164
FXUS01 KWBC 121838
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
236 PM EDT Wed Aug 12 2026

Valid 00Z Thu Aug 13 2026 - 00Z Sat Aug 15 2026

...Dangerous heat continues from the central/southern Plains into
the Southeast...

...An active pattern will keep the threat of heavy rainfall/flash
flooding in the forecast throughout much of the Midwest and
western U.S...

A heatwave has begun to settle in from the central/southern Plains
east through the Southeast as an upper-high strengthens overhead.
Forecast highs in the upper 90s to low 100s along with high
humidity will lead to heat indices in the 105-115 degree range.
Some potential record-tying/breaking temperatures are possible
with many areas forecast to see their hottest temperatures so far
this year or even in the past few years. Morning lows only
dropping into the mid-70s to low 80s will provide little relief
from the heat overnight. Widespread Major to Extreme HeatRisk
(levels 3 and 4 out of 4) is expected indicating oppressive heat
dangerous to anyone without access to adequate cooling or
hydration. Unfortunately, the heatwave is forecast to continue
well beyond the current forecast period through at least
mid-August.

Meanwhile, scattered to widespread storms continue across the
Midwest to Ohio Valley/central Appalachians under stronger
upper-flow and along a quasi-stationary frontal boundary to the
north of the upper-high. A Moderate Risk of Excessive Rainfall
(level 3/4) remains in effect into this evening (Wednesday) across
portions of eastern Indiana into central Kentucky where additional
rounds of rainfall over already saturated grounds from storms the
days before may lead to scattered to numerous instances of flash
flooding. A Slight Risk (level 2/4) is in place more broadly
through the region for more scattered instances of flash flooding.
The Storm Prediction Center also maintains a Slight Risk of severe
weather (level 2/5) mainly for the threat of some damaging winds
through the rest of this evening. Storms will continue the next
couple of days as this stagnant pattern remains in place, with a
Slight Risk of Excessive Rainfall throughout the region Thursday
and then focused on the Upper Mississippi Valley for Friday, as
scattered instances of flash flooding remain a concern.

An active storm pattern is also present along the western side of
the upper-ridge from the Southwest/Four Corners region north into
the Great Basin, Rockies, and adjacent areas of the
northern/central High Plains. The greatest storm coverage and
influx of moisture Pacific moisture rounding the upper-ridge, and
subsequent threat for heavy rainfall/flash flooding, will vary day
to day as the flow adjusts ahead of an upper-trough entering the
Northwest. However, at least isolated instances of flash flooding
can be expected through the next few days. Through this evening,
the locally higher threat/Slight Risk covers portions of the
Southwest/Four Corners region. This risk broadens on Thursday to
include portions of the Great Basin as well as the central Rockies
and northern/central High Plains. For Friday, a Slight Risk is in
place for the central High Plains. In addition to flash flooding,
the SPC has also included a Slight Risk of severe weather over
portions of the central to northern Plains for the rest of this
evening for the threat of large hail and damaging winds.

Elsewhere, daily thunderstorm chances can be expected for Florida
mainly through Thursday. Some showers and thunderstorms are also
possible through New England over the next couple of days. Most of
the country will see around or even below average, more mild
temperatures outside of the heatwave over the South. Forecast
highs will generally be in the 70s and 80s across the northern
Plains to Upper Midwest and New England as well as throughout most
of the West outside of the Deserts, where highs will still be
below average but into the 90s to low 100s.

Putnam

Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php




$$