…There is a Slight Risk of excessive rainfall over parts of the
Southwest and Great Basin on Wednesday and expanding into parts of the
Central/Southern Rockies on Thursday…
…There is a Slight Risk of severe thunderstorms over parts of the
Northern High Plains on Wednesday…
…There are Excessive Heat Warnings and Heat Advisories over parts of the
Southern Plains…
A front over the Northern Rockies will move slowly eastward to the
Northern Plains by Friday. The boundary will produce showers and severe
thunderstorms over northeastern Montana and northwestern North Dakota.
Therefore, the SPC has issued a Slight Risk (level 2/5) of severe
thunderstorms over parts of the Northern High Plains through Thursday
morning. The hazards associated with these thunderstorms are frequent
lightning, severe thunderstorm wind gusts, hail, and a minimal threat of
tornadoes. However, there is an increased threat of severe thunderstorm
wind gusts 65 knots or greater.
In addition, an upper-level low over the Northeast will help create rain
with an embedded thunderstorm over parts of the Northeast through
Thursday. Moreover, upper-level energy over the Middle Mississippi Valley
will move southeastward to the Southeast, developing a weak upper-level
low by Thursday evening. With ample moisture over the area, showers and
thunderstorms will develop over parts of the Southeast through Friday.
Furthermore, monsoonal moisture and upper-level energy will aid in
producing showers and thunderstorms with heavy rain over parts of Arizona
and southern Utah. Therefore, the WPC has issued a Slight Risk (level
2/4) of excessive rainfall over parts of the Southwest and Great Basin
through Thursday morning. The associated heavy rain will create mainly
localized areas of flash flooding, with urban areas, roads, small streams,
low-lying areas, narrow canyons/gullies, and burn scars the most
vulnerable.
On Thursday, the monsoonal moisture will extend farther northward over the
area. Likewise, the upper-level energy and monsoonal moisture will produce
showers and thunderstorms with heavy rain over parts of southeastern Utah,
northern Arizona, southwestern Colorado, and northwestern New Mexico.
Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive
rainfall over parts of the Southwest, Great Basin, and Central/Southern
Rockies from Thursday through Friday morning. The associated heavy rain
will create mainly localized areas of flash flooding, with urban areas,
roads, small streams, low-lying areas, narrow canyons/gullies, and burn
scars the most vulnerable.
Moreover, as the front over the Northern High Plains moves eastward on
Thursday, showers and strong to severe thunderstorms will develop over
parts of the Northern/Central Plains and the Central High Plains.
Therefore, the SPC has issued a Marginal Risk (level 1/5) of severe
thunderstorms over parts of the Northern/Central Plains and the Central
High Plains from Thursday into Friday morning. The hazards associated with
these thunderstorms are frequent lightning, severe thunderstorm wind
gusts, hail, and a minimal threat of tornadoes.
Elsewhere, as upper-level low moves southward along the Northwest Coast
will develop rain over parts of the Pacific Northwest through Friday.
Meanwhile, an upper-level high over the Southern Plains will allow high
temperatures to be in the upper 90s and low 100s, with dew points in the
upper 60s and low 70s, prompting Excessive Heat Warnings and Advisories
over parts of the Southern Plains. Additionally, with low temperatures in
the lower 80s and upper 70s, little relief from the heat will occur
overnight. Therefore, people spending more time or effort outdoors or in a
building without cooling in areas with heat warnings are still at an
increased risk of heat-related illness.
Ziegenfelder
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php