175
FXUS63 KLOT 282355
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
655 PM CDT FRI MAR 28 2025
KEY MESSAGES
- WINDY AND WARM WITH SOUTHWEST WINDS GUSTING TO AROUND 40 MPH
THROUGH THIS EVENING.
- A COLD FRONT WILL MOVE SOUTH INTO NORTHERN IL SATURDAY
AFTERNOON, TURNING TEMPS MUCH COOLER NEAR LAKE MICHIGAN.
- SCATTERED SHOWERS AND A FEW STORMS ARE POSSIBLE SATURDAY
AFTERNOON AND NIGHT.
- STRONG TO SEVERE STORMS WILL BE POSSIBLE SUNDAY AS A LOW
PRESSURE SYSTEM TRACKS THROUGH THE UPPER-MISSISSIPPI RIVER
VALLEY.
- ACTIVE WEATHER PATTERN CONTINUES NEXT WEEK, WITH THE POTENTIAL
FOR 2 ADDITIONAL STORM SYSTEMS MODELED AT THE MIDDLE AND END
OF NEXT WEEK.
DISCUSSION
ISSUED AT 256 PM CDT FRI MAR 28 2025
THROUGH SATURDAY NIGHT:
A COMPACT WAVE INTERACTING WITH A SHALLOW LAYER OF MID-LEVEL
MOISTURE RESULTED IN HIGHER CLOUD AND SHOWER COVERAGE ACROSS
MUCH OF THE CENTRAL AND SOUTHERN CWA THROUGH EARLY AFTERNOON.
THIS DELAYED MIXING/WARMING AND STRONGER WINDS BY A FEW HOURS,
BUT RECENT OBS TRENDS INDICATE THE FORECAST IS MOSTLY BACK ON
TRACK WITH TEMPS IN THE MID TO UPPER 70S AND SOUTHWEST GUSTS TO
40-45 MPH (ESPECIALLY TOWARD CENTRAL ILLINOIS OVER THE NEXT FEW
HOURS).
A 60 KNOT LLJ DEVELOPING OVER THE FORECAST AREA THIS EVENING
WILL MAINTAIN GUSTY CONDITIONS WELL AFTER SUNSET. WITH ONLY
SOME MID/UPPER-LEVEL CLOUDS FILTERING OVER THE AREA, THERE MAY
BE SUFFICIENT NEAR-SURFACE STABILITY TO WARD OFF THE STRONGEST
GUSTS FROM REACHING THE SURFACE. HAVE THEREFORE HELD OFF ON A
WIND ADVISORY THROUGH THIS EVENING, BUT CANNOT RULE OUT A
RESURGENCE OF GUSTS OVER 40 MPH FOR A FEW HOURS DURING THE MID-
EVENING.
A STRONG LOW-LEVEL BAROCLINIC ZONE DRAPED ACROSS CENTRAL
WISCONSIN WILL REMAIN MOSTLY STATIONARY THROUGH THIS EVENING AS
A WEAK SURFACE LOW SHIFTS ALONG IT TO THE EAST. THIS WILL FORCE
A COLD FRONT TOWARD NORTHERN ILLINOIS THROUGH THE DAY ON
SATURDAY. HAVE CONTINUED TO LEAN ON GUIDANCE (HRRR/3KM NAM) THAT
PRODUCES A STRONGER AND FASTER SURGE OF THE FRONT INTO
NORTHEAST ILLINOIS DURING THE AFTERNOON AND EARLY EVENING, WITH
THE FRONT STALLING AROUND THE I-80 CORRIDOR SATURDAY NIGHT.
BEHIND THE FRONT, TEMPS WILL PLUMMET FROM AROUND 70 TO THE 40S
AND BE ACCOMPANIED BY SOME FOG AND DRIZZLE OR LIGHT RAIN.
ELSEWHERE, MOST OF THE FORECAST AREA WILL REMAIN IN A LULL IN
DYNAMICS AND PRECIP THROUGH THE DAY SATURDAY AND WELL INTO
SATURDAY NIGHT, WITH GENERALLY CLOUDY SKIES AND SOME SPOTTY
SHOWERS OR DRIZZLE. THE ONE EXCEPTION WILL BE EAST OF I-57
WHERE A CONVECTIVELY-ENHANCED WAVE CROSSING INDIANA BRINGS
SCATTERED SHOWERS AND PERHAPS A FEW STORMS LATE MORNING INTO
EARLY EVENING.
