Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Fri Sep 30 2022

Valid 12Z Fri Sep 30 2022 - 12Z Sun Oct 02 2022

...Hurricane Ian forecast to make second landfall in South Carolina Friday
bringing wind, heavy rain, and the threat of severe weather to the
Carolinas and Mid-Atlantic...

...Unseasonably cool temperatures forecast across the Eastern U.S. to
start the weekend...

...Showers and thunderstorms expected across portions of the Rockies,
Great Basin, and Southwest...

Hurricane Ian is currently forecast by the National Hurricane Center to
make a second U.S. landfall Friday afternoon in South Carolina bringing
high winds, heavy rain, and the threat of severe weather to the Carolinas
and southern Mid-Atlantic. In terms of rainfall, there is a Moderate Risk
of Excessive Rainfall for portions of eastern South Carolina, central
North Carolina, and southwestern Virginia Friday as storm forecast totals
of around 4-8 inches are expected, with isolated higher totals of up to 12
inches possible closer to the coast in the immediate vicinity of where Ian
makes landfall.  Slight Risks remain in effect for Saturday along the
immediate coast in the Mid-Atlantic where higher moisture will push
northward as the system transitions into an extratropical low, and over
portions of the central Appalachians where terrain influences will help to
produce bouts of heavier rainfall. The Storm Prediction Center has also
issued a Slight Risk of Severe Weather for coastal portions of far
southeastern Virginia, North Carolina, and far northeastern South Carolina
as increasing shear due to the approach and passage of Hurricane Ian may
lead to a few isolated tornadoes. 

Elsewhere across the East, unseasonably cool temperatures are forecast due
to the influence of an expansive high pressure system from Canada and
behind a secondary cold front moving across the Southeast behind Hurricane
Ian. In fact, Freeze Warnings and Frost Advisories are in effect early
Friday Morning for the Interior Northeast as forecast low temperatures
will dip into the low to mid-30s. Highs in the 60s are forecast from the
Northeast south through the Mid-Atlantic, Appalachians, and into the
Southeast outside of the Florida Peninsula. 

In the West, an upper-level low will linger over the region as a frontal
system moves slowly southeast through the Rockies and Great Basin, with
showers and thunderstorms expected both Friday and Saturday. Marginal
Risks of Excessive Rainfall are in effect both days as anomalously high
moisture and the influence of terrain may lead some of these storms to
produce 1-2 inches of rain and the risk for flash flooding, particularly
in the vicinity of burn scars, slot canyons, and dry washes. Bouts of wet
snow are expected for higher elevations in the Rockies, generally above
9000 feet. Unseasonably warm temperatures are forecast to the east and
west of the Rockies/Great Basin outside of the influence of the
upper-level low. Highs will range from the 70s in the Northern Plains to
the 80s in the Central and Southern Plains, with some highs at or above 90
not out of the question. High temperatures in the 70s for the Pacific
Northwest on Friday will warm into the 80s on Saturday, with highs at or
above 90 possible for the Rogue Valley of Oregon. 


Putnam


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