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