KLUBER
SUNDAY THROUGH FRIDAY:
THE APPROACHING LOW PRESSURE SYSTEM WILL LIFT WARM, MOIST AIR
INTO THE REGION THROUGHOUT SUNDAY MORNING AS THE WARM FRONT
LIFTS ACROSS NORTHERN ILLINOIS. THIS WILL INCREASE THE
POTENTIAL FOR STRONG TO SEVERE STORMS DURING THE AFTERNOON AND
EVENING. MUCAPE VALUES INCREASE SUNDAY MORNING ACROSS THE AREA,
RISING INTO THE 1000-1500 J/KG RANGE BY MIDDAY WITH THE CHANCE
UPWARDS OF 2000 J/KG ACROSS THE FAR SOUTHERN CWA. BETTER
INSTABILITY FACTORS WILL OCCUR WELL TO THE SOUTH OF OUR AREA,
HOWEVER THE CAPE ALONG WITH THE CLOSE PROXIMITY OF THE LOW CORE
SHOULD ALLOW FOR STORM DEVELOPMENT AHEAD OF THE FRONT DURING THE
AFTERNOON INTO THE EVENING. SPC HAS A LEVEL 3 OUT OF 5 ROUGHLY
SOUTH OF THE I-80 CORRIDOR, WITH A 2 OUT OF 5 TO THE NORTH. THE
VERTICAL WIND PROFILE OF THIS SYSTEM AS IT TRACKS THROUGH THE
REGION WILL BE FAIRLY UNIFORM, WHICH SHOULD ALLOW FOR STORMS TO
TRACK FROM THE WSW TO ENE. CANNOT RULE OUT TORNADO POTENTIAL,
BEING IN CLOSE PROXIMITY TO THE LOW CORE, HOWEVER THE BEST
THREAT AT THIS TIME APPEARS TO BE WIND. WITH THE INCREASE IN
WIND INDICATORS, THIS COULD ALSO RESULT IN MORE OF A BOWING LINE
OR SEGMENTS WHICH WOULD HAVE THE POTENTIAL OF PRODUCING QLCS
TORNADOES. WILL CONTINUE TO MONITOR THIS SYSTEM WITH FURTHER
UPDATES.
THE MAIN TROF AXIS PUSHES THROUGH THE REGION SUNDAY NIGHT, WHERE
THERE COULD BE SOME LINGERING PRECIPITATION TRYING TO SLIDE DOWN
FROM THE NORTH EARLY MONDAY. A SMALL CHANCE FOR SNOWFALL, WHICH
COULD LEAD TO SLUSHY ACCUMULATIONS, HOWEVER THE MAIN THOUGHT IS
THAT MAJORITY WOULD REMAIN LIQUID RAIN. DRIER CONDITIONS WILL
MOVE BACK INTO THE MIDWEST FOR THE FIRST PART OF NEXT WEEK, AS A
HIGH PRESSURE RIDGE TAKES OVER...ALTHOUGH TEMPERATURES WILL BE
LIMITED BY STRONG NORTHWEST AIRFLOW INTO THE REGION MONDAY
TURNING MORE EASTERLY OFF THE LAKE AND INTERIOR INDIANA TUESDAY.
ANOTHER WEATHER SYSTEM IS FORECAST TO TRACK THROUGH THE REGION
WEDNESDAY, WITH CURRENT MODEL GUIDANCE SHOWING A POTENTIAL FOR
A ROUGHLY SIMILAR TRACK TO SUNDAY'S SYSTEM. SOME EARLY
INDICATIONS WITH THE MID-WEEK SYSTEM POINT TO THE POTENTIAL OF
STRONG TO SEVERE STORMS AGAIN, HOWEVER WITH IT BEING SO FAR OUT,
THERE LIKELY WILL BE CHANGES OVER THE NEXT COUPLE OF DAYS SO
STAY TUNED FOR MORE UPDATES WITH THIS SYSTEM. A BREAK COMES
AROUND THURSDAY, HOWEVER SHORT LIVED, AS THE ACTIVE PATTERN
CONTINUES INTO THE END OF NEXT WEEK AND EARLY NEXT WEEKEND.
BAKER/KLUBER
AVIATION /00Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 655 PM CDT FRI MAR 28 2025
FORECAST CONCERNS FOR THE TERMINALS...
- BREEZY SOUTHWEST WINDS TONIGHT THROUGH SATURDAY AFTERNOON WITH
GUSTS AROUND 20-25 KT.
- LLWS THREAT BETWEEN 03Z AND 10Z TONIGHT.
- PERIODS OF RAIN AND FOG SATURDAY AFTERNOON/EVENING BEHIND A
COLD FRONT RESULTING IN MVFR CEILINGS AND VISIBILITIES.
THE EARLIER GUSTY SOUTHWEST WINDS WILL CONTINUE TO SUBSIDE THIS
EVENING AND OVERNIGHT, BUT THE WARM AIRMASS SHOULD ALLOW
OCCASIONAL 20-25 KT GUSTS TO LINGER THROUGH THE NIGHT.
