Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
346 PM EDT Tue Aug 29 2023

Valid 00Z Wed Aug 30 2023 - 00Z Fri Sep 01 2023

...Hurricane Idalia expected to produce life-threatening storm surge and
hurricane conditions along portions of the Gulf Coast of Florida tonight
and Wednesday...

...Dangerous flash flooding threat associated with Idalia extends into
southern Georgia and the Carolinas through early Thursday...

...Heavy rain and scattered flash flooding chances across the Appalachians
and northern Great Basin through tonight...

...Excessive Heat forecast throughout the Desert Southwest and Southern
California...

Outer rainbands from Hurricane Idalia, currently located over the eastern
Gulf of Mexico this afternoon, have already begun impacting parts of the
Florida Peninsula as the storm continues to trek north on a path to make
landfall near the Florida Big Bend region and Nature Coast by Wednesday
morning. Idalia is anticipated to strengthen into a major hurricane by
this timeframe and produce catastrophic impacts from storm surge and
destructive waves from Aucilla River to Yankeetown, Florida.
Life-threatening storm surge inundation is likely elsewhere along portions
of the Florida Gulf Coast where a Storm Surge Warning is in effect.
Additionally, destructive and life-threatening winds associated with the
core of Idalia are forecast to move onshore the Big Bend region of
Florida. Strong winds will also spread inland across portions of northern
Florida and southern Georgia near the center of Idalia. These strong winds
could produce downed trees and power outages. Heavy rainfall is also
forecast to accompany Idalia as deep tropical moisture surges northward.
Isolated maximum rainfall amounts of 12 inches is possible near the
landfall location in northern Florida. This may lead lead to areas of
flash, urban, and river flooding across portions of the western coast of
Florida, the Florida Panhandle, and southern Georgia. Meanwhile,
thunderstorms along the eastern flanking rainbands may produce damaging
wind gusts and a few tornadoes from west-central Florida to the Florida
Big Bend.

By Wednesday and Thursday, a weakening Idalia is forecast to push
east-northeast through southern Georgia and the Carolinas before exiting
to the south of the Outer Banks of North Carolinas. Heavy rain is likely
to continue along and just to the north of the center of Idalia as a
frontal boundary provides focus for congealing tropical downpours.
Numerous flash flooding are likely from southern Georgia through much of
South Carolina and southern North Carolina. Here, a Moderate Risk (level
4/5) of Excessive Rainfall has been issued valid Wednesday morning through
Thursday morning. Although Idalia is expected to weaken to a Tropical
Storm by Wednesday night, gusty winds and rough surf can still be expected
along the southeast coastline through Thursday.

To the north of Idalia and along a frontal boundary stretching from the
Deep South to the central Appalachians, slow-moving thunderstorms could
produce areas of heavy rain and flash flooding into tonight. Scattered
flash floods are most likely from northern Georgia to central
Pennsylvania, where a Slight Risk (level 2/4) of Excessive Rainfall is in
effect through early Wednesday. A cold front swinging across the Northeast
on Thursday will help steer Idalia off the southern Mid-Atlantic
coastline, while also ushering in comfortable high temperatures into the
mid-to-low 70s. Elsewhere, a potent cold front could spark thunderstorms
capable of contain intense rainfall rates and severe weather throughout
the northern Great Basin today. Flash flood watches have been issued from
northern Washington to northern Idaho.

Summer continues to soar throughout the Desert Southwest as highs are
forecast to reach well into the triple digits over the next few days.
Excessive Heat Warnings are in effect for portions of California and
Arizona. Dangerous heat will also be found throughout southern California
in areas just inland from the cooler Pacific waters. The other hot spot in
the Lower 48 will be across southern and southeast Texas through Friday,
where high temperatures right around the century mark are anticipated.

Snell


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