563
FXUS01 KWBC 060825
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
424 AM EDT Sun Apr 06 2025

Valid 12Z Sun Apr 06 2025 - 12Z Tue Apr 08 2025

...Significant heavy rainfall and flash flood threat shifts
eastward into parts of the Central/Southern Appalachians and
Southeast Sunday...

...Severe weather risks for portions of the southern Mid-Atlantic
and Southeast Sunday and Monday...

...Series of frontal systems to bring bouts of unsettled weather
to the Pacific Northwest and northern Rockies the next few days...

...Wintry weather returns to the Great Lakes and Northeast through
the early part of the week...

...Amplified flow pattern leads to large temperature swings across
the Continental U.S. the next few days...


After several days of extreme rainfall and devastating flooding
across parts of the Ohio Valley, Mid-South, Middle and Lower
Mississippi Valleys, the threat for significant heavy rainfall and
flash flooding shifts eastward into the Appalachians and Southeast
on Sunday. The frontal boundary which had been stubbornly slow to
move and caused repeated rounds of torrential downpours across the
region is finally beginning to push eastward, taking with it the
excessive rainfall threat that caused life-threatening flash
flooding for many. With its eastward push, moisture along and
ahead of the front will become focused from the Appalachians to
the Central Gulf Coast, setting the stage for intense downpour
producing thunderstorms throughout the day. A broad Slight Risk
(level 2/4) remains in place while a targeted Moderate Risk (level
3/4) has been introduced across central Alabama and extreme
west-central Georgia. The forward speed of the front should
prevent the level of catastrophic flooding seen in previous days,
but storms with heavy rainfall that locally track over the same
areas may still lead to significant instances of flash flooding.
Fortunately, the risk of heavy rainfall and flash flooding
decreases significantly on Monday, with just a Marginal Risk
(level 1/4) highlighted from southeast Virginia to northern
Florida.

Similar to the flooding threat, the risk for severe weather also
shifts eastward Sunday into Monday, targeting parts of the
southern Mid-Atlantic and Southeast as we round out the weekend
and start the new work week. Moisture, instability, and wind shear
along and ahead of the eastward advancing cold front will support
a broken line of strong to severe thunderstorms across the region,
with the most severe storms capable of producing damaging wind
gusts and even a few tornadoes. The Storm Prediction Center
continues to maintain Slight Risks (level 2/5) from northern
Georgia to the central Gulf Coast on Sunday, and from southeast
Georgia to northern Florida on Monday. Farther north across
portions of the Appalachians and southern Mid-Atlantic, Marginal
Risks (level 1/5) are in effect to account for the potential for
stronger storms to produce damaging winds.

A series of fronts will bring episodes of unsettled weather to the
Pacific Northwest on Sunday and the northern Rockies/Intermountain
West Monday into Tuesday. These frontal systems will push inland
from the Pacific, bringing moisture and intermittent showers to
much of the region. Rain will fall across coastal locations and
the lower elevations while snow will fly in the high country. As
these fronts cross the terrain, they will weaken and eventually
dissipate. As a result, rain and snow amounts will become
increasingly lighter with eastern extent. The highest snowfall
totals will mostly be confined to the higher elevations of the
Olympic Mountains and the Cascades where several inches up to 1 to
3 feet will fall.

To the north of the flooding and severe threats, and on the colder
side of the Eastern U.S. frontal boundary, wintry weather will
return to parts of the Great Lakes and the Northeast through the
early part of the upcoming week. On Sunday, as the rain associated
with a departing system ends, snow may mix in across some of the
higher elevations in northern New England. Any accumulations would
be light. Colder air filters in on Sunday night, setting the stage
for more widespread wintry weather on Monday as a developing wave
of low pressure moves in from the southwest. Parts of the
Northeast, and especially northern New England, stand to see a
modest snowfall with forecast accumulations of at least a few
inches, with the potential for more than 6 inches in the higher
elevations. Just to the south of the snow, a wintry mix of snow,
sleet, and possibly freezing rain will make for slippery
conditions across portions of northern Pennsylvania, New York, and
southern New England. Then on Tuesday, a reinforcing blast of much
colder air will bring snow to the Great Lakes region, with bands
of lake-effect snow downwind.

Large temperature swings can be expected across the Continental
U.S. the next few days as an amplified flow pattern remains in
place. Well above normal warmth across the Mid-Atlantic and
Southeast on Sunday will give way to much colder air Monday and
especially Tuesday as reinforcing cold fronts make their way
through. Just to the west, the coldest anomalies on Sunday will be
found from the eastern Great Lakes to the southern Plains, with
temperatures making it feel more like winter than spring. An
overall warming trend continues across the Western U.S. through
the early part of the week, though the unsettled weather expected
across the Pacific Northwest may put a damper on the warm up. By
Tuesday, above normal warmth will spread from the West into the
Plains, while the eastern half of the country from the Great Lakes
to Florida experience temperatures that are much colder than
average.


Miller



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