICH WAS MORE
UNCERTAIN DUE TO THE CLOUD COVER, TEMPERATURES LOOK TO MORE
SOLIDLY WARM INTO THE 50S ACROSS THE AREA, INCLUDING NEAR THE
LAKESHORE. IN FACT, SOME OF THE WARMER GUIDANCE (RAP/HRRR)
SUGGEST SOME AREAS COULD REACH 60. AN INLAND PUSH OF THE LAKE
BREEZE WILL CUT THE WARMTH SHORT NEAR THE LAKESHORE WHERE
TEMPERATURES WILL QUICKLY FALL BACK INTO THE 40S IN THE
AFTERNOON.
MONDAY AND TUESDAY:
EXPANSIVE UPPER-LEVEL RIDGING WILL BUILD ACROSS THE REGION ON
MONDAY AND SET THE STAGE FOR THE WARMEST DAY OF THE YEAR SO FAR
WITH HIGHS POTENTIALLY IN THE UPPER 50S TO LOWER 60S AREAWIDE
(THIS WOULD BREAK RECORD HIGHS FOR FEB 16 AT BOTH ROCKFORD AND
CHICAGO-O'HARE). AS IS OFTEN THE CASE ON ANOMALOUSLY WARM DAYS
IT WILL LIKELY BE PAIRED WITH GUSTY SOUTHWEST WINDS POTENTIALLY
GUSTING UP TO 30-35 MPH IN THE AFTERNOON.
TUESDAY NIGHT THROUGH WEDNESDAY MORNING:
THE WESTERN CONUS UPPER TROUGH BEGINS TO EJECT OFF THE ROCKIES
TOWARD MIDWEEK WITH LEE CYCLOGENESIS EXPECTED ACROSS THE
NORTHERN PLAINS. THIS FEATURE IS THEN EXPECTED TO DRIFT EAST
ACROSS THE UPPER MIDWEST WITH AN EXPANSIVE REGION OF WARM
ADVECTIVE PRECIPITATION EXPECTED TO DEVELOP OUT AHEAD OF IT.
THIS COULD LEAD TO A PERIOD OF RAIN LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING OVER PORTIONS OF THE AREA (WITH THE WINTRY
PRECIPITATION LIKELY REMAINING NORTH OF THE WI/IL STATELINE). A
BRIEF PERIOD OF ELEVATED INSTABILITY COULD SUPPORT A FEW
EMBEDDED LIGHTNING STRIKES, HOWEVER, GIVEN LOWER CONFIDENCE,
OPTED TO MAINTAIN A CAP OF 15% ON THUNDER CHANCES.
WEDNESDAY THROUGH THE END OF THE WEEK:
CONFIDENCE IN THE DETAILS DECREASES IN THE WAKE OF THE TUESDAY
NIGHT SYSTEM WITH DIFFERENCES IN HOW FAR NORTH THE VARIOUS
SUBSEQUENT SYSTEMS TRACK, WITH THE LOCAL AREA POTENTIALLY
RESIDING ON EITHER SIDE OR RIGHT ALONG IT. OPTED TO NOT MAKE
BIG CHANGES TO THE BLENDED GUIDANCE FOR NOW, WHICH LEANS TOWARD
THE WARMER GUIDANCE ON WEDNESDAY WITH HIGHS POTENTIALLY WELL
INTO THE 60S (UPPER 60S SOUTH OF I-80) WITH PERIODIC LOW PRECIP
CHANCES (20-40%). TEMPERATURES THEN GENERALLY TREND COLDER (AND
MORE SEASONABLE) TOWARD THE END OF THE WEEK WHICH COULD FEATURE
WINTRY PRECIPITATION DEPENDING ON WHERE THE AFOREMENTIONED SYSTEMS
TRACK.
PETR
AVIATION /06Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 1107 PM CST SAT FEB 14 2026
KEY AVIATION MESSAGES FOR THE 06Z TAFS:
- SOME PATCHY BR POSSIBLE PRIOR TO SUNRISE AT RFD/GYY.
- LOW CONFIDENCE IN WEAK LAKE BREEZE LATE SUNDAY AFTERNOON/EARLY
EVENING, MAINLY AT MDW AND GYY THOUGH CAN'T RULE OUT ORD.
SURFACE LOW PRESSURE WAS OVER ARKANSAS LATE SATURDAY EVENING,
AND WILL CONTINUE TO TRACK EAST THROUGH SUNDAY MORNING WITH ITS
ASSOCIATED AREA OF RAIN AND LOWER VIS/CIG CONDITIONS REMAINING
WELL SOUTH OF THE TERMINALS. NORTH OF THE LOW, A WEAK AND
DIFFUSE RIDGE OF SURFACE HIGH PRESSURE WILL LINGER ACROSS THE
TERMINALS, AND WILL SUPPORT LIGHT (<5 KT) SOUTH-SOUTHWEST WINDS
OVERNIGHT. WINDS WILL EVENTUALLY TURN MORE WESTERLY TOWARD
DAYBREAK, AND EVENTUALLY WEST-NORTHWEST OR NORTHWEST BEHIND A
SURFACE LOW PRESSURE TROUGH WHICH WILL PASS MIDDAY. WHILE THESE
WINDS ARE ONLY EXPECTED TO BE AROUND 10 KTS, MODEL GUIDANCE
CONTINUES TO TREND WEAKER WITH A LAKE BREEZE WHICH LOOKS TO BE
CONFINED TO NEAR THE IL SHORE AND INTO NORTHWEST IN LATE IN THE
DAY/EARLY EVENING. HAVE INDICATED A BRIEF SHIFT TO NORTHEAST
WINDS AT GYY AND MDW IN THE 23-00Z TIMEFRAME, WITH LOWER
CONFIDENCE OF A SHARPER WIND SHIFT AT ORD. IT DOES APPEAR
HOWEVER THAT WINDS WILL WEAKEN AND FLOP TO SOUTH-SOUTHWEST AT
ALL SITES EARLY-MID SUNDAY EVENING (INCLUDING ORD).
HAVE STARTED TO SEE SOME LIGHT (6-7SM) BR DEVELOPING AT KRFD AT
ISSUANCE TIME, WHERE HIGH CLOUDS HAVE STARTED TO THIN/SCATTER.
THERE COULD BE SOME BRIEF MVFR VIS THERE, THOUGH WITH WINDS
EVENTUALLY TURNING SOUTHWEST AND INCREASING SLIGHTLY AND A
PATCH OF VFR MID-LEVEL CLOUDS EXPECTED TO SPREAD IN FROM EASTERN
IA PREDAWN, AM NOT CURRENTLY EXPECTING FOG TO BECOME WIDESPREAD
OR SIGNIFICANTLY DENSER. SURFACE DEW POINTS ARE ALSO A BIT
HIGHER AT GYY, THUS SOME MVFR BR CAN'T BE RULED OUT THERE PRIOR
TO SUNRISE. OTHERWISE, VFR CONDITIONS ARE EXPECTED TO PREVAIL
THROUGH THE PERIOD.
RATZER
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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