085
FXUS63 KIWX 300028
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
828 PM EDT SUN JUN 29 2025
KEY MESSAGES
- ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE TONIGHT MAINLY
NORTHWEST INDIANA AND EXTENDING INTO NORTHEAST INDIANA ALONG
AND SOUTH OF US ROUTE 24.
- RAIN/STORMS ARE POSSIBLE MONDAY MORNING, THEN LIKELY MONDAY AFTERNOON
AND EVENING. A FEW STORMS COULD BE STRONG TO SEVERE WITH
DAMAGING WINDS AND HEAVY RAINFALL.
- DRY, SEASONABLE, AND LESS HUMID BY MID TO LATE IN THE WEEK.
DISCUSSION
ISSUED AT 231 PM EDT SUN JUN 29 2025
A WARM FRONT HAS LIFTED NORTHWEST ACROSS THE AREA TODAY, WHICH WILL
ALLOW FOR HIGHS IN THE MID TO UPPER 80S THIS AFTERNOON ALONGSIDE A
NOTICEABLE INCREASE IN HUMIDITY. SOUTHERLY LOW-LEVEL FLOW HAS
HELPED TO PULL IN MOISTURE FROM THE GULF, WHICH HAS BROUGHT
DEWPOINTS UP INTO THE LOW 70S TODAY. HEAT INDICES ARE EXPECTED
TO PEAK IN THE LOW TO MID 90S THIS AFTERNOON. A FEW ISOLATED
SHOWERS/STORMS WILL BE POSSIBLE THIS AFTERNOON AND EVENING
ACROSS NORTH-CENTRAL INDIANA, MAINLY SOUTH OF US 24 AND WEST OF
US 31.
WAA CONTINUES INTO THE DAY ON MONDAY WITH HIGHS IN THE 80S AND
DEWPOINTS IN THE LOW TO MID 70S. AN AREA OF LOW PRESSURE WILL LIFT
ACROSS THE MIDWEST AND IT'S ATTENDANT COLD FRONT WILL BRING HIGH
CHANCES (60-80%) FOR SHOWERS AND STORMS. WITH THE AFOREMENTIONED
HEAT AND HUMIDITY, THIS SHOULD ALLOW FOR DESTABILIZATION TO
OCCUR DURING THE DAY MONDAY AND FOR THUNDERSTORMS TO DEVELOP.
THE STORM PREDICTION CENTER HAS MAINTAINED THE MARGINAL RISK
(LEVEL 1 OF 5) FOR OUR ENTIRE FORECAST AREA, MEANING A FEW
STORMS COULD BE STRONG TO SEVERE. OVERALL, MONDAY LOOKS FAIRLY
UNIMPRESSIVE AND DISORGANIZED FOR SEVERE WEATHER, ESPECIALLY
CONSIDERING THERE MAY BE SOME SHOWERS TO DEAL WITH IN THE
MORNING. AN INITIAL ROUND OF SCATTERED SHOWERS (NOT AS MUCH
CONFIDENCE IN THUNDERSTORMS) WILL BE POSSIBLE MONDAY MORNING AS
A SHORTWAVE LIFTS OUT OF THE ST LOUIS AREA. A SECOND,
POTENTIALLY STRONGER, ROUND OF STORMS WILL THEN BE POSSIBLE
MONDAY AFTERNOON AND EVENING WITH THE COLD FRONT. MULTICELL
CLUSTERS/A BROKEN LINE OF THUNDERSTORMS SHOULD DEVELOP AHEAD OF
THE COLD FRONT AND SWEEP THROUGH THE AREA. THESE STORMS WILL
HAVE MODEST INSTABILITY (1500-3000 J/KG) TO WORK WITH, HOWEVER
LAPSE RATES WILL BE POOR AND THERE WILL BE LITTLE TO NO SHEAR IN
PLACE AS VERTICAL WIND PROFILES ARE UNIDIRECTIONAL OUT OF THE
SOUTHWEST. LINGERING SHOWERS AND CLOUDS IN THE MORNING AND EARLY
AFTERNOON MAY ALSO HINDER SEVERE CHANCES. CONFIDENCE IN SEVERE
WEATHER IS LOW. IF ANY STORMS DO MANAGE TO REACH SEVERE
THRESHOLDS, THE PRIMARY THREAT WILL BE DAMAGING WINDS. LOCALLY
HEAVY RAIN IS ALSO POSSIBLE WITH LONG, SKINNY CAPE PROFILES, A
DEEP WARM CLOUD LAYER, AND PWATS OF 1.75-2" MONDAY AFTERNOON AND
EVENING.
