…Major to locally extreme Heat Risk will expand across the northern High
Plains as heat gradually becomes less intense over the Central Valley of
California and the Great Basin…
…Scattered showers and thunderstorms will affect a large section of the
eastern half of the U.S. with heavy rain emerging near the Texas coast on
Wednesday…
…Monsoonal thunderstorms continue across the Great Basin and into the
Four Corners region with threat of localized flash flooding…
A slow-to-evolve summertime weather pattern will continue across much of
the U.S. mainland as a more progressive Pacific cold front sweeps across
the northwestern part of the country through the next couple of days.
Under this weather pattern, unsettled weather and relatively cool
temperatures for July will continue across the eastern half of the country
as the ongoing heat wave over the western U.S. will gradually become less
intense with the arrival of the Pacific cold front. The stronger forcing
associated with this front will push the heat dome east of the Great
Basin, resulting in the expansion of major to locally extreme Heat Risk
across the northern High Plains through the next couple of days. High
temperatures are forecast to reach well up into the 100s over the northern
High Plains through Thursday with little to no rainfall expected.
Meanwhile, the heat will gradually become less intense over the Central
Valley of California and the Great Basin with time. Please continue to
practice heat safety in the western U.S. and as the heat spreads into the
northern High Plains.
In contrast, cooler than normal temperatures will prevail across the
mid-section of the country and into portions of the eastern U.S. where a
stalled front will keep plenty of clouds along with scattered
thunderstorms. These thunderstorms are not expected to be potent but they
could result in localized flooding issues from time to time across the
southern tier states and up and down the East Coast. A slight risk of
flash flooding is anticipated for areas just inland from the western Gulf
states for today from Texas to central Mississippi. By Wednesday, a
coastal front could set off heavy rain and thunderstorms near the Texas
coast into southwestern Louisiana where flash flooding is possible.
Farther north, another cold front from eastern Canada dipping into the
northern tier states will bring additional thunderstorms across the Great
Lakes to New England through Wednesday. By Thursday morning, the Great
Lakes should clear out from the rain but northern New England will see an
increasing chance of showers and thunderstorms as a low pressure wave
approaches from the west. Meanwhile, monsoonal thunderstorms will
continue across the Great Basin and the Four Corners region with the
threat of localized flash flooding for the next couple of days.
Kong
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php