785
FXUS63 KLOT 280740
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
240 AM CDT FRI MAR 28 2025
KEY MESSAGES
- SCATTERED THUNDERSTORMS THROUGH MID MORNING. THE STRONGEST
STORMS MAY PRODUCE NICKEL SIZE HAIL AND BRIEF HEAVY RAIN.
- WINDY AND WARM WITH SOUTHWEST WINDS GUSTING TO 40 MPH THIS
AFTERNOON.
- A COLD FRONT WILL MOVE SOUTH INTO NORTHERN IL SATURDAY
AFTERNOON, TURNING TEMPS MUCH COOLER, ESPECIALLY NEAR LAKE
MICHIGAN.
- SCATTERED SHOWERS, POSSIBLE THUNDERSTORMS SATURDAY/SATURDAY
NIGHT, AS THE COLD FRONT LIFTS BACK NORTH AS A WARM FRONT.
- SCATTERED THUNDERSTORMS SUNDAY AFTERNOON. SOME STORMS COULD BE
SEVERE AND PRODUCE DAMAGING WINDS, ESPECIALLY TOWARD CENTRAL
ILLINOIS AND CENTRAL INDIANA.
- RAIN WEDNESDAY MORNING, THEN WINDY WEDNESDAY AFTERNOON/
EVENING.
DISCUSSION
ISSUED AT 240 AM CDT FRI MAR 28 2025
THROUGH SATURDAY:
SCATTERED THUNDERSTORMS CONTINUE TO DEVELOP AND MOVE EAST ACROSS
THE AREA EARLY THIS MORNING AND WILL CONTINUE THROUGH MID
MORNING, SLOWLY ENDING FROM WEST TO EAST. THE STRONGEST STORMS
WILL HAVE THE POTENTIAL TO PRODUCE HAIL TO NICKEL SIZE AS WELL
AS BRIEF HEAVY RAIN. WHILE THE BULK OF THIS ACTIVITY LOOKS TO BE
EXITING THE CWA BY MID MORNING (13Z-14Z), SOME OF THE CAMS ARE
SHOWING AN AXIS OF INSTABILITY LINGERING ALONG THE I-80 CORRIDOR
WHERE A FEW SHOWERS OR A FEW THUNDERSTORMS MAY LINGER THROUGH
EARLY AFTERNOON. CONFIDENCE IS LOW, BUT MAINTAINED SLIGHT CHANCE
POPS THROUGH 18Z. ONCE THIS POTENTIAL ENDS, DRY WEATHER IS
EXPECTED THROUGH SATURDAY MORNING.
WINDS WILL BECOME SOUTHWESTERLY AFTER SUNRISE AND STEADILY
INCREASE THROUGH THE MORNING. THE STRONGEST WINDS ARE EXPECTED
THIS AFTERNOON ONCE THE CLOUDS CLEAR AND THE LOW LEVELS BEGIN TO
MIX DEEPLY. GUSTS INTO THE 40 MPH RANGE ARE EXPECTED FROM MID
AFTERNOON THROUGH SUNSET AND ITS POSSIBLE SOME GUSTS WILL REACH
45 MPH. THESE MAY BE BRIEF AND ISOLATED AND THUS NOT PLANNING
ANY WIND ADVISORY, BUT TRENDS WILL NEED TO BE MONITORED INTO
THIS AFTERNOON. SPEEDS AND GUSTS WILL DIMINISH SOME WITH SUNSET,
BUT GUSTS INTO THE 30-35 MPH ARE STILL EXPECTED THIS EVENING,
ESPECIALLY IN THE METRO AREA, DIMINISHING FURTHER OVERNIGHT
INTO SATURDAY MORNING.
WITH THE EXPECTATION THAT SKIES WILL BECOME MOSTLY SUNNY THIS
AFTERNOON, TEMPERATURES ARE EXPECTED TO EASILY RISE INTO THE
MID/UPPER 70S ACROSS THE ENTIRE AREA. TEMPS OFTEN OVERPERFORM IN
THESE SITUATIONS, THUS A FEW LOCATIONS TAGGING 80 IS CERTAINLY
POSSIBLE. LOW TEMPS WILL LIKELY ONLY DROP INTO THE MID/UPPER 50S
TONIGHT.
SOUTHWEST WINDS WILL BE GUSTING INTO THE 30 MPH RANGE AS TEMPS
WARM INTO THE MID/UPPER 60S SATURDAY. A COLD FRONT WILL BE
MOVING SOUTH ACROSS WI AND WILL LIKELY SURGE SOUTH DOWN LAKE
MICHIGAN IN THE AFTERNOON, STALLING ON THE SOUTH END OF THE
LAKE BY EVENING. THIS WILL TURN TEMPS MUCH COLDER NORTH OF THIS
FRONT AND ESPECIALLY NEAR THE LAKE. THERE WILL BE A LARGE
TEMPERATURE DIFFERENCE BETWEEN THIS FRONT THOUGH HIGHS INTO THE
LOWER 70S ARE POSSIBLE ACROSS THE SOUTHERN CWA SATURDAY
AFTERNOON.
