356
FXUS63 KIWX 051123
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
623 AM EST MON JAN 5 2026
KEY MESSAGES
- CLOUDS DECREASING THIS MORNING, BUT INCREASE AGAIN THIS
AFTERNOON AND TONIGHT.
- TODAY WILL MARK THE BEGINNING OF A WARMER PERIOD WITH ABOVE NORMAL
TEMPERATURES EXPECTED FOR MUCH OF THE WORK WEEK.
- FOG IS EXPECTED TO DEVELOP TONIGHT INTO WEDNESDAY WITH SOME AREAS
OF DRIZZLE AND LIGHT RAIN ALSO POSSIBLE.
- RAIN SHOWERS BECOME LIKELY THURSDAY INTO FRIDAY, TURNING
COOLER FOR THE WEEKEND WITH SOME LINGERING RAIN/SNOW SHOWER
CHANCES.
DISCUSSION
ISSUED AT 305 AM EST MON JAN 5 2026
ISENTROPIC LIFT AND A PROGRESSIVE MID LEVEL TROUGH ACROSS THE GREAT
LAKES HAS PRODUCED A WINTRY MIX OVERNIGHT ACROSS PORTIONS OF CENTRAL
LOWER MICHIGAN. SOME OF THIS LIGHT PRECIP MAY GLANCE SOUTH CENTRAL
MICHIGAN (PRIMARILY SOUTHEAST LOWER MICHIGAN) THROUGH ABOUT 09Z
AS A NARROW OF AXIS OF SLIGHTLY ENHANCED LOW LEVEL MOISTURE
ACCOMPANIES THE NOSE OF STRONGER LOW LEVEL FLOW ASSOCIATED WITH
WARM FRONT. A WEAK GLANCING SHOT OF LOW LEVEL CAA WON'T MAKE
MUCH SOUTHWARD PROGRESS ACROSS MICHIGAN THIS MORNING, BUT SHOULD
TEND TO ENHANCE A LOW LEVEL BAROCLINIC ZONE ACROSS SOUTHERN
LOWER MICHIGAN. LOW LEVEL WINDS WILL BACK LATER THIS AFTERNOON
IN RESPONSE TO ANOTHER FAST MOVING MID LEVEL TROUGH EXPECTED TO
REACH IA/NORTHERN MO BY THIS EVENING. WARM/MOIST ADVECTION OVER
THIS BOUNDARY SHOULD TREND TO PROMOTE REDEVELOPMENT OF LOW
CLOUDS PARTICULARLY ALONG AND NORTH OF US 6 GIVEN ANTICIPATED
FRONTAL PLACEMENT. OTHERWISE, AFTER DECREASING CLOUDS THIS
MORNING, SOME RENEWED MID AND HIGH CLOUDS SHOULD OVERSPREAD THE
REST OF THE AREA THIS AFTERNOON. SEVERAL FACTORS WILL BE
COMPETING IN TERMS OF TEMP FORECAST TODAY, WITH CONTINUED
SNOWPACK ACROSS THE NORTH ACTING TO SHARPEN A LOW LEVEL
INVERSION WITH DEVELOPING WAA. THIS LINGERING SNOW COVER WILL
LIKELY LIMIT TEMP REBOUND SOMEWHAT TODAY ACROSS THESE LOCATIONS,
BUT AREAS WITH LESS SNOWCOVER ACROSS THE FAR SOUTH/SOUTHWEST
SHOULD BE ABLE TO WARM INTO THE LOW TO POSSIBLY MID 40S.
FOR THIS EVENING, INCREASING NEAR SFC MOISTURE CONVERGENCE WITH LOW
LEVEL JET IMPINGING ON STALLED SOUTHERN GREAT LAKES BOUNDARY SHOULD
RESULT IN EXPANSION OF STRATUS AND EVENTUALLY DRIZZLE AND FOG AS
BULK OF THIS MOISTURE RECOVERY WILL BE VERY SHALLOW IN NATURE.
