733
FXUS63 KIWX 200611
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
211 AM EDT SUN JUL 20 2025
KEY MESSAGES
- THE NEXT BEST CHANCES OF SHOWERS AND THUNDERSTORMS ARE SUNDAY
INTO SUNDAY NIGHT,THEN THURSDAY AFTERNOON INTO FRIDAY.
- ANOTHER HEATWAVE IS LIKELY WEDNESDAY THROUGH FRIDAY.
- THERE IS A MODERATE SWIM RISK FOR SOUTHEAST LAKE MICHIGAN
BEACHES IN LA PORTE AND BERRIEN COUNTIES FOR SUNDAY.
UPDATE
ISSUED AT 925 PM EDT SAT JUL 19 2025
THE MCV RESPONSIBLE FOR A NARROW SWATH OF 2 TO 5 INCHES OF RAIN
JUST SOUTH OF THE I-80/90 CORRIDOR IS ABOUT TO EXIT NW OHIO AT
THIS TIME. THE THREAT OF SEVERE WEATHER HAS ENDED ACROSS THE
AREA TONIGHT, WITH ADDITIONAL RAINFALL EXPECTED TO BE MORE
SCATTERED IN NATURE. SOME AREAS MAY BE EXPERIENCING SOME
LINGERING FLOODING, ESPECIALLY ACROSS THE MORE URBANIZED AREAS
ACROSS PORTIONS OF LA PORTE COUNTY THAT EXPERIENCED THE HEAVIER
RAIN AMOUNTS.
ANOTHER SMALL SCALE SYNOPTIC WAVE IS TRACKING ACROSS CENTRAL
LOWER MI AND COULD LEAD TO ISOLATED-SCATTERED CONVECTION ACROSS
THOSE LOCATIONS. OTHERWISE, HAVE LIMITED POPS TO SLIGHT CHANCE
DURING THE OVERNIGHT HOURS, WITH GREATER CHANCES OF RAIN AND
EMBEDDED THUNDERSTORMS EXPECTED AFTER DAYBREAK SUNDAY AS ANOTHER
PROGRESSIVE WAVE ACROSS THE CENTRAL PLAINS INTERACTS WITH
STALLED FRONTAL BOUNDARY ACROSS THE AREA.
DISCUSSION
ISSUED AT 141 PM EDT SAT JUL 19 2025
A BROKEN LINE OF STORMS WITH A FEW DISCRETE CELLS AHEAD OF THE
MAIN LINE HAD FORMED OVER NORTHERN INDIANA. THIS FRACTURED LINE
WAS ORIGINALLY AN UPSTREAM MCS THAT HAD DEGENERATED INTO AN AREA
OF RAIN WITH A FEW EMBEDED STORMS. THE BEST CHANCE FOR ANYTHING
STRONG TO SEVERE SHOULD BE SOUTHEAST OF WARSAW WHERE CELLS WILL
BE ABLE TO TAP INTO AN UNMODIFIED AIRMASS. SPC MESOANALYSIS
SHOWS A BULK SHEAR MAXIMUM AXIS IN THE VICINITY OF THE BROKEN
LINE FROM WHITE CO TO JAY COUNTY (MONTICELLO TO PORTLAND) WHERE
THE STRONGEST STORMS IN OUR AREA SHOULD FORM LATE THIS AFTERNOON.
MORE STORMS ARE POSSIBLE SUNDAY, BUT SINCE THE FRONT HAD MOVED
SOUTH OF THE AREA, BELIEVE STORMS WILL NOT BE SEVERE GIVEN (1)
LIGHT WIND FLOW AND VERY LIMITED SHEAR IN THE LOWER LAYERS, (2)
LACK OF SURFACE CONVERGENCE AND (3) VERY LIMITED/THIN CAPE.
ANOTHER HEAT WAVE IS SLATED TO DEVELOP OVER THE AREA DURING THE
MIDDLE AND LATTER PART OF THIS UPCOMING WEEK. THE HOTTEST
TEMPERATURES ARE FORECAST FOR THURSDAY. HEAT HEADLINES ARE
LIKELY TO BE EVENTUALLY ISSUED AS THIS EVENT NEARS.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 153 AM EDT SUN JUL 20 2025
VFR CONDITIONS AS OF THIS WRITING AT BOTH TERMINALS, THOUGH
EXPECT A DETERIORATION TO MVFR AND POSSIBLY IFR VISIBILITIES AS
WE HEAD INTO THE MORNING HOURS. STARTED TEMPO GROUPS AT 8-9Z FOR
MVFR CEILINGS BETWEEN 1500-2500 FT, BEGINNING AT KSBN AS THE
COLD FRONT SINKING SOUTHWARD FROM WI/CENTRAL AND NORTHERN LOWER
MI REACHES FAR NORTHERN IN/SOUTHERN MI. IT'S UNCERTAIN EXACTLY
WHERE THE FRONT WILL STALL, BUT INCREASING MOISTURE TRANSPORT
WITH THE LLJ AHEAD OF THE FRONT TONIGHT (COMBINED WITH THE
RAINFALL FROM STORMS/SHOWERS EARLIER IN THE DAY) INCREASES MY
CONFIDENCE IN AT LEAST LOWER-END MVFR CEILINGS IF NOT IFR
CEILINGS AT BOTH SITES. AT THE MOMENT, CEILINGS ALONG AND AHEAD
OF THE FRONT TO THE NORTH ARE IN THE 600-700 FT RANGE. KEPT
CEILINGS LIMITED TO 700 FT AT BOTH SITES (THROUGH 16Z AT KSBN,
17Z AT KFWA) BUT IT'S POSSIBLE KSBN DROPS A LITTLE LOWER THAN
THAT. VISIBILITIES UPSTREAM ARE HIGHLY VARIABLE, WITH POCKETS OF
GROUND FOG WITH VISIBILITIES OF 1/2-1 SM IN PLACES, AND MOST
OTHERS IN THE 4-7SM RANGE. WE'VE SEEN OCCASIONAL DROPS AT KSBN
AND JUST NORTH/EAST OF KFWA OVER THE PAST COUPLE OF HOURS, AND
WOULDN'T BE SHOCKED TO SEE SIMILAR CONDITIONS DEVELOP AT THE
TERMINALS. WAS ON THE FENCE ABOUT INCLUDING A TEMPO AT KFWA
EARLIER THAN THE CURRENT 9Z TIME-WILL AMEND IF NEEDED. OTHERWISE
POSSIBLE RAINSHOWERS BETWEEN 12-16Z AT KSBN (MAYBE DRIZZLE), AND
BETWEEN 13-17Z AT KFWA. AFTER 18Z, CEILINGS IMPROVE BUT THERE IS
POTENTIAL FOR KFWA TO BE SWIPED BY THUNDERSTORMS THROUGH ABOUT
00Z-BUT MUCH OF GUIDANCE KEEPS THE COMPLEX SOUTH OF THE
TERMINAL. HAVE VCTS WITH PROB30 FOR THE POSSIBILITY AT THIS
POINT-WILL KNOW MORE FOR 12Z TAFS ONCE WE SEE HOW FAR THE
FRONTAL ZONE HAS MOVED ALONG.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
UPDATE...MARSILI
DISCUSSION...SKIPPER
AVIATION...MCD
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