Today Through the Fourth Friday (22 to 28 days) Weather Outlook for the U.S. and a Six-Day Forecast for the World: posted June 20, 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
Thu Jun 20 2024
Valid 12Z Thu Jun 20 2024 – 12Z Sat Jun 22 2024…Heavy rain/flooding threats and gusty winds over South Texas gradually
decrease today as Tropical Storm Alberto makes landfall in Mexico and
dissipates……Heavy rain and flash flooding concerns increase across the northern
Plains to the upper Midwest later Thursday into Friday as scattered
thunderstorms could result in localized flooding issues from the southern
High Plains to the Four Corners……A heat wave will persist over the Great Lakes, Ohio Valley, and
portions of the Northeast into the weekend as heat intensifies in the
western U.S….Tropical Storm Alberto centered over the southwestern Gulf of Mexico has
begun heading west toward northern Mexico early this morning. Organized
bands of heavy rain extending north from the center have already brought
close to 10 inches of rain locally near the mid-Texas coast. As the heavy
rain bands continue to steadily move west through the Rio Grande Valley
into northern Mexico today, the heavy rain and flooding threats will
gradually decrease across South Texas. Strong and gusty winds will also
gradually weaken with time. Some of the tropical moisture from Alberto
will be drawn northward and energize the scattered showers and
thunderstorms from the southern High Plains to the Four Corners heading
into the weekend. These showers/storms will be more numerous during the
late afternoon to early evening hours in these areas.Meanwhile, the National Hurricane Center continues to monitor the
potential of tropical cyclone formation over the western Atlantic as a
tropical wave moves west-northwest in the general direction of
northeastern Florida and Georgia. Some enhanced rainfall with gusty winds
can be expected to reach these areas Thursday night and will likely linger
through much of Friday.Across the northern tier states, relatively less active weather is
expected today as a high pressure system brings cooler and more stable air
from Canada. However, the next piece of energy exiting the central
Rockies will set up the next episode of heavy rain and strong to severe
storms across the northern Plains to the upper Midwest beginning tonight.
A couple rounds of heavy rain focusing just north of a nearly stationary
front across the region will result in slight to moderate risks of
excessive rainfall from eastern South Dakota, across southern Minnesota
into western Wisconsin through Saturday morning. Farther east, scattered
thunderstorms are likely across the Great Lakes region and the Northeast
near and north of the stationary front. Marginal to slight risks of
severe storms are delineated each day from the Storm Prediction Center
(mainly for the threat of severe wind but with some low chances for hail),
and marginal risks of excessive rainfall are in place as well.All these rain and thunderstorm areas are taking place along the periphery
of an upper ridge/heat dome that edges from the Mid-Atlantic into the
Mid-South over the next couple of days and sustains a heat wave across the
Great Lakes, Northeast, and Mid-Atlantic. Afternoon high temperatures and
warm overnight lows will challenge daily records and even some monthly and
all-time records. Heat index readings are expected to peak from 100 to 105
degrees in many locations. Those without access to reliable air
conditioning are urged to find a way to cool down. Record warm overnight
temperatures will prevent natural cooling and allow the heat danger to
build over time indoors without air conditioning. Temperatures may be
lower and less hazardous closer to the coast if/where sea breezes form. By
Friday, conditions should improve over New England as cooler air dips a
bit farther south into the area behind a front, but temperatures well into
the 90s and higher heat indices are forecast to continue across the Ohio
Valley to Mid-Atlantic. Meanwhile, cooler than average highs are likely
into the southern High Plains with the clouds and rain forecast, but
temperatures over the West will gradually rise above normal Thursday and
Friday. In the western U.S., it appears that the heat will increase by
Saturday as triple-digit high temperatures are forecast for the Central
Valley of California and the Great Basin.