826
FXUS63 KIWX 081818
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
218 PM EDT SUN MAR 8 2026
KEY MESSAGES
- MORE RAIN AND THUNDERSTORMS ARE EXPECTED TUESDAY NIGHT INTO WEDNESDAY.
THERE IS POTENTIAL FOR HEAVY RAIN AND SEVERE STORMS WITH THIS
SYSTEM BUT CONFIDENCE IN DETAILS IS VERY LOW AT THIS FORECAST
DISTANCE.
- TEMPERATURES WARM BACK UP FOR MONDAY AND TUESDAY WITH NEAR-
RECORD OR RECORD HIGHS POSSIBLE.
- A COUPLE OF SYSTEMS ARE POSSIBLE AGAIN LATE WEEK INTO THE
WEEKEND.
DISCUSSION
ISSUED AT 210 PM EDT SUN MAR 8 2026
COOLER AND REMAINING DRIER TODAY THAN YESTERDAY'S HIGHS IN THE
MID 60S. THE BIGGEST ISSUE, IF YOU COULD CALL IT THAT, IS THE
WIND GUSTS WITH 20 TO 30 MPH GUSTS RELAXING BY THIS EVENING.
TODAY'S HIGHS IN THE UPPER 50S TO LOW 60S ACTUALLY RISE INTO THE
UPPER 60S TO LOW 70S FOR MONDAY AND INTO THE LOW TO MID 70S FOR
TUESDAY AS WARM ADVECTION CONTINUES. THERE'S ACTUALLY
REASONABLE MODEL CONFIDENCE BEHIND TUESDAY'S HIGHS WITH OVER 80%
OF THE ECMWF CDF TO THE RIGHT OF THE M- CLIMATE AND LOW LEVEL
TEMPERATURE 1 TO 2 TO AS MUCH AS 3 SDS ABOVE NORMAL FOR THIS
TIME PERIOD. THE ISSUE FOR TUESDAY MAY BE SOME LOW CLOUD COVER
THOUGH. MIXING IS BETTER ON MONDAY, UP TO, OR SLIGHTLY ABOVE 900
MB COMPARED TO TUESDAY. MONDAY'S AND TUESDAY'S HIGH TEMPS COULD
CONTEST RECORD HIGHS.
AFTER A DRY SUNDAY AND MONDAY, A BAROCLINIC ZONE SINKS SOUTHWARD
TOWARD THE IN/MI STATE LINE MONDAY NIGHT. WITH CONTINUED THETA-E
ADVECTION, MOISTENING OF THE LOW LEVELS OCCURS AFTER 00Z AND SOME
WEAKER ENERGY COMBINED WITH A TEMP DIFFERENTIAL APPROACHES THE AREA
FROM THE SOUTHWEST. THE NAM AND ECMWF HAS AN AXIS OF MID LEVEL
INSTABILITY PUSHING THROUGH OVERHEAD AND THIS COMBINATION MAY ALLOW
FOR SOME RAIN AS MODELS HAVE BEEN INTENT ON CAUSING PRECIPITATION
DURING THIS OVERNIGHT PERIOD. THERE IS ALSO A 30 TO 40 KT LOW LEVEL
JET SOUTH OF US-24 AS WELL. SOME QUESTION REMAINS ABOUT IF THIS
WOULD JUST BE STRATUS OR DRIZZLE INSTEAD THOUGH.
CONTINUED STREAMING OF THETA-E INTO THE AREA ON TUESDAY AND MODELS
ARE CONTINUING TO PRINT OUT LIGHT QPF ACROSS THE AREA. THIS IS
LIKELY JUST CLOUD COVER WITH HOW MUCH SHALLOW LOW LEVEL MOISTURE IS
THERE AS WELL AS SOME CAPPING. BETTER FORCING ARRIVES JUST SOUTH OF
THE BAROCLINIC BOUNDARY LATER TUESDAY (CLOSER TO 00Z) AS THE LOW
PRESSURE CENTER ARRIVES AND THIS IS WHAT THE SLIGHT RISK OF SEVERE
WEATHER IS FOR, FOR MUCH OF IN INTO SW LOWER MI. 30 KTS OF EFFECTIVE
SHEAR BEGINS TO WORK INTO THE AREA AS EARLY AS AROUND 21Z AND THAT
PUSHES NORTHEASTWARD TOWARDS DETROIT BY JUST AFTER 3Z ACCORDING TO
THE NAM. THE MAIN POCKET OF SHEAR ADVANCES CLOSER TO 6Z TOWARDS THE
AREA WITH A MORE SUCCINCT POCKET OF 40 TO 50 KTS OF EFFECTIVE SHEAR
PUSHING THROUGH DURING THE MORNING HOURS TUESDAY. THE MID LEVELS
APPEAR WARMER WITH ABOVE NORMAL TEMPERATURES, BUT MID LEVEL LAPSE
RATES ARE ABLE TO REACH 7+ C/KM 21 TO 3Z. WE'LL ALSO HAVE A POCKET
OF 1000 J/KG OF MLCAPE AND 200+ M2/S2 OF EFFECTIVE HELICITY MOVING
THROUGH DURING THIS WINDOW. DOWNDRAFT CAPE DRAWS NEAR TO 1000 J/KG
OVER IL BUT SLOWLY DECREASES AS IT ENTERS IN AFTER 21Z. THIS WOULD
PUT ALL HAZARDS ON THE TABLE, ESPECIALLY SINCE THERE'S SOME
PROPENSITY FOR BOUNDARY PARALLEL SHEAR ALLOWING FOR LINEAR
SEGMENTS THAT COULD HAVE SOME POTENTIAL FOR TRAINING THE LATER
CELLS ARE ABLE TO FORM. MBE VECTORS GO WEAK AFTER 6Z TUESDAY
NIGHT CONTRIBUTING TO A POTENTIAL HEAVY RAIN/FLOODING THREAT.
