621
FXUS63 KIWX 092303
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
703 PM EDT SAT MAY 9 2026
KEY MESSAGES
- LOCALLY GUSTY WINDS AND SMALL HAIL ARE POSSIBLE OVER NORTHWEST
OHIO INTO THIS EVENING.
- SEASONABLY COOL AND DRY SUNDAY AND MONDAY WITH HIGHS AROUND 60
TO 65.
- FROST IS POSSIBLE MONDAY AND TUESDAY MORNING, MAINLY NORTH OF
THE TOLL ROAD.
- NEXT CHANCE OF PRECIPITATION ARRIVES LATE TUESDAY INTO
TUESDAY NIGHT.
DISCUSSION
ISSUED AT 1225 PM EDT SAT MAY 9 2026
A COLD FRONT ALREADY ARRIVING IN OUR NORTHWEST BY 18Z MEANS BETTER
CHANCES FOR STORMS ALONG AND EAST OF I-69. MID LEVEL VORTICITY MOVES
MORE EASTWARD AS OPPOSED TO SOUTHEASTWARD, BUT SOME 700 MB VORTICITY
EXISTS IN THE 21Z WINDOW CAUGHT UP BEHIND THE FRONT AND THAT PAIRED
WITH THE MOISTURE CONVERGENCE ALONG THE THERMAL GRADIENT SHOULD BE
ENOUGH TO ERUPT SHOWERS AND STORMS. THE MAIN LIMITING FACTOR FOR
THESE STORMS APPEARS TO BE MOISTURE, WHICH WITH SFC DEW POINTS AND
850 MB DEW POINTS IN THE MID TO UPPER SINGLE DIGITS IS JUST BELOW
THRESHOLD FOR BETTER FLOODING POTENTIAL. GIVEN 500 TO 1000 J/KG OF
CAPE AND STRONG LOW LEVEL LAPSE RATES ALLUDING TO SOMEWHAT OF AN
INVERTED-V PROFILE, WIND DAMAGE AND PERHAPS A HAIL THREAT APPEAR TO
BE THE MOST LIKELY STORM HAZARDS. EFFECTIVE SHEAR IS RIGHT AROUND 30
KTS, BUT LOW LEVEL TURNING APPEARS TO BE WEAKER AND, ALONG WITH A
DRIER PROFILE, THE TORNADO THREAT SHOULD ALSO BE LIMITED. EITHER
BECAUSE IT VACATES THE AREA OR THE INSTABILITY WANES, AN INITIAL
GUESS AT SEVERE WEATHER COMING TO AN END IS AROUND 00Z THIS EVENING.
HOWEVER, THERE IS A POST-FRONTAL THERMAL GRADIENT THAT MOVES WEST TO
EAST IN CONJUNCTION WITH SOME MORE 700 MB VORTICITY AND THIS MAY
KEEP SHOWERS AND PERHAPS SOME THUNDERSTORMS GOING IN A TRAINING
ENVIRONMENT SOUTH OF US-24. IT IS POSSIBLE THAT WE SEE SOME PONDING
OR FLOODING THERE AS LONG AS STORMS CONTINUE TO FIRE ALONG THAT
STALLED FRONT.
SURFACE HIGH PRESSURE BEGINS TO POKE INTO THE AREA ON SUNDAY BEHIND
THE COLD FRONT LEADING TO A DRY DAY. THAT DRY WEATHER CONTINUES INTO
TUESDAY MORNING. AS THE RELATIVELY COOLER AIR SWINGS THROUGH THE
AREA DURING THIS PERIOD, WE'LL HAVE TO WATCH FOR SOME FRONT
POTENTIAL. FOR MONDAY MORNING, THE BETTER 850 MB TEMPERATURES, LEAST
CLOUDY THREAT, AND WEAKEST LOW LEVEL PRESSURE GRADIENT EXISTS
BETWEEN MONDAY AND TUESDAY MORNINGS. TUESDAY, THE THETA-E PLUME IS
ON OUR DOORSTEP AROUND 12Z AND THIS MAY BE ENOUGH TO PROTECT THE
AREA. HOWEVER, WE'LL HAVE TO SEE IF TEMPS DROP QUICKLY JUST AFTER
SUNSET AND IF WE CAN FORM FROST EARLIER IN THE OVERNIGHT. BOTH OF
THESE MORNINGS LOOK LIKE ALONG AND NORTH OF THE TOLL ROAD COULD SEE
FROST.
THE THETA-E PLUME IS INTO THE AREA DURING THE DAYTIME ON TUESDAY IN
CONJUNCTION WITH THE LOW PRESSURE SYSTEM ARRIVING. AS SUCH, THERE IS
A GOOD AREA OF LARGE SCALE ASCENT. IT IS INTERESTING TO SEE THE
LARGE SCALE ASCENT WEAKENS BY THE TIME WE GET TO THE AFTERNOON. THE
INSTABILITY AXIS WAITS UNTIL AFTER 00Z TO GET INTO THE AREA, THOUGH,
AND THAT MAY AFFECT THE OVERALL INTENSITY OF STORMS. OVERNIGHT, THE
LOW CONTINUES TO DEEPEN AND DEVELOPS INTO AN UPPER LOW PRESSURE
SYSTEM OVER THE GREAT LAKES REGION AND COLD AIR SPILLS IN FOR
WEDNESDAY. THERE IS SOME QUESTION ABOUT MOISTURE CONTENT FOR
WEDNESDAY, BUT THERE COULD BE SOME ISOLATED TO SCATTERED SHOWERS.
GIVEN WHAT APPEARS TO BE A LAKE SHADOW REMOVING LOW LEVEL LAPSE
RATES THROUGH THE DAY, AM SKEPTICAL OF THUNDERSTORM POTENTIAL,
ESPECIALLY GIVEN WEAKER CAPE VALUES. A 40 KT LLJ WILL PROBABLY MAKE
IT EASY TO GET BREEZY WINDS BETWEEN 25 AND 35 MPH DURING THE
DAYTIME, ESPECIALLY AHEAD OF THE RAIN.
HIGH PRESSURE AND MID LEVEL RIDGING FOLLOW FOR THURSDAY AND AT LEAST
THE FIRST HALF OF FRIDAY. THE THETA-E PLUME PROBABLY WAITS UNTIL
SATURDAY (THE GFS IS PROBABLY TOO FAST), BUT AM NOT CONFIDENT ENOUGH
TO REMOVE POPS ENTIRELY FROM FRIDAY YET.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 657 PM EDT SAT MAY 9 2026
A FEW REMAINING SCATTERED SHOWERS AND THUNDERSTORMS ARE
CURRENTLY MOVING EASTWARD OUT OF THE AREA AND CHANCES WILL
DECREASE THROUGH THE EVENING. WINDS WILL BEGIN TO DIURNALLY WEAKEN
AFTER 00Z SUN. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO
CONTINUE THROUGH THIS TAF PERIOD WITH DIURNAL GUSTY
NORTHWESTERLY WINDS INCREASING AGAIN AFTER 18Z SUN FOR BOTH
SITES. GUSTS WILL APPROACH 20 KTS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...SKIPPER
AVIATION...ANDERSEN
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