811
FXUS63 KIWX 140840
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
340 AM EST TUE JAN 14 2025
KEY MESSAGES
- A BRIEF PERIOD OF SNOW THIS MORNING THROUGH MIDDAY BRINGS
REDUCED VISIBILITY AND A CHANCE FOR SLIPPERY TRAVEL.
- LAKE EFFECT SNOW SHOWERS CONTINUE TODAY BUT TAPER OFF
OVERNIGHT.
- VERY COLD THROUGH THURSDAY MORNING WITH WIND CHILLS BELOW ZERO
OUTSIDE OF LAKE EFFECT CLOUDS.
DISCUSSION
ISSUED AT 337 AM EST TUE JAN 14 2025
A BROAD BUT POTENT UPPER-LEVEL LOW IS DROPPING SOUTH OUT OF
WISCONSIN. AHEAD OF THIS FEATURE IS A NARROW BAND OF SNOW RACING
ACROSS IOWA AND INTO ILLINOIS. VISIBILITY OF 1.5 TO 2 MILES HAS
BEEN RECORDED AT SOME IA ASOS WITH RECORDED PRECIPITATION OF T TO
0.01". THIS FEATURE APPEARS TO BE MAINTAINING ITS STRENGTH DESPITE
ENCOUNTERING LOWER DEW POINTS OVER IL (VS IA). OUR DEW POINTS ARE
SOME 5F TO 8F DRIER THAN THOSE ALONG THE MISSISSIPPI RIVER. NO
MATTER, PERHAPS, BECAUSE DEW POINTS HAVE BEEN RISING VERY SLOWLY
EARLY THIS MORNING THANKS TO LOW-LEVEL SOUTHERLY FLOW. FURTHERMORE,
SNOW HAS BEEN RECORDED AT STATIONS WITH DEW POINTS DEPRESSIONS AS
GREAT AS 6F.
I DO EXPECT A BURST OF SNOW TO RACE THROUGH THE FORECAST AREA THIS
MORNING. THE 500-MB JET IS FORECAST TO AMPLIFY TO 75 KNOTS; 850MB TO
40 KNOTS. THIS FORCING WILL ALSO WORK TO SATURATE THE COLUMN. WE'LL
RESIDE IN THE FAVORABLE LEFT EXIT REGION FOR PLENTY OF LIFT. CROSS
SECTIONS ARE MENACING WITH A DGZ NEARLY ON THE GROUND THANKS TO THIS
COLD AIR MASS. THIS DGZ IS BISECTED WITH LOW-LEVEL FRONTOGENESIS AND
STOUT OMEGA VALUES AS WELL. THIS PERFECTION IS SHORT LIVED AS
FRONTOGENESIS IS THE REFOCUSED ALOFT, OUTSIDE OF THE DGZ. FACTOR IN
THE SWIFT FORWARD SPEED OF 40 KNOTS AND THE RESIDENCE OF TIME OF
BANDED SNOWFALL WILL BE BRIEF. THIS WILL LIMIT ACCUMULATIONS OVERALL
BUT CAN CERTAINLY CATCH MOTORISTS OFF GUARD THIS MORNING THROUGH
MIDDAY BEFORE DISSIPATING.
THIS CLIPPER WILL BE OVER NORTHEAST OHIO BY EARLY THIS AFTERNOON AND
LAKE EFFECT WILL BE REJUVENATED IN ITS WAKE. HIGH RESOLUTION
GUIDANCE FAVORS A SINGLE-BAND TRANSITION TO A MULTIBAND SET UP
BEFORE LES IS UNDERCUT BY SURFACE HIGH PRESSURE PRIOR TO DAYBREAK
WEDNESDAY. A LACK OF RESIDENCE TIME WILL ONCE AGAIN KEEP SNOW TOTALS
IN CHECK.
OTHERWISE, REMAINING VERY COLD WITH WIND CHILLS BELOW ZERO THROUGH
AT LEAST THURSDAY MORNING. THURSDAY WILL ALSO FEATURE ANOTHER CLIPPER
SYSTEM AND LAKE EFFECT SNOW. BRIEF WARM-UP FRIDAY WITH A CHANCE OF
RAIN CHANGING TO SNOW. THIS IS PUNCTUATED BY BRUTAL COLD EARLY NEXT
WEEK; COLDER THAN CURRENT CONDITIONS.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1218 AM EST TUE JAN 14 2025
LAKE EFFECT SHOWERS HAVE CONTINUED TO STAY NORTH OF KSBN THIS
MORNING HOWEVER, WINDS WILL BEGIN TO TURN MORE NORTHWESTERLY
AFTER 15Z TUE FOR BOTH SITES AHEAD OF A QUICK MOVING
DISTURBANCE WHICH WILL LOWER CIGS TO MVFR LEVELS AND ALSO BRING
SNOW SHOWERS ACROSS THE AREA WHICH WILL KEEP VSBYS ALSO MVFR.
WITH SOME OF THE HEAVIER SHOWERS THERE IS THE EXPECTATION WE
LOOK TO SEE VSBYS DROP TO IFR CAT ON THE ONSET FOR KSBN DUE TO
SOME LAKE ENHANCEMENT AND PERIODS OF IFR CIGS FOR BOTH TAF
SITES AS THE DISTURBANCE PUSHES THROUGH. AROUND 01Z WED WE WILL
SEE A RETURN TO VFR CONDITIONS AS THE SYSTEM PUSHES OUT OF THE
AREA EASTWARD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR LMZ043-046.
DISCUSSION...BROWN
AVIATION...
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