312
FXUS63 KIWX 270549
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
149 AM EDT TUE OCT 27 2026
KEY MESSAGES
- WARM AND DRY CONDITIONS PERSIST THROUGH TOMORROW WITH HIGHS
GENERALLY IN THE LOW 70S AND LOWS IN THE LOW 50S.
- LIGHT RAIN IS POSSIBLE ON THURSDAY. THE BEST CHANCES (50-80%) WILL
BE NEAR LAKE MICHIGAN.
- BETTER CHANCES FOR WIDESPREAD RAIN ARRIVE ON SUNDAY BUT
FORECAST CONFIDENCE FOR THIS PERIOD IS LOW.
DISCUSSION
ISSUED AT 146 AM EDT TUE OCT 27 2026
YESTERDAY'S FRONTAL BOUNDARY HAS WASHED OUT COMPLETELY ACROSS OUR
AREA BUT WE DO HAVE A BRIEF RETURN TO EASTERLY FLOW THIS MORNING.
LUCKILY NUMEROUS HIGH CLOUDS, A STEADY GRADIENT WIND AND AN OVERALL
WARMER/DRIER BOUNDARY LAYER ARE KEEPING FOG IN CHECK. FLOW VEERS TO
A MORE S/SE DIRECTION BY THIS AFTERNOON AND HIGHS SHOULD RECOVER TO
AROUND 70F OUTSIDE OF OUR FAR NE. WARM/MOIST AIR ADVECTION THEN
STEADILY INCREASES TONIGHT THROUGH THU AHEAD OF THE NEXT COLD FRONT
HEADED FOR OUR AREA. EXPECT MORE MID 70S ON WED AND SOME UPPER 70S
POSSIBLE BY THU DEPENDENT ON EXACT FRONTAL TIMING. AS PREVIOUSLY
MENTIONED, THURSDAY'S FRONTAL PASSAGE WILL FEATURE A MUCH BETTER
PREFRONTAL LLJ AND THETA-E SURGE, ENOUGH TO AT LEAST PARTIALLY
OFFSET THE INCREDIBLY DRY AND STABLE AIRMASS THAT HAS BEEN IN PLACE
FOR SO LONG. MID/UPPER LEVEL SUPPORT IS STILL NOT GREAT THIS FAR
SOUTH WITH FAR BETTER CVA AND UPPER JET SUPPORT OVER LAKE SUPERIOR
AND POINTS NORTH. STILL, ENOUGH MOISTURE ADVECTION AND LOW LEVEL
CONVERGENCE TO GENERATE SOME VERY LIGHT RAIN SHOWERS WITH THE BEST
CHANCES NEAR LAKE MICHIGAN THURSDAY AFTERNOON. LATEST GUIDANCE EVEN
SUGGESTS A FEW SPRINKLES SURVIVING INTO OUR SE THU EVENING. NO
IMPACTS ANTICIPATED THOUGH. REMOVED THE BRIEF/SMALL NBM THUNDER
MENTION GIVEN NEAR TOTAL LACK OF INSTABILITY ON FORECAST SOUNDINGS.
A RETURN TO LESS EXTREME WARMTH FRI AND SAT WITH HIGHS AROUND 70F. A
VERY HIGH LEVEL OF SPREAD STILL EXISTS AMONG ALL SOURCES OF
DETERMINISTIC AND ENSEMBLE GUIDANCE FOR THE WEEKEND INTO NEXT WEEK.
THIS UNCERTAINTY CENTERS AROUND AN UNUSUALLY SOUTHWARD DISPLACED
PACIFIC JET STREAK/SHORTWAVE EMANATING FROM THE DATA-SPARSE REGIONS
OFF THE MEXICAN COAST THAT WILL EVENTUALLY LIFT NORTHEAST INTO OUR
REGION. MODELS STRUGGLING WITH THIS AND ANOTHER UPPER LOW THAT
DEVELOPS OFF THE NORTHWEST U.S. COAST. VERY LOW CONFIDENCE REGARDING
FORECAST DETAILS SAT-TUE. STILL THINK HALLOWEEN WILL BE MOSTLY DRY
FOR TRICK-OR-TREAT ACTIVITIES BUT NBM MAINTAINS SOME LOW CHANCE
POP'S AND CAN'T ENTIRELY RULE IT OUT. MUCH BETTER RAIN CHANCES SEEM
TO ARRIVE SUNDAY WITH REMARKABLE UNCERTAINTY REGARDING A POTENTIAL
SECOND SYSTEM AROUND TUESDAY OF NEXT WEEK.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 146 AM EDT TUE OCT 27 2026
A MID LEVEL RIDGE AXIS WILL SHIFT ACROSS THE EASTERN GREAT LAKES
THIS MORNING ALLOWING CONTINUATION OF SOME MID LEVEL WARM
ADVECTION CLOUDINESS. FOG POTENTIAL CONTINUES TO LOOK MUCH LOWER
IN COMPARISON TO PREVIOUS SEVERAL MORNINGS, AND A VFR FORECAST
HAS BEEN MAINTAINED WITH THE 06Z TAFS. SURFACE HIGH PRESSURE
ACROSS SOUTHERN ONTARIO WILL SPREAD ACROSS SOUTHEAST
ONTARIO/SOUTHERN QUEBEC THIS AFTERNOON AS LARGER SCALE SFC
PRESSURE FALLS DEVELOP ACROSS THE UPPER MIDWEST DOWNSTREAM OF AN
UPPER LEVEL SHORT WAVE TROUGH. THIS EVOLUTION WILL ALLOW FOR
INITIAL EASTERLY WINDS TO VEER SOUTHEAST TODAY, BUT SPEEDS
SHOULD BE 10 KNOTS OR LESS THROUGH THE DAY. A SOUTHERN STREAM
SHORT WAVE ACROSS THE SOUTHERN PLAINS WILL REACH THE OHIO VALLEY
TONIGHT, BUT ANY WEAKLY POOLED MOISTURE TO THE NORTH OF STALLED
BAROCLINIC ZONE WILL RETREAT TO THE NORTH. THIS WILL KEEP DRY
CONDITIONS IN PLACE THROUGH THIS PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...AGD
AVIATION...MARSILI
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