ADDITIONALLY, THERE IS A THREAT FOR LOW-LEVEL WIND SHEAR LATE
THIS EVENING THROUGH THE PREDAWN HOURS SATURDAY MORNING (03Z TO
10Z) AS A 50-55 KT LOW-LEVEL JET DEVELOPS OVERHEAD. WHILE THE
LINGERING WIND GUSTS MAY SUBDUE THIS THREAT A BIT, IF WINDS
SUBSIDE MORE THAN FORECAST THEN THE WIND SHEAR THREAT WILL
INCREASE. THEREFORE, HAVE DECIDED TO MAINTAIN THE FORMAL LLWS
MENTION IN THE TAFS. OTHERWISE, EXPECT VFR CONDITIONS TO PREVAIL
OVERNIGHT INTO SATURDAY MORNING.
HEADING INTO SATURDAY, THE FORECAST BECOMES A BIT MORE
COMPLICATED DUE TO A COLD FRONT TO OUR NORTH AND A SHORTWAVE
DISTURBANCE TO OUR SOUTH. THE SOUTHERN DISTURBANCE IS FORECAST
TO PIVOT INTO THE TENNESSEE AND OHIO RIVER VALLEYS SATURDAY
MORNING WHICH SHOULD ALLOW SCATTERED SHOWERS TO DEVELOP ACROSS
CENTRAL IL AND IN. AT THIS TIME IT APPEARS THE BULK OF THESE
SHOWERS WILL STAY SOUTH OF THE TERMINALS AND THUS A DRY FORECAST
HAS BEEN MAINTAINED, BUT THEY COULD GET CLOSE TO GYY SO WILL
HAVE TO MONITOR FORECAST TRENDS CLOSELY. REGARDLESS, A COLD
FRONT IS EXPECTED TO MOVE THROUGH NORTHERN IL AND DOWN LAKE
MICHIGAN SATURDAY AFTERNOON AND EVENING BEFORE STALLING
SOMEWHERE NEAR THE I-80 CORRIDOR SATURDAY NIGHT. GIVEN THE
SHALLOW NATURE OF THE FRONT CONFIDENCE ON WHEN EXACTLY THE FRONT
WILL MOVE THROUGH THE TERMINALS REMAINS ON THE LOWER SIDE SO
EXPECT CURRENT FORECAST TIMING TO SHIFT A BIT. THOUGH, ONCE THE
FRONT MOVES THROUGH A PERIOD OF RAIN SHOULD MOVE IN AND PERSIST
THROUGH SATURDAY EVENING. ADDITIONALLY, FOG IS EXPECTED TO
DEVELOP OVER THE OPEN WATERS OF LAKE MICHIGAN WHICH SHOULD GET
ADVECTED INLAND GIVEN THE EASTERLY WINDS BEHIND THE FRONT.
HOWEVER, THE INTENSITY AND INLAND EXTENT OF THE FOG REMAINS
LOWER CONFIDENCE AT THIS TIME BUT SUSPECT AT LEAST ORD, MDW, AND
PERHAPS GYY WILL SEE AT LEAST SOME MVFR VISIBILITIES.
REGARDLESS OF FOG COVERAGE, CEILINGS WILL LOWER TO MVFR BEHIND
THE FRONT WITH THE POTENTIAL (30-40% CHANCE) FOR IFR CEILINGS TO
DEVELOP THROUGH SATURDAY EVENING AT ALL THE TERMINALS. THE
LOWER CEILINGS ARE EXPECTED TO PREVAIL THROUGH THE END OF THE
FORECAST PERIOD AND LIKELY INTO SUNDAY MORNING AS WELL.
NOTE: THE ABOVE CONDITIONS WILL LIKELY IMPACT GYY AFTER THE END
OF THEIR TAF PERIOD WHICH IS WHY THESE CONDITIONS HAVE NOT BEEN
FORMALLY INCLUDED YET. THAT SAID, EXPECT THESE FEATURES TO BE
INCLUDED WITH THE 06Z TAF ISSUANCE.
YACK
MARINE
ISSUED AT 256 PM CDT FRI MAR 28 2025
- GALE WARNING REMAINS IN EFFECT FOR THE ILLINOIS AND PORTIONS
OF THE NORTHWEST INDIANA NEARSHORE WATERS OF LAKE MICHIGAN
THROUGH THIS EVENING.
GALE FORCE GUSTS IN EXCESS OF 35 KNOTS WILL CONTINUE THROUGH
THIS EVENING, WITH A PERIOD OF GUSTS SURPASSING 40 KNOTS AT THE
HIGHER PLATFORMS THIS EVENING. SINCE WATER TEMPERATURES REMAIN
COLD (LEADING TO STABILITY OVER THE LAKE), THE THREAT FOR GALE
FORCE WINDS WILL BE WITHIN THE FIRST FEW MILES OF THE LAKESHORE.
NWS CHICAGO
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...GALE WARNING UNTIL 3 AM CDT SATURDAY FOR THE IL AND IN
NEARSHORE WATERS.
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