540
FXUS63 KIWX 031826
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
226 PM EDT SUN MAY 3 2026
KEY MESSAGES
- BRIEF WARMUP AND TURNING BREEZY TODAY INTO MONDAY.
- THERE IS A CHANCE (20-40%) FOR SCATTERED SHOWERS THIS
AFTERNOON.
- CHANCES FOR SCATTERED SHOWERS AND STORMS (30-50%) INCREASE
MID AFTERNOON MONDAY INTO MONDAY NIGHT. A FEW STORMS COULD
BECOME STRONG TO SEVERE (WIND/HAIL).
- TURING COOLER WITH PERIODS OF RAIN TUESDAY INTO TUESDAY NIGHT.
- COOL MIDWEEK THROUGH NEXT WEEKEND WITH OCCASIONAL CHANCES FOR
RAIN SHOWERS.
DISCUSSION
ISSUED AT 121 PM EDT SUN MAY 3 2026
A WEAK SHORTWAVE MOVING SOUTHEASTWARD IN CONJUNCTION WITH A COLD
FRONT ALLOWS AN AREA OF SHOWERS TO SWING EASTWARD THROUGH THE AREA
THIS AFTERNOON. GIVEN THE DRY AIRMASS, RAP TIME-SECTIONS INDICATE A
FAIRLY DRY AIRMASS IN THE LOW LEVELS OF THE ATMOSPHERE AND THIS
PROBABLY KEEPS THE MAJORITY OF THE MORNING RAIN AS JUST VIRGA.
BETTER LOW LEVEL MOISTURE ARRIVES DURING THE AFTERNOON AND THIS
HELPS TO INCREASE CONFIDENCE THAT AT LEAST A COUPLE OF HOURS OF RAIN
WILL BE POSSIBLE. TEMPERATURES DON'T FALL AS FAR TONIGHT,DESPITE DEW
POINTS IN THE UPPER 20S AND LOW 30S, BECAUSE THE TEMPERATURE PROFILE
IS MUCH WARMER (FINALLY ABOVE FREEZING) THAN WE HAD IT BOTH WEEKEND
MORNINGS (BELOW FREEZING).
WE'LL HAVE BEEN ON A WARMING TREND FOR TEMPERATURES DESPITE TODAY'S
COLD FRONT ALLOWING OUR HIGHS IN THE 50S ON SATURDAY TO REACH THE
70S ON MONDAY. DEW POINTS ALSO TREND HIGHER WITH THE PASSAGE OF THE
THETA-E PLUME THIS EVENING AND ANOTHER PUSH OF IT INTO THE AREA
MONDAY. EVEN STILL, MODELS RESTRICT SFC DEW POINTS TO THE 50S AND
850 MB DEW POINTS TO THE SINGLE DIGITS. THE NORMALLY MOIST BIASED
NAM IS INDICATING THAT CLOSER TO THE ARRIVING COLD FRONT, THERE
COULD BE SOME BETTER MOISTURE (CLOSER TO 60F IN SFC DEW POINTS AND
AROUND 10C IN 850 MB DEW POINTS, BUT BOY IS IT DISCONTINUOUS). THERE
IS STILL THE WARM FRONT-LIKE FEATURE THAT TRIES TO PUSH INTO THE
AREA LATER IN THE AFTERNOON THAT MAY HELP BRING BETTER MOISTURE TO
THE AREA AS WELL. OVERALL, THE FORCING APPEARS RATHER DIFFUSE AND
WEAK, BUT THE NAM TRIES TO BRING SOME BETTER LARGE SCALE ASCENT IN
BY THE EVENING (WHICH MAY BE CONVECTIVELY ENHANCED). THERE ARE
POCKETS OF EFFECTIVE SHEAR BETWEEN 30 AND 40 KTS TO WORK WITH, WHICH
MAY BE ON THE STRONG SIDE OF SHEAR TO GET DRY MICROBURSTS OUT OF THE
INVERTED-V PROFILES THAT SHOW UP ON THE HRRR SOUNDINGS. AGAIN, THE
NORMALLY MOIST-BIASED NAM HAS MUCH MORE MOISTURE IN THOSE PROFILES.
