Weather Thursday June 27 2024 Fair in the Northeast ... Rain over the southeast... delays in Atlanta Dry Texas and California

Monsoon-like conditions persist for the Four Corners Region...
...There is an Enhanced Risk of Severe Thunderstorms across portions of
the Northern/Central Plains on Thursday...
An upper-level trough will move into the Canadian Maritimes, while an
upper low glides across the Northwest and an upper ridge expands across
the southern tier of the country late this week. Scattered thunderstorm
activity is forecast to develop along a surface front extending from the
Northeast/Ohio Valley down to the Lower Mississippi Valley and back up
into the Great Plains. The Storm Prediction Center issued Slight Risks of
Severe Thunderstorms for portions of the; Ohio Valley, Northeast and
Mid-Atlantic; ArkLaTex and Lower Mississippi Valley; and the
Central/Southern High Plains tonight. Damaging winds will be the main
concern in the Northeast while hail and gusty/damaging winds may cause
issues in the High Plains. Some storms in the Ohio Valley could produce
high enough rain rates to generate flash flooding tonight. Thus, there's a
Slight Risk (at least 15%) of Excessive Rainfall for portions of the
favored terrain of the Central Appalachians, eastern Ohio, western
Pennsylvania and northwestern Ohio. Monsoonal moisture will continue
flowing into the Four Corners region tonight with mid-level energy aloft
enhancing potential for thunderstorms and heavy rainfall. There's a Slight
Risk (at least 15%) of Excessive Rainfall leading to Flash Flooding for
portions of northeastern Arizona and much of New Mexico, as a result.
The focus for Severe Weather and Flash Flooding shift into the Great
Plains and Mississippi Valley on Thursday. The once stationary front
draped over the Great Plains will turn warm and move into the Northern
Plains. A deepening surface low pressure system beneath a potent
upper-level low will promote scattered thunderstorm activity across the
Northern/Central Plains throughout the day. Storms should pick up in
intensity by Thursday afternoon/evening. SPC issued an Enhanced Risk
(level 3/5) of Severe Thunderstorms across portions of eastern Montana,
western Dakotas, northeastern Wyoming, western Nebraska and northeast
Colorado, where wind gusts exceeding 80 mph, large hail greater than 2.5
inches and a couple of tornadoes will be possible. There's isolated
potential for Excessive Rainfall over parts of the Northern Plains and
Lower Missouri Valley where Slight Risks are in effect. Monsoon conditions
are expected to continue over the Four Corners with a Slight Risk of
Excessive Rainfall in effect for portions of western Colorado down into
northwestern/central New Mexico. Some slow moving pieces of mid-level
energy will slowly make its way across the Carolina coast and promote
Severe Storm potential early Thursday evening.
Diffluent energy associated with the upper-level low moving through the
Northern Plains will help advance the strong surface low pressure system
into the Mississippi Valley on Friday. A rising warm front out of the
south will promote additional thunderstorm activity across the
Upper/Middle Mississippi Valley. Excessive Rainfall and Severe
Thunderstorm chances pick up over parts of the aforementioned areas Friday
evening. Temperatures remain below average across the South while below
average conditions expand over the Northern Plains behind the cold front
this weekend.