889
FXUS01 KWBC 131855
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
248 PM EDT Thu Aug 13 2026

Valid 00Z Fri Aug 14 2026 - 00Z Sun Aug 16 2026

...Dangerous heat continues from the Central/Southern Plains to
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 burgeoning heatwave continues across much of the southern U.S.
from the central/southern Plains east through the Middle/Lower
Mississippi Valley and into the Southeast as an upper-level ridge
builds over the region. Forecast highs in the upper 90s to low
100s along with high Summer-time humidity in place will lead to
heat indices in the 105 to 115 degree range. Some
record-tying/breaking highs will be possible as many areas see
their hottest temperatures of the year so far, or even in the past
few years in some cases. Low temperatures only dropping into the
mid-70s to low 80s will provide little relief from the heat
overnight. These factors have contributed to widespread areas of
Major to Extreme levels of HeatRisk (levels 3 and 4 out of 4),
indicating a level of heat dangerous to anyone without access to
adequate air conditioning or hydration. Unfortunately, the
heatwave looks to continue well beyond the current forecast period
through at least mid-August.

Meanwhile, areas of scattered to widespread thunderstorms within
the stronger upper-flow rounding the ridge continue to bring a
heavy rain/flash flooding and severe weather threat. One such
region is across the Midwest from the Middle Missouri/Upper
Mississippi Valley southeast into the Ohio Valley and
central/southern Appalachians. Repeated rounds of heavy rainfall
leading to saturated soils and ongoing flooding have prompted a
Moderate Risk of Excessive Rainfall (level 3/4) across portions of
central to southeastern Indiana through this evening/tonight
(Thursday) as scattered to widespread flash flooding will remain a
threat. Additionally, the Storm Prediction Center has noted a
Slight Risk for severe weather (level 2/5) as some storms may
produce damaging winds or an isolated tornado. A much broader
Slight Risk of Excessive Rainfall (level 2/4) covers the rest of
the region in general for more scattered, possibly locally
significant instances of flash flooding. Another Moderate Risk has
now been issued for portions of south-central to southeastern Iowa
and northwestern Illinois for Friday where additional scattered to
widespread and possibly significant instances of flash flooding
can be expected, with another broad Slight Risk in place across
the region. A more focused Slight Risk is in place from the Upper
Mississippi Valley into the southern Great Lakes region Saturday
as the storm track shifts a bit north.

To the west, additional areas of storms with a heavy
rainfall/flash flood threat are also expected through the Interior
West and into the High Plains within the southwesterly flow along
the western side of the upper-ridge. The greatest storm coverage
and relative highest influx of moisture rounding the upper-ridge
will vary day-to-day as the flow adjusts ahead of an upper-trough
moving into the Northwest. However, at least isolated heavy
downpours/flash flooding can be expected throughout the region
through the next couple of days. Through this evening, the
greatest threat is expected across portions of the
central/southern High Plains as well as across portions of the
Southwest and Great Basin, where Slight Risks are in effect for
scattered instances of flash flooding. For Friday, the greatest
threat will concentrate along the central High Plains as well as
across portions of the Southwest, with additional Slight Risks in
effect. A Slight Risk continues for the central High Plains on
Saturday while the storm threat looks to decrease across the Great
Basin/Southwest and into the northern High Plains.

Elsewhere, daily rounds of scattered thunderstorms are forecast
from the Mid-Atlantic and into the Southeast and Florida.
Temperature-wise, conditions will be around to below average and
more mild for most of the country away from the heat wave over the
southern U.S. Forecast highs generally range in the 70s and 80s
from the Northeast west through the Great Lakes, Northern Plains,
and into the Interior West outside of the Deserts, where highs
into the 90s and low/mid-100s will be hotter but still below
average. Portions of the northern High Plains as well as much of
the West Coast will see the relatively coolest temperatures, with
highs only into the 60s.

Putnam

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




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