THIS WOULD AT LEAST POINT TO SOME SORT OF WIND THREAT. IT ALSO
APPEARS THAT THE MID LEVEL LAPSE RATES MIX OUT OVERHEAD LESSENING A
HAIL THREAT, BUT IT'S NOT COMPLETELY REMOVED GIVEN SHEAR AND
INSTABILITY. TORNADO IS CERTAINLY A LESSER THREAT, BUT COULD EXIST
WITH ENOUGH LIFT ALONG AND SOUTH OF THE APPROACHING WARM FRONT LATER
IN THE DAY (SOUTH OF US-24 AREA). THE LOW LEVEL JET REMAINS SOUTH OF
US-24 DURING THE OVERNIGHT AND THE NAM INDICATES THERE ARE AREAS OF
LOW LEVEL MOISTURE FLUX CONTINUING TO MOVE THROUGH WHICH WOULD POINT
TO MAYBE A FLOOD THREAT LINGERING INTO THE OVERNIGHT.
THE COLD FRONT IS SLOW TO MOVE SOUTHEASTWARD TUESDAY AND IS
CONTINUING TO BE FLAGGED BY THE NBM (WHICH USES OLD DATA BY ABOUT 6
TO 18 HRS) AS WELL AS AN ENSEMBLE OF MEDIUM RANGE GUIDANCE AS
ALLOWING 1 IN OR MORE RAINFALL DURING THE 24 HOURS PRIOR TO 6 TO 12Z
TUESDAY NIGHT MAINLY SOUTH OF US-24. THERE ARE SIGNS THAT WEAK LOWS
MAY TRY TO MOVE ALONG THE SLOW MOVING FRONT DURING THIS TIME. WPC
HAS AN ERO OF MRGL FOR THIS PERIOD. THE FRONT IS OUT OF THE AREA
LATER TUESDAY NIGHT AS SLIGHT HEIGHT RISES EXIST IN THE MID LEVELS
AND HIGH PRESSURE NOSES IN. A COOLER TREND EXISTS WITH THE HIGHS
WITH 50S BECOMING MORE COMMON TUESDAY THROUGH THURSDAY.
HEIGHT FALLS COMMENCE WEDNESDAY NIGHT AND INTO THURSDAY AS THE BASE
OF THE UPPER TROUGH SWINGS THROUGH, BUT WE ARE MUCH DRIER THEN AND
MODEL QPF OUTPUT IS RATHER MEAGER. THIS ALSO FITS WITH THE UPPER
COOLER/DRYING NORTHWEST FLOW AND THERE NOT BEING A THETA-E PLUME TO
WORK WITH. BETTER WARMING AND DEW POINTS ARRIVE FOR FRIDAY ALTHOUGH
WE'RE STILL IN THAT UPPER NW FLOW. A WEAKER WAVE MOVES THROUGH IN
THE TROUGH, BUT THIS WOULD SEEM TO PROVIDE A SLIGHTLY BETTER
OPPORTUNITY. HIGHS TREND WARMER FROM FRIDAY INTO THE WEEKEND WITH A
RETURN TO HIGHS IN THE 60S.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 126 PM EDT SUN MAY 3 2026
VFR CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THIS TAF
PERIOD. A FEW LIGHT SCATTERED SHOWERS WILL MOVE THROUGH THIS
AFTERNOON FROM 18Z THROUGH 21Z SUN. GUSTY SOUTHWESTERLY WINDS
HAVE DEVELOPED AS EXPECTED WITH GUSTS UP TO AROUND 30 KTS. A
PERIOD OF SLIGHT DECOUPLING OVERNIGHT AFTER 12Z WILL ALLOW
WINDS TO RELAX TEMPORARILY BUT AFTER 15Z MON GUSTS INCREASE
DIURNALLY TO AROUND 20 TO 25 KTS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-
046.
DISCUSSION...ROLLER
AVIATION...ANDERSEN
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