482
FXUS63 KIWX 041754
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1254 PM EST TUE NOV 4 2025
KEY MESSAGES
- VERY LOW HUMIDITY IS EXPECTED THIS AFTERNOON AND ANYONE
PLANNING BURNS SHOULD EXERCISE CAUTION.
- THE NEXT CHANCE OF LIGHT RAIN ARRIVES EARLY FRIDAY.
- MUCH COLDER TEMPERATURES ARE EXPECTED EARLY NEXT WEEK AND SNOW
IS POSSIBLE BUT IT IS FAR TOO EARLY TO PIN DOWN EXACT AMOUNTS
OR LOCATIONS.
DISCUSSION
ISSUED AT 338 AM EST TUE NOV 4 2025
FIRE WX IS THE MAIN CONCERN AGAIN TODAY AS VERY DRY AIRMASS HAS
SETTLED INTO THE AREA WITH SURFACE DEWPOINTS IN THE LOW/MID 20S
SOUTH AND AROUND 30F NORTH. WINDS ARE SWITCHING AROUND TO THE
SOUTHWEST BUT THIS WILL PROVIDE LITTLE RELIEF DURING THE DAY GIVEN
MODEST MIXING TO AROUND 850MB (LIMITED SOMEWHAT BY INCREASING
MID/UPPER LEVEL CLOUDS). ANTICIPATE LOW 20S DEWPOINTS EVERYWHERE BY
THE AFTERNOON WHICH LEADS TO RH VALUES AROUND 25 PERCENT GIVEN HIGHS
AROUND 60F. LUCKILY WIND SPEEDS ARE MUCH LIGHTER TODAY (SUSTAINED
ONLY AROUND 10 MPH) WHICH WILL LIMIT THE FIRE WX THREAT. HOWEVER,
ANYONE PLANNING TO BURN LEAVES (OR ANYTHING) TODAY SHOULD STILL
EXERCISE CAUTION IN LIGHT OF THE RECENT DRY CONDITIONS.
THE NEXT JET STREAK AND ATTENDANT MIDLEVEL WAVE DIVES INTO THE GREAT
LAKES EARLY WED. WITH A TRACK VERY SIMILAR TO MONDAY'S SYSTEM, OUR
AREA REMAINS IN THE UNFAVORABLE RIGHT EXIT REGION. BEST CVA AND
UPPER JET DYNAMICS WILL BYPASS US TO THE N/NE. HELD ONTO SOME NBM
SLIGHT CHANCE POP'S NORTH AS (SIMILAR TO MONDAY) CAN'T RULE OUT SOME
BRIEF SPRINKLES IN THE NORTH BUT OVERALL NO IMPACT. SW WINDS AHEAD
OF THE SYSTEM GET A BIT BREEZY TONIGHT AND LOWS WILL ONLY BE IN THE
MID/UPPER 40S AS A RESULT. AFTER A BREEZY AND WARM DAY ON WED WITH
HIGHS IN THE MID 60S SOUTH, CAA DROPS LOWS BACK INTO THE LOW 30S FOR
WED NIGHT. THE SEESAW PATTERN STARTS OVER AGAIN ON THU WITH
INCREASING SOUTHERLY WINDS/WAA PUSHING HIGHS BACK TO NEAR 60F AND
LOWS THU NIGHT ONLY IN THE 40S.
WE FINALLY GET A MORE FAVORABLE TRACK FOR THE NEXT TROUGH SLATED TO
ARRIVE EARLY FRI. THIS TROUGH DIVES MUCH FURTHER SOUTH AND IS ABLE
TO CAPITALIZE ON SOME BETTER (THOUGH STILL NOT GREAT) LOW LEVEL
MOISTURE/INSTABILITY. SOME ISOLATED THUNDERSTORMS ARE POSSIBLE BUT
CERTAINLY NO SEVERE THREAT. EVEN RAINFALL AMOUNTS WILL LIKELY BE
LIMITED TO AROUND A QUARTER INCH GIVEN QUICK-MOVING NATURE OF THIS
SYSTEM. STILL, IT IS BETTER THAN NOTHING GIVEN ONGOING EXTREME
DROUGHT IN OUR SE.
ANOTHER SYSTEM IS THEN EXPECTED ON SAT NIGHT AND THIS ONE COULD MARK
THE ARRIVAL OF THE FIRST TRULY COLD AIR OF THE SEASON. WHILE
DETERMINISTIC RUNS SHOW GENERAL AGREEMENT, ENSEMBLE GUIDANCE STILL
SHOWS A FAIR AMOUNT OF SPREAD, PARTICULARLY IN SUBTLE BUT IMPORTANT
DIFFERENCES HEADING INTO SUN/MON. AT THIS POINT, BULK OF THE
SYNOPTIC PRECIP SAT NIGHT IS EXPECTED TO BE RAIN, THOUGH SOME SNOW
CAN'T BE RULED OUT IN HEAVIER RATES ACROSS THE NORTH IF THE MORE
SOUTHERN TRACK VERIFIES. COLD AIR DOESN'T REALLY ARRIVE UNTIL LATE
SUN INTO MON. THIS IS WHEN LAKE EFFECT SNOW IS LIKELY TO SOME DEGREE
BUT EXACT LOCATIONS AND AMOUNTS WILL DEPEND ON SUBTLE VARIATIONS IN
FLOW TRAJECTORIES AND INSTABILITY PROFILES THAT ARE IMPOSSIBLE TO
RESOLVE SIX DAYS OUT. SUFFICE IT TO SAY, ANY RAW MODEL SNOWFALL MAPS
SHOULD BE MET WITH A HIGH DEGREE OF SKEPTICISM AT THIS TIME
RANGE.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1248 PM EST TUE NOV 4 2025
VFR CONDITIONS WILL CONTINUE THIS PERIOD, WITH WINDY CONDITIONS
AND LOW LEVEL WIND SHEAR AS THE PRIMARY AVIATION WEATHER
CONCERNS. LOW LEVEL RIDGE AXIS WILL CONTINUE TO SHIFT OFF TO THE
EAST THIS AFTERNOON ALLOWING FOR RETURN SOUTHERLY FLOW. A BROAD
LOW AMPLITUDE UPPER TROUGH SWINGING ACROSS THE NORTHERN PLAINS
INTO THIS EVENING WILL INDUCE STRENGTHENING WARM/MOIST ADVECTION
TONIGHT. STRONG SFC PRESSURE FALLS ARE EXPECTED TO DEVELOP
ACROSS THE GREAT LAKES REGION IN RESPONSE, WHICH SHOULD ENHANCE
SOUTHERLY LOW LEVEL FLOW. PREVIOUS TAF MENTION OF LLWS MENTION
HAS BEEN MAINTAINED WITH THE 18Z TAFS, WITH SOME SFC GUSTS TO
AROUND 20 KNOTS POSSIBLE LATE EVENING AND OVERNIGHT AS THE LOW
LEVEL JET STRENGTHENS. A STRONG PRE-FRONTAL PRESSURE GRADIENT
FOLLOWED BY DEEPENING MIXED LAYER IN POST-FRONTAL COLD ADVECTION
WILL SET THE STAGE FOR WINDY CONDITIONS WEDNESDAY, WITH PEAK
GUSTS EXPECTED FROM THE WEST-NORTHEAST MIDDAY INTO MID AFTERNOON
TO AROUND 30-35 KNOTS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 AM EST
THURSDAY FOR LMZ043-046.
DISCUSSION...AGD
AVIATION...MARSILI
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