950
FXUS63 KIWX 051709
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
109 PM EDT MON OCT 5 2026
KEY MESSAGES
- DRY CONDITIONS ARE EXPECTED THROUGH THIS WORK WEEK.
- AFTER STARTING OUT WITH SLIGHTLY BELOW NORMAL HIGH TEMPS,
HIGHS SLIGHTLY ABOVE NORMAL TAKE OVER FOR THE END OF THE WORK
WEEK.
- COLD TUESDAY MORNING WITH LOWS DIPPING DOWN TO THE 30S FOR
SOME AREAS NORTH OF US-6.
DISCUSSION
ISSUED AT 103 PM EDT MON OCT 5 2026
SURFACE HIGH PRESSURE MOVES THROUGH TONIGHT AND SHIFTS OFF THE EAST,
TUESDAY. THIS OPENS THE DOOR FOR WARM ADVECTION TO BE ON OUR
DOORSTEP. WARM ADVECTION OFTEN PAIRS WITH ENTERING CLOUD COVER,
USUALLY OF THE MID TO UPPER CLOUD VARIETY. THIS TIME, BOTH THE RAP
AND THE NAM ARE PICKING UP ON 850 MB MOISTURE THAT REMAINS OVERHEAD
FOR A GOOD PORTION OF THE AREA BEFORE SOME UPPER MOISTURE PUSHES
INTO NORTHWESTERN AREAS. IF THAT 850 MB MOISTURE CAN CONDENSE INTO
CLOUDS, THAT REALLY BECOMES A PROBLEM FOR CREATING FROST OVERNIGHT
TONIGHT BECAUSE IT AFFECTS ESPECIALLY THOSE AREAS THAT HAVE A CHANCE
TO DIP DOWN INTO THE UPPER 30S. CHANCES ARE AT ABOUT 15 TO 25
PERCENT OF LESS THAN 38F ACROSS PARTS OF ST JOSEPH, BRANCH, AND
HILLSDALE COUNTIES OF MI. IF ABOUT 3 HOURS OF SUCH
TEMPERATURES OCCURS, FROST BECOMES MORE POSSIBLE, BUT TODAY'S
MODELS CAME IN A LITTLE WARMER MAKING IT LESS POSSIBLE. SOIL
MOISTURE CONTENT IS LOWER ACROSS THE AREA THAT COULD RECEIVE THE
FROST AND THEREFORE, COULD ENHANCE RADIATIONAL COOLING. IF
RADIATIONAL COOLING IS ABLE TO TAKE EFFECT BECAUSE CLOUD COVER
STAYS AWAY LONG ENOUGH OR ALTOGETHER AND WINDS SLACKEN ENOUGH TO
ALLOW DECOUPLING, THIS FROST STILL OCCUR. IT PROBABLY STAYS
MORE RELEGATED TO OUTLYING AREAS THOUGH. AT THIS POINT, GIVEN
THE ABOVE COMBINATION OF FACTORS, HAVE HELD OFF WITH ANY FROST
HEADLINES. WITH THE WARM ADVECTION THAT ENSUES TUESDAY, TEMPS
ARE FORECAST TO WARM THROUGH WEDNESDAY, WHEN MID TO UPPER 70S
ARE POSSIBLE.
A COLD FRONT WASHES OUT WEDNESDAY TO THURSDAY AND BRINGS HIGH
TEMPS BACK TO THE UPPER 60S AND LOW 70S FOR THURSDAY AND FRIDAY.
THEN, ANOTHER TROUGH ENTERS THE WESTERN US AND WARM ADVECTION
BRINGS US BACK SECURELY INTO THE 70S FOR SATURDAY WITH LOW 80S
POSSIBLE ON SUNDAY. THE WARM FRONT IS PRODUCING RAIN IN MODEL
OUTPUT FOR FRIDAY NIGHT/SATURDAY MORNING, BUT IT APPEARS TO BE
TOO DRY IN OUR AREA TO SEE THE RAIN. IT'S ALSO INTERESTING TO
SEE THAT THE SYSTEM IN THE SOUTH THAT TRIED TO GET UP TO THE
AREA NEXT SUNDAY TO PROVIDE SOME RAIN IS STAYING JUST SOUTH OF
THE AREA AS THE DRY AIR HANGS TOUGH. AS LONG AS THIS LASTS, IT
COULD BE UNTIL THE FOLLOWING WEEK BEFORE WE SEE ANY APPRECIABLE
RAIN.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1212 PM EDT MON OCT 5 2026
HIGH PRESSURE WILL CONTINUE TO PROMOTE VFR CONDITIONS, LITTLE IN
THE WAY OF CLOUD COVER, AND LIGHT WINDS THROUGH THE TAF CYCLE.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...ROLLER
AVIATION...STEINWEDEL
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