631
FXUS63 KIWX 170524
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1224 AM EST SAT JAN 17 2026
KEY MESSAGES
- ADDITIONAL ISOLATED TO SCATTERED SNOW SHOWERS ARE POSSIBLE
TONIGHT, BUT LITTLE TO NO SNOW ACCUMULATION IS EXPECTED.
- LAKE EFFECT SNOW CHANCES WILL INCREASE AGAIN LATER SATURDAY
AFTERNOON INTO SATURDAY NIGHT WITH SOME LIGHT SNOW
ACCUMULATIONS POSSIBLE.
- MUCH COLDER TEMPERATURES ARE IN STORE FOR THE WEEKEND WITH
ANOTHER CLIPPER SYSTEM BRINGING RENEWED LIGHT SNOW AND LAKE
EFFECT SNOW CHANCES SUNDAY AND SUNDAY NIGHT.
- DANGEROUS WIND CHILLS AROUND 15 BELOW ZERO ARE EXPECTED BOTH
SUNDAY NIGHT AND MONDAY NIGHT.
DISCUSSION
ISSUED AT 340 PM EST FRI JAN 16 2026
THE BAND OF SNOW WHICH BROUGHT LIGHT SNOW ACCUMULATIONS TO THE
REGION HAS DEPARTED TO THE EAST AS A STRONG MID/UPPER LEVEL FRONTAL
ZONE DEPARTS. SOME DRIER MID LEVEL AIR HAS ADVECTED INTO
NORTHERN INDIANA BEHIND THE ACCOMPANYING UPPER LEVEL WAVE. ONE
AREA OF LINGERING SNOW SHOWERS IS ACROSS NORTH CENTRAL INDIANA
IN CLOSER PROXIMITY TO POCKET OF COLDER MID LEVEL TEMPERATURES.
LOOKING UPSTREAM, SCATTERED SNOW SHOWERS HAVE DEVELOPED ACROSS
CENTRAL ILLINOIS WHICH APPEAR TO BE AIDED BY SOME FAIRLY STRONG
DIFFERENTIAL THERMAL ADVECTION LEADING TO SOME AVAILABLE VERY
WEAK SFC/NEAR SFC BASED INSTABILITY. SOME QUESTION AS TO HOW
THESE ISOLATED SNOW SHOWERS WILL BE MAINTAINED EASTWARD EARLY
THIS EVENING AS LOCAL AREA IS POSITIONED BETWEEN STRONGER MID
LEVEL WAVES. SOME COMPOSITE LOW LEVEL TROUGHING COULD BE ONE
POSITIVE FACTOR TOWARD MAINTAINING ISOLATED/SCATTERED SNOW
SHOWERS INTO WESTERN INDIANA THIS EVENING. IT STILL APPEARS
BETTER CHANCE OF SCATTERED SNOW SHOWERS WILL BE MORE IN THE LATE
EVENING/EARLY OVERNIGHT PERIOD AS STRONGER LOW LEVEL
BAROCLINICITY SHIFTS EASTWARD. SOME BETTER COVERAGE SNOW
SHOWERS ARE CURRENTLY ACROSS SOUTH CENTRAL/SOUTHEAST IOWA AT
LEADING EDGE OF THIS STRONGER BAROCLINIC ZONE. WILL MAINTAIN LOW
TO MID RANGE CHANCE POPS FOLLOWING THE EASTWARD SHIFT OF THIS
LOW LEVEL FRONT LATER TONIGHT, AND ALSO COINCIDENT WITH APPROACH
OF NEXT MORE PRONOUNCED SHEARED MID LEVEL SHORT WAVE. WHILE A
FEW OF THESE SNOW SHOWERS MAY BE MORE VIGOROUS GIVEN STEEP LOW
LEVEL LAPSE RATES, OVERALL ORGANIZATION SHOULD BE LACKING GIVEN
FLOW FIELDS WILL ONLY BE WEAKLY FRONTOGENETIC (PERHAPS A BROKEN
LINE OF SNOW SHOWERS). OVERALL, GIVEN CELLULAR NATURE AND
STRONGER MID/UPPER SUPPORT REMAINING TO THE SOUTH ACROSS THE
OHIO VALLEY, EXPECTING LITTLE TO NO ACCUMULATION MOST
LOCATIONS.
