483
FXUS63 KLOT 010456
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1056 PM CST SAT FEB 28 2026
KEY MESSAGES
- A RELATIVELY QUIET PATTERN WILL CONTINUE THROUGH THE WEEKEND
WITH A FEW SNOW SHOWERS TODAY NEAR THE WISCONSIN STATE LINE,
AND NEAR THE LAKE MICHIGAN SHORELINE TONIGHT INTO SUNDAY.
- A PERIOD OF WARMER, AND WETTER, CONDITIONS IS EXPECTED NEXT
WEEK INTO THE SECOND FULL WEEK OF MARCH.
DISCUSSION
ISSUED AT 129 PM CST SAT FEB 28 2026
THROUGH SUNDAY NIGHT:
IT'S A RATHER BANAL DAY ACROSS THE REGION WITH BROKEN UPPER-
LEVEL CLOUD COVER AND NORTHEASTERLY WINDS. A BAND OF SNOW
CONTINUES TO MEANDER ACROSS SOUTHEASTERN MINNESOTA AND SOUTHERN
WISCONSIN, WITH DRY AIR LARGELY LIMITING ANY MEANINGFUL
SOUTHWARD PENETRATION INTO NORTHERN ILLINOIS. TEMPERATURES
ACROSS THE AREA VARY FROM NORTH TO SOUTH, RANGING FROM NEAR
FREEZING ALONG THE WISCONSIN STATE LINE TO AROUND 50 NEAR US-24.
TONIGHT, A 1035MB SURFACE HIGH WILL BUILD INTO THE UPPER GREAT
LAKES AND SUPPORT AN INCREASE IN NORTHEASTERLY FLOW AND COLD AIR
ADVECTION DOWN LAKE MICHIGAN. IN SPITE OF MARGINAL INVERSION
HEIGHTS (A CONSEQUENCE OF THE CYCLONIC SHEAR AXIS OF THE UPPER-
LEVEL FLOW REMAINING WELL NORTHEAST OF OUR AREA), INCREASING
SHORELINE CONVERGENCE SHOULD SUPPORT A GRADUAL INCREASE IN LAKE-
INDUCED STRATUS, FLURRIES, AND A FEW SHOW SHOWERS. IN ALL, THIS
SET-UP LOOKS PRETTY DARN MARGINAL, SO WILL ONLY ADVERTISE A
DUSTING TO PERHAPS A FEW TENTHS OF AN INCH OF SNOW ACCUMULATIONS
SHOULD BONAFIDE SNOW SHOWERS ACTUALLY DEVELOP. ELSEWHERE,
TONIGHT WILL BE RELATIVELY CHILLY WITH OVERNIGHT LOWS IN THE
UPPER TEENS (NORTHWEST) TO MID 20S (SOUTHEAST).
LAKE EFFECT FLURRIES AND SNOW SHOWERS MAY CONTINUE NEAR THE
LAKE MICHGIAN SHORE THROUGH SUNDAY MORNING BEFORE TAPERING IN
COVERAGE DURING THE AFTERNOON AS THE SURFACE HIGH MEANDERS
THROUGH THE CENTRAL GREAT LAKES. PARTLY CLOUDY SKIES AND
CONTINUED NORTHEASTERLY WINDS WILL OTHERWISE DEFINE AN
UNREMARKABLE DAY WITH HIGHS GENERALLY IN THE 30S.
TOMORROW NIGHT LOOKS SIMILARLY QUIET WITH LIGHT EASTERLY FLOW,
BROKEN CLOUD COVER, AND OVERNIGHT LOWS GENERALLY IN THE UPPER
TEENS TO LOWER 20S. WITH THE BAROCLINIC ZONE EXPECTED TO STALL
ACROSS SOUTHERN MISSOURI, ILLINOIS, AND INDIANA, ANY
PRECIPITATION WITH THE NEXT WAVE PROPAGATING INTO THE
MISSISSIPPI RIVER VALLEY SHOULD MISS OUR AREA.
