The Weather Prediction Center

Short Range Forecast Discussion

[Abbreviations and acronyms used in this product]
Geographic boundaries:    Map 1- [Color] [B/W Print Version]      Map 2 - [Color] [B/W Print Version]

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
415 PM EDT Sun Jul 22 2018

Valid 00Z Mon Jul 23 2018 - 00Z Wed Jul 25 2018

...Heavy rain and flash flooding to continue across the
Mid-Atlantic and Northeast...

...Unsettled weather expected across the central and eastern Gulf
of Mexico....

...Severe weather possible across the Northern and Central Plains
through tonight...

...Dangerous heat to continue across the southern central and
portions of the western U.S...

Several days of heavy rainfall are expected across the Mid
Atlantic and Northeast. Heavy rain will continue across the
coastal mid-Atlantic this evening as a low pressure system that
has been traversing northward up the mid-Atlantic Coast, falls
apart while moving inland this evening. Portions of the coastal
Mid Atlantic are under a moderate risk of excessive rainfall
through tonight, due to the threat of moderate to heavy rainfall
on top of already saturated soils from impressive rains that moved
through the region yesterday.

Meanwhile, an expansive frontal system that pushed across much of
the southeast over the last 24 hours has now slowed significantly
as it nears the Gulf of Mexico coast and extends northward into
the mid Atlantic. This frontal boundary is acting as the focus for
showers and thunderstorms across these regions. Much of Florida,
southern Georgia, and southern Mississippi remain in a slight risk
for severe thunderstorms this evening and overnight. A severe
thunderstorm watch has also been issued by the Storm Prediction
Center, valid until 8pm EDT this evening for this same area. A
slight risk of severe thunderstorms will be possible along
southern Louisiana and southern Alabama during the day Monday as
the frontal system becomes stalled along the coast. A strong surge
of easterly flow along the entire Atlantic coast over the next
several days will result in continued rain across this region.
Excessive rainfall and flash flooding are likely for these areas,
as has been outlined in the Days 2 and Days 3 Excessive Rainfall
Outlook issued by the Weather Prediction Center.

Another frontal system will slide across the northern High Plains
today--firing off convection along the boundary which will
continue into the overnight. Severe thunderstorms will be
possible, particularly from North Dakota southward into western
Nebraska--where the Storm Prediction Center has issued a slight
risk. By Monday, a plume of moisture will extend into the eastern
High Plains of Colorado and New Mexico where flash flooding could
occur along favorable terrain. Thunderstorms will also impact the
Central Great Basin and along the Sierra Nevada mountain range
over the next couple of days. These regions could also see
isolated flash flooding from this convective activity. 

Dangerous heat remains in place across the southern Plains, lower
Mississippi Valley, and much of the Southwest and far western
United States. This heat is expected to remain in place through
Monday across the southern Plains and Lower Mississippi Valley,
and through at least mid-week for the Southwest and much of the
western coast. Excessive heat watches, warnings and heat
advisories are currently in place across these regions. By
Tuesday, the Desert Southwest will see temperatures climb well
above 110 degrees--with places like Phoenix, AZ forecast to reach
117 degrees, Las Vegas, NV forecast to reach 114 degrees, and
locations in southern California nearing 120 degrees for highs. 


Graphics available at

Last Updated: 415 PM EDT Sun Jul 22 2018