The Nation’s Weather

…Showers and thunderstorms expected to reach the Desert Southwest
tonight and then the Four Corners on Monday with a risk for flash
flooding…

…A round of rain expected for the northern Rockies/High Plains tonight
into Monday morning with gusty winds…

…Heavy rain and severe thunderstorms expected to impact the Northern
Plains on Monday, then across the Central Plains later on Monday into
Tuesday morning with gusty winds…

…Tropical moisture lingering and becoming more focused across South
Florida…

June 2025 will begin with an anomalously deep low pressure system
departing New England as increasingly unsettled weather is forecast to set
up across the Southwest Sunday into Monday, and then across the
mid-section of the country Monday into Tuesday. As the deep cyclone
gradually moves further into southeastern Canada today, rain across
interior New England will continue to taper off. The size and proximity
of this system will continue to bring gusty winds through much of the
Northeast for today while funneling in much cooler air into the region
from Canada.

Farther south, scattered thunderstorms are expected across the
south-central Plains today associated with a forming frontal boundary
trailing from a weak low pressure wave. Some of the thunderstorms will
also extend farther east across the Tennessee Valley into the southern
Mid-Atlantic region in association with the eastern extension of the
front. These activities are expected to largely dissipate by tonight as a
cool and more unstable high pressure system settles and dominates the
eastern U.S. by Monday.

While the eastern U.S. enjoys cool and mostly fine weather, an
increasingly unsettled weather pattern is setting up across the western
U.S. A strong cold front arriving from the Pacific is bringing an end to
the recent spell of heat across the northwestern part of the country.
This front will gradually push into the northern Plains on Monday before
colliding with moisture streaming up from Mexico and the southern Rockies
to produce a around of heavy rain and severe thunderstorms across the
mid-section of the country Monday into Tuesday. The moisture coming from
Mexico is associated with an upper-level low which carries some of the
remnant moisture from former eastern Pacific tropical storm Alvin. This
batch of moisture is expected to bring a around of showers and scattered
thunderstorms across the Desert Southwest tonight and then move into the
Four Corners on Monday where locally terrain-enhanced rainfall could pose
a risk for flash flooding. The northern piece of moisture is associated
with the Pacific cold front mutually interacting with a high pressure
system building south from western Canada. This interaction is forecast
to bring a round of rain for the northern Rockies into the northern High
Plains tonight into Monday morning with gusty winds.

Monday will likely find a low pressure system developing over the central
High Plains with a sharp front extending across the northern Plains. The
dynamics associated with the sharp front will trigger showers and possibly
severe thunderstorms which are expected to form over the central High
Plains Monday evening, then spreading rapidly eastward across the northern
Plains through Monday night into Tuesday morning behind the sharp front.
Heavy downpours associated with these storms can result in flash flooding
issues. In addition, these storms can produce very large hail and
damaging winds. Blustery north to northwestern winds behind the front will
usher much cooler air into the central Plains Monday night to dispel the
near-record high temperatures in the upper Midwest Monday afternoon.
Scattered thunderstorms will also be active farther south ahead of a dry
line where severe thunderstorms are also possible down across the southern
High Plains Monday evening/night.

Across the Sunshine State, tropical moisture in the vicinity of a stalled
front is forecast to linger and gradually become more focused across South
Florida where heavy rain becomes possible by later on Monday.

Kong

Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php