Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
333 AM EDT Thu Jul 29 2021
Valid 12Z Thu Jul 29 2021 - 12Z Sat Jul 31 2021
...There is an Enhanced Risk of severe thunderstorms over parts of the
Mid-Atlantic through Friday morning...
...There is a Slight Risk of excessive rainfall over parts of the
Southwest, Great Basin, and the Central Rockies through Friday morning and
again on Friday into Saturday morning...
...Heat Advisory over parts of the Middle/Lower Mississippi Valley and
adjacent Plains as well as the Pacific Northwest; Excessive Heat Warning
over parts of the same areas...
A front extending from the Mid-Atlantic westward to the Northern Rockies
will settle southward to the Southeast northwestward to the Central Plains
and Central Rockies by Saturday. Moisture pooling along the boundary and
strong dynamics will aid in producing showers and thunderstorms across the
region. Therefore, the SPC has issued an Enhanced Risk of severe
thunderstorms over parts of the Mid-Atlantic and a Slight Risk from the
Mid-Atlantic to the Middle Mississippi Valley through Friday morning. The
hazards associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. The severe
thunderstorm threat will reduce slightly on Friday into Saturday over the
southern Mid-Atlantic and the Middle Mississippi Valley. In addition,
there is a threat of heavy rain with these thunderstorms through Saturday,
too. Additionally, tropical moisture over the Gulf Coast into parts of the
Southeast will produce daily showers and thunderstorms through Saturday.
Meanwhile, showers and thunderstorms will continue over the Southwest,
Central/Southern Rockies, and Great Basin through Saturday.
The monsoonal moisture streams back into the Southwest as strong
upper-level energy and other impulses passes over the region on Thursday
into Saturday. Therefore, the WPC has issued a Slight Risk of excessive
rainfall over the Southwest and parts of the Central Rockies on Thursday
into Friday morning. The associated heavy rain will create mainly
localized areas of flash flooding, with urban areas, roads, and small
streams the most vulnerable through Friday morning. On Friday into
Saturday, the excessive rainfall threat increases with a Slight Risk
threat moving into more of the Great Basin and Central Rockies.
Two areas across the lower forty-eight will have heat problems; there is
an Excessive Heat Warning over parts of Oregon and the Middle
Mississippi/Tennessee Valleys and adjacent regions, where temperatures
will be above average. Furthermore, Heat Advisories are currently in
effect for portions of the Pacific Northwest/Northern California and over
Middle/Lower Mississippi/Tennessee Valleys and adjacent Plains. Moreover,
several regions have Air Quality Alerts due to wildfires over the
Northwest into the Northern Rockies and Upper Midwest.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php