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Tropical Storm Ida Intermediate Advisory Number 18A
NWS National Hurricane Center Miami FL AL092021
100 PM CDT Mon Aug 30 2021
...IDA MOVING NORTH-NORTHEASTWARD OVER WESTERN MISSISSIPPI...
...HEAVY RAINFALL AND FLASH FLOODING THREAT SPREADING OVER MUCH OF
MISSISSIPPI, ALABAMA, AND THE WESTERN FLORIDA PANHANDLE...
SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
ABOUT 20 MI...30 KM WSW OF JACKSON MISSISSIPPI
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NNE OR 15 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.45 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for...
* Mouth of the Pearl River to the Alabama/Florida border
A Tropical Storm Warning is in effect for...
* Mouth of the Pearl River to the Alabama/Florida border
A Storm Surge Warning means there is a danger of life-threatening
inundation from rising water moving inland from the coastline in
the indicated locations. For a depiction of areas at risk, please
see the National Weather Service Storm Surge Watch/Warning Graphic,
available at hurricanes.gov.
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.
For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.
DISCUSSION AND OUTLOOK
At 100 PM CDT (1800 UTC), the center of Tropical Storm Ida was
located near latitude 32.2 North, longitude 90.5 West. Ida is moving
toward the north-northeast near 9 mph (15 km/h), and this general
motion is forecast to continue today. A faster northeastward motion
is expected to begin by tonight and continue through Tuesday night.
On the forecast track, the center of Ida will move farther inland
over western and central Mississippi this afternoon. Ida is then
forecast to move over northeastern Mississippi tonight, and move
across the Tennessee Valley on Tuesday and near the central
Appalachians on Wednesday.
Maximum sustained winds are near 40 mph (65 km/h) with higher
gusts. Weakening is forecast during the next day or so, and Ida is
expected to become a tropical depression later this afternoon.
Tropical-storm-force winds extend outward up to 195 miles (315 km)
mainly to southeast of the center over water.
The estimated minimum central pressure from surface observations is
997 mb (29.45 inches).
HAZARDS AFFECTING LAND
Key messages for Ida can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC,
and on the web at hurricanes.gov/graphics_at4.shtml?key_messages.
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...
Mouth of the Pearl River to AL/FL border including Mobile
Morgan City, LA to the Mouth of the Pearl River including Lake
Lake Maurepas and Lake Pontchartrain...1-3 ft
AL/FL border to Okaloosa/Walton County Line including Pensacola
Surge-related flooding depends on the relative timing of the surge
and the tidal cycle, and can vary greatly over short distances.
For information specific to your area, please see products issued
by your local National Weather Service forecast office.
WIND: Tropical storm conditions will continue over portions of
southern Mississippi and southern Alabama through this afternoon.
RAINFALL: Through Tuesday morning across portions of southeast
Louisiana into far southern Mississippi, Ida will produce additional
rainfall totals of 2 to 4 inches with localized higher amounts
possible. Storm total rainfall accumulations of 10 to 18 inches with
isolated maximum amounts of 24 inches are expected. Heavy rain
combined with storm surge has resulted in catastrophic impacts along
the southeast coast of Louisiana with considerable flash flooding
and riverine flooding continuing farther inland.
Ida will continue to turn northeast this morning and is forecast to
track across the Middle Tennessee Valley, Ohio Valley and
Mid-Atlantic through Wednesday, producing the following rainfall
Coastal Alabama to the far western Florida panhandle: An additional
4 to 8 inches resulting in storm total accumulations of 6 to 12
inches with isolated maximum amounts of 15 inches, today through
Central Mississippi into far western Alabama: 4 to 8 inches with
isolated maximum amounts of 12 inches, today through tonight.
Middle Tennessee Valley, Ohio Valley, Central/Southern
Appalachians into the Mid-Atlantic: 3 to 6 inches with isolated
higher amounts, Tuesday into Wednesday.
Considerable flash flooding is possible from the Lower Mississippi
Valley through the Middle Tennessee Valley, Ohio Valley,
Central/Southern Appalachians, and into the Mid-Atlantic. Widespread
minor to isolated major riverine flooding is occurring or forecast
from the Lower Mississippi Valley into far western Alabama. Rivers
will remain elevated into next week.
TORNADOES: A few tornadoes are possible through tonight, mainly
across southeast Mississippi, southern Alabama, and the western
Florida Panhandle. The threat for a few tornadoes will shift east on
Tuesday and become centered across eastern Alabama, western Georgia,
and the Florida Panhandle.
SURF: Swells will continue to affect portions of the northern Gulf
coast through today. These swells are likely to cause life-
threatening surf and rip current conditions. Please consult
products from your local weather office.
Next complete advisory at 400 PM CDT.