289
FXUS63 KLOT 231735
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
ISSUED BY NATIONAL WEATHER SERVICE LINCOLN IL
1235 PM CDT WED APR 23 2025
KEY MESSAGES
- SCATTERED SHOWERS/STORMS TO LIFT NEAR AND NORTH OF INTERSTATE
80 THIS MORNING. RAINFALL TOTALS WILL GENERALLY RANGE BETWEEN
A TENTH AND ONE-HALF INCH.
- THE STRETCH OF WARM WEATHER WILL CONTINUE, PAUSING BRIEFLY ON
SATURDAY BEFORE TEMPERATURES TURN EVEN WARMER EARLY NEXT WEEK.
- AN ACTIVE SPRING STORM TRACK WILL TAKE AIM AT THE LOWER GREAT
LAKES NEXT WEEK, BRINGING THE PROSPECT FOR SEVERE WEATHER.
UPDATE
ISSUED AT 933 AM CDT WED APR 23 2025
UPDATED PRECIPITATION CHANCES AND SKY COVER PRIMARILY WITH THE
MORNING UPDATES. STILL EXPECT SHOWERS AND ISOLATED THUNDERSTORMS
TO DIMINISH SOUTH OF I-88 GENERALLY...WITH CHANCES LINGERING
AROUND I-88 AND NORTH THROUGH THE AFTERNOON HOURS.
NWS LINCOLN
DISCUSSION
ISSUED AT 403 AM CDT WED APR 23 2025
NEAR TERM
(THROUGH THIS AFTERNOON)
A CLUSTER OF ELEVATED THUNDERSTORMS CONTINUES TO LIFT NORTH OF
THE I-80 CORRIDOR EARLY THIS MORNING IN TANDEM WITH THE NOSE OF
A MODEST 850-MB JET. A QUICK GLANCE AT THE IR SATELLITE REVEALS
WARMING CLOUD TOPS AS THIS CONVECTIVE ACTIVITY BEGINS TO
OUTPACE THE MEAGER INSTABILITY, AND THIS TREND WILL CONTINUE AS
THE CLUSTER LIFTS FURTHER NORTH THROUGHOUT THE MORNING. STILL,
WE COULD SEE SOME PRETTY EFFICIENT RAIN RATES, WITH NEARBY
RADARS DEPICTING RATES OF 0.5-1"/HR. THIS LINES UP REASONABLY
WELL WITH RECENT HREF 3-HR PMM QPF GUIDANCE, WHICH OFFERS
0.1"-0.5" WITH THIS ACTIVITY. ONE BYPRODUCT OF THESE EARLY
MORNING STORMS IS ITS ASSOCIATED CONVECTIVE DEBRIS/OUTFLOW WHICH
MAY RESULT IN A BUSTED TEMPERATURE FORECAST THIS AFTERNOON. A
FEW OF THE HI-RES GUIDANCE, NAMELY THE HRRR, CONTINUE TO HINT AT
THIS POSSIBILITY, EVEN OFFERING ADDITIONAL SHOWERY ACTIVITY
THIS AFTERNOON NORTH OF I-88 AS SUBTLE MID-LEVEL SHORTWAVE
ENERGY INTERACTS WITH A LINGERING SFC BOUNDARY. AREAS SOUTH OF
I-80 SHOULD REMAIN DRY AND EASILY REACH THE UPPER 70S THIS
AFTERNOON, WHILE AREAS NORTH OF I-88 MAY STRUGGLE TO BREACH THE
UPPER 60S.
SHORT TERM
(TONIGHT THROUGH SATURDAY)
A POCKET OF MID-LEVEL DRY AIR WILL MOVE ACROSS THE AREA TONIGHT
THROUGH THURSDAY, KEEPING RAIN CHANCES AT BAY. CONTINUED WARM
ADVECTION WILL PUSH TEMPERATURES NEAR 80 DEGREES IN AREAS SOUTH
OF I-80 THURSDAY AFTERNOON. THE JOKE WILL ONCE AGAIN BE ON
AREAS NORTH OF I-88, BUT PARTICULARLY ALONG THE LAKEFRONT, AS A
BACKDOOR FRONT SAGS INTO THE LOWER GREAT LAKES REGION. THE NET
EFFECT WILL BE SHARP TEMPERATURE GRADIENT ACROSS OUR CWA, WITH
LOWER 70S NORTH OF I-88 AND LOWER 60S SMACK-UP AGAINST THE
LAKESHORE. A SIMILAR TREND THEN CONTINUES FOR FRIDAY AS THE
EAST- WEST FRONT STALLS IN THE VICINITY OF I-80.
RAIN CHANCES RE-EMERGE FRIDAY MORNING OR FRIDAY AFTERNOON AS
MID-LEVEL SHORTWAVE ENERGY AND WEAK SFC LOW PRESSURE GLIDE
ALONG THE STATIONARY FRONT. OVERALL, THE VERTICAL MOISTURE
PROFILE WITH THIS ACTIVITY LOOKS FAIRLY PALTRY WITH SOME
RESIDUAL MID-LEVEL DRY AIR IN PLACE. WHILE THIS SETUP DOESN'T
APPEAR LIKE IT WILL DELIVER MUCH RAIN, THERE IS AN AXIS OF
MODEST MLCAPE (500-1000 J/KG) NEAR AND SOUTH OF THE FRONT WHERE
CONVECTIVE PRECIP MAY OVERACHIEVE OUR CURRENT QPF (< 0.5")
EXPECTATIONS.
