The Nation’s Weather

…Thunderstorms and locally heavy rain over the southern Plains into th
Mid-South Monday…

…Cool temperatures persist for the central Plains to the Northeast…

…Warm/hot temperatures for the Gulf Coast region…

A wavy frontal boundary will meander in place from the southern Rockies
eastward through Texas/Oklahoma and into the Southeast. This separates
warm/hot temperatures to the south (80s/90s to low 100s over parts of
Texas) and much cooler temperatures to the north (60s/70s). For South
Texas, HeatRisk levels will approach Major/Extreme levels and record high
temperatures are possible (along with heat indices near and above 110F).
Showers and thunderstorms are favored at times near and south of the
frontal boundary on Memorial Day into Tuesday, especially in the
afternoon. Some areas may see heavier rain with localized flooding,
especially if those areas have seen rain in the past day or two. There is
a Slight Risk of excessive rainfall and flash flooding for northeastern
Texas into the Mid-South on Monday. The Storm Prediction Center also
denotes a Slight Risk for severe weather over parts of Texas on Monday,
with the main hazards being large hail and damaging winds in severe
thunderstorms. To the north of the front, scattered showers and perhaps
some thunderstorms are possible on Monday over the central Plains where
temperatures will be cooler.

By Tuesday, the heavier rainfall threat will move eastward but become less
focused. Isolated heavier rainfall along with some severe thunderstorms
are possible from Texas northeastward through the Southeast/Tennessee
Valley into the Midwest as an area of low pressure forms Tuesday morning
near Middle Tennessee. Showers will also spread to the southern
Appalachians which will remain cooler than normal due to the cloud cover
and easterly flow off the still cold Atlantic Ocean.

Into the Northeast, the long-lived system will finally pull away by
tomorrow with only isolated showers mainly in the mountains. Temperatures
will trend a few degrees warmer than on Sunday but will remain below
normal for late May — only in the 60s/70s. By Tuesday, temperatures will
continue to moderate through the 70s.

For the West, an incoming system will bring some light rain to the Pacific
Northwest and northern Rockies before weakening over Montana. Cooler
temperatures on Monday (60s/70s) will quickly rebound on Tuesday back to
above normal readings — 70s/80s.

Fracasso

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