054
FXUS63 KIWX 170618
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
218 AM EDT TUE MAR 17 2026
KEY MESSAGES
- LAKE EFFECT SNOW SHOWERS WILL IMPACT THE MORNING COMMUTE. SNOW
COVERED ROADS AND AREAS OF REDUCED VISIBLILTY ARE EXPECTED.
- LAKE EFFECT SNOW SHOWERS DIMINISH LATE THIS AFTERNOON.
- REMAINING COLD THROUGH WEDNESDAY MORNING WITH LOWS IN THE
TEENS.
- CLIPPER SYSTEMS RACE THROUGH ON WEDNESDAY AND THURSDAY.
DISCUSSION
ISSUED AT 218 AM EDT TUE MAR 17 2026
LAKE EFFECT SNOW CONTINUES EARLY THIS MORNING WITH THREE DOMINANT
BANDS, ATTEMPTING TO BECOME MULTICELLULAR; ONE NEAR HOLLAND MI AND
THE OTHER SLICING THROUGH BERRIEN COUNTY. A THIRD BAND, DRIVEN BY
CONVERGENCE, EXTENDS FROM WI THROUGH TO FAR NORTHERN HUNTINGTON
COUNTY. DRIVING THROUGH THESE BANDS ENROUTE TO THE OFFICE PRESENTED
NEAR WHITE-OUT CONDITIONS FOR BRIEF STRETCHES, AND AREA ASOS/AWOS
ARE RECORDING PERIODS OF 1/2 OR EVEN 0 MI VISIBILITY.
THE UPPER-LEVEL LOW RESPONSIBLE FOR NORTHWEST FLOW AND SUBSEQUENT
LES CONTINUES TO LIFT NORTHEAST THROUGH MICHIGAN WHILE THE SURFACE
LOW IS NOW OVER INTERIOR QUEBEC. FAVORABLE LES PARAMETERS, INCLUDING
ALMOST 9K FT CLOUD TOPS, A SATURATED DGZ, AND OF COURSE A DELTA-T OF
20C, BECOME LESS FAVORABLE THIS AFTERNOON AS HIGH PRESSURE OVER THE
NORTHERN PLAINS EDGES IN. THIS RESULTS IN DECREASED INVERSION HEIGHTS
AND DISRUPTS NORTHWESTERLY FETCH AS WELL. THE ONGOING WINTER WEATHER
ADVISORY REMAINS ON TRACK TO END NEAR 15Z. LOOK FOR AN ADDITIONAL 1
TO 2 INCHES, PRIMARILY BEFORE SUNRISE.
WITH THE LAST OF THE UPPER-LEVEL VORTICITY MAXIMUM ROTATING THROUGH
THIS AFTERNOON, WE COULD SEE NUMEROUS SNOW SHOWERS DEVELOP SIMILAR
TO MONDAY. CONFIDENCE IS MEDIUM AT BEST WITH FORECAST SOUNDINGS
DISPLAYING A RATHER DRY AIRMASS.
COLD ONCE AGAIN TONIGHT WITH LOWS WEDNESDAY MORNING NEAR 20.
INCREASING CLOUDS FROM A SHORTWAVE STREAKING THROUGH THE NORTHERN
PLAINS AND INTO THE MIDWEST KEEP OVERNIGHT LOWS FROM GETTING TOO OUT
OF HAND, ESPECIALLY OVER FRESH SNOWPACK. SOUNDINGS DEPICT A PERIOD
OF SNOW MOVING FROM WEST TO EAST EARLY WEDNESDAY MORNING. PRECEDING
DRY AIR AND EVENTUALLY, DISJOINTED FORCING VS AND ELEVATED DGZ POINT
TO A CLIPPER OF MINIMAL CONSEQUENCE WITH NOW ACCUMULATIONS OF LESS
THAN 1 INCH. AFTERNOON TEMPERATURES WILL WARM WELL INTO THE 30S,
APPROACHING 40.
ACTIVE NORTHWEST FLOW PERSISTS INTO THURSDAY WHEN ANOTHER CLIPPER
RACES THROUGH. UPPER-LEVEL HEIGHTS WILL HAVE AMPLIFIED FURTHER
RESULTING IN RAIN. A 500-MB RIDGE OVER THE FOUR CORNERS CONTINUES TO
AMPLIFY THROUGH THE WEEK RESULTING IN WARMING TREND LOCALLY. THE
NEXT SYSTEM LOOKS TO DEGRADE THIS RIDGE A BIT BY SUNDAY, A DAY THAT
MAY FEATURE A SHARP NORTH-SOUTH TEMPERATURE GRADIENT. HIGHS IN THE
50S AND EVEN 60S LATE THIS WEEK WILL BE WELCOME RELIEF FROM THE
CURRENT RETURN OF WINTER.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 120 AM EDT TUE MAR 17 2026
LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT
BOTH TAF SITES BUT EXACT TIMING OF LOWER VISIBILITIES REMAINS
DIFFICULT TO PIN DOWN WITH A LOT OF VARIABILITY EXPECTED TO
CONTINUE. WINDS BACK SLIGHTLY BY LATE MORNING AND MIDLEVEL
TROUGH EXITS. SOME SNOW SHOWERS WILL LIKELY CONTINUE THROUGH THE
AFTERNOON JUST NORTH/NORTHWEST OF THE TERMINALS. CONFIDENCE IS
LOW THAT ANY SNOW WILL IMPACT THE TERMINALS AFTER 17Z BUT LATEST
HI-RES SUGGESTS SOME POTENTIAL AT KFWA AND WILL ADD A PROB30
ACCORDINGLY. DRY/VFR CONDITIONS ASSURED BY 21Z AS WINDS BACK
MORE SIGNIFICANTLY AHEAD OF THE NEXT SYSTEM. LIGHT SNOW IS
EXPECTED AT KSBN EARLY WED MORNING BUT JUST OUTSIDE THIS
FORECAST WINDOW.
IWX WATCHES/WARNINGS/ADVISORIES
IN...WINTER WEATHER ADVISORY UNTIL 11 AM EDT /10 AM CDT/ THIS
MORNING FOR INZ005-006-103-104-204.
OH...NONE.
MI...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
MIZ078-079-177-277.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-
046.
DISCUSSION...BROWN
AVIATION...AGD
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