Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Wed Mar 29 2023

Valid 12Z Wed Mar 29 2023 - 12Z Fri Mar 31 2023

...Storm system brings more heavy rainfall/mountain snow to the West with
cooling temperatures...

...Snow squalls possible over the Interior Northeast on Wednesday...

...Precipitation chances increase over the Midwest and Plains Thursday
with a Critical Risk of Fire Weather for the Central/Southern High
Plains...

A frontal system will continue to move through the West Wednesday-Thursday
with accompanying heavy rainfall in California and moderate to locally
heavy snowfall in the mountains as Pacific moisture overspreads the
region. Rainfall totals in California Wednesday will likely be lower than
Tuesday and with prior systems that have impacted the region. However,
given the very wet antecedent conditions, there is a Marginal Risk of
Excessive Rainfall (level 1/4) along the coast as a couple rounds of
storms with moderately heavy rain rates may lead to some localized
flooding concerns in terrain sensitive and urban areas. Moderate to
locally heavy snow is also forecast to continue for the Sierra and higher
elevation mountain ranges across the Great Basin Wednesday, spreading into
the Northern and Central Rockies on Thursday. Little to no snow
accumulations are currently forecast for most lower elevation valley
locations, though there is a chance for a few inches of snow in the
Northern High Plains Thursday. Winds will also be quite gusty Wednesday as
the Pacific front pushes through the Interior West, with wind-related
advisories out from southern California into the southern Great Basin and
Desert Southwest. These high winds are forecast to continue into the
Southern Rockies on Thursday, with gusts upwards of 70 mph possible. Well
below average highs in the 40s and 50s for the western Great Basin and
California Wednesday will spread further east into the eastern Great Basin
Thursday following the passage of the Pacific front, with highs dropping
into the 60s for the Desert Southwest. Highs will remain more seasonable
in the Pacific Northwest, with 50s and 60s forecast.

Meanwhile, a fast moving upper-level shortwave and accompanying surface
cold front will pass through the Interior Northeast Wednesday bringing a
chance of snow showers. While any snow accumulations are not expected to
be particularly high, the snow that does fall is expected to come with
snow squalls producing brief very heavy snow rates and gusty winds,
leading to rapid onset whiteout conditions and dangerous travel. In
addition, there is the potential for a flash freeze as temperatures
quickly fall behind the cold front, leading to icy roads and slippery
conditions. Generally seasonable high temperatures in the 40s and 50s for
New England and the 50s and 60s for the Mid-Atlantic Wednesday will fall
into the 30s and 40s for New England and the 40s and 50s for the
Mid-Atlantic Thursday.  Temperatures will remain well below average and
quite chilly in the presence of a cold Canadian airmass behind the front
over the Northern Plains and Upper Great Lakes. Highs on Wednesday are
forecast to only reach the 20s and 30s, with lows Thursday morning falling
into the single digits for many locations. A warm front moving northward
into the region will significantly warm up temperatures from South Dakota
eastward into the Lower Great Lakes, with highs into the 50s and 60s,
while temperatures remain frigid to the north.

The frontal system pushing through the West will enter the High Plains
Thursday afternoon as a lee cyclone organizes over the Central High
Plains, with a dryline extending southward over the Central/Southern
Plains. Warm, moist return flow from the Gulf will push northward
following a warm front into the Central Plains and Midwest. These features
will be the focus for increasing precipitation chances in the region. To
the north, some moderate to locally heavy rainfall is possible late
Thursday evening into early Friday morning with storms forming along the
advancing warm front over the Midwest. There is a Marginal Risk of
Excessive Rainfall as the potential for storms to repeatedly move over the
same locations in the vicinity of the front may lead to some isolated
flash flooding concerns. At the same time, a cold front pushing southward
from Canada will help to reinforce the colder airmass north of the front
as increasing moisture streams in from the south. Some light to moderate
snow accumulations will be possible overnight Thursday from North Dakota
into the Upper Great Lakes. A few isolated thunderstorms are also possible
along the dryline, with the Storm Prediction Center highlighting portions
of central Oklahoma and northwest Texas for a Marginal Risk (level 1/5) of
severe weather. Moderate buoyancy, strengthening winds aloft, and a low
level jet developing Thursday evening will provide the necessary
ingredients for any storms that do form to pose a risk for hail, gusty
winds, and a tornado. Further west behind the dryline over the Central and
Southern High Plains, very strong, gusty downsloping winds will lead to
warming temperatures on top of very dry conditions, prompting a Critical
Risk of Fire Weather from the Storm Prediction Center. Generally cool
highs in the 50s and 60s across the Central/Southern Plains into the
Mississippi/Ohio Valleys and Southeast on Wednesday will warm up into the
70s Thursday as the warm front lifts northward. The downsloping flow over
the Central and Southern High Plains will send highs into the upper 70s
and 80s Thursday.

Putnam


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php