ON SATURDAY, ANOTHER SURGE OF DRIER MID LEVEL AIR IS EXPECTED BEHIND
THE MORNING SHORT WAVE. THE PRIMARY UPPER LOW ACROSS THE MID MS
VALLEY WILL DIG SOUTHEAST, AND WILL REACH CENTRAL IN BY LATER
SATURDAY NIGHT. SOME BETTER LOW/MID LEVEL MOISTURE RECOVERY SHOULD
OCCUR LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT. THIS SHOULD
REINVIGORATE SOME LAKE EFFECT SNOW SHOWERS ACROSS SOUTHWEST
LOWER MICHIGAN GIVEN WESTERLY FETCH. SOME WEAK DEFORMATION
FORCING TO THE NORTHWEST OF THIS TROUGH MAY ALSO AID IN SOME
LIGHT LAKE EFFECT SNOW ACCUMULATIONS LATER SATURDAY
AFTERNOON/SATURDAY NIGHT. THE STRONG COLD ADVECTION AND SNOW
COVER WILL LIMIT TEMP RESPONSE ON SATURDAY, WITH A LIKELY NEAR
STEADY TEMPERATURE TREND IN AFTERNOON IN THE 20 TO 25 DEGREE
RANGE.
ANOTHER CLIPPER SYSTEM IS EXPECTED TO REINFORCE LOW LEVEL COLD
AIR LATE SUNDAY INTO MONDAY WITH A POTENTIAL OF SOME SYSTEM
LIGHT SNOW ACCUMULATIONS AND ANOTHER WESTERLY FETCH LAKE EFFECT
SETUP FOR MAINLY SOUTHERN LOWER MICHIGAN. SNOW ACCUMULATIONS
COULD BE IN THE 1-3 TO 2- 4" RANGE FOR THE LAKE EFFECT PORTION
OF THIS EVENT GIVEN THE DURATION FROM SUNDAY NIGHT THROUGH
MONDAY. SOME WEAK FGEN CONTRIBUTION IS ALSO POSSIBLE WITH THESE
LAKE EFFECT SNOW SHOWERS AS THE STRONG THERMAL TROUGH SLIDES TO
THE SOUTH OF GREAT LAKES MODIFIED LOW LEVEL ENVIRONMENT.
DANGEROUSLY COLD CONDITIONS WILL END UP BEING THE MAIN FORECAST
CONCERN FROM SUNDAY NIGHT THROUGH TUESDAY WITH A POTENTIAL OF A FEW
NIGHTS OF WIND CHILLS REACHING ADVISORY CRITERIA. CONDITIONS SHOULD
MODERATE SLIGHTLY TOWARD LATTER PORTIONS OF NEXT WEEK AS LARGE SCALE
FLOW BEINGS TO LOSE SOME AMPLITUDE. CONSENSUS MEDIUM RANGE GUIDANCE
IN THIS DEAMPLIFYING PATTERN WOULD MAINTAIN STRONG BAROCLINICITY
ACROSS THE REGION THROUGH LATE WORK WEEK THAT WOULD MAKE THE
AREA SUSCEPTIBLE TO ADDITIONAL PROGRESSIVE LOW AMPLITUDE WAVES
LATE IN THIS PERIOD. IN THIS PATTERN, LOW SNOW CHANCES WERE
MAINTAINED THROUGH MUCH OF THE EXTENDED PERIOD WITH BELOW NORMAL
TEMPS CONTINUING.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1224 AM EST SAT JAN 17 2026
ANOTHER SHORTWAVE AND COLD FRONT IS CURRENTLY PASSING THROUGH
THE AREA AND MAY BRING SOME BRIEF LIGHT SNOW DURING THE NEXT 3-6
HOURS. ANY ACCUMULATION WILL BE VERY LIGHT BUT BRIEF MVFR
(POSSIBLY FUEL ALTERNATE AT KFWA) CONDITIONS ARE POSSIBLE. DRY
AIR ADVECTION BY LATE MORNING SHOULD MAINTAIN VFR CONDITIONS
AFTER 12Z. HOWEVER, ANOTHER WAVE ARRIVES AT THE END OF THE
PERIOD AND MAY BRING SOME MORE LIGHT SNOW/MVFR CEILINGS AT KSBN.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.
DISCUSSION...MARSILI
AVIATION...AGD
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