167
FXUS01 KWBC 190730
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
229 AM EST Sun Jan 19 2025

Valid 12Z Sun Jan 19 2025 - 12Z Tue Jan 21 2025

...Winter storm to bring moderate to heavy snow to the
Mid-Atlantic and Northeast Sunday...

...Intrusion of Arctic Air bringing dangerously cold conditions to
much of the nation...

...Impacts from a rare, significant winter storm across the South
next week will begin for Texas Monday night...

...A Critical Risk of Fire Weather returns for southern California
Monday...

A winter storm is forecast to produce heavy snow across portions
of the Mid-Atlantic and Northeast today (Sunday). Some snow
showers over the Ohio/Tennessee Valleys and rain showers in the
Southeast will linger into Sunday morning following the passage of
a cold front off the East Coast. Meanwhile, an upper-level wave
will help to deepen an area of low pressure along a cold front
Sunday morning which will move to the northeast just off the coast
through Sunday night. This will lead to a band of enhanced
snowfall developing inland to the northwest of the low track over
the Appalachians Sunday morning and from the northern Mid-Atlantic
into New England during the day. The heaviest snow will likely
stay to the north and west of the I-95 corridor. However, 3-6" of
snow with locally higher amounts is expected form northern
Maryland through Boston. Some rain/wintry mix will be possible
from northern Virginia to southern New Jersey.

Precipitation chances elsewhere through Monday include bands of
heavy lake-effect snow for favorable downwind locations of the
Great Lakes with cold northwesterly flow in place. Some snow
showers will return to the central/southern Rockies and adjacent
High Plains on Monday as a shortwave passes over the region and in
the presence of post-frontal upslope flow.

Another big story this weekend and heading into next week will be
the bitterly cold Arctic airmass spreading across most of the
central/eastern U.S. Temperatures have already plummeted across
the Rockies, Plains, and Mississippi Valley, and will reach the
East Coast Sunday as the noted cold front pushes offshore. This
will be the coldest air of the Winter season thus far, and in many
cases the coldest in several years. Forecast highs the next couple
of days range from below zero to the single digits in the northern
Plains/Upper Midwest; the single digits and teens across the
Rockies, central Plains, and Midwest; the teens and 20s across the
Northeast and Mid-Atlantic; and the 20s and 30s for Texas and the
Southeast. Wind chills will reach dangerously cold levels, with
minimum wind chills from 30 to 55 below zero at times Sunday and
Monday in the Rockies, northern Plains and Upper Midwest. Sub-zero
wind chills are expected to reach as far south as Oklahoma and the
Tennessee/Ohio Valleys by Sunday night.

The combination of this frigid air reaching the Gulf Coast and the
development of a low pressure system over the Gulf will lead to a
significant winter storm across the Gulf Coast/Southeast next
week. Initial impacts are expected to begin by late Monday night
across eastern and southern Texas. A corridor of potentially heavy
snow is expected near and just south of the Interstate 20
corridor, with a wintry mix of snow, sleet, and freezing rain
closer to the Interstate 10 corridor. Given the rare southerly
track of this winter storm, major traffic and travel disruptions
are likely through mid-week.

Some of this Arctic airmass will reach portions of the Great
Basin/Interior West as well, with highs by Monday only in the 20s
and 30s for most locations. Forecast highs are generally more mild
and around average along the West Coast, with 40s for the Pacific
Northwest, the 50s and 60s for California, and the 60s to low 70s
for the Desert Southwest. Unfortunately, these mild conditions
along with gusty winds and very low humidity have prompted the
Storm Prediction Center to issue a Critical Risk of Fire Weather
(level 2/3) Monday for southern California.

Putnam

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