141
FXUS63 KIWX 071003
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
603 AM EDT TUE APR 7 2026
KEY MESSAGES
- DRY WEATHER IS EXPECTED THROUGH WEDNESDAY EVENING.
- TEMPERATURES WILL DROP BELOW FREEZING AGAIN TONIGHT RANGING
FROM THE LOWER 30S ACROSS WEST CENTRAL INDIANA TO THE MID 20S
ACROSS SOUTH CENTRAL LOWER MICHIGAN.
- RAIN CHANCES INCREASE AGAIN LATE WEDNESDAY NIGHT INTO FRIDAY,
AND THEN AGAIN MONDAY AND TUESDAY OF NEXT WEEK. THUNDERSTORMS
WILL ALSO BE POSSIBLE, PARTICULARLY EARLY NEXT WEEK.
- TEMPERATURES WILL MODERATE FOR THURSDAY AND FRIDAY, WITH MUCH
ABOVE NORMAL TEMPERATURES AGAIN BY NEXT MONDAY AND TUESDAY.
DISCUSSION
ISSUED AT 330 AM EDT TUE APR 7 2026
LOW LEVEL COLD, DRY AIR ADVECTION CONTINUES THIS MORNING IN WAKE OF
A COLD FRONTAL PASSAGE. WINDS HAVE REMAINED A BIT GUSTY OVERNIGHT
WITH SOME OCCASIONAL GUSTS TO 20 MPH AT TIMES, BUT LOW LEVEL FLOW
MAGNITUDES WILL DECREASE THROUGH THE MORNING AS A BROAD 1035 MB
ANTICYCLONE BEGINS TO DROP SOUTHEAST INTO THE WESTERN GREAT
LAKES. LOW LEVEL NORTHERLY WINDS WILL VEER EASTERLY TODAY WITH
TEMPERATURE ADVECTION BECOMING MORE NEUTRAL THIS AFTERNOON. THIS
EVOLUTION WILL KEEP TEMPERATURES WELL BELOW NORMAL (10 TO 15
DEGREES BELOW NORMAL) FOR THE DATE DESPITE THE EXPECTATION OF
PLENTY OF INSOLATION TODAY UNDER THE INFLUENCE OF LOW/MID LEVEL
SUBSIDENCE. A WEAK LAKE BREEZE IS EXPECTED TO FORM DUE TO THIS
WEAKENING GRADIENT, BUT WEAK LAKE/LAND THERMAL CONTRAST AND
EASTERLY GRADIENT SHOULD KEEP THIS BOUNDARY CLOSER TO THE LAKE
MICHIGAN SHORELINE.
HIGH CLOUDS WILL INCREASE MORE SUBSTANTIALLY TONIGHT AS A MID LEVEL
RIDGE AXIS BEGINS TO APPROACH FROM THE WEST WHICH WILL ALSO MARK A
PERIOD OF STRONGER LOW/MID LEVEL WARM ADVECTION. SUB-FREEZING
TEMPERATURES ARE EXPECTED ONCE AGAIN WITH LOWS LIKELY RIGHT AROUND
THE FREEZING MARK FAR SOUTHWEST AND INTO THE MID 20S FAR NORTHEAST.
THE OFFICIAL START OF GROWING SEASON HAS NOT BEGUN LOCALLY AS OF
THIS WRITING, BUT STEPS SHOULD BE TAKEN TO PROTECT ANY TENDER
VEGETATION. THE SHARPEST TEMPERATURE DROPS TONIGHT ARE EXPECTED
THIS EVENING, AND TEMPS SHOULD LEVEL DURING THE OVERNIGHT HOURS
WITH GREATER UPPER LEVEL CLOUD COVERAGE AND STRONGER WARM
ADVECTION.
FOR WEDNESDAY, A BROAD LOW LEVEL THERMAL RIDGE WILL BE SHIFTING EAST
ACROSS THE SOUTHERN GREAT LAKES/OHIO VALLEY WITH THE STRONGEST WARM
ADVECTION EXPECTED FROM THE MID MS VALLEY INTO THE WESTERN GREAT
LAKES. TEMPS SHOULD BE CLOSER TO CLIMATOLOGICAL NORMS FOR
WEDNESDAY AND LIKELY A BIT ABOVE NORMAL ACROSS THE WEST IN
CLOSER PROXIMITY TO STRONGER WAA. IT WILL ALSO BECOME
BREEZY/WINDY WEDNESDAY AFTERNOON WITH PEAK AFTERNOON WIND GUSTS
OF 25 TO 35 MPH (STRONGEST ACROSS WESTERN IN INTO SW LOWER MI).
