…Record heat continues into the end of the week across the Southern
Plains…
…There is a Slight Risk of excessive rainfall over parts of the
Southwest, Great Basin, and Central/Southern Rockies on Thursday…
…Record cold develops across California Friday into Saturday…
…There are Excessive Heat Warnings and Heat Advisories over parts of the
Southern Plains…
A front over the Pacific Northwest Coast will move slowly eastward to the
Northern High Plains to the Great Basin and then into Southeastern
California by Saturday. The boundary will be on the leading edge of an
upper-level trough, bringing colder temperatures in the mid-70s to
California. The associated upper-level low will develop rain over parts of
the Pacific Northwest and Northern California through Saturday.
Furthermore, monsoonal moisture and upper-level energy will aid in
producing 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 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.
The threat of excessive rainfall will decrease slightly over the Four
Corners Region on Friday. However, there will still be a threat of heavy
rain. Therefore, the WPC has issued a Marginal Risk (level 1/4) of
excessive rainfall over parts of the Southwest, Great Basin, and
Central/Southern Rockies from Friday into Saturday morning. The
associated heavy rain will create localized areas of flash flooding,
affecting low-lying areas, narrow canyons/gullies, and burn scars that
experience rapid runoff with heavy rain.
Additionally, a second front extending from the Northern Plains to the
Great Basin will move northward as a warm front over the Northern Tier
States by Saturday. On Thursday, the boundary will produce showers and
thunderstorms over parts of the Northern/Central Plains into parts of the
Upper Mississippi Valley. The showers and thunderstorms will expand into
parts of the Upper Great Lakes and Middle Mississippi Valley on Friday.
Moreover, another upper-level low over the Northeast will help create rain
with an embedded thunderstorm over parts of the Northeast through late
Thursday night. Further, an area of upper-level energy moving into the
Southeast will develop a weak upper-level low by Thursday evening. With
ample moisture over the area and a lingering boundary, showers and
thunderstorms will develop over parts of the Southeast through Saturday.
Additionally, upper-level energy trapped under an upper-level high and
moisture moving northward off the Gulf of Mexico will create scattered
showers and thunderstorms over parts of the Southern Plains through
Saturday.
Meanwhile, the 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
