Weather Forecast: Today, Tonight, Tomorrow, Next Day, Five Days, and Intermediate-Term Outlooks for the U.S. and a Five-Day Forecast for the World: posted March 8, 2023

First, the 48-Hour Forecast (It is a 48 to 72 Hour Forecast actually)

Daily weather maps. I try to keep the below three maps updated. The Day 1 map updates twice a day and the Day 2 and 3 maps update only once a day. I will be doing the updating during the period described in the title of the article but if you happen to read this article later, you can get updates by clicking HERE

TODAY (or late in the day the evening/overnight map will appear)

TOMORROW

 NEXT DAY

This animation shows how things may play out over the next 60 hours. To update click here.

ATMOSPHERIC RIVERS

This tells us what is approaching the West Coast. Click HERE to update If I have not gotten around to doing the update.   Here is some useful information about Atmospheric Rivers.

Continuation of the NWS Short Range Forecast. It is updated by NWS twice a day and these updates can be found here. We post at least one of those updates daily, sometimes both. The Highlights are shown in the lede paragraph of this article.

A multi-day heavy rain and flash flood threat is expected to continue over
portions of the Southern Plains and Lower Mississippi Valley Wednesday and
Thursday after an initial round of heavy rain late Tuesday night. A
quasi-stationary surface boundary sits beneath southwesterly flow aloft
with ample moisture flowing in from both the Gulf of Mexico and an
additional stream sourced from the Pacific. A shortwave passing over the
region is forecast to trigger another round of thunderstorms Wednesday
afternoon and evening. Finally, a cold front will help to initiate a final
round of thunderstorms late Thursday. Marginal Risks (level 1/4) of
Excessive Rainfall have been issued for both Wednesday and Thursday from
southern Oklahoma/northern Texas into southern Arkansas as a chance of
isolated regions of flash flooding will be possible as a result of
repeated instances of thunderstorms. There will be quite a stark contrast
in temperatures north and south of this stationary boundary, with highs
generally in the upper 70s and 80s to the south over Texas and the Lower
Mississippi Valley. Some highs may reach the low to mid-90s along and near
the Rio Grande. On the other hand, highs will be in the 40s and 50s to the
north over portions of the Central Plains and Middle-Mississippi Valley.
Temperatures in the Southern High Plains appear more likely to recover
Wednesday as the boundary lifts north of the area, bringing warm air into
portions of the Southern Plains. A cold frontal passage late Thursday
evening will bring more seasonable temperatures across the South Plains on
Friday.

On a broader scale, conditions across the West and Plains will be cooler
and more unsettled than the East as this winter’s dominant pattern of
upper-level troughing over the West with downstream ridging to the east
continues. A persistent storm system lingering off the northwest Pacific
coast and upper-level energy rotating around the trough in place will
result in nearly continuous lower elevation valley/coastal rain and higher
elevation mountain snow chances for the Pacific Northwest and northern
California before an even more impactful Atmospheric River approaches
Thursday. Some thunderstorms will be possible along the coast, with
chances of light snow for some valley locations, especially Wednesday
night along the I-5 urban corridor of the Northwest. Additional snow
showers are possible for the Northern/Central Rockies Wednesday as a
lingering surface boundary remains draped across the region and the
upper-level energy passes through. Forecast precipitation markedly
increases on Thursday with the arrival of the Atmospheric River, raising
snow levels and bringing the threat for heavy rainfall and flooding
portions of the West. A Moderate Risk (level 3/4) of Excessive Rainfall is
in effect on Thursday and Friday over central coastal California and the
central interior valleys as the threat of several inches of heavy rain,
including some areas of higher terrain with a snowpack, will impact the
area. Rainfall at higher-elevations may contribute to rapid snowmelt,
which may lead to numerous flooding instances downstream. At higher
elevations in the mountains, 12″+ of snow will be possible for portions of
the Cascades and Sierra, with additional heavy snowfall also forecast for
the Blue Mountains of Oregon and Snake River Ranges in Idaho. Temperatures
on Wednesday and Thursday will be unseasonably cool over most of the West.
High temperatures will be in the 20s and 30s for the Northern/Central
Rockies, 30s and 40s for the Great Basin, 40s for the Pacific Northwest,
and 50s and 60s for much of California. Portions of the Southwest and
Southern Rockies will be comparatively warmer, with temperatures
maximizing in the 60s and 70s for much of the region.

Light snow showers over the Northern Plains/Upper Midwest and a wintry
mix/rain for the Central Plains will linger through the day Wednesday
before a more potent shortwave approaches from the west, helping to better
organize the frontal system currently over the Plains and increase
precipitation chances overall. The chances for locally heavier snow are
highest for the western Dakotas late Wednesday night and into the day
Thursday, which will stretch into the Upper Midwest on Thursday. Some
gusty winds may lead to a few areas of blowing snow and difficult travel
conditions. Further east, some light snow showers will be possible for the
Interior Northeast, but otherwise conditions will be mostly dry for the
East Coast through Thursday. High temperatures during the latter half of
the week will generally be seasonable with temperatures in the 30s and 40s
for New England/the northern Mid-Atlantic, 50s and 60s for the southern
Mid-Atlantic and the Carolinas, and 60s and 70s for the Southeast and
Florida. The system over the Midwest will begin to push towards the
Appalachians/East Coast late Thursday night/early Friday morning,
increasing precipitation chances towards the end of the current forecast
period. The initial burst of precipitation may fall as snow along the I-95
corridor, but accumulations will be light the mode of precipitation
changes to rain. There also may be some light ice accumulations at higher
elevations, particularly in the northern Appalachians.

Below is the current five-day cumulative forecast of precipitation (Updates can be found HERE)

Now we look at Intermediate-Term “Outlook” maps for three time periods. Days 6 – 10, Days 8 – 14, and Weeks 3 and 4.  An outlook differs from a forecast based on how NOAA uses these terms in that an “outlook” presents information as deviation from normal and the likelihood of these deviations.

Below are the links to obtain updates and additional information. They are particularly useful if you happen to be reading this article significantly later than when it was published. I always try to provide readers with the source of the information in my articles.

Temperature month to date can be found at https://hprcc.unl.edu/products/maps/acis/MonthTDeptUS.png

Precipitation month to date can be found at  https://hprcc.unl.edu/products/maps/acis /MonthPNormUS.png

Worldwide Tropical Forecast (This is a NOAA Product)