BULLETIN
Tropical Depression Ida Advisory Number  21
NWS Weather Prediction Center College Park MD   AL092021
400 AM CDT Tue Aug 31 2021

...TROPICAL DEPRESSION IDA WAS OVER NORTHERN MISSISSIPPI..
...CONSIDERABLE HEAVY RAIN AND FLOOD THREAT WILL CONTINUE TO SPREAD
FROM THE TENNESSEE AND OHIO VALLEYS INTO THE CENTRAL AND SOUTHERN
APPALACHIANS AND MID ATLANTIC THROUGH WEDNESDAY...


SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...34.1N 88.9W
ABOUT 145 MI...235 KM NNE OF JACKSON MISSISSIPPI
ABOUT 185 MI...300 KM SW OF NASHVILLE TENNESSEE
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...NE OR 55 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
Flood and Flash Flood Watches extend from the Gulf Coast
Region across the Tennessee and Ohio Valleys, central and southern
Appalachians, into the Mid-Atlantic and southern New England.


DISCUSSION AND OUTLOOK
----------------------
At 400 AM CDT (0900 UTC), the center of Tropical Depression Ida was
located near latitude 34.1 North, longitude 88.9 West. The
depression is moving toward the northeast near 12 mph (19 km/h), and
Ida is expected to continue gradually accelerating to the northeast
over the next couple days.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.
Little change in strength is forecast during the next 48 hours.

The estimated minimum central pressure is 998 mb (29.47 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL: Tropical Depression Ida will track across the Middle
Tennessee Valley, Lower Ohio Valley, and northern Mid-Atlantic
through Thursday, producing the following rainfall totals:

Portions of the Southeast, including the western Florida panhandle,
eastern and northern Alabama, and northern Georgia: An additional 1
to 3 inches through Wednesday morning.

Middle Tennessee Valley, Ohio Valley, Central and Southern
Appalachians into the Mid-Atlantic: 3 to 6 inches with isolated
higher amounts through Thursday morning.

Southern New England: 2 to 4 inches with isolated higher amounts,
Wednesday into Thursday.

Considerable flash flooding is possible from the Middle Tennessee
Valley, Ohio Valley, Central and Southern Appalachians, into
the Mid-Atlantic and southern New England, and is most likely from
northern West Virginia and western Maryland into southern
Pennsylvania. Widespread minor to isolated major riverine flooding
is occurring or forecast from the Lower Mississippi Valley into far
western Alabama, Allegheny Mountains, and Mid-Atlantic. Rivers will
remain elevated into next week.

For the latest rainfall reports and wind gusts associated with
Tropical Depression Ida, see the companion storm summary at
WBCSCCNS4 with the WMO header of ACUS44 KWBC or at the following
link:

available at www.wpc.ncep.noaa.gov/discussions/nfdscc4.html


TORNADOES: The threat for a few tornadoes will be centered today
across eastern Alabama, western Georgia, and the Florida Panhandle.
On Wednesday, the threat will shift into portions of the Mid
Atlantic.


NEXT ADVISORY
-------------
Next complete advisory at 1000 AM CDT.


Forecaster Lamers

FORECAST POSITIONS AND MAX WINDS

INIT  31/0900Z 34.1N  88.9W   25 KT  30 MPH...INLAND
 12H  31/1800Z 35.0N  87.5W   20 KT  25 MPH...INLAND
 24H  01/0600Z 36.3N  84.8W   20 KT  25 MPH...INLAND
 36H  01/1800Z 37.7N  81.3W   20 KT  25 MPH...INLAND
 48H  02/0600Z 38.8N  77.6W   25 KT  30 MPH...POST-TROP/INLAND
 60H  02/1800Z 39.5N  74.6W   30 KT  35 MPH...POST-TROP/EXTRATROP
 72H  03/0600Z 40.4N  70.4W   35 KT  40 MPH...POST-TROP/EXTRATROP