Today Through the Fourth Friday (22 to 28 days) Weather Outlook for the U.S. and a Six-Day Forecast for the World: posted August 18, 2024
This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks and a six-day World weather outlook which can be very useful for travelers.
First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.
Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sun Aug 18 2024
Valid 12Z Sun Aug 18 2024 – 12Z Tue Aug 20 2024….There is a Slight Risk of excessive rainfall over parts of the
Mid-Atlantic on Sunday……There is a Slight Risk of severe thunderstorms over parts of the
Mid-Atlantic to Southeast/Lower Mississippi Valley on Sunday……There are Excessive Heat Warnings and Heat Advisories over parts of the
Southern Plains and Lower Mississippi Valley…A front extending from the Lower Great Lakes/Ohio Valley across the
Tennessee/Lower Mississippi Valleys and then to the Central High Plains
will move off most of the Eastern Seaboard Atlantic while lingering over
the Southeast and southward off most of the Gulf Coast and then across
parts of the Southern Plains by Tuesday. The boundary will produce showers
and severe thunderstorms from the Mid-Atlantic, Southeast, and Gulf Coast
States. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe
thunderstorms over parts of the Mid-Atlantic to Southeast/Lower
Mississippi Valley through Monday morning. The hazards associated with
these thunderstorms are frequent lightning, severe thunderstorm wind
gusts, hail, and a few tornadoes.Also, the showers and thunderstorms produced by the boundary will create
heavy rain over parts of the northern Mid-Atlantic. Therefore, through
Monday morning, the WPC has issued a Slight Risk (level 2/4) of excessive
rainfall over parts of the northern Mid-Atlantic. The associated heavy
rain will create mainly localized areas of flash flooding, with urban
areas, roads, small streams, and low-lying areas the most vulnerable.Additionally, an upper-level low just off the Northwest Coast will produce
rain, with maybe an embedded thunderstorm over parts of the Pacific
Northwest on Sunday. Furthermore, upper-level energy moving over the top
of an upper-level ridge over the Central Plains will produce showers and
thunderstorms over parts of the Central/Southern Plains on Sunday.Moreover, monsoonal moisture and daytime heating will create showers and
thunderstorms over parts of the Southwest, Eastern Great Basin, and
Northern/Central Rockies from late afternoon into late evening on Sunday
and Monday.On Monday, showers and thunderstorms will develop over parts of the
Northeast, Mid-Atlantic, and Southeast. While, upper-level energy will
trigger showers and thunderstorms over parts of the Central/Southern
Plains and Lower Mississippi Valley. Further, disorganized upper-level
energy over the Northern Rockies into the Northern Plains will produce
showers and thunderstorms over the region.Meanwhile, upper-level ridging over parts of the Southern Plains and Lower
Mississippi Valley will produce high temperatures in the low-100s with dew
points in the low to mid-70s, which have prompted Excessive Heat Warnings
and Heat Advisories over parts of the Southern Plains and Lower
Mississippi Valley. The sweltering summer heat will continue over the
south as the prolonged stretch of high temperatures in the triple digits
will focus on portions of the Southern Plains and Gulf Coast through
Tuesday. Low temperatures in the low-80s/upper-70s are also forecast along
the Gulf Coast, providing little relief from the heat overnight. Moreover,
the combination of summer heat and high humidity will support daily
maximum heat indices near 110F. Therefore, people spending more time or
effort outdoors or in a building without cooling are at an increased risk
of heat-related illness.