018
FXUS63 KIWX 212220
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
620 PM EDT TUE APR 21 2026
KEY MESSAGES
- SCATTERED SHOWERS AND STORMS ARE EXPECTED THIS EVENING AND EARLY
OVERNIGHT. SMALL HAIL, GUSTY WINDS, AND HEAVY RAIN POSSIBLE.
- ADDITIONAL CHANCES FOR RAIN AND STORMS RETURN TOMORROW
AFTERNOON (20-30% CHANCES SOUTH OF US 30) AND ON FRIDAY
(40-80% CHANCES AREA- WIDE).
- MILD OVER THE NEXT SEVERAL DAYS WITH HIGHS IN THE 70S TODAY
THROUGH FRIDAY. SEASONABLE IN THE 60S BY THE WEEKEND INTO NEXT
WEEK.
DISCUSSION
ISSUED AT 223 PM EDT TUE APR 21 2026
VISIBLE SATELLITE AND RADAR IMAGERY SHOWS A LINE OF DEVELOPING
SHOWERS AND STORMS ACROSS SOUTHERN WISCONSIN AND CENTRAL LAKE
MICHIGAN AHEAD OF AN INCOMING COLD FRONT. AIDED BY A 500MB
SHORTWAVE, THESE STORMS ARE EXPECTED TO MOVE FROM NORTHWEST TO
SOUTHEAST ACROSS OUR FORECAST AREA BETWEEN 4 PM EDT TODAY TO 2 AM
EDT WEDNESDAY. STRONG SOUTHERLY WIND GUSTS AND LOW LEVEL WAA HAVE
BOOSTED AFTERNOON TEMPERATURES UP INTO THE MID TO LOW 70S TODAY.
HOWEVER, GIVEN LIMITED INSTABILITY (~500 J/KG AT MOST) AND A CAP
DEPICTED IN FORECAST SOUNDINGS, SEVERE WEATHER WILL BE INCREDIBLY
ISOLATED TODAY. MOISTURE WILL ALSO BE RATHER LIMITED WITH PEAK
DEWPOINTS OF ONLY 50-55 DEGREES THIS EVENING. SPC DID ADD A MARGINAL
RISK WEST OF US 31 FOR WIND, BUT IF AN ISOLATED STORM DOES BECOME
SEVERE, IT SHOULD BE SHORT LIVED. AS RAIN AND STORMS PROGRESS TO THE
SOUTHEAST THIS EVENING, MID LEVEL LAPSE RATES WILL BE BETWEEN 7-8
C/KM. THIS WOULD SUPPORT SMALL HAIL IN ANY OF THE TALLEST STORM
CORES. HEAVY RAIN WILL ALSO BE POSSIBLE IN ANY STORMS. THE
AFOREMENTIONED COLD FRONT IS EXPECTED TO STALL IN THE VICINITY OF
THE US 30 CORRIDOR AROUND 06Z. SHOWERS AND STORMS WILL ONLY LAST FOR
A FEW HOURS IN ANY GIVEN LOCATION TODAY AND TONIGHT, BUT SOUTH OF US
24 MAY SEE LINGERING STORMS UNTIL ABOUT 09Z. DEPENDING ON WHERE
EXACTLY THE COLD FRONT STALLS AND HOW QUICKLY IT PUSHES SOUTHEAST
DURING THE DAY TOMORROW, SCATTERED STORMS MAY REDEVELOP ALONG THE
STALLED BOUNDARY WEDNESDAY SOUTH OF US 30 BETWEEN 2-8 PM EDT. STORMS
WILL BE HIT OR MISS, BUT WITH AN UNCAPPED ENVIRONMENT, SLIGHTLY
IMPROVED MOISTURE WITH DEWPOINTS AROUND 60 DEGREES, AND UP TO 1000
J/KG OF SBCAPE, I WOULD NOT BE SURPRISED TO SEE GUSTY WINDS, SMALL
HAIL, AND HEAVY RAIN.
TEMPERATURES WILL BECOME INCREASINGLY MILD MIDWEEK THROUGH FRIDAY
WITH HIGHS IN THE MID TO UPPER 70S EACH DAY. OUR AREA WILL BE WARM
AND DRY THURSDAY AMIDST BRIEF YET AMPLIFIED UPPER LEVEL RIDGING
BUILDING IN ACROSS THE UPPER GREAT LAKES. A DEEPENING LOW PRESSURE
SYSTEM WILL TRAVERSE THE NORTHERN PLAINS INTO MANITOBA ON THURSDAY.
THE SYSTEM'S ATTENDANT COLD FRONT WILL MOVE THROUGH OUR AREA BY
FRIDAY, BRINGING RAIN AND MAYBE ANOTHER CHANCE FOR STORMS. AIDED BY
A POTENTIAL GULF CONNECTION, SOUTHERLY WINDS WILL IMPROVE MOISTURE
RETURN AND BOOST DEWPOINTS INTO THE LOW TO MID 60S ON FRIDAY.
DEPENDING ON WHAT TIME THE FRONT MOVES THROUGH (LATE MORNING VS
AFTERNOON/EVENING), THE BETTER ENVIRONMENT FOR STORMS MAY BE
DISPLACED FROM THE FRONTAL PASSAGE. SEVERE WEATHER IS NOT EXPECTED
FOR FRIDAY AT THIS TIME.
HIGH PRESSURE BUILDS IN FOR THE WEEKEND, WITH NORTHERLY WINDS
USHERING IN MORE SEASONABLE AIR. HIGHS WILL LIKELY BE IN THE 60S BY
THE WEEKEND AND CONTINUING INTO EARLY NEXT WEEK. AN ACTIVE WEATHER
PATTERN LOOKS TO RESUME EARLY NEXT WEEK WITH SEVERAL ADDITIONAL
CHANCES FOR RAIN.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 616 PM EDT TUE APR 21 2026
SLOWING, NARROW, LINE OF CONVECTION OVER KSBN AS OF 22Z WILL
MAKE ITS WAY DOWN INTO KFWA BTW 00-04Z THIS EVENING WITH IFR TO
MVFR VIS RESTRICTIONS POSSIBLE IN HEAVIER THUNDERSHOWERS. DRY
THERAFTER WITH MVFR TO LOW VFR CIGS LIKELY SETTLING IN NEAR A
WEAK FRONT LATE TONIGHT INTO WEDNESDAY MORNING.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-
046.
DISCUSSION...JOHNSON
AVIATION...STEINWEDEL
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