255  
FXUS63 KIWX 082325  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
625 PM EST WED JAN 8 2025  
   
KEY MESSAGES
 
 
- SCATTERED TO NUMEROUS SNOW SHOWERS PERSIST INTO THIS EVENING,  
MAINLY NORTH OF US 30 WHERE LIGHT ACCUMULATIONS AND MINOR  
TRAVEL DISRUPTIONS WILL BE POSSIBLE.  
 
- WIDESPREAD LIGHT SNOW (1-3") FRIDAY INTO FRIDAY NIGHT, MAINLY  
DURING THE PM HOURS. SLIPPERY TRAVEL CONDITIONS POSSIBLE.  
 
- CONTINUED NEAR TO BELOW NORMAL TEMPERATURES THROUGH THIS  
WEEKEND.  
 
- ARCTIC AIR AND CHANCES FOR LAKE EFFECT SNOW AND SUB-ZERO WIND  
CHILLS ARRIVE FOR THE FIRST HALF OF NEXT WEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 141 PM EST WED JAN 8 2025  
 
SCATTERED TO NUMEROUS SNOW SHOWERS WILL PERSIST THIS AFTERNOON AND  
EVENING FOR LOCATIONS MAINLY NORTH OF US 30. A POTENT MID LEVEL  
SHORTWAVE DROPPING SOUTH THROUGH THE AREA AND AN ASSOCIATED LAKE  
ENHANCED PLUME/TROUGH THE CULPRIT, WITH EMBEDDED LAKE EFFECT  
MESOSCALE VORTICITY CENTERS AND CLOUD TOPS INTO AT LEAST THE  
LOWER PORTION OF THE DGZ LIKELY SUPPORTING BRIEF HEAVIER SNOW  
SHOWERS WITHIN THE TROUGH AXIS. ADDITIONAL LIGHT ACCUMS AND  
MINOR TRAVEL DISRUPTIONS REMAIN POSSIBLE.  
 
RIDGING DOES BUILD IN THROUGH THE COLUMN OVERNIGHT INTO THURSDAY.  
THIS WILL BRING AN ABRUPT END TO THE SNOW SHOWER ACTIVITY WITH SOME  
SUNSHINE ANTICIPATED. ENJOY IT BECAUSE CLOUDS AND LIGHT SYNOPTIC  
SNOW MOVE IN FOR FRIDAY AND FRIDAY EVENING IN ADVANCE OF AN  
AMPLIFYING POSITIVELY TILTED UPPER TROUGH AND ASSOCIATED COLD FRONT.  
DECENT ISENTROPIC ASCENT AND MOISTURE ADVECTION (2-2.5 G/KG IN THE  
85-7H LAYER) UNDER A POTENT 150 KT PLUS UPPER JET CROSSING THE OH  
VALLEY SHOULD SUPPORT INCREASING COVERAGE OF LIGHT SNOW DURING THIS  
TIME. GFS ENSEMBLE PROBS ARE NEAR 90%, AND ECMWF ENSEMBLE 60-70% FOR  
A TENTH OF AN INCH OR MORE OF QPF WITH THE BULK OF GUIDANCE  
GENERALLY SUGGESTING A 1-3" TYPE SNOWFALL.  
 
DEEP TROUGH WILL EXIT EAST IN TIME FOR THE WEEKEND WITH DRY AND  
SEASONABLY COLD WX SATURDAY INTO MOST OF SUNDAY. A HYBRID CLIPPER  
SYSTEM AND ARCTIC FRONT ARRIVES LATE SUNDAY INTO MONDAY WITH THE  
NEXT OPPORTUNITY FOR A NUISANCE LIGHT SNOW (WAA DRIVEN FOLLOWED BY  
FRONTAL FORCING). MODELS THEN IN GENERAL AGREEMENT WITH A SHOT OF  
BLUSTERY/COLD WNW WINDS MONDAY THROUGH WEDNESDAY WITH CHANCES  
FOR SUB-ZERO WIND CHILLS AND PERIODIC BOUTS OF LAKE EFFECT SNOW  
FOR WNW FLOW SNOW BELTS.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
 
 
ISSUED AT 624 PM EST WED JAN 8 2025  
 
THE BULK OF LAKE EFFECT SNOW SHOWERS HAVE DIMINISHED AT KSBN,  
WITH CHANCES PERSISTING AT KFWA UNTIL 02 OR 03Z. THE NEXT STRONG  
UPPER LEVEL VORT MAX IS DROPPING SOUTH ACROSS THE SOUTHERN GREAT  
LAKES TONIGHT, MORE TIED TO THE NOSE OF A 90 KNOT UPPER JET  
STREAK. THIS SYNOPTIC FORCING HAS ENHANCED THE LAKE EFFECT SNOW  
SHOWERS, PARTICULARLY ACROSS WEST CENTRAL LOWER MICHIGAN.  
SLIGHT BACKING OF LOW LEVEL WINDS AND ENTRAINMENT OF DRIER LOW  
LEVEL AIR FROM THE WEST SHOULD KEEP THE POTENTIAL OF THE HEAVIER  
LAKE EFFECT SNOW SHOWERS TO THE NORTH AND EAST OF THE TERMINALS  
THIS EVENING. PASSAGE OF THIS VORT MAX SHOULD SEE AN  
ACCOMPANYING DECREASE IN LAKE EFFECT SNOW SHOWER COVERAGE  
OVERNIGHT ALONG WITH SCATTERING LOW CLOUDS. CONDITIONS SHOULD  
REMAIN VFR THIS PERIOD OUTSIDE OF THE POTENTIAL OF BRIEF CIGS  
BELOW 3000 FEET THROUGH 01Z OR 02Z THIS EVENING AT KFWA. WINDS  
TO BECOME SOUTH AROUND 10 KNOTS ON THURSDAY AS LOW LEVEL RIDGE  
DROPS ACROSS OHIO VALLEY.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
OH...NONE.  
MI...NONE.  
MARINE...NONE.  
 

 
 

 
 
DISCUSSION...STEINWEDEL  
AVIATION...MARSILI  
 
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