625
FXUS63 KIWX 272322
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
622 PM EST SAT DEC 27 2025
KEY MESSAGES
- UNSEASONABLY WARM SUNDAY WITH A 60-80% CHANCE OF RAIN AFTER
DAYBREAK. THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN
THE AFTERNOON.
- WINDY AND MUCH COLDER SUNDAY NIGHT WITH LAKE EFFECT SNOW
DEVELOPING. TEMPERATURES WILL FALL INTO THE 20S BY EARLY
MONDAY MORNING.
- WESTERLY WIND GUSTS OF 45 TO 50 MPH ARE EXPECTED SUNDAY NIGHT
THROUGH MONDAY.
- LAKE EFFECT SNOW AND GUSTY WINDS CAN HAMPER TRAVEL IN
SOUTHWEST MICHIGAN AND FAR NORTHERN INDIANA MONDAY.
DISCUSSION
ISSUED AT 153 PM EST SAT DEC 27 2025
A POWERFUL MID-LATITUTE CYCLONE WILL BRING UNSEASONABLE WARMTH
AND RAIN SUNDAY ALONG WITH A MARGINAL RISK OF SEVERE
THUNDERSTORMS. THIS WILL BE PUNCTUATED BY A STRONG COLD FRONT
OVERNIGHT BRINGING 45-50 MPH WIND GUSTS, TEMPERATURES NEAR 20
DEGREES AND LAKE EFFECT SNOW THROUGH MONDAY.
THE INCOMING STORM SYSTEM COMPRISES OF AN UPPER-LEVEL LOW
SWIRLING OVER THE NORTHERN ROCKIES AND A BROAD TROUGH
APPROACHING THE FOUR CORNERS REGION AS OF THIS WRITING. THESE
TWO FEATURES ARE FORECAST TO PHASE (MORE OR LESS) OVER THE
CENTRAL US PRIOR TO BLASTING THROUGH THE MIDWEST. INCREASING
WARM AIR ADVECTION TONIGHT AND A MODEST LOW-LEVEL JET SHOULD BE
ENOUGH TO PROMPT SOME RAIN SHOWERS, WITH PROBABILITIES
INCREASING TOWARD DAYBREAK.
THE UPPER-LEVEL TROUGH DEEPENS SUNDAY AND WITH IT, THE UPPER-
LEVEL WIND FIELD. A PERIOD OF HEAVY RAIN IS ANTICIPATED ALONG
THE WARM FRONT WHICH WILL SURGE TOWARD THE SOUTHERN MICHIGAN
STATE LINE. ANOMALOUS PRECIPITABLE WATER VALUES, DEEP WARM CLOUD
DEPTHS AND NARROW DEW-POINT DEPRESSIONS POINT TO EFFICIENT RAIN
RATES. HOWEVER, BOUNDARY PARALLEL FLOW IS ABSENT AND THIS
SYSTEM AS A WHOLE WILL BE MOVING QUICKLY TO LIMIT ANY FLOODING
RISK. ALAS, MUCH NEEDED RAIN WILL RESULT IN RISING STREAM FLOWS.
FOR THE MARGINAL SEVERE WEATHER RISK, PRIMARILY AFTER 3PM EST
SUNDAY, POOR INSTABILITY AND LAPSE RATES WILL BE LIMITING
FACTORS. AN INITIAL LOOK AT FORECAST SOUNDINGS DEPICT TALL,
SKINNY PROFILES WITH LITTLE LOW-LEVEL TURNING. WITH 60+ KNOTS OF
SHEAR, EVEN SMALL CAPE PROFILES COULD SPARK SEVERE STORMS.
GIVEN THE ROBUST WIND FIELD AS LOW AS 925MB, ANY TALL
THUNDERSTORMS COULD PRODUCE DAMAGING WIND GUSTS. THE BEST
INSTABILITY LOOKS TO TAKE SHAPE OVER CENTRAL IL, WANING QUICKLY
OVER OUR AREA. CONFIDENCE IS LOW IN SEVERE WEATHER OCCURING, BUT
TRENDS WILL BE MONITORED CLOSELY OVER THE NEXT 24 HOURS.
