557
FXUS63 KIWX 251050
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
650 AM EDT WED MAR 25 2026
KEY MESSAGES
- HIGHS IN THE 60S TODAY, THEN RISING INTO THE 70S AND EVEN LOW
80S THURSDAY. THERE IS A 40 TO 60% CHANCE FOR HIGHS AT OR
ABOVE 80 DEGREES ALONG AND SOUTH OF A LINE FROM PULASKI
COUNTY TO ADAMS COUNTY, IN ON THURSDAY.
- A STRONG COLD FRONT BRINGS CHANCES (60-90%) FOR SHOWERS AND
STORMS THURSDAY AFTERNOON INTO THURSDAY EVENING. SOME STORMS
COULD BE SEVERE WITH DAMAGING WIND GUSTS, LARGE HAIL, AND
ISOLATED TORNADOES POSSIBLE. THE GREATEST SEVERE WEATHER
THREAT APPEARS TO BE BETWEEN 5PM AND 11PM EDT ON THURSDAY.
SOME LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE.
- COOLER AIR FILTERS IN FOR FRIDAY WITH HIGHS IN THE 40S, BUT
TEMPERATURES TREND WARMER STARTING THIS WEEKEND AND PERSIST
THROUGH THE MIDDLE OF NEXT WEEK, WHEN HIGHS WILL BE IN THE
70S.
DISCUSSION
ISSUED AT 231 AM EDT WED MAR 25 2026
THE PATTERN IN THE NEAR TERM HAS A TROUGH ACROSS THE EASTERN US WITH
A RIDGE ACROSS THE WESTERN US. BOTH PARTS OF THIS PATTERN ARE
DAMPENED, THOUGH, AS A SURFACE HIGH WORKS INTO THE EASTERN US AND A
LOW PRESSURE SYSTEM PUSHES THROUGH THE WESTERN US.
THE AREA OF LOW PRESSURE PUSHES EASTWARD TOWARDS THE AREA TODAY AND
TONIGHT AS THE UPPER JET PUSHES INTO THE GREAT LAKES AND THE LOW
LEVEL JET STRENGTHENS IN THE OHIO VALLEY DUE TO INCREASED PRESSURE
GRADIENT THERE. AT THE SAME TIME, A THETA-E PLUME TRANSLATES THROUGH
THE AREA BETWEEN TONIGHT AND THURSDAY NIGHT. ONE SHORTWAVE PUSHES
THROUGH BETWEEN 00Z AND 12Z TONIGHT AND DEW POINTS INCREASING ABOVE
50 DEGREES TRAVERSE THE AREA SOUTH OF US-30. WHILE SURFACE-BASED
INSTABILITY APPEARS TO BE LACKING, ELEVATED INSTABILITY WITH 500 TO
1000 J/KG OF MUCAPE AND ~7 C/KM MID LEVEL LAPSE RATES TRAVERSE THE
AREA AFTER 6Z SO SOME THUNDERSTORMS CAPABLE OF PRODUCING HAIL COULD
BE POSSIBLE, BUT GIVEN WEAK SHEAR, THINK ANY HAIL PRODUCED WOULD BE
SMALL.
IT LOOKS LIKE THE LOW LEVELS WILL BE SATURATED THURSDAY MORNING SO
WE'LL HAVE SOME WORK TO DO TO GET INSTABILITY CREATED AHEAD OF OUR
THUNDERSTORM CHANCE LATER THURSDAY. ANOTHER STRONGER AREA OF MID
LEVEL LAPSE RATES PUSH INTO THE AREA DURING THE DAY THURSDAY AND
THIS HELPS TO KEEP THE LID ON THE AREA UNTIL THE AFTERNOON OR
EVENING. WE'LL PROBABLY NEED TO WAIT UNTIL BETTER LARGE SCALE ASCENT
ARRIVES TO BREAK THIS CAP AND, WHILE THE NAM PUSHES THROUGH A SMALL
AREA OF LARGE SCALE ASCENT WITH AN INITIAL WAVE ROTATING THROUGH,
THE BETTER CHANCE OF SUCH A CAP BREAK OCCURS LATER, TOWARDS 21-00Z
TIME FRAME. ALREADY BY MIDDAY THURSDAY, 60 DEGREE DEW POINTS WORK
INTO THE AREA AND PWAT ANOMALIES REACH 3 TO 5 SDS ABOVE NORMAL
CLOSER TO THE ARRIVING COLD FRONT 21-00Z. IT APPEARS INITIAL SHEAR
MAY BE PERPENDICULAR TO THE BOUNDARY, BUT WILL BE QUICK TO TURN
PARALLEL MEANING ANY INITIAL CELLS THAT AREA ABLE TO FORM OUT
IN FRONT OF THE BOUNDARY COULD HAVE DISCRETE CHARACTERISTICS,
BUT WILL BE QUICK TO CONGEAL INTO A LINEAR STRUCTURE. 40 TO 60
KTS OF EFFECTIVE SHEAR SWINGING THROUGH AND POCKETS OF 200 UNITS
OF EFFECTIVE HELICITY WILL MAKE WIND DAMAGE AND LARGE HAIL THE
MAIN THREATS, BUT ESPECIALLY IF THOSE DISCRETE CELLS ARE ABLE TO
FORM, THERE COULD BE SOME ROTATING CELLS OUT IN FRONT OF THE
LINE. DEPENDING ON HOW QUICKLY THE LINE MOVES, THERE COULD BE
SOME EMBEDDED VORTICIES WITHIN THE LINE TO MAKE TORNADOES A
THREAT AS WELL, BUT CONFIDENCE ON THOSE FORMING IS LOWER THAN
THE ABOVE TWO THREATS. GIVEN THE BOUNDARY PARALLEL SHEAR
TENDENCY, FLOODING WILL BE POSSIBLE LATER IN THE LINE'S
EVOLUTION, BUT THIS WOULD LIKELY BE FROM TRAINING CELLS AS
OPPOSED TO BACKBUILDING CELLS. THE MBE VECTOR APPEARS STRONG
ENOUGH ACCORDING TO NAM BUFKIT. IT APPEARS THE STRONGEST PART OF
THE LINE WILL BE OUT OF THE AREA BY 11 PM OR SO BUT SOME RAIN
COULD LAG THE LINE.