BORCHARDT
MONDAY ONWARD:
A BROADER ZONAL FLOW REGIME WITH AN EMBEDDED SLOW-MOVING TROUGH
OVER THE CENTRAL ROCKIES EARLY IN THE WEEK WILL TRANSITION TO A
MUCH MORE MERIDIONAL PATTERN HIGHLIGHTED BY DEEP WESTERN
TROUGHING FOR THE SECOND HALF OF THE WEEK. MEANWHILE, AN
EXPANSIVE BERMUDA HIGH WILL FOSTER A PERSISTENT FEED OF GULF AND
CARIBBEAN MOISTURE TOWARD THE CENTRAL CONUS THROUGH THE PERIOD.
THIS WILL ULTIMATELY RESULT IN A SEASONABLY MILD TO
UNSEASONABLY WARM PERIOD WITH SEVERAL ROUNDS OF RAIN AND
LOCALIZED CONVECTION OVER THE AREA. WHILE AXES OF HEAVY RAIN
APPEAR LIKELY OVER THE MID-MISSISSIPPI AND OHIO RIVER VALLEYS,
IT REMAINS TO BE SEEN WHERE THOSE AXES SET-UP AND WHETHER THOSE
AXES ALIGN OVER THE SAME LOCATION AND RESULT IN FLOODING
CONCERNS.
INITIALLY, BROAD LOW-LEVEL ISENTROPIC ASCENT COMBINED WITH
MODEST MOISTURE TRANSPORT WILL BRING THE FIRST AREA OF PRECIP
OVER THE AREA LATE MONDAY NIGHT INTO TUESDAY. WHILE RAIN IS
FAVORED, LOW-LEVEL WET-BULB TEMPS NEAR FREEZING COULD RESULT IN
MINOR IMPACTS FROM LIGHT FREEZING RAIN CLOSE TO THE WISCONSIN
STATE LINE THROUGH MID-MORNING.
BEYOND TUESDAY, THE SPREAD IN THE ENSEMBLE SUITE, OWING TO THE
DIFFERENCES IN THE EVOLUTION OF THE WESTERN TROUGH, OFFERS LESS
CONFIDENCE ON EXACTLY WHEN AND WHERE HEAVY RAIN AXES DEVELOP.
HOWEVER, WITH PWATS AROUND 1.5" (300% OF NORMAL), ANY PRONOUNCED
WAVE EMANATING FROM THE WESTERN TROUGH WILL INDUCE SUFFICIENT
FORCING TO REALIZE FOCUSED AXES OF HEAVY RAIN. AS A WHOLE, THE
BEST FOCUS MID TO LATE WEEK REMAINS JUST SOUTH OF THE FORECAST
AREA TUESDAY NIGHT.
WILL ALSO NEED TO KEEP AN EYE ON THE POTENTIAL FOR MORE
ORGANIZED CONVECTION IN OR AROUND THE AREA LATE THURSDAY AND
ESPECIALLY FRIDAY AS A LARGE PORTION OF THE WESTERN TROUGH
EJECTS TOWARD THE MID TO UPPER-MISSISSIPPI RIVER VALLEY.
KLUBER
AVIATION /06Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 1056 PM CST SAT FEB 28 2026
BREEZY NORTHEASTERLY WINDS WILL CONTINUE THROUGH SUNDAY MORNING
BUT THE STRONGEST GUSTS WILL CONTINUE TO GRADUALLY EASE THROUGH
TONIGHT. MVFR CIGS WILL PREVAIL TONIGHT, ALTHOUGH THERE IS SOME
INDICATION CIGS MAY LIFT TO VFR PERIODICALLY TONIGHT INTO
SUNDAY MORNING. AT RFD, VFR WILL LIKELY RETURN OVERNIGHT
TONIGHT. GIVEN THE CONTINUED FLOW OFF THE LAKE, HAVE MAINTAINED
MVFR AT THE CHICAGO-AREA TERMINALS THROUGH MIDDAY SUNDAY, BUT
ADJUSTMENTS MAY BE NEEDED. VFR CONDITIONS ARE EXPECTED SUNDAY
NIGHT WITH WINDS GRADUALLY TURNING SOUTHEASTERLY.
CARLAW
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 PM CST SUNDAY FOR THE IL AND IN
NEARSHORE WATERS.
VISIT US AT WEATHER.GOV/CHICAGO
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