Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
354 AM EDT Sat Sep 23 2023
Valid 12Z Sat Sep 23 2023 - 12Z Mon Sep 25 2023
...Tropical Storm Ophelia to produce heavy rain, gusty winds, and
dangerous storm surge over parts of the Mid-Atlantic this weekend...
...Severe thunderstorms and instances of flash flooding likely across
eastern Oklahoma into the Lower Missouri Valley through tonight...
...Summer heat continues across portions of the southern Plains, while
much cooler temperatures and a wet weather pattern enters the Pacific
Northwest...
A cool, damp, and blustery weekend is in store for the Mid-Atlantic as
Tropical Storm Ophelia moves northward through eastern North Carolina
today. Ophelia remains a relatively large system, with tropical storm
force winds extending as far as 270 miles from the center. The strongest
winds (up to 70 mph) closer to the core of the storm are expected to
impact eastern North Carolina today, with scattered tree damage and power
outages possible. The large wind field will help produce widespread marine
hazards and storm surge concerns along the Mid-Atlantic coastline. Strong
east-northeasterly winds to the north of the storm along a nearby frontal
boundary will also allow for additional coastal flooding potential as far
north as Long Island. Storm Surge and Coastal Flood Warnings are in
effect. Additionally, heavy rain associated with the transport of tropical
moisture may lead to locally considerable flash and urban flooding impacts
from North Carolina to New Jersey through Sunday. The highest rainfall
totals (through Sunday morning) are expected to occur throughout eastern
North Carolina and southeast Virginia, where isolated rainfall amounts
around 8 inches are possible. Ophelia is forecast to rapidly weaken into a
post-tropical cyclone by Sunday as it nears southern Maryland, with heavy
rain remaining possible across the northern Mid-Atlantic from southeastern
Pennsylvania to Long Island. Conditions should generally improve by Monday
across the region outside of some lingering showers.
Active weather is also anticipated across the central U.S. as a potent
fall storm system creates chances for excessive rainfall and severe
thunderstorms. Showers and storms developing along a cold front may
overlap and/or exhibit slow forward movement as they enter eastern
Oklahoma, northeast Arkansas, and southeast Missouri. Several inches of
rainfall within a short period of time into the overnight hours are likely
to lead to instances of flash flooding. A Moderate Risk (level 3/4) of
Excessive Rainfall has been issued for this area valid through early
Sunday morning. Additionally, thunderstorms are likely to contain large to
very large hail, damaging winds, and the potential for tornadoes. This
severe threat overlaps with the heavy rain potential over eastern Oklahoma
and parts of Missouri. Heavy rain and potent storms are also possible as
far north as eastern South Dakota and southern Minnesota, closer to a
strengthening low pressure system. By Sunday, the unsettled weather is
forecast to confine to the southern Plains and Lower Mississippi Valley.
Elsewhere, record-breaking heat continues across the southern Plains and
particularly the Lone Star State until temperatures return closer to
average on Monday. Highs into the upper 90s and low 100s will linger for
the final full weekend of September, challenging and few daily high
temperature records across Texas and parts of New Mexico. Meanwhile, a
strong low pressure system developing over the northeast Pacific Ocean
will usher in widespread shower activity across the Pacific Northwest
beginning Sunday night. Rain may be heavy enough to lead to localized
flooding concerns across southwest Oregon and northwest California.
Snell
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php