PRECIP TRENDS ARE UNCERTAIN FOR SATURDAY. THERE MAY BE SOME
SHOWERS, ISOLATED THUNDER ACROSS THE SOUTHERN CWA SATURDAY
MORNING WITH MANY DRY HOURS EXPECTED ACROSS THE ENTIRE AREA,
THEN A CHANCE OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS BY
LATE SATURDAY AFTERNOON. OVERALL CONFIDENCE IS LOW AND CURRENT
POPS IN THE 40-50% RANGE FOR SATURDAY AFTERNOON MAY BE TOO HIGH,
BUT NO CHANGES PLANNED. CMS
SATURDAY NIGHT THROUGH THURSDAY:
ISSUED AT 327 PM CDT THU MAR 27 2025
FOCUS THEN TURNS TO THE POTENTIAL FOR SEVERE WEATHER OVER AT
LEAST PART OF THE FORECAST AREA ON SUNDAY. VEERING LOW-LEVEL
FLOW WITH ONLY SPOTTY UPSTREAM PRECIP SATURDAY NIGHT SHOULD
ALLOW THE FRONT TO RETREAT NORTHWARD AS A WARM FRONT. A LARGER
SURFACE LOW WILL THEN TRAVERSE ALONG OR NEAR THE WARM FRONT
SOMEWHERE ACROSS NORTHERN ILLINOIS ON SUNDAY. LIKE ON SATURDAY,
THE GEFS HAS TRENDED MUCH FARTHER NORTH WITH THE WARM FRONT,
WITH MUCH OF THE GUIDANCE NOW PUTTING AT LEAST THE SOUTHERN HALF
OF THE CWA IN THE WARM SECTOR. IMPRESSIVE MID TO UPPER-LEVEL
DYNAMICS, SPECIFICALLY WITH AN INCOMING 70 KNOT MID-LEVEL JET
STREAK, OVER MODEST LOW-LEVEL MOISTURE ADVECTION WILL SUPPORT A
SEVERE STORM RISK SOUTH OF I-80, AND POTENTIALLY FARTHER NORTH
AND WEST DEPENDING ON IF/WHERE THE WARM FRONT STALLS DUE TO THE
INFLUENCE OF LAKE MICHIGAN. SHEAR VECTORS AND SOMEWHAT
UNIDIRECTIONAL LOW-LEVEL FLOW FAVOR LINEAR/BOWING CONVECTIVE
SEGMENTS WITH WIND DAMAGE AS THE PRIMARY THREAT (LARGE HAIL WITH
ANY MORE DISCRETE CELLS). BUT AGAIN CLIMATOLOGICALLY SPEAKING,
BOTH THE STORM MODE (BROKEN/BOWING SEGMENTS) IN THIS AREA AND
THE POTENTIAL FOR A STALLED WARM FRONT DOES SUPPORT A LOW END
TORNADO RISK (PARTICULARLY QLCS). STILL A FEW DAYS OUT TO REFINE
THESE DETAILS, WITH FRONTAL LOCATION BEING A SIGNIFICANT FACTOR
WITH HOW THE FORECAST EVOLVES THIS WEEKEND.
AS THE MAIN TROUGH AXIS CROSSES THE FORECAST AREA SUNDAY NIGHT,
A RESIDUAL BAND OF RAIN SHOULD MIX WITH OR EVEN TRANSITION TO
SNOW. THERE IS A LOW (10%) CHANCE OF SOME MINOR SLUSHY
ACCUMULATIONS LATE SUNDAY NIGHT INTO MONDAY MORNING, BUT OVERALL
EXPECTATIONS ARE FOR LITTLE IMPACT AT THIS TIME. DRIER AND
COLDER CONDITIONS WILL FOLLOW THROUGH TUESDAY WITH HIGHS
GENERALLY IN THE 40S. LONG-TERM ENSEMBLE GUIDANCE CONTINUES TO
HIGHLIGHT ANOTHER STRONG MID-LATITUDE CYCLONE ACROSS THE CENTRAL
CONUS WEDNESDAY INTO THURSDAY MORNING. FORECAST UNCERTAINTY IS
QUITE HIGH LOCALLY AS THE ASSOCIATED WARM FRONT IS FAVORED TO
SETTLE ACROSS THE WESTERN GREAT LAKES REGION. ANY PUSH INTO THE
WARM SECTOR OF THIS SYSTEM WILL BRING AN INCREASE IN SEVERE
STORM POTENTIAL.
KLUBER
AVIATION /06Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 100 AM CDT FRI MAR 28 2025
- ISOLATED TO WIDELY SCATTERED SHRA EXPECTED OVERNIGHT INTO THE
MORNING WITH MVFR CIGS POSSIBLE AT TIMES.
