557
FXUS63 KPAH 122321
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
621 PM CDT Wed Aug 12 2026

.KEY MESSAGES...

- Extreme heat and humidity will continue through the weekend.
  The Heat Advisory has been upgraded to an Extreme Heat Warning
  Thursday through Sunday. High temperatures in the 95-100
  degree range and heat index values in the 105-112 range are
  expected.

- A 20-50% chance of thunderstorm is forecast this afternoon,
  mainly for the Evansville Tri State area, where a few severe
  thunderstorms with damaging winds and tornadoes will be
  possible. Localized heavy rainfall will also be possible. A
  20-30% chance of showers and thunderstorms will continue
  through most of the Quad State tonight.

- Somewhat less hot and humid conditions are expected the first
  half of next week, as small chances of showers and
  thunderstorms return.

&&

.DISCUSSION...
Issued at 200 PM CDT Wed Aug 12 2026

Colliding outflow boundaries over southwest Indiana will be a
focus for potentially severe thunderstorms this afternoon. One
outflow boundary will continue to push south through the I-64
corridor, while another one extends south southeast from Gibson
county through eastern Daviess county. This boundary may be more
stationary or drift slightly to the east through the afternoon.
With at least moderate instability and considerable downdraft
CAPE, damaging winds will be the primary severe concern this
afternoon. However, a tornado threat will exist near the
intersection of the two boundaries which is approaching the
White River. Severe Thunderstorm Watch 577 is in effect for most
of the Evansville Tri State through 8 PM.

Farther southwest, a few showers have developed over southern
portions of southeast Missouri. These showers are not expected
to be terribly long-lived or intense, but a few lightning
strikes will be possible.

More showers and thunderstorms will be possible overnight into
early Thursday morning once again mainly over the Tri State. A
few stronger storms cannot be ruled out, but severe weather is
not expected.

The upper level ridge will gradually build over the Quad State
through Saturday and linger into Sunday before dropping back to
the south for early next week. Today is the 4th day of 105 heat
indices over much of southeast Missouri and adjacent portions of
southern Illinois and west Kentucky, and tomorrow will be the
4th day for the rest of the Quad State. Therefore, with 105+
heat indices expected Thursday through Sunday, we have upgraded
the Advisory to a Warning beginning at 11 AM Thursday and have
extended it through 8 PM Sunday.

Through Sunday, temperatures are expected to trend upward
through the upper 90s, as dewpoints trend a bit lower each day.
So, it is possible we see some triple digit temperatures over
the weekend, while heat indices may struggle to climb above 105.
Regardless, this will be at least a week long extreme heat
event, so the Warning will be worthwhile even if a few locations
don`t quite reach 105 over the weekend.

The upper ridge retreats to the south early next week, but
southern portions of the Quad State could still see high
temperatures in the middle 90s and heat indices may reach the
triple digits again Monday. Highs will remain above normal,
albeit in the lower and middle 90s through Wednesday.

Precipitation chances will come in from the north late Sunday
night and especially Monday afternoon. Intermittent 15% PoPs
will then linger through Tuesday and into Wednesday. Confidence
in coverage and timing of precipitation early next week is very
low.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 621 PM CDT Wed Aug 12 2026

The TAF sites seem to be clear of the afternoon convection, but
did leave a Prob30 at KEVV and KOWB for a little later this
evening, just in case the current convection to their west
sneaks in there. Convection has had a hard time building south
toward KCGI all afternoon, and figure that will continue, but
will have to monitor the cluster southwest of St Louis that is
currently headed that way. Otherwise, the forecasts are dry.
Kept a mention of MVFR fog at KMVN.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Heat Advisory until 9 PM CDT this evening for ILZ075>078-
     081>094.
     Extreme Heat Warning from 11 AM Thursday to 8 PM CDT Sunday
     for ILZ075>078-080>094.
     Extreme Heat Warning until 9 PM CDT this evening for ILZ080.
MO...Heat Advisory until 9 PM CDT this evening for MOZ076-086-087-
     100-107>112-114.
     Extreme Heat Warning from 11 AM Thursday to 8 PM CDT Sunday
     for MOZ076-086-087-100-107>112-114.
IN...Heat Advisory until 9 PM CDT /10 PM EDT/ this evening for
     INZ081-082-085>088.
     Extreme Heat Warning from 11 AM CDT /noon EDT/ Thursday to 8
    PM CDT /9 PM EDT/ Sunday for INZ081-082-085>088.
KY...Heat Advisory until 9 PM CDT this evening for KYZ001>022.
     Extreme Heat Warning from 11 AM Thursday to 8 PM CDT Sunday
     for KYZ001>022.

&&

$$

DISCUSSION...DRS
AVIATION...DRS