Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Tue Jan 17 2023

Valid 12Z Tue Jan 17 2023 - 12Z Thu Jan 19 2023

...Localized flash flooding, severe weather, and heavy snow expected with
storm system moving through the center of the country...

...Much above normal temperatures for much of the Southern U.S., with a
Critical Risk of Fire Weather Wednesday in Texas...

...Light to moderate precipitation chances for the Great Lakes and East
Coast Tuesday...

...Heavy mountain snow continues in the Four Corners region ahead of
another storm system moving through the West Wednesday...

A multi-hazards storm system will develop in the Plains as an area of low
pressure deepens in the lee of the Rockies ahead of an upper-level trough
approaching from the West. This low is forecast to track northeastward
into the Midwest through Wednesday morning, with a trailing cold front
sweeping across the Plains and into the Mississippi Valley. Heavy snow is
expected to begin for portions of the Central High Plains Tuesday evening
to the north of the developing surface low. This snow will spread to the
northeast through the day Wednesday to the north of the surface low track,
roughly following an axis from northeastern Colorado/Wyoming through
Nebraska, Iowa, and into Wisconsin. Accumulations of 4-8 inches, locally
higher, are forecast through Thursday morning. The snow will begin to
taper off late Wednesday from west to east, with snow continuing into the
day Thursday for the Upper Midwest. A wintry mix of sleet and freezing
rain will be likely along the rain-snow transition. While deviations in
the track of the system will have an effect on the type and amount of
precipitation seen, the locations currently most likely to see light
accumulations of freezing rain are from northern Kansas and southeastern
Nebraska northeast through northern Missouri and southern Iowa. Colder
temperatures will follow the passage of the low pressure system, with
highs in the 20s spreading southward from the Northern Plains Tuesday into
the Central Plains Wednesday.

Warm, anonymously moist air from the Gulf returning northward ahead of the
cold front will help to fuel the development of showers and thunderstorms
on Wednesday from the Southern Plains to the Ohio Valley. There is a
Slight Risk of Excessive Rainfall (level 2/4) for portions of the Lower
Mississippi and Ohio Valleys as localized heavier downpours and repetitive
rounds of storms may lead to a few scattered instances of flash flooding.
In addition, the Storm Prediction Center has issued a Slight Risk for
severe weather (level 2/5) roughly overlapping the same areas from the
Lower Mississippi Valley into the Lower Ohio Valley. Strong, mostly
unidirectional wind shear over the region will help to promote organized
lines of thunderstorms with the threat for damaging winds and a few
tornadoes.

Besides the widespread hazardous heavy precipitation expected,
temperatures will be unseasonably warm across the southern tier of the
country ahead of the storm system. Highs will be upwards for 15-25 degrees
above average for some locations Tuesday and Wednesday, with 60s, 70s, and
even some 80s in south Texas forecast. A handful of record-tying and
record-breaking highs will be possible from south Texas northeast into the
Lower Mississippi Valley. The warm temperatures combined with drier air
and gusty winds following the passage of the cold front in Texas Wednesday
have prompted a Critical Fire Weather Outlook from the Storm Prediction
Center for portions of western Texas.

Further east, a weakening low pressure system will be moving from the
Great Lakes towards the Interior Northeast Tuesday. Light snow and ice
accumulations will be possible. Some rain showers along a trailing cold
front will also move through the Mid-Atlantic, Carolinas, and Southeast.
Highs will be unseasonably mild for most locations Tuesday, with 40s for
the coastal Northeast, 50s in the Mid-Atlantic and Carolinas, 60s in the
southeast, and 70s in Florida. Temperatures will warm up by around 10
degrees more on Wednesday after the precipitation moves out, with 50s
spreading northward into the coastal Northeast, 60s for the Mid-Atlantic,
and 70s into the Southeast.  

Heavy snow will continue for the mountain ranges of the Four Corners
region Tuesday before the upper-level trough/storm system begin to move
east over the Plains later Tuesday evening. A period of dry conditions
will be in place from California eastward through the Great Basin ahead of
a Pacific storm system moving into the Pacific Northwest late Tuesday,
bringing lower elevation valley/coastal rain and snow to the Cascades. The
system will move southeastward into the Great Basin/California during the
day Wednesday increasing precipitation chances. However, both rain and
snow accumulations are expected to remain light outside of some heavier
snow in the Sierra.

Putnam

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