…Wet Sunday for much of the eastern U.S., including beneficial rainfall
for the Northeast…
…An Atmospheric River will bring heavy coastal rain and high elevation
snowfall to portions of the Pacific Northwest beginning Sunday night…
…Above average temperatures will continue into next week for most of the
country…
A broad area of showers and thunderstorms ahead of a low pressure
system/arcing frontal boundary through the Midwest south into the
Mississippi Valley early Sunday morning will continue eastward through the
day, bringing an expanding area of moderate to heavy rainfall over the
eastern U.S. The front will push eastward through the Ohio Valley/interior
Northeast and into New England and the Mid-Atlantic by Sunday evening,
bringing beneficial rainfall following many weeks of little to no
precipitation. Further south, the front will make slower progress and keep
additional storm chances focused over the Tennessee and Lower Mississippi
Valleys following heavy rain Saturday. Moisture streaming northward from
the Gulf, influenced in part by Tropical Storm Rafael, will lead to some
locally heavy downpours, with isolated flash flooding possible. A
localized Slight Risk of Excessive Rainfall (level 2/4) is in place over
central Louisiana where continued rainfall early Sunday over very
saturated grounds/ongoing flooding may lead to a few more scattered
instances of flash flooding. An additional area of showers and
thunderstorms is expected for portions of the coastal Carolinas/Georgia
and into Florida in vicinity of a wavy frontal boundary. Most of the
rainfall should come to an end by early Monday as the front begins to
clear the coast over the Northeast and moisture return decreases to the
south, though some lingering showers will remain possible for the interior
Northeast as a secondary cold front passes through.
Some light to moderate lower elevation rain showers and higher elevation
snows will continue over portions of the Pacific Northwest/northern
Rockies through Sunday afternoon as a wavy frontal boundary lingers in the
region. Then, a stronger Pacific storm system/Atmospheric River will
approach the Pacific Northwest Sunday evening bringing moderate to heavy
coastal rains by Sunday night. This system will continue inland into the
day Monday with an expanding area of precipitation across the Pacific
Northwest, northern Great Basin/Rockies, and northern/central California.
Favorable upslope areas along the coastal mountain ranges may see 2-3″ of
rain, with some potentially moderate to heavy accumulating snows for
higher elevations of the Cascades, Sierra Nevada, and northern Rockies.
Another system just beyond the current forecast period looks to bring
another round of heavy rain and mountain snows mid-week.
Most areas of the country will continue to see temperatures 5-15 degrees
above average over the next couple of days. Forecast highs Sunday range
from the 50s for the Pacific Northwest, Great Basin, northern
Rockies/Plains, Great Lakes, and New England; the 60s in California,
central Plains, Ohio Valley, and Mid-Atlantic; and the 70s and 80s for the
Desert Southwest, Texas, Lower Mississippi Valley, and the Gulf Coast.
Much of the East Coast will see even warmer highs on Monday as rain clears
out, with highs rising into the 60s for coastal New England and the 70s
for the Mid-Atlantic, Carolinas, and Georgia. One region that will remain
colder will be portions of the central/southern Rockies and High Plains
where grounds remain snow covered following this past Friday’s historic
storm, with highs mainly in the 40s to low 50s.
Putnam
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
