…A break in the heat continues for much of the Heartland but dangerous
heat will build across the interior Pacific Northwest this weekend and
into next week…
…Scattered thunderstorms continue across the South and Southeast as
monsoonal thunderstorms linger across the Four Corners region…
…Scattered thunderstorms over the central Plains today will gradually
shift into the southern Plains by Monday while a cold front will bring new
rounds of thunderstorms across the northern tier states…
An cooler than normal air-mass that has settled in throughout much of the
Heartland will stick around not only for the remainder of the weekend but
into the first half of the upcoming week. After seeing some parts of the
Lower Missouri River Valley registering daytime highs only in the 70s, a
cold front will continue to advance south tonight through the Southern
Plains. By Sunday, daytime highs in the 70s and 80s (as low as 15 to 20
degrees below normal in the southern High Plains) will be common from
central New Mexico to as far east as the Middle Mississippi River Valley.
Meanwhile, a stalled frontal boundary over the Mid-South is responsible
for daily rounds of showers and storms. The expansive cloud cover
throughout the South will keep daytime highs capped generally in the
mid-upper 80s, which is several degrees below normal (lone exception is
Florida and south Texas where highs will be in the 90s on Sunday). The
footprint of unusually cool temperatures for late July will persist in the
Southern and Central Plains through Monday.
While cooler than normal temperatures envelope much of the Heartland,
dangerous heat will be a mainstay in the West through early next week. The
experimental HeatRisk product depicts Major to Extreme heat risks from
parts of the Lower Colorado River Valley and Mojave Desert to as far north
as the Snake River Plain and Columbia River Basin. Some daily record highs
and warm minimum temps are likely to be broken in these areas with the
interior Northwest most likely to witness the bulk of the record heat.
Major HeatRisk levels return to California’s Great Valley by Monday and
look to expand throughout the center of the Golden State by Tuesday.
Overall, these areas can expect highs in the 90s to 100s with little
relief overnight thanks to lows in the 60s and 70s. Those in affected
areas should stay hydrated, limit outdoor activities, and use fans when
air conditioning is not available.
This stagnant weather pattern will make for a stormy southern tier of the
U.S. into next week. An elongated frontal boundary will spark numerous
showers and storms from the Southern Rockies and Plains to the Southeast
and Mid-Atlantic through Monday. Today, SPC does have a couple Marginal
Risk areas(threat level 1/5) in the Southeast and in both the Southern and
Central High Plains. However, an unusually high concentration of moisture
aloft is supporting a rather wide area for Excessive Rainfall potential.
WPC has issued a couple Slight Risks (threat level 2/4) for parts of the
southern Mid-Atlantic and in both central New Mexico and southeast
Arizona. A Marginal Risk (threat level 1/4) for Excessive Rainfall include
much of the Four Corners region, the central Plains, and the Southeast.
This will be a common theme for both Sunday and Monday with Slight Risks
posted in parts of the Southwest on Sunday and in both the Southern
Rockies and Southern Plains. The Marginal Risk areas each day are
expansive, encompassing much of the Southern U.S. and portions of the
southern Mid-Atlantic. Lastly, a frontal system will trigger scattered
showers and storms across parts of the Midwest this afternoon and Sunday.
Hit-or-miss showers and storms will remain in the forecast across the
Midwest and Great Lakes early next week.
Mullinax
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