THE AFOREMENTIONED MID MS VALLEY SHORT WAVE SHOULD SHIFT ACROSS
NORTHERN INDIANA SHORTLY AFTER DAYBREAK TUESDAY WITH A MID LEVEL
DRY SLOT LIKELY TO PUNCH ACROSS PORTIONS OF NE IN/NW OH. A
BAGGY/WEAK LOW LEVEL GRADIENT ACCOMPANYING THIS MID LEVEL TROUGH
AND GRADUALLY MELTING SNOWPACK SHOULD SUPPORT STRATUS/FOG
POTENTIAL THROUGH MUCH OF THE DAY, ALTHOUGH FOG POTENTIAL COULD
DIMINISH IN AFTERNOON ACROSS SOUTHWEST PORTIONS OF THE AREA
WHERE SNOWPACK IS LESS AND SLIGHTLY WARMER SFC TEMPERATURES ARE
EXPECTED. THIS PATCHY FOG COULD VERY WELL LINGER INTO TUESDAY
NIGHT FOR MANY LOCATIONS. LOW LEVEL COLD ADVECTION BEHIND
TUESDAY MID LEVEL TROUGH SHOULD BE WEAK AND SHORT-LIVED AS MID
LEVEL HEIGHT RISES FOLLOW DURING THE DAY WEDNESDAY WITH QUICK
TRANSITION BACK TO LOW LEVEL WAA. HIGHS ACROSS THE SOUTH
WEDNESDAY AFTERNOON COULD PUSH THE 50 DEGREE MARK.
THURSDAY AND FRIDAY STILL APPEAR TO BE THE WARMEST DAYS OF THIS
FORECAST PERIOD AS STRONG WAA AND EVENTUAL STRONG LOW LEVEL MOISTURE
TRANSPORT LIFT NORTHWARD INTO OHIO VALLEY/SOUTHERN GREAT LAKES.
WHILE GUIDANCE CONTINUES TO HAVE EXPECTED LARGE DIFFERENCES
REGARDING COMPLEX UPPER WAVE EVOLUTION FOR LATE WORK WEEK INTO NEXT
WEEKEND, SOME BROADER SCOPE IDEAS SEEM TO BE CONVERGING. A CUT-OFF
UPPER LOW DEVELOPING WEST OF BAJA OF CA TODAY SHOULD EJECT NORTHEAST
IN ADVANCE OF PRIMARY EASTERN PACIFIC TROUGH TO BRING A GOOD SURGE
OF LOW LEVEL MOISTURE TRANSPORT AND WARM ADVECTION THURSDAY, WITH
WIDESPREAD RAIN EXPECTED TO DEVELOP IN THIS WARM/MOIST ADVECTIVE
REGIME. THIS INITIAL FRONTAL WAVE SHOULD BE FOLLOWED BY ANOTHER LOW
LEVEL REFLECTION DEVELOPING ACROSS THE MID MS VALLEY FRIDAY IN
RESPONSE TO DIGGING LARGER SCALE SYNOPTIC TROUGH ACROSS THE SOUTHERN
ROCKIES.
THE SECOND PHASE OF THIS SYSTEM IS MUCH MORE UNCERTAIN IN REGARDS TO
PRECIP AMOUNTS/TIMING WITH A POTENTIAL THAT BEST MOISTURE COULD BE
SHUNTED WELL EAST AND SOUTHEAST IN PRE-FRONTAL ENVIRONMENT. THIS
SYSTEM MAY TEND TO OCCLUDE ACROSS SOUTHERN GREAT LAKES EARLY WEEKEND
WITH SOME LIKELY INSTABILITY RAIN/SNOW SHOWERS CONTINUING WITH SOME
WRAP AROUND LOW/MID LEVEL MOISTURE. CONFIDENCE REMAINS ON THE HIGHER
SIDE REGARDING TREND BACK TO COLDER, MORE SEASONABLE TEMPERATURES
FOR THE WEEKEND IN WAKE OF THIS SYSTEM. CONFIDENCE IN TEMPS HEADING
INTO NEXT WEEK IS ON THE LOWER SIDE AS MULTI-MODEL ENSEMBLE MEAN
CONSENSUS POINTS TO LOCAL AREA BEING IN VICINITY OF STRONG LOW LEVEL
BAROCLINICITY WITH A NORTHWEST FLOW PATTERN THAT COULD BRING SOME
ADDITIONAL CLIPPERS AND WOULD ALLOW THIS BAROCLINIC ZONE TO WAVER
ACROSS THE REGION.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 614 AM EST MON JAN 5 2026
MOSTLY CLEAR SKIES THIS MORNING GIVE WAY TO INCREASING CLOUDS
THROUGH THE AFTERNOON. WARM, MOIST ADVECTION FROM THE SOUTH
LATER TODAY IS ANTICIPATED TO FOSTER MVFR CEILINGS. STRATUS IS
NOTED ACROSS WI PUSHING SOUTH AS WELL. AFTER 06Z, A WARM FRONT
LIFTS IN AND FOG IS EXPECTED TO DEVELOP IN ITS WAKE. LOW
CONFIDENCE ON START TIME. CEILINGS LIKELY TANK TO LIFR JUST
BEYOND THIS TAF PERIOD ALONG WITH A CHANCE OF RAIN, ESPECIALLY
AT KSBN.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...MARSILI
AVIATION...BROWN
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