842
FXUS63 KIWX 270756
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
356 AM EDT MON APR 27 2026
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS WILL DEVELOP TODAY, SOME STORMS
ACCOMPANIED BY STRONG TO DAMAGING WINDS LATE TODAY AND EARLY
TONIGHT. LOCALLY HEAVY RAINFALL LIKELY.
- WARM TODAY WITH HIGHS IN THE 70S.
- DRY AND COOL WEDNESDAY THROUGH SATURDAY WITH HIGHS IN THE 50S.
- FROST LIKELY AT TIMES WEDNESDAY NIGHT THROUGH SATURDAY NIGHT.
DISCUSSION
ISSUED AT 355 AM EDT MON APR 27 2026
THE GREATEST FORECAST CHALLENGES LOOMING AHEAD INCLUDE TIMING
AND COVERAGE OF STRONG TO SEVERE STORMS LATER TODAY AND TONIGHT.
THE LEADING UPSTREAM CONVECTIVE CLUSTER HAD ALREADY MOVED INTO
WESTERN IL AT THE TIME OF THIS WRITING (3AM EDT). MOISTURE
WILL SURGE NORTH INTO NORTHERN INDIANA LATER TODAY AHEAD OF
THIS ACTIVITY WITH DEW POINTS IN THE 60S GIVEN THE LATEST HRRR
MODEL DATA. GIVEN ALL OF THE CHARACTERISTICS OF THE UPSTREAM
AIRMASS, AN 80 KNOT MID LEVEL JET AND THE ASSOCIATED KINEMATICS
WITH THIS SYSTEM, SEVERE THUNDERSTORMS ARE EXPECTED LATE TODAY
INTO EARLY TONIGHT WITH DAMAGING WINDS THE GREATEST THREAT.
A FAIRLY STRONG LOW LEVEL CAP SHOULD ERODE QUICKLY AS THIS
STRONG SYSTEM APPROACHES FROM THE WEST. SHOWERS AND THUNDERSTORMS
WILL FILL IN RAPIDLY WEST OF THE FORECAST AREA THIS MORNING. THE
ACTIVITY WILL INTENSIFY AND MOVE EAST AS THE POTENTIAL FOR DAMAGING
WINDS INCREASES. THE BEST CHANCES FOR SEVERE STORMS IS EXPECTED
TO BE FROM ABOUT 3PM TO 9PM EDT.
MUCH COLDER AIR WILL SETTLE ACROSS THE FORECAST AREA LATE THIS
WEEK BRINGING THE LIKELIHOOD FOR FROST AND THE POTENTIAL FOR
FREEZING TEMPERATURES. GIVEN THE RECENT MILD TEMPERATURES AND
THE DEVELOPMENT OF SENSITIVE VEGETATION, FROST AND POSSIBLY
FREEZE HEADLINES WILL LIKELY BE NEEDED DURING THIS TIME.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 130 AM EDT MON APR 27 2026
SEVERAL ROUNDS OF THUNDERSTORMS ARE EXPECTED LATER TODAY AS A
POTENT SHORTWAVE LIFTS INTO THE REGION. THE FIRST ROUND IS
ASSOCIATED WITH WAA AND UPSTREAM CONVECTION LIFTING INTO THE
AREA ROUGHLY 18-23Z. CONFIDENCE IN THUNDERSTORMS IMPACTING THE
TERMINALS IS LOWER WITH THIS FIRST ROUND AND WILL THEREFORE HOLD
WITH PROB30. THERE IS HIGHER CONFIDENCE IN THE SECOND ROUND
EXPECTED AFTER 00Z BUT THERE IS STILL SOME UNCERTAINTY IN THE
EXACT TIMING AND PLACEMENT OF THE STRONGEST STORMS DURING THIS
PERIOD. THUNDERSTORMS ARE LIKELY AT SOME POINT BUT WILL NEED TO
CONTINUE TO FINE-TUNE THE TIMING IN LATER FORECASTS AS UPSTREAM
CONVECTION EVOLVES.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 AM EDT
TUESDAY FOR LMZ043-046.
DISCUSSION...SKIPPER
AVIATION...AGD
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