Today Through the Fourth Friday (22 to 28 days) Weather Outlook for the U.S. and a Six-Day Forecast for the World: posted February 18, 2024
It is difficult to find a more comprehensive Weather Outlook anywhere else with the ability to get a local 10-day Forecast also.
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 update can be found here if I have not updated it.
Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sun Feb 18 2024
Valid 12Z Sun Feb 18 2024 – 12Z Tue Feb 20 2024…There’s a Moderate Risk of Excessive Rainfall leading to Flash Flooding
over portions of Southern California……Heavy Snow likely over Sierra Nevada and Shasta Siskiyous…
…Warming trend continues across Central U.S. through midweek…
A closed upper-level low will direct a plume of subtropical moisture into
California over the next few days. A low pressure system at the surface
will focus the moisture along its attendant surface fronts as it makes
it’s way into the state. Heavy Rainfall is expected for the coastal areas
as well as much of the inland valleys of northern/central California and
into the windward foothills of the Sierra beginning this evening. Some
instability will work it’s way into portions of southern California
tonight and continue into Monday morning, which will lead to the chance
for thunderstorms and increased rain rates. Thus, a Moderate Risk of
Excessive Rainfall leading to Flash Flooding (level 3/4) is in effect for
portions of Santa Barbara County tonight and expanding into Ventura on
Monday as the heavy rain drifts southward along a cold front. Slight Risks
(level 2/4) are in effect for Humboldt down to Ventura today and then
expanding down to Orange through Tuesday.Meanwhile, heavy snow will develop over the Sierra and Shasta Siskiyous
tonight. This snowfall is expected to continue into Tuesday when the
Pacific moisture feed is likely to end. Between 2-4 feet of snow are
forecast for the Sierra and Shasta by Tuesday morning with locally higher
amounts possible. Elsewhere, a stalled out surface front will focus
showers and thunderstorms across the Florida Peninsula today. A stripe of
1-2 inches of rain is probable across central/southern portions of the
peninsula. Lake effect snow showers continue downwind of the Great Lakes
through Sunday night. An upper ridge with embedded shortwave energy will
support a warming trend across the Great Plains, Mississippi Valley and
Midwest over the next several days.