Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
250 PM EST Fri Jan 27 2023

Valid 00Z Sat Jan 28 2023 - 00Z Mon Jan 30 2023

...Heavy snow impacting the northern Rockies and northern High Plains to
spread into parts of the central Plains and Midwest tonight...

...Arctic air surging southward into the central United States this
weekend to produce potentially dangerous wind chills...

...Instances of heavy rain and flash flooding possible throughout the Gulf
Coast and Southeast on Sunday...

The main story over the next few days will be the arctic cold front slowly
traversing southward through the Great Plains and Intermountain West,
bringing plunging temperatures in its wake, including the chance for snow.
In the build-up to the surge of cold air, an initial system tracking
across the Great Lakes will continue to bring the chance for light to
moderate snow, especially along western-facing lake shores, where cold,
gusty northwesterly winds will produce lake-enhanced snow showers through
Friday evening. Further west, snow is expected to increase in intensity
throughout the Northern Rockies through Friday evening as the arctic
frontal boundary pushes southward from Canada into the region, producing
conditions favorable for moderate to heavy snow. Widespread Winter Storm
Warnings and Winter Weather Advisories have been issued for much of the
region due to the potential for a swath of accumulating snowfall
throughout lower elevations and totals exceeding 12" into the higher
terrain. The snow could be heavy at times and drastically reduce
visibility, making travel potentially treacherous.

Low pressure developing along the frontal boundary on Friday evening will
push into the central Plains, producing an axis of moderate snow on the
northern side of the low. A narrow swath of 4-6" is forecast from western
Nebraska into the Great Lakes through early Sunday, with higher amounts
possible across southeastern South Dakota and central Michigan. In
addition to the potential for snow, bitterly cold temperatures will
overspread much of the region as strong high pressure in western Canada
sends a surge of arctic southward behind the frontal boundary draped
across the Intermountain West and Plains. Temperatures 20 to 40 degrees
below average are forecast to spread into the northern Rockies and
northern/central Plains by Sunday, with highs only reaching into the
single digits and lows dropping into the minus teens. Gusty winds will
make it feel even colder and could lead to dangerous conditions for
individuals spending an extended amount of time outdoors.

As the arctic frontal boundary progresses southward into the southern
Plains, a northward surge of warm, moist air ahead of the system will
produce showers and thunderstorms across the Gulf Coast, with the
potential existing for heavy rainfall leading to flash flooding this
weekend. As a result, a Marginal Risk of Excessive Rainfall has been
issued for southeastern Texas and western Louisiana on Saturday, with the
threat expanding in severity and areal coverage on Sunday, as a Slight
Risk of Excessive Rainfall covers the entirety of the Gulf Coast.

Russell

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