A VORT MAX SWINGS THROUGH FRIDAY USHERING COOLER AND DRIER AIR INTO
THE AREA AS SURFACE HIGH PRESSURE FOLLOWS BEHIND. WHILE HIGHS ARE
EXPECTED TO RISE INTO THE 70S WITH A FEW 80 DEGREE READINGS POSSIBLE
THURSDAY, THE COOLER AIR ANTICIPATED CAUSES HIGHS TO DROP BACK INTO
THE 40S ON FRIDAY. LOWS IN THE LOW TO MID 20S ARE FORECAST FOR
FRIDAY NIGHT. THEN, WARM ADVECTION ENSUES BETWEEN SATURDAY AND
MONDAY CAUSING A WARMING TREND ALLOWING TEMPS TO RISE BACK INTO THE
60S AND LOW 70S MONDAY.
AS THOSE WARM TEMPERATURES RETURN, SUNDAY NIGHT INTO MONDAY MORNING,
THERE IS SOME MODEL CONSENSUS AROUND CREATING SOME LIGHT SHOWERS IN
A WAA SET UP. AM NOT CONFIDENT IN PRECIPITATION HAPPENING THOUGH, AS
THE LOW LEVELS LOOK DRY ENOUGH TO ALLOW EVAPORATION AND THE AREA OF
LOW PRESSURE APPEARS TO BE WEAKENING WITH TIME. WE'LL HAVE TO WATCH
BETWEEN MONDAY AND TUESDAY, THOUGH, FOR A WARM FRONT THAT COULD
ALLOW FOR SCATTERED SHOWERS AND PERHAPS SOME THUNDERSTORMS, BUT
ITS PLACEMENT WILL BE KEY. SOME MODELS TAKE IT INTO MI SO THAT
WE AVOID THE RAIN.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 635 AM EDT WED MAR 25 2026
VFR CONDITIONS AT THE TERMINALS TO START THE PERIOD, WITH
POTENTIAL FOR MVFR CEILINGS/VISIBILITIES LATE TONIGHT INTO EARLY
THURSDAY MORNING. MAINLY MID-HIGH LEVEL CLOUD COVER WITH LIGHT
SOUTHEASTERLY WINDS SHIFTING SOUTHWEST THROUGH THE PERIOD. GUSTS
OF 20-25 MPH ARE POSSIBLE AT BOTH TERMINALS THIS AFTERNOON
BEFORE WE DECOUPLE OVERNIGHT. MODELS HAVE BACKED OFF ON THE
INTENSITY OF THE LLWS FROM THE PREVIOUS FORECAST (DOWN TO
35-40KTS AT BOTH SITES VS PREVIOUSLY FORECASTED 45-50 KNOTS), SO
HAVE ADJUSTED ACCORDINGLY.
A SHORTWAVE MOVES THROUGH LATE TONIGHT, BRINGING POTENTIAL FOR
RAIN SHOWERS AND ISOLATED THUNDERSTORMS. CONFIDENCE WASN'T HIGH
ENOUGH IN THUNDER POTENTIAL TO INCLUDE THIS ISSUANCE, BUT HAVE
PRECIPITATION CHANCES AND CEILINGS AROUND 5-10KFT MOVING IN THIS
EVENING INTO THE OVERNIGHT. IT'S POSSIBLE THE PRECIPITATION AND
T-STORMS MOVE SOUTH OF KSBN AND WEST-SOUTHWEST OF KFWA, BUT DID
INCLUDE A PROB30 FOR 4SM -SHRA/BR WITH BKN025 CEILINGS. SOME OF
THE GUIDANCE HAD IFR CEILINGS DEVELOP AT KSBN AROUND 9-12Z, BUT
HELD OFF ON INCLUDING THAT FOR NOW GIVEN LOW CONFIDENCE.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...ROLLER
AVIATION...MCD
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