THE COLD FRONT ARRIVES EARLY SUNDAY NIGHT BRINGING 45-50 MPH
WIND GUSTS WHICH ARE FAVORED TO PREVAIL THROUGH MONDAY.
TEMPERATURES WILL PLUMMET TOWARD FREEZING SOON AFTER MIDNIGHT
AND BOTTOM OUT IN THE 20S (A 30 DEGREE TEMPERATURE DROP IN 9
HOURS AT SOUTH BEND, FOR EXAMPLE). THIS COULD RESULT IN FLASH
FREEZE CONCERNS, THOUGH AS WAS THE CASE A COUPLE WEEKS AGO,
STRONG WIND MAY AID IN THE DRYING OF SURFACES.
LASTLY, LAKE EFFECT SNOW TAKES SHAPE EARLY MONDAY MORNING THROUGH
TUESDAY MORNING. WHILE ADVISORY-LEVEL WIND GUSTS MAY HAVE SUBSIDED
LATE IN THE LAKE EFFECT SNOW EVENT, THE COMBINATION OF STRONG WIND
AND SNOW MAY BE ENOUGH TO WARRANT A WINTER WEATHER ADVISORY IN
COMING SHIFTS DESPITE ONLY 2-5 INCHES OF SNOW. THE DENDRITIC
GROWTH ZONE WILL HAVE FAVORABLE OVERLAP OF DEPTH AND LIFT MONDAY
MORNING, THOUGH STRONG WINDS WILL HAMPER SNOWFALL RATES DUE TO
DENDRITES BEING SHREDDED. BECAUSE OF THIS SHREDDING, SNOW
RATIOS MAY BE LIMITED.
REMAINING COLD THROUGH THE REMAINDER OF THE WEEK (EVEN BY LATE
DECEMBER STANDARDS) WITH CLIPPERS POSSIBLE WEDNESDAY AND
THURSDAY.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 617 PM EST SAT DEC 27 2025
UPSTREAM OBSERVATIONS INDICATE A SOUPY LIFR ENVIRONMENT WILL
SPILL OVER KSBN AND KFWA IN THE COMING HOURS. LOW CEILINGS, FOG,
AND DRIZZLE PREVAIL PAST DAYBREAK SUNDAY. THE WILDCARD WITHIN
THIS TAF PERIOD IS HOW FAR NORTH AN INCOMING WARM FRONT
ADVANCES. HIGH CONFIDENCE THIS PASSES KFWA OFFERING A BRIEF
WINDOW WHERE DRY CONDITIONS ARE POSSIBLE AND LIFR CONDITIONS
IMPROVE BEFORE SHOWERS AND EVEN A THUNDERSTORM MOVE THROUGH
ALONG A COLD FRONT. THIS WARM FRONT MAY LINGER RIGHT NEAR KSBN,
KEEPING LIFR CONDITIONS IN PLAY THROUGH SUNDAY. SHOULD THE WARM
FRONT LIFT NORTH, A BRIEF PERIOD OF IMPROVEMENT WOULD OCCUR
NEAR 18Z.
IWX WATCHES/WARNINGS/ADVISORIES
IN...WIND ADVISORY FROM 1 AM EST /MIDNIGHT CST/ TO 7 PM EST /6 PM
CST/ MONDAY FOR INZ005>009-012>015-017-018-020-022>027-
032>034-103-104-116-203-204-216.
OH...WIND ADVISORY FROM 1 AM TO 7 PM EST MONDAY FOR OHZ001-002-004-
005-015-016-024-025.
MI...WIND ADVISORY FROM 1 AM TO 7 PM EST MONDAY FOR MIZ078>081-177-
277.
MARINE...STORM WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON
FOR LMZ043-046.
DISCUSSION...BROWN
AVIATION...BROWN
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