High temperatures will remain well below average Friday from the Central Plains to the Gulf Coast after another morning of widespread record low temperatures as a persistent Arctic airmass remains in place. Forecast highs generally range from the teens and 20s in the Central Plains/Middle Mississippi Valley, the 30s and 40s from Texas east through the Southeast/Gulf Coast, and the 50s and 60s into Florida.
While not quite as below average, chilly temperature also continue across the Midwest and Northeast with highs in the 20s and 30s and into the Mid-Atlantic with highs in the 30s and 40s.
Dangerously cold sub-zero wind chills are expected through early Friday morning throughout the central Plains and as far south as the Texas Panhandle.
The airmass will finally begin to modify a bit on Saturday with temperatures running about 10 degrees warmer for most locations.
Areas of south Texas will remain the most below average with highs in the 40s.
Despite the warming trend, morning lows will still fall near or below freezing, which will remain a risk to more sensitive areas in the South not as accustomed to freezing temperatures.
Downsloping winds along and east of the Rockies will bring the most significant warm up as temperatures rise into the 40s and 50s, above average for this time of year.
An upper-level wave/accompanying Pacific frontal system will bring lower elevation coastal/valley rain and some very high elevation snow to the Pacific Northwest Friday ahead of a more substantial second Pacific system/Atmospheric River reaching the region on Saturday.
Moderate to locally heavy rainfall will be possible along upslope portions of the Coastal Ranges and Cascades, particularly on Saturday.
Additional heavy rainfall is expected to continue into Sunday just beyond the current forecast period.
Warm Pacific air with the Atmospheric River will keep snow levels very high limiting any accumulations to some of the higher mountain peaks of the northern Cascades.
Moisture will spread further inland bringing lower elevation rain and high elevation snow to the northern Great Basin/Rockies as well, with increasing amounts through Saturday.
Snow levels will also be very high here with limited accumulations.
In fact, Flood Watches are in place for portions of the northern Rockies where the combination of runoff from rain and snowmelt given the warm temperatures could lead to river flooding.
Warming temperatures will be a theme across the rest of the West, with highs above average for most locations by Saturday.
Highs in the 40s and 50s will be common to the north and through the interior with 60s and 70s for California and the Desert Southwest.
Conditions will be mostly dry the next couple of days for the rest of the country.
Some light lake-effect snows will continue for the Great Lakes and light freezing rain will be possible for areas of central and south Texas late Friday into Saturday morning.
An area of low pressure will bring increasing shower and thunderstorm chances to the western Gulf Coast on Saturday. ■