BY WEDNESDAY NIGHT ATTENTION TURNS TO AN UPPER LEVEL LOW CURRENTLY
TRACKING ACROSS SOUTHWEST CANADA THIS MORNING, AS IT MAKES ITS WAY
ACROSS MN/WESTERN ONTARIO. GIVEN STRENGTH OF THIS SYSTEM FORCING AND
AXIS OF BETTER PRE-FRONTAL MOISTURE, WOULD EXPECT SOME SHOWERS TO
DEVELOP IN ADVANCE OF THE FRONT LATE WEDNESDAY INTO EARLY THURSDAY
WITH THE GREATEST COVERAGE ACROSS SOUTHERN GREAT LAKES ON SOUTHERN
PERIPHERY OF LARGER SCALE HEIGHT FALLS. PRECIP WILL LIKELY DIMINISH
LATER DURING THE DAY THURSDAY, BUT AN UPSTREAM MID LEVEL WAVE DIVING
SOUTHEAST ACROSS CENTRAL CONUS LATE THURSDAY INTO EARLY FRIDAY
SHOULD INDUCE STRONGER ADVECTIVE FORCING OVER THIS STALLED BOUNDARY
WITH ADDITIONAL CHANCES OF SHOWERS AND PERHAPS A FEW STORMS. PASSAGE
OF THIS MID LEVEL TROUGH WILL TAKE THIS BAROCLINIC ZONE
SOUTHEAST OF THE AREA ON SATURDAY. SOME LOW RAIN CHANCES WERE
MAINTAINED FAR WEST-NORTHWEST ON SATURDAY, BUT BULK OF THE
WEEKEND THROUGH SUNDAY AFTERNOON SHOULD BE DRY AS FAVORED SHORT
WAVE TRACK LIKELY SHOULD SHIFT WEST AND NORTHWEST OF THE AREA.
MUCH OF THE LATE WEEKEND/EARLY NEXT WEEK PERIOD IS SHAPING UP MUCH
ABOVE NORMAL TEMPERATURE-WISE AS INITIAL INGESTION OF CUT-OFF
UPPER LEVEL LOW FROM SW CONUS INDUCES STRONGER WARM ADVECTION
LATE SATURDAY INTO SUNDAY. THE NORTHEAST EJECTION OF THIS
FEATURE SHOULD ALSO ENHANCE RAIN SHOWERS MONDAY
AFTERNOON/EVENING (50-70%) WITH A POTENTIAL OF SCATTERED STORMS
AS LOW LEVEL MOISTURE QUALITY SHARPLY IMPROVES. THE MORE ACTIVE
PRECIP PERIOD EARLY NEXT WEEK WILL LIKELY CONTINUE INTO
TUE/POSSIBLY WEDNESDAY AS LEFTOVER STALLED FRONTAL BOUNDARY FROM
MONDAY'S DAMPENING SYSTEM SHOULD BE IN PLACE FOR ANOTHER
SOUTHERN STREAM UPPER LEVEL LOW LIFTING INTO CENTRAL CONUS FOR
TUE/WED. NORTHWARD EXTENT OF THUNDER THREAT IS A BIT UNCLEAR AT
THIS TIME AND WILL DEPEND ON EXACT FRONTAL PLACEMENT. THE
OVERALL CONSENSUS IN MEDIUM RANGE DETERMINISTIC/ENSEMBLE
SOLUTIONS IS FOR THIS BOUNDARY TO BE LOCATED ACROSS THE UPPER
OHIO VALLEY OR SOUTHERN GREAT LAKES REGION.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 600 AM EDT TUE APR 7 2026
A BROAD ANTICYCLONE WILL DROP INTO THE SOUTHERN GREAT LAKES
REGION TODAY INTO THIS EVENING BRINGING DIMINISHING WINDS AND
MAINLY CLEAR SKIES. A SLACKENING GRADIENT RESULTING FROM THIS
RIDGE OF HIGH PRESSURE MAY ALLOW A WEAK LAKE BREEZE TO DEVELOP
THIS AFTERNOON, BUT THIS SHOULD BE LIMITED TO CLOSE PROXIMITY TO
THE LAKE MICHIGAN SHORELINE. OTHERWISE, NORTH WINDS THIS MORNING
AROUND 10 KNOTS WILL VEER LIGHT EASTERLY THIS AFTERNOON, AND
THEN SOUTHEAST THIS EVENING AS THE HIGH DEPARTS TO THE EAST.
SOME PATCHY HIGH CLOUDS TODAY WILL GIVE WAY TO MORE SOLID MID
LEVEL CLOUD COVERAGE TONIGHT AS WARM ADVECTION BEGINS TO
STRENGTHEN. VFR CONDITIONS SHOULD PERSIST THROUGH THIS FORECAST
VALID PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LMZ043-
046.
DISCUSSION...MARSILI
AVIATION...MARSILI
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