398
FXUS63 KIWX 072318
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
618 PM EST WED JAN 7 2026
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES PERSIST THROUGH FRIDAY, ESPECIALLY
LATE THURSDAY INTO FRIDAY MORNING WHEN TEMPERATURES REACH
WELL INTO THE 50S TO NEAR 60 DEGREES.
- SHOWERS POTENTIALLY CLIP MAINLY NW IN AND SW MI THURSDAY
AFTERNOON.
- MORE WIDESPREAD RAIN (80-100%) AND A SLIGHT CHANCE FOR THUNDER
THURSDAY NIGHT, WITH LIGHT RAIN POTENTIALLY LINGERING INTO
FRIDAY MORNING.
- RAIN CHANCES (60-80%) RETURN LATE FRIDAY NIGHT INTO SATURDAY.
- COLDER AND BREEZY WITH PERIODS OF SNOW SHOWERS SATURDAY NIGHT
INTO SUNDAY. LIGHT SNOW ACCUMS POSSIBLE, MAINLY NEAR LAKE MI.
DISCUSSION
ISSUED AT 113 PM EST WED JAN 7 2026
LOW STRATUS TRAPPED BENEATH A SUBSIDENCE INVERSION SHOULD
SCATTER OUT FROM SW TO NE THIS AFTERNOON INTO EARLY THIS EVENING
AS DRIER AIR CONTINUES TO ADVECT IN UNDER RETURN SOUTHWEST
FLOW. MILD/DRY OTHERWISE INTO TONIGHT AS HIGH CLOUDS OVERSPREAD
IN ADVANCE OF AN APPROACHING STORM SYSTEM.
PATTERN THEN BECOMES MORE ACTIVE LATER THURSDAY THROUGH THIS WEEKEND
AS A SERIES OF UPPER LEVEL WAVES AND DEVELOPING SFC REFLECTIONS LIFT
NORTH THROUGH THE MIDWEST AND GREAT LAKES. THE FIRST UPPER WAVE AND
SUBTROPICAL MOISTURE PLUME JUST OFF THE BAJA CALIFORNIA COAST WILL
GET BOOTED QUICKLY NORTHEAST THROUGH THE CENTRAL PLAINS AND
WESTERN GREAT LAKES THURSDAY INTO THURSDAY NIGHT IN RESPONSE TO
AN UPPER TROUGH DIGGING INTO THE WESTERN US. TRACK OF THE SFC
REFLECTION HAS TRENDED A BIT WEST IN THE LAST SEVERAL MODEL
CYCLES SUGGESTING THE SWATH OF HEAVIER/STEADIER RAINFALL WILL
PASS WEST OF THE AREA, AND FOR A SLIGHTLY LATER ARRIVAL TIME OF
BETTER RAIN CHANCES LOCALLY FROM WEST TO EAST LATER THURSDAY
INTO THURSDAY NIGHT. REGARDLESS, DEEP AND STRONG SOUTHWEST FLOW
WILL TRANSPORT A MOISTURE-LADEN 1" PLUS PWAT AIR MASS INTO THE
AREA DURING THIS TIME WITH NUMEROUS SHOWERS AND PERHAPS SOME
EMBEDDED THUNDER (HEAVIER GUSTY SHOWERS) TRACKING THROUGH (QPF
GENERALLY 0.25-0.50", LOCALLY HEAVIER WITH ANY LOW TOPPED
CONVECTIVE ELEMENTS). SURFACE TEMPS WILL ALSO SURGE INTO THE 50S
TO NEAR 60 THURSDAY NIGHT WITHIN THE LOW LEVEL JET CORE.
SYSTEM COOL FRONT DOES SHIFT EAST-SOUTHEAST OF THE AREA DURING THE
DAY ON FRIDAY WITH A TREND TOWARD DRY AND COOLER CONDITIONS. ANOTHER
ROUND OF MORE ORGANIZED RAIN THEN REENTERS THE PICTURE LATER FRIDAY
NIGHT INTO SATURDAY AS PHASING OF THE NORTHERN AND SOUTHERN STREAM
BRANCH INDUCES CYCLOGENESIS NORTHWARD INTO THE GREAT LAKES REGION. A
BRIEF SHOT OF COLDER AIR AND WRAP AROUND SNOW SHOWERS THEN FOLLOW IN
SATURDAY NIGHT INTO SUNDAY NIGHT WITH MINOR SNOW ACCUMS/IMPACTS
MAINLY FOCUSED IN OUR WNW FLOW LES BELTS THANKS TO SOME ENHANCEMENT.
TRANQUIL WX THEN TO FOLLOW INTO MONDAY AND TUESDAY.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 618 PM EST WED JAN 7 2026
WITH HIGH PRESSURE DEPARTING TO THE EAST, WARM ADVECTION TAKES OVER
TONIGHT AHEAD OF AN ARRIVING TROUGH. THIS LOOKS TO REMOVE THE
STRATUS THAT WE'VE HAD TODAY, BUT THIS MAY BE ENOUGH TO REPOPULATE
SOME LOW LEVEL MOISTURE UNDERNEATH A FORMING INVERSION TONIGHT.
GUIDANCE, RIGHT NOW, KEEPS THE IMPACTFUL FOG CHANCES NORTH AND EAST
OF THE TERMINALS, BUT WOULDN'T BE SURPRISED TO SEE SOME FOG CHANCES
THURSDAY MORNING GIVEN THIS SETUP. YES, IT IS AN ADVECTION FOG AND
CROSS-OVER TEMPS DON'T NECESSARILY POINT OUT ADVECTION FOG
SCENARIOS, BUT THOSE ARE CONDUCIVE TO FOG DEVELOPMENT FOR THURSDAY.
WIND IS MARGINAL AT AROUND 5 TO 7 KTS OVERNIGHT AND THURSDAY
MORNING, BUT WITH THE 10 KT SUSTAINED WIND GETTING GOING EARLIER AT
SBN THAN FWA. NAM BUFKIT SOUNDINGS SEEM TO GO WITH MORE OF A STRATUS
LOOK KEEPING THE INVERSION ALOFT INSTEAD OF NEAR THE GROUND. EVEN
WITH ALL OF THIS, CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE ADVERSE
FLIGHT CONDITIONS IN THESE TAFS ASIDE FROM A TEMPO GROUP OF 5SM
HZ/BR AROUND 5Z AT SBN.
ONLY 35 KTS OF LLJ PUSHES INTO THE AREA TONIGHT SO IT'S PROBABLY NOT
STRONG ENOUGH TO INCLUDE LLWS IS TAFS TONIGHT. SHEAR GUIDANCE
APPEARS TO KEY INTO LATE MORNING THU WHEN THE STRONGER PART OF THE
LLJ MOVES INTO THE AREA, BUT BY THEN THE WIND GOES A LITTLE MORE
UNIDIRECTIONAL. SHEAR IS ESPECIALLY TOO MARGINAL FOR INCLUSION AT
FWA WITHIN THE FIRST 18 HOURS OF THIS TAF PERIOD. HOWEVER, WILL
INCLUDE IT FOR SBN IN THE MIDDAY TO AFTERNOON HOURS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THURSDAY TO 10 AM EST FRIDAY
FOR LMZ043-046.
DISCUSSION...STEINWEDEL
AVIATION...ROLLER
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