- CONFIDENCE IN A PERIOD OF TSRA IS HIGHEST BETWEEN ~9-13Z.
SMALL HAIL WILL BE POSSIBLE WITH THE STRONGEST STORMS WITH
ASSOCIATED MVFR CIGS/VSBYS.
- STRONG SW WINDS DEVELOP THIS AFTERNOON WITH GUSTS TO ~35 KTS.
- PERIOD OF LLWS POSSIBLE TONIGHT, PARTICULARLY IF SURFACE GUSTS
EASE MORE THAN EXPECTED.
SPOTTY LIGHT ALREADY SHOWERS ARE ALREADY UNDERWAY ACROSS THE
AREA EARLY THIS MORNING WITH SOME EMBEDDED THUNDERSTORMS WELL
SOUTHWEST OF THE TERMINALS. THESE SHOULD BE FAIRLY HIT AND MISS
FOR AT LEAST A COUPLE MORE HOURS. GUIDANCE CONTINUES TO SUGGEST
A MORE CONSOLIDATED AXIS OF SHOWERS WILL DEVELOP AND LIFT ACROSS
THE TERMINALS AS WE GET CLOSER TO DAYBREAK. OPTED TO SHIFT THE
TEMPO FOR TSRA AN HOUR LATER AT ALL SITES (9-11Z RFD, 10-13Z FOR
DPA/ORD/MDW/GYY) BASED ON LATEST RADAR AND MODEL TRENDS. THE
STRONGEST STORMS WILL BE CAPABLE OF PRODUCING SMALL HAIL.
CONFIDENCE IN CIG TRENDS IS ON THE LOWER SIDE OVERNIGHT. SO FAR
MVFR STRATUS HAS BEEN RATHER SPARSE, OTHER THAN A NARROW AXIS
FROM NEAR MDW TO GYY. DUE TO THIS, HAVE TRENDED LESS PESSIMISTIC
WITH THIS UPDATE FOR MOST SITES, RELEGATING THE PERIOD OF MVFR
CIGS/VSBYS TO THE TIMING OF GREATEST SHOWER/STORM COVERAGE.
WIDELY SCATTERED SHOWERS MAY LINGER FURTHER THE MORNING HOURS
AS A TRAILING SHORTWAVE CURRENTLY OVER NORTHWEST IOWA PUSHES
ACROSS NORTHERN ILLINOIS. ACCORDINGLY, OPTED TO HANG ONTO -SHRA
THROUGH 15Z AND VCSH THROUGH MIDDAY.
WINDS ARE EXPECTED TO STEADILY INCREASE INTO THE AFTERNOON WITH
A PERIOD OF STRONG SOUTHWESTERLY WIND GUSTS UP TO AROUND 35 KT
EXPECTED. PREVAILING GUSTS SHOULD BEGIN TO EASE WITH SUNSET,
THOUGH A STRONG LOW-LEVEL JET WILL MOVE OVERHEAD WHICH COULD
ALLOW FOR AT LEAST SPORADIC STRONG GUSTS TO PERSIST THROUGH THE
EVENING HOURS. DUE TO THE POTENTIAL FOR CONTINUED STRONG SURFACE
GUSTS, OPTED TO HOLD OFF ON A FORMAL LLWS MENTION, THOUGH IT IS
POSSIBLE THIS MAY NEED TO BE ADDED WITH LATER UPDATES.
PETR
MARINE
ISSUED AT 1030 PM CDT THU MAR 27 2025
A SEASONABLY STRONG LOW PRESSURE SYSTEM WILL MOVE FROM THE
NORTHERN PLAINS TOWARD THE GREAT LAKES CAUSING A SURFACE WARM
FRONT TO LIFT NORTHWARD THROUGH THE REGION ON FRIDAY. BEHIND
THE FRONT, SOUTHWESTERLY WINDS WILL INCREASE QUICKLY IN
MAGNITUDE ON FRIDAY AFTERNOON. GALE FORCE GUSTS IN EXCESS OF 35
KTS ARE EXPECTED, AND WILL THEN LAST INTO THE EVENING HOURS,
ALTHOUGH GALES MAY BECOME MORE INTERMITTENT WITH TIME,
PARTICULARLY ACROSS THE INDIANA NEARSHORE ZONES. A FEW GALES
ABOVE 40 KTS APPEAR POSSIBLE DURING THE AFTERNOON, PARTICULARLY
ACROSS THE ILLINOIS NEARSHORE. 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.
THE GALE WATCH HAS BEEN UPGRADED TO A GALE WARNING FOR THE
NEARSHORE WATERS.
NWS CHICAGO
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...GALE WARNING FROM 1 PM THIS AFTERNOON TO 3 AM CDT SATURDAY FOR
THE IL AND IN NEARSHORE WATERS.
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