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 February 21, 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.

The arrival of a large arctic air mass from Canada interacting with two
energetic troughs/fronts forecast to move through the western half of the
country will bring numerous weather hazards and highly anomalous
temperatures coast-to-coast this week with almost all of the country
experiencing some form of notable weather. First of all, snow will spread
south and eastward across the West followed by the northern tier of the
country into Wednesday as a trough deepens over the West as embedded
shortwave energy helps to push multiple frontal systems across the region.
Ample moisture associated with the Pacific fronts will combine with
increasingly warm and moist air streaming in from the Gulf of Mexico, and
then clash with the arctic air surging in from Canada to fuel heavy snow
rates. Snow totals of 1-2 feet, locally higher, are expected for most of
the mountain ranges across the West. The heavy accumulating snow should
be limited to higher elevations in the mountains, with a lighter rain/snow
mix for the interior valleys. Moderate to locally heavy rain as well as
some thunderstorms are forecast for the lower elevation/coastal Pacific
Northwest Tuesday. Snow will begin to mix in with the rain as temperatures
cool Tuesday night into Wednesday, and there is even a chance to see some
light snow in the central California valleys. In addition to the snow, a
deepening low pressure system over the Great Basin and multiple fronts
pushing through the West will bring widespread very strong, gusty winds of
50-60 mph, locally as high as 80 mph in favorable terrain locations, to
most of the West and adjacent High Plains through Wednesday. These winds
will lead to blizzard conditions for portions of the northern/central
Rockies, and areas of blowing dust across the interior Southwest to the
southern High Plains. Meanwhile, an elevated risk of fire weather is
forecast to continue for the southern High Plains through Wednesday in
stark contrast with the snowy and bitterly cold weather to the north.

An axis of heavy snow will expand eastward across the northern Plains and
into the upper Midwest/Great Lakes and interior Northeast/New England
through Wednesday as a strong low pressure system consolidates in the lee
of the Rockies and moves northeastward across the Plains then into
Midwest. Some locations across the Upper Midwest/Great Lakes will have
only a very brief reprieve from a clipper system exiting the region before
this next round of heavy snow moves in. There is a high probability of
snow totals over 8″ front South Dakota eastward through southern
Minnesota, northern Wisconsin, and the Upper Peninsula/northern Lower
Peninsula of Michigan. Locally higher totals of 1-2 feet are possible,
particularly across southern Minnesota. Heavy snow rates of 1-2″ per hour
and gusty winds producing areas of blowing snow will lead to treacherous,
potentially impossible travel conditions and possible power outages. By
Thursday, much of central New England will see snow streaming in from the
southwest as a low pressure wave develops along the slowing warm front
across the Mid-Atlantic. A zone of freezing rain and/or sleet can also be
expected farther south toward southern New England before a slow tapering
off trend sets in during the day on Thursday. Snow totals of 12″ or more
are also likely for higher elevations in the Interior Northeast including
the Adirondacks and the Green and White Mountains, with lighter
accumulations of around 2-4 inches at lower elevations across upstate New
York and central New England. A heavy wintry mix of snow, sleet, and
freezing rain is expected along the southern end of the snow axis across
the upper Mississippi Valley and into the lower Great Lakes. Ice
accumulations of 0.1-0.25″, locally higher, are possible, especially
across lower Great Lakes Wednesday into early Thursday. Meanwhile, the
upper Midwest should see snow and blustery conditions continuing as the
center of the main low tracks across the lower Great Lakes. Slow
improvement of these conditions should gradually spread from west to east
during the afternoon on Thursday.

Widespread showers and thunderstorms are forecast to develop near and
north of the low pressure system’s leading warm as a cold front transforms
into a dry line structure across west of the Mississippi Valley late
Tuesday night into Wednesday. Intense low-level and upper-level dynamics
as well as additional moisture streaming northward from the Gulf may lead
to some locally heavy rain rates. There is a Slight Risk of Excessive
Rainfall (level 2/4) from northeast Missouri into northern Illinois,
northern Indiana, and southern Michigan where there may be a few scattered
instances of flash flooding. It should be noted that uncertainty with the
location of the warm front could shift the location where the heavier,
convective rains transition to the heavy wintry mix expected just to the
north. Strong low-level, deep-layer shear and expected instability have
also prompted a slight risk of severe weather (level 2/5) from the Storm
Prediction Center from central Oklahoma northeastward through central
Missouri for the chance of some damaging winds.

Besides the numerous weather hazards expected this week, another major
story will be the significantly anomalous warm temperatures for February
over the East and cold temperatures over the West. Highs on Wednesday
will be 20-30 degrees above average for many locations across the southern
Plains, Midwest, and Southeast and 20-30 degrees below average over the
northern/central Plains and much of the West. Many record-tying/breaking
highs can be expected particularly for the Ohio/Tennessee Valleys, where
temperatures will be into the 70s, and closer to the Gulf Coast/Florida,
where highs will be into the 80s. Many record-tying/breaking minimum high
temperatures will also be possible over the West, with highs in the 30s
and 40s for the Pacific Northwest and in the 50s for California. Bitterly
cold wind chills 20-30 degrees below zero are expected for the Northern
Plains. These highly anomalous temperatures are forecast to continue
later into the week.

Unsettled weather is forecast to continue spreading farther south down the
West Coast on Thursday as additional upper-level energy digs southward off
the coast. Meanwhile, the Pacific Northwest will begin to clear out by
then as the arctic air mass settles into the region with low temperatures
dipping below freezing even at the coast. California will see rain
becoming more widespread during the day, with snow picking up in intensity
over the mountains, including the Sierra Nevada. Mixed rain and snow is
also expected to reach into the higher elevations of the interior
Southwest.

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)