Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Tue Jan 03 2023

Valid 12Z Tue Jan 03 2023 - 12Z Thu Jan 05 2023

...Heavy snow and rain/freezing rain over parts of the Northern Plains
into the Upper Mississippi Valley/Upper Great Lakes...

...There is an Enhanced Risk of severe thunderstorms over parts of the
Lower Mississippi Valley/Southeast on Tuesday and a Slight Risk of severe
thunderstorms over parts of the Southeast/Eastern Gulf Coast on
Wednesday...

...There is a Slight Risk of excessive rainfall over parts of the Central
Gulf Coast/Tennessee Valley/Southern Appalachians on Tuesday and a
Moderate Risk of excessive rainfall over parts of the Northern/Central
California Coast on Wednesday...

... Snow for the Sierra Nevada Mountains, Great Basin, Southwest, and
Central Rockies; Temperatures will be 20 to 35 degrees above average from
Middle/Lower Mississippi Valley eastward to parts of the Lower Great
Lakes/Mid-Atlantic...

On Tuesday, a storm over parts of the Middle Mississippi Valley will
slowly move eastward to the Lower Great Lakes by Thursday. The system will
produce snow, rain, and freezing rain from Northern Plains to the Upper
Great Lakes. Snow, rain, and freezing rain will move into Northern New
England on Wednesday.

The system will produce a large swath of moderate to very heavy snow,
significant freezing rain, and some sleet is expected across the Northern
Plains through Tuesday, continuing across the Upper Midwest through
Wednesday. Intense snow rates of 1-3 inches per hour (accompanied by
thunder) are quite likely from parts of Nebraska and South Dakota into
Minnesota early Tuesday. Snowfall will rapidly accumulate to more than 12
inches over this region. In addition, gusty winds around 30 mph will
produce areas of blowing and drifting snow throughout the day on Tuesday.
The precipitation will result in snow-covered roads, reduced visibility,
and difficult-to-impossible travel.

Localized significant ice accumulations (freezing rain) exceeding 0.25
inches are likely from portions of eastern Nebraska through southern
Minnesota. The freezing rain may lead to dangerous travel, scattered power
outages, and tree damage. In addition, ahead of the front over parts of
the Southern Plains into the Ohio Valley and Mid-Atlantic, temperatures
will be 20 to 35 degrees above average from the Middle/Lower Mississippi
Valley eastward to parts of the Lower Great Lakes/Mid-Atlantic.

Furthermore, moisture from the Western Gulf of Mexico will surge northward
over the Lower Mississippi Valley/Southeast. The storm s associated front
moves into the moisture, producing showers and severe thunderstorms over
the area on Tuesday. Therefore, the SPC has issued an Enhanced Risk of
severe thunderstorms over the Lower Mississippi Valley/Southeast from
Tuesday through Wednesday morning. The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind gusts,
hail, and a few tornadoes. There will also be an increased threat of
EF2-EF5 tornados over the region.

In addition, the showers and thunderstorms will produce heavy rain.
Therefore, the WPC has issued a Slight Risk of excessive rainfall over
parts of the Central Gulf Coast/Tennessee Valley/Southern Appalachians
from Tuesday into Wednesday morning. The associated heavy rain will create
mainly localized areas of flash flooding, with urban areas, roads, and
small streams the most vulnerable. Further, rain will develop over parts
of the Middle Mississippi/Ohio Valleys and the Great Lakes on Tuesday.

On Wednesday, the threat of severe thunderstorms decreases slightly and
excessive rainfall ends. Therefore, the SPC has issued a Slight Risk of
severe thunderstorms over the Southeast/Eastern Gulf Coast from Wednesday
through Thursday morning. The hazards associated with these thunderstorms
are frequent lightning, severe thunderstorm wind gusts, a few tornadoes,
and a minimal threat of hail. Showers and thunderstorms will extend as far
north as Mid-Atlantic. The showers and thunderstorms will mainly end by
Thursday morning along most of the East Coast.

Moreover, rain will move into the Northeast on Tuesday afternoon and
continue into Tuesday evening. Overnight Tuesday, there is a risk of
rain/freezing rain over parts of Northern New England. On Wednesday, the
rain will continue over parts of the Northeast, while snow and
rain/freezing rain will develop over parts of Northern New England.

Meanwhile, multiple fronts will move into the West Coast. One front will
move near Southern California and dissipate by late Tuesday afternoon.
Snow and lower-elevation rain will move into the Southwest and snow over
parts of the Central/Southern Rockies. Light snow will also develop over
parts of the interior Northwest Tuesday morning.

The second front will approach the Northwest late Tuesday afternoon,
producing a new round of coastal rain and higher-elevation snow as far
south as Northern California. Finally, the third front will move onshore
over the West Coast by Thursday morning.

Ahead of the front, a plume of moisture will move into California
producing heavy rain on Wednesday. Therefore, the WPC has issued a
Moderate Risk of excessive rainfall over parts of the Northern/Central
California coast from Wednesday into Thursday morning. The associated
heavy rain will create numerous areas of flash flooding. Furthermore, many
streams may flood, potentially affecting larger rivers.

Additionally, heavy snow will return to the Sierra Nevada Mountains on
Wednesday. Late Wednesday afternoon, coastal rain and higher-elevation
snow will also return to the Pacific Northwest. In addition, a few areas
of rain/freezing rain will develop over interior Washington State
overnight Wednesday into Thursday morning.


Ziegenfelder


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