JULY WILL START ON A SEASONABLE AND DRY NOTE AS SURFACE HIGH
PRESSURE AND AN UPPER LEVEL RIDGE BUILD IN BY MIDWEEK. TUESDAY
THROUGH FRIDAY CURRENTLY LOOKS TO BE MAINLY DRY, WITH LOWER LEVELS
OF HUMIDITY AND SEASONABLE TEMPERATURES. SOME DIURNAL CHANCES FOR
RAIN/STORMS MAY BE POSSIBLE FOR THE 4TH OF JULY AND INTO THE HOLIDAY
WEEKEND DEPENDING ON HOW AMPLIFIED THE UPPER LEVEL RIDGE IS. FOR
NOW, HAVE KEPT POPS LOW AT 20-30% AT TIMES THROUGH THE WEEKEND.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 806 PM EDT SUN JUN 29 2025
RESIDUAL LOW LEVEL BOUNDARY IS SLOWLY RETREATING NORTHWARD AS A
WARM FRONT/MOISTURE GRADIENT BOUNDARY, WITH EARLIER OUTFLOWS
FROM STORMS SOUTH OF KFWA HELPING TO PUSH THIS BOUNDARY
NORTHWARD. A STRONG INSTABILITY GRADIENT IS IN PLACE ACROSS
NORTHERN INDIANA WITH BEST SURFACE BASED INSTABILITY RESIDING
ACROSS NW INDIANA GENERALLY ALONG US 24 CORRIDOR. LOSS OF PEAK
DIURNAL INSTABILITY, WEAK MID/UPPER LEVEL FORCING, AND SOUTHWARD
DISPLACEMENT OF BETTER INSTABILITY SHOULD KEEP SHOWER/STORM
THREAT SOUTH AND SOUTHWEST OF THE TERMINALS FOR MUCH OF THE
EVENING/EARLY OVERNIGHT. BY LATE TONIGHT, EXPECTING SOME MODEST
INCREASE IN ELEVATED INSTABILITY AS SOME INCREASE IN LOW LEVEL
MOISTURE IS EXPECTED IN ADVANCE OF WHAT COULD BE A RESIDUAL WEAK
LEAD SHORT WAVE ENHANCED BY UPSTREAM CONVECTION THIS AFTERNOON.
EXPECTING SHOWER COVERAGE TO TO BE ISOLATED/SCATTERED WITH
CONFIDENCE AT THIS TIME LIMITED TO PROB30 SHRA MENTION LATE
TONIGHT. BETTER CHANCE OF SHOWERS AND STORMS STILL APPEARS TO BE
MONDAY AFTERNOON WITH POTENTIAL INFLUENCE OF PRE-FRONTAL TROUGH
TYPE FEATURE AND WHEN A WEAK UPPER SPEED MAX SHIFTS ACROSS THE
SOUTHERN GREAT LAKES. APPROACH OF MAIN MID LEVEL TROUGH AND COLD
FRONT WILL KEEP SHOWER/STORM CHANCES IN THE PICTURE THROUGH
MONDAY EVENING BEFORE DIMINISHING FROM WEST TO EAST. VFR
CONDITIONS ARE EXPECTED THROUGH THIS PERIOD OUTSIDE OF ANY
HEAVIER SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON/EVENING.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...JOHNSON
AVIATION...MARSILI
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