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

Valid 00Z Thu Mar 30 2023 - 00Z Sat Apr 01 2023

...Storm system brings another round of rain and mountain snow into the
Great Basin and Intermountain West...

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

...Strong storm system will result in severe thunderstorms, heavy rain,
and a Critical Risk of Fire Weather for the Central/Southern High Plains...

A frontal system currently pushing through Nevada and southern California
is resulting in a variety of weather-related hazards across the West as
Pacific moisture overspreads the region. Moderate to locally heavy
rainfall is forecast to impact southern California along with the cold
frontal passage. Given the wet antecedent soil conditions, even moderate
rainfall may result in localized flash flooding, especially over higher
terrain and in urban areas. Therefore, a Marginal Risk of Excessive
Rainfall (level 1/4) is in effect along the central and southern
California coast. The cold front associated with this system is forecast
to move through areas of the Great Basin and Intermountain West on
Thursday and Friday. Moderate to locally heavy upslope snow is expected
along with this cold frontal passage, though little to no snow
accumulations are expected in the lower elevation valley locations. Gusty
winds are anticipated following the cold frontal passage, with
wind-related advisories currently in effect for portions of the Great
Basin and Desert Southwest. Temperatures over the region will be generally
10 to 15 degrees cooler than average to end the work week, especially
after the cold front passes through the region. Highs on Thursday will
generally be in the 40s and 50s across the West, with 60s forecast over
portions of Desert Southwest.

An energetic upper-level shortwave along with its strong surface-based
cold front currently located over the the Great Lakes will quickly
progress eastward into portions of the Interior Northeast Wednesday
evening into Thursday. Light snow is generally expected over the region,
although current atmospheric conditions over Upstate New York and northern
New England may be supportive for heavier bands of snow squalls, producing
brief periods of heavy snow and gusty winds. A rapid onset of snow may
create whiteout conditions and dangerous travel. Additionally, there will
be rapid cooling behind the frontal passage, leading to a potential flash
freeze, further worsening the travel hazards. Temperatures will be
seasonal prior to the frontal passage Wednesday evening and Thursday
morning. However, high temperatures on Thursday will be in the 30s and
lower 40s, about 10-15 degrees below average for this time of year. High
temperatures will rise significantly on Friday as a strong warm front
approaches the region. To the west, temperatures will remain well below
average as the cold Canadian airmass remains in place over the
Northern/Central High Plains. Lows on Thursday morning will fall into the
single digits for many locations. While warmer temperatures are expected
on Thursday through Central High Plains, temperatures will stay cold over
the northern High Plains going into the weekend.

The frontal system currently impacting the West will eject off the Rockies
into the Northern/Central High Plains and rapidly strengthen on Thursday.
This system will feature impressive fronts, with a cold, Canadian airmass
to the north and a warm, moist Gulf airmass to the south. Southerly flow
over the Southern/Central Plains will warm temperatures significantly and
increase precipitation chances on Thursday over the Central Plains. High
temperatures on Thursday afternoon will generally be in the 60s and 70s
across a broad region of the High Plains. Precipitation will begin from
north to south across the High Plains on Thursday afternoon into the
overnight period, with snow expected over the Northern High Plains and
rain expected to the south. Precipitation will intensify overnight, with
widespread coverage expected by Friday morning. Moderate to locally heavy
rainfall is anticipated as this system progresses northeastward through
the Central Plains and into the Ohio River Valley. A Marginal Risk for
Excessive Rainfall is in effect for portions of the Mid-South, Ohio River
Valley, and Upper Midwest on Friday as relatively wet antecedent soil
conditions will contribute to localized regions of flash flooding.
Moderate snowfall accumulations are expected through Friday evening over
the High Plains and Upper-Midwest, with probabilities of 4+" snowfall
reaching 70-90% across a band stretching from South Dakota to Michigan's
Upper Peninsula. Additionally, given the moist, moderately buoyant airmass
in place over the Central Plains, the Storm Prediction Center has issued a
Marginal Risk of severe weather (level 1/5) in effect on Thursday for the
Southern/Central Plains, and an Enhanced Risk (level 3/5) of severe
weather in effect on Friday for much of the Mid-South and Ohio River
Valley. On Thursday, isolated thunderstorms are possible along a dryline
forecast to situate over western Texas and into Oklahoma, with the
possibility of producing hail, gusty winds, and a tornado. The severe risk
on Friday is heightened on Friday, as the airmass becomes more buoyant.
Strong scattered thunderstorms are expected over the Enhanced Risk region,
with the primary severe threats being strong, gusty winds and a few
tornadoes. Additionally, a Critical Risk of Fire Weather is expected over
portions of the Central/Southern High Plains as dry conditions and gusty
winds behind the dryline create conditions favorable for fire weather.

Genz


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