129
FXUS63 KIWX 070603
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
203 AM EDT THU MAY 7 2026
KEY MESSAGES
- COLD AND DRY TONIGHT INTO EARLY FRIDAY MORNING, WITH VARIABLE
CLOUD COVER AND LOWS FALLING INTO THE MID TO UPPER 30S. THERE
IS A FROST ADVISORY IN EFFECT FOR MICHIGAN COUNTIES, WHERE
AREAS OF FROST COULD HARM SENSITIVE OUTDOOR VEGETATION. PATCHY
FROST IS POSSIBLE FOR IN/OH COUNTIES, MAINLY NORTH OF US 6.
- CHANCES FOR RAIN SHOWERS LATE THURSDAY AFTERNOON INTO FRIDAY
MORNING, MAINLY IN MICHIGAN AND FOR AREAS SOUTH OF US 30.
HIGHS WILL BE IN THE MID-UPPER 50S, LOW 60S. LOWS IN THE 40S.
- BETTER CHANCES FOR RAIN FRIDAY AFTERNOON INTO SATURDAY
MORNING, THEN AGAIN SATURDAY NIGHT INTO SUNDAY. ISOLATED
THUNDERSTORMS ARE POSSIBLE FOR AREAS SOUTH OF US 30 ON FRIDAY
AFTERNOON. HIGHS WILL BE IN THE MID TO UPPER 60S AND LOW 70S
SATURDAY, AND IN THE 60S FRIDAY AND SUNDAY.
DISCUSSION
ISSUED AT 404 PM EDT WED MAY 6 2026
CLOUD COVER WILL LINGER THROUGH LATE THIS EVENING, GRADUALLY
BECOMING MORE SCATTERED OR CLEARING ALL TOGETHER. WINDS WILL REMAIN
OUT OF THE WEST AT 5 MPH OR LESS, WITH TEMPERATURES FALLING INTO THE
MID TO UPPER 30S (COLDEST IN MICHIGAN COUNTIES INLAND FROM LAKE MI).
ISSUED A FROST ADVISORY FOR THE MICHIGAN COUNTIES TONIGHT, WITH
AREAS OF FROST DEVELOPING LATE TONIGHT INTO EARLY FRIDAY MORNING-
INLAND FROM LAKE MI. FROST COULD HARM SENSITIVE OUTDOOR VEGETATION.
SENSITIVE OUTDOOR PLANTS MAY BE KILLED IF LEFT UNCOVERED.
PATCHY FROST IS POSSIBLE IN IN/OH, MAINLY NORTH OF US 6 AND WEST OF
US 31--BUT TEMPS WILL LIKELY REMAIN AT 37 OR ABOVE GIVEN CLOUD COVER
IS EXPECTED TO LINGER LONGER (ESPECIALLY ALONG/SOUTH OF US 24).
OTHERWISE, RAIN CHANCES (20-40 PERCENT) INTRODUCED FOR LATE THURSDAY
AFTERNOON AND THU NIGHT-ESPECIALLY FOR AREAS SOUTH OF US 30 AND
FURTHER NORTH IN MICHIGAN COUNTIES. AN UPPER LEVEL TROUGH STEMMING
FROM A CLOSED LOW OVER HUDSON BAY WILL CROSS THROUGH DURING THIS
PERIOD. COLD TEMPERATURES ALOFT WILL BRING INSTABILITY TO THE AREA,
WITH WAA AT THE SURFACE CREATING SOME WEAK ISENTROPIC ASCENT. THIS
COULD FORCE SHOWERS ALONG OUR SOUTHERN CWA BORDER BY LATE AFTERNOON--
WHERE MODELS SUGGESTING A STATIONARY FRONT-LIKE FEATURE SETTING UP
AND PRODUCING SHOWER ACTIVITY THROUGH THE NIGHT. ADDITIONAL ACTIVITY
WITH THE TROUGH IS POSSIBLE IN THE MICHIGAN COUNTIES AS WELL.
OVERALL FOR BOTH AREAS, HAVE CAPPED MOST POPS AT 20-30 PERCENT (UP
TO 40 PERCENT LATE THU EVENING) AS MODELS ARE GREATLY CONFLICTED AS
TO THE EXTENT AND EXACT LOCATION OF THE PRECIPITATION--MOISTURE IS
FAIRLY LIMITED-ESPECIALLY INITIALLY. THE HRRR TAKES THE BOUNDARY
FURTHER SOUTH OF OUR CWA--WHICH WOULD DROP OUR PRECIPITATION CHANCES
ALL TOGETHER--WHEREAS THE RAP AND THE NAM HAVE A MORE ROBUST FEATURE
FOR AREAS SOUTH OF US 30 (MAINLY IN). OTHERWISE, HIGHS THURSDAY WILL
BE IN THE 50S AND PERHAPS LOW 60S (WARMEST SOUTH OF US 30). LOWS
WILL BE IN THE 40S.
