…A dangerous heatwave to continue across portions of the Southwest into
California and from the Southern Plains into the South…
…Heavy rains, flash flooding and severe thunderstorms possible over the
next few days across portions of the Plains, Lower Missouri Valley and
Middle to Upper Mississippi Valley…
Two strong upper level highs, one stretching from the Southern Plains into
the South and another building along the West coast will be the drivers
for the continuation of a dangerous heatwave across much of California
into the Southwest and from the Southern Plains into the South. Excessive
Heat warnings and heat advisories are currently in effect across these
regions where the combination of hot temperatures and high relative
humidities will produce potentially major to extreme heat impacts over the
next few days. Record high temperatures are possible through the interior
valleys of California over the next few days, with the potentially record
heat then expected to expand into the Pacific Northwest by the end of this
week and weekend. While there are not expected to be many record high
temperatures with the Southern Plains to South portion of the heatwave,
much more numerous record warm minimum temperatures are possible across
these areas, exacerbating the effects of the heatwave as there is less
chance to cool off significantly at night. Currently over 80 million
people are under some form of heat warning or advisory across the nation,
with this number likely to remain near this level or increase as we go
into the middle and later part of the holiday week.
In addition to the heat risks across portions of California, the Southwest
and the Southern Plains with the ongoing heatwave, fire risks will also be
threat across these areas given the combination of hot temperatures, low
relative humidities and very low chances of any precipitation.
While much of the country will see temperatures above average over the
next few days, areas from the Northern Rockies into the Northern and
Central Plains will see cooler than average temperatures. High
temperatures across these regions are forecast to be 10 to 15 degrees
cooler than average.
While heat will keep a gripe on large portions of the West and South,
stormy weather will continue across portions of the Plains into the Lower
Missouri Valley and Middle to Upper Mississippi Valley. An initial round
of heavy rains, flash flooding potential and severe thunderstorms are
forecast to affect areas from the Upper Great Lakes into the Upper to
Middle Mississippi Valleys and Lower Missouri Valley late Tuesday
afternoon into Tuesday night/early hours of Wednesday. This will be
followed by potential for another round of active thunderstorms to push
east Wednesday afternoon from the Central Plains and into the Lower
Missouri/Middle Mississippi Valleys Wednesday night into the early hours
of Thursday. Soil moisture values are above average across the Upper to
Middle Mississippi Valley/Lower Missouri Valley regions from rains over
the past several weeks, leading to increasing flash flood risk as
multiple rounds of additional heavy rains push across these regions over
the next two days.
Oravec
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