THE GROUND IS WETTER AND 5 POINTS ALONG OUR AREA RIVERS HAVE
RISEN INTO ACTION STAGE OR ARE FORECAST TO DO SO AFTER OUR LAST
SEVERE WEATHER EVENT. GIVEN THE LOW LEVEL MOISTURE AND RELATIVE
WARMTH, HAIL MAY BE A LESSER THREAT, BUT STILL ONE THAT CANNOT
BE RULED OUT. GIVEN THE SHEAR AND LOW LCLS, A TORNADO THREAT IS
ALSO POSSIBLE IF SURFACE-BASED INSTABILITY IS REALIZED.
THE MAIN LOW PRESSURE AREA TRANSLATES EASTWARD WEDNESDAY SO THAT THE
COLD FRONT ALSO PUSHES EASTWARD. THIS ALLOWS FOR ANOTHER CHANCE FOR
THUNDERSTORMS PROBABLY EAST OF I-69 DEPENDING ON THE TIMING OF THE
COLD FRONT THROUGH THE AREA. 30 TO 50 KTS OF EFFECT SHEAR STILL
RESIDES ALONG AND EAST OF THE FRONT WITH INSTABILITY OUT IN FRONT AS
WELL, ESPECIALLY IF IT SLOWS DOWN. MODELS CONTINUE TO PRINT OUT QPF
COINCIDING WITH THE LOW PRESSURE SYSTEM. WHERE OUTFLOW BOUNDARIES
FROM OVERNIGHT THUNDERSTORMS END UP PROBABLY PLAYS A ROLE IN
WEDNESDAY SEVERE CHANCES. IT COULD ALSO BE REMNANT COLD POOLS/
LINGERING RAIN SAVE US FROM THUNDER CHANCES ON WEDNESDAY. IT DOES
LOOK BREEZY ON WEDNESDAY WITH 20 TO 40 MPH GUSTS POSSIBLE, HIGHEST
SOUTH OF US-24, WHERE THE BETTER AIRMASS IS.
A VERY STRONG SHORTWAVE DIVES SOUTHEASTWARD THROUGH IN WEDNESDAY
NIGHT ALLOWING NEGATIVE SINGLE DIGITS AT 850 MB TO PUSH INTO THE
AREA. DIFFERENCES IN THE DEPTH OF MOISTURE BEHIND THE COLD FRONT AND
HOW FAR SOUTHEASTWARD THE VORT DROPS DICTATE WHETHER OR NOT A MORE
SUCCINCT AREA OF SNOW FORMS AS THE COLD AIR MOVES IN OR IF THE
MOISTURE DRIES OUT.
OUR NEXT SYSTEM PASSES BY TO THE NORTH THURSDAY NIGHT INTO EARLY
FRIDAY. DIFFERENCES IN PLACEMENT AND STRENGTH OF THE VORT CONTRIBUTE
TO DIFFERENCES IN PRECIPITATION OUTPUT. THE ECMWF IS MUCH FARTHER
SOUTH WITH A CHANCE FOR SNOW, WHEREAS THE GFS CUTS IT OFF ACROSS
SOUTHERN LOWER MI. ANOTHER SYSTEM WOULD BE POSSIBLE NEXT
WEEKEND. TEMPERATURES DURING THIS PERIOD RANGE FROM NORMAL TO
SLIGHTLY ABOVE NORMAL SO ANY SNOW WOULD HAVE TO HAPPEN AT NIGHT
OR EARLY MORNING.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 101 PM EDT SUN MAR 8 2026
LOW PRESSURE TRACKING TOWARD THE HUDSON BAY IS AT ODDS WITH
ROBUST HIGH PRESSURE OVER THE MID-MISSISSIPPI VALLEY. FORECAST
SOUNDINGS THIS DEPICT SHALLOW BUT AMPLE LOW-LEVEL MIXING, GOOD
FOR GUSTS NEAR 30 KNOTS THIS AFTERNOON. UPSTREAM OBSERVATIONS
HAVE GENERALLY RANGED FROM G25 TO THE OCCASIONAL G35-38 KTS.
WIND DIMINISHES ONLY SOMEWHAT TONIGHT AS THE PRESSURE GRADIENT
REMAINS IN PLAY.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
046.
DISCUSSION...ROLLER
AVIATION...BROWN
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