AFTER A LULL IN PRECIPITATION FRIDAY MORNING INTO EARLY AFTERNOON, A
SURFACE LOW WILL CROSS FROM SOUTHERN IL EASTWARD INTO OHIO. INITIAL
PRECIPITATION CHANCES FRIDAY AFTERNOON INTO THE EVENING WILL BE
ASSOCIATED WITH WARM AIR ADVECTION/ISENTROPIC ASCENT AHEAD OF THE
WARM FRONT, THEN WITH THE DEFORMATION ZONE ON THE BACKSIDE OF THIS
LOW FRIDAY NIGHT INTO EARLY SATURDAY MORNING. HAVE CHANCES AROUND 40-
70 PERCENT, WITH THE BEST CHANCES ALONG/SOUTH OF US 24 FRI EVENING.
THERE ARE LOW CHANCES FOR THUNDERSTORMS (NON-SEVERE) SOUTH OF US 30
FRIDAY AFTERNOON.
SATURDAY WE'LL SEE A BRIEF RIDGE OF HIGH PRESSURE AT THE SURFACE
WITH GUSTY SOUTHWESTERLY FLOW. HIGHS WILL CLIMB INTO THE UPPER 60S
AND LOW TO MID 70S, WARMEST SOUTH. THE LOW OVER HUDSON BAY SINKS
SOUTHWARD INTO JAMES BAY-SO WE'LL SEE SEVERAL PRECIPITATION CHANCES
WITH EACH PASSING TROUGH/SHORTWAVE RIPPLING THROUGH THE FLOW. THERE
ARE LOW CHANCES (20-30 PERCENT) FOR SHOWERS AND POSSIBLY A
THUNDERSTORM LATE SAT AFTERNOON AND EVENING, THEN BETTER CHANCES FOR
RAIN OVERNIGHT INTO SUNDAY (40-70 PERCENT) AS THE MAIN TROUGH AXIS
SWINGS THROUGH. HIGH TEMPS ON SUNDAY WILL DROP BACK INTO THE 60S.
MOSTLY DRY AND COOLER MONDAY INTO EARLY TUESDAY, WITH HIGHS IN THE
60S. ANOTHER WAVE WILL BRING ADDITIONAL CHANCES FOR RAIN (30-60
PERCENT) BY TUE AFTERNOON INTO WED. ISOLATED STORMS ARE POSSIBLE TUE
AFTERNOON-EVENING.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 149 AM EDT THU MAY 7 2026
BROAD UPPER LEVEL CYCLONIC FLOW IS CHARACTERIZED BY SEVERAL
SMALLER SCALE SHORT WAVES THIS MORNING. THESE SHORT WAVES ARE
WORKING WITH LIMITED MOISTURE AND THE ONLY EFFECT THROUGH THIS
MORNING WILL LIKELY ONLY BE EVIDENT WITH SOME INCREASING HIGH
AND MID CLOUD. A STRONGER VORT MAX WILL DROP ACROSS THE SOUTHERN
GREAT LAKES THIS AFTERNOON AND SOME INCREASING
ADVECTIVE/FRONTOGENETIC FORCING IN WAKE OF THIS UPPER TROUGH
COULD INDUCE SOME SHOWER ACTIVITY FROM NORTH CENTRAL ILLINOIS
INTO PORTIONS OF NORTHERN/NORTHEAST INDIANA INTO THIS EVENING.
SOME LOW LEVEL MOISTURE RECOVER IS EXPECTED IN THE WAKE OF THE
UPPER TROUGH WHERE THE ADVECTIVE FORCING IS STRONGEST, BUT
SUBCLOUD LAYERS WILL REMAIN QUITE DRY WITH VERY LIMITED
INSTABILITY. WILL CARRY A PROB30 GROUP AT KFWA FOR TONIGHT
WHERE SOME LOW LEVEL MOISTURE RECOVER IS EXPECTED ALONG PRIMARY
WESTERLY LOW LEVEL JET AXIS. OTHERWISE, VFR CONDITIONS SHOULD
PERSIST THIS PERIOD WITH SOME INCREASE IN WESTERLY WIND SPEEDS
TODAY INTO THE 10 TO 15 KNOT RANGE (SOME GUSTS NEAR 20 KNOTS)
DURING PEAK DIURNAL MIXING.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ078>081-177-
277.
MARINE...NONE.
DISCUSSION...MCD
AVIATION...MARSILI
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page