057
FXUS63 KPAH 170743
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
243 AM CDT Fri Jul 17 2026

.KEY MESSAGES...

- Daily chances of showers and thunderstorms will persist into
  the weekend. A stronger gusty storm cannot be ruled out on
  Saturday, especially in the northeast across southwest
  Indiana.

- Hot and humid conditions will continue into next week with
  heat index values peaking nearing 105 degrees on Tuesday, with
  relief from the heat arriving Wednesday.

- Any sustained northerly flow (the best chance of which is
  Wednesday behind the cold front) could bring in unhealthy air
  quality conditions due to the Northwestern Ontario wildfire
  smoke.

&&

.DISCUSSION...
Issued at 242 AM CDT Fri Jul 17 2026

Broad upper-level ridging remains across most of the country
today. Calm winds and yesterday`s rain will result in some fog
formation early this morning. Remnants of a weak disturbance,
along with plenty of moisture (PWs near 2 inches) will help
produce scattered showers and thunderstorms today, mainly in the
afternoon. Some nuisance flooding is possible with slow moving
storms. Higher chances are located near the Evansville Tri-State
as a front is positioned NW to SE across Indiana. MLCAPE values
peak around 2000-2500J/kg, with shear of 15-20kts holding back
severe weather.

Tomorrow, in addition to the peak heating afternoon convective
potential, there is also a late evening-overnight frontal
passage. An SPC slight risk extends through Central Indiana for
this front but, with an unfavorable overnight timing, and being
far from the low pressure center speeding from the Great Lakes
to Quebec, severe weather potential is limited to a marginal
risk for straight-line winds for the Evansville Tri-State. Shear
and lapse rates will be a little more favorable than today.
Troughing digs into the northeast as this system moves through,
bringing northwesterly flow aloft through the Quad State.
Precip chances are trending higher Sunday as a disturbance moves
around the western ridge.

The NBM trends drier early next week with dry to slight chance
PoPs Monday and Tuesday. This might be an underestimate Tuesday
as low pressure moves through the Great Lakes. Regardless of
positioning, northeastern portions would be more favored for
rain Tuesday vs southwestern areas. Today through Tuesday, highs
slowly tick upward with 90s becoming widespread early next week.
Heat indices around 100 rise to 105 on Tuesday. Cooler air
arrives Wednesday following the Tuesday/Tuesday night cold
front.

One potential issue would be with any sustained northerly
flow as massive active wildfires in Canada have produced
extremely high PM2.5 concentrations. Currently, PM2.5 readings
of 400+ug/m3 are located in northeastern Minnesota, 250-400 in
Michigan/Chicago, and 150-300 in OH/PA/NJ, For context, the
NAAQS air quality standard for PM2.5 is 35.5 ug/m3 (the
threshold level for the Unhealthy for Sensitive Groups
category), while unhealthy is 55.5-150.4, very unhealthy is
150.5-250.4, and hazardous is 250.5+. Those traveling
north/northeast of the Quad State should check air quality
information and take precautions, especially if you have a
health condition that puts you at higher risk.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1152 PM CDT Thu Jul 16 2026

Most locations are close to saturation already, so mentioned
MVFR fog at all sites overnight. Scattered SHRA/TSRA could
impact all sites mostly through the afternoon, but there is a
signal for activity to linger into the evening at KEVV and KOWB.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.

&&

$$

DISCUSSION...ATL
AVIATION...DRS