Today Through the Fourth Friday (22 to 28 days) Weather Outlook for the U.S. and a Six-Day Forecast for the World: posted September 16, 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
Mon Sep 16 2024
Valid 12Z Mon Sep 16 2024 – 12Z Wed Sep 18 2024…Potential Tropical Cyclone Eight will bring wind and heavy rain to the
Carolinas and Mid-Atlantic……A strong upper low will bring unsettled weather and well below normal
temperatures to the West with high elevation snow in the Sierra Nevada and
Intermountain West……Severe thunderstorms possible for the Northern and Central High Plains
Tuesday…While Francine’s remnants have been dissipating over the Southeast,
Potential Tropical Cyclone Eight has been strengthening off the Southeast
Coast. This disturbance is forecast to bring gusty winds and heavy rain to
portions of the Carolinas and Mid-Atlantic and dangerous coastal and beach
conditions to much of the Southeast and Mid-Atlantic coasts. The forward
motion of Potential Tropical Cyclone Eight will be slowed down by strong
high pressure over the Northeast, which will increase the chance of heavy
rainfall totals in the Carolinas today. Flash flooding will be a concern,
especially in the eastern Carolinas where the highest rainfall totals are
forecast, and flooding could have locally significant impacts. This
disturbance is forecast to gradually move north across the Carolinas into
the Mid-Atlantic, bringing a threat of locally heavy rainfall to the
region mid-week.In the West, a deep upper low will bring unsettled weather and well below
normal temperatures to the region this week. The upper low is accompanied
by a strong surface frontal system that will push east across the
Intermountain West today and into the Plains Tuesday afternoon. This
system will bring widespread precipitation chances and gusty winds to much
of the West. Precipitation will fall mainly in the form of showers and
thunderstorms, but temperatures will be cold enough for the high
elevations of the Sierra Nevada and Intermountain West to see some early
season snow. Winter Weather Advisories are in effect through this evening
for the Sierra Nevada above 8000 feet where up to 4 inches of snow may
fall, and Wind Advisories are in effect through this evening for portions
of the Southwest where wind gusts could exceed 45 mph.The surface low pressure system is forecast to strengthen in the lee of
the Rockies over Wyoming and Montana, and will bring a threat of scattered
severe thunderstorms to the northern and central High Plains Tuesday
afternoon and evening. The Storm Prediction Center has highlighted these
areas with a Slight Risk of Severe Thunderstorms (level 2/5), and the main
storm hazards will be severe wind gusts and hail. Showers and
thunderstorms will push east across the Plains Tuesday night and move
towards the Mississippi Valley on Wednesday.Temperatures will have a broad range across the United States over the
next few days. The deep upper low will result in well below normal
temperatures in the West through at least mid-week, with the coldest
anomalies over the Great Basin and California where high temperatures will
be as low as 15-25 degrees below normal. On the flip side, temperatures
will be well above normal in the Central U.S. and Northeast. High
temperatures will generally be in the 80s and 90s for these regions. Below
normal temperatures are also forecast for the Southeast and Mid-Atlantic
today and Tuesday due to expected precipitation and cloud cover, but
temperatures should return to near normal for these regions by Wednesday.