MUCH COOLER TEMPERATURES WILL SPILL ACROSS THE REGION FRIDAY
NIGHT INTO SATURDAY AS A ROBUST MID-LEVEL TROUGH DIGS ACROSS THE
UPPER-MISSISSIPPI VALLEY AND HELPS FLUSH OUR LINGERING FRONT
WELL TO THE SOUTH. TEMPERATURES SATURDAY AFTERNOON WILL ONLY
WARM INTO THE LOWER 60S INLAND, AND LOWER 50S ALONG THE
LAKEFRONT.
LONG TERM
(SUNDAY THROUGH TUESDAY)
AFTER A SEASONABLY CHILLY SATURDAY, TEMPERATURES BOUNCE WARMER
BY SUNDAY AS A RIDGE OF HIGH PRESSURE QUICKLY BUILDS ACROSS THE
PLAINS AHEAD OF A DEEP WESTERN TROUGH. AN IMPRESSIVE WARM
ADVECTION REGIME WILL PUSH TEMPERATURES INTO THE 70S BY SUNDAY
AND INTO THE LOWER 80S MONDAY & TUESDAY. OF COURSE, WE CAN'T
SURGE INTO THE 80S THIS TIME OF YEAR WITHOUT IT BEING
ACCOMPANIED WITH GUSTY SOUTHERLY WINDS. A QUICK GLANCE AT
GEFS/EPS GUIDANCE SUPPORTS MEAN WIND GUSTS AROUND 30-40 MPH
DURING THIS TIME AS THE SURFACE PRESSURE GRADIENT TIGHTENS
AHEAD OF AN IMPENDING STORM SYSTEM. AT THIS JUNCTURE, WIDESPREAD
THUNDERSTORM ACTIVITY LOOKS POSSIBLE LATE MONDAY AND THROUGH
TUESDAY, AND THIS IDEA IS STOKED BY MULTIPLE MACHINE- LEARNING
TOOLS WHICH HIGHLIGHT THE MID- MISSISSIPPI VALLEY AND LOWER
GREAT LAKES REGIONS FOR SEVERE WEATHER.
NWS LINCOLN
AVIATION /18Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 1235 PM CDT WED APR 23 2025
THE MAIN AVIATION WEATHER MESSAGES ARE:
- GENERALLY S/SW WINDS DEVELOPING THIS AFTERNOON. SOME POTENTIAL
FOR WINDS TO FLIP SE/E AT THE CHICAGO-AREA TERMINALS THIS
EVENING, BUT CHANCES TOO LOW FOR A MENTION.
- MAIN THREAT FOR SHRA/TS SHIFTING NORTH OF THE CHICAGO-AREA
SITES THIS AFTERNOON AND EVENING.
- SMALL POTENTIAL FOR TS INVOF RFD THIS AFTERNOON, BUT CHANCES
ARE TOO LOW/BRIEF FOR A FORMAL VCTS MENTION AT THIS TIME.
- EVENTUAL NORTH/NORTHEAST WIND SHIFT WITH A COLD FRONT THURSDAY
MORNING/AFTERNOON. TIMING REMAINS A BIT UNCERTAIN.
LINGERING MORNING CONVECTION HAS LARGELY DIMINISHED AND SHIFTED
EAST OF THE TERMINALS. WHILE THERE REMAINS ABOUT A 10-20% CHANCE
FOR AN ADDITIONAL SHOWER OR STORM THIS AFTERNOON, CHANCES ARE
TOO LOW FOR A PRECIP MENTION AT THE CHICAGO-AREA SITES. AT RFD,
HAVE PREVAILED VCSH WHERE ADDITIONAL SPOTTY ACTIVITY WILL LIKELY
MATERIALIZE OUT OF A MID-LEVEL CLOUD DECK THROUGH THE AFTERNOON.
WILL NEED TO KEEP AN EYE ON TRENDS, AS THE TS POTENTIAL IS NOT
ZERO, BUT CURRENTLY IS TOO LOW TO JUSTIFY A FORMAL VCTS MENTION.
WIND TRENDS ARE ALSO A BIT UNCERTAIN THIS EVENING, WITH SOME
GUIDANCE INDICATING WINDS WILL FOLD OVER OUT OF THE EAST OR
SOUTHEAST WITH VERY WEAK FLOW IN PLACE ACROSS THE REGION. FOR
NOW, HAVE CONTINUED WITH A MENTION OF JUST LIGHT SW WINDS, BUT
WILL CLOSELY MONITOR OBSERVATIONS AND MODEL TRENDS. REGARDLESS,
WINDS WILL BECOME LIGHT THIS EVENING AND OVERNIGHT, OUTSIDE OF
ANY CONVECTIVE OUTFLOW THAT GETS KICKED SOUTHWARD OUT OF
AFTERNOON CONVECTION ACROSS WISCONSIN.
A COLD FRONT WILL PRESS SOUTH THROUGH THE REGION THURSDAY
MORNING AND AFTERNOON. TIMING THIS WIND SHIFT REMAINS UNCERTAIN,
BUT THE INHERITED MID-LATE MORNING TIMING STILL SEEMED
APPROPRIATE AND MADE MINIMAL CHANGES THERE. AT THIS TIME, IT
APPEARS THE THREAT FOR LOW CLOUDS WITH THIS FRONT REMAIN PRETTY
MINIMAL, WITH VFR CONDITIONS EXPECTED TO PREVAIL.
CARLAW
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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