ZCZC NFDTCPAT4 ALL TTAA00 KWNH DDHHMM BULLETIN Tropical Depression Ida Advisory Number 25 NWS Weather Prediction Center College Park MD AL092021 500 AM EDT Wed Sep 01 2021 ...TROPICAL DEPRESSION IDA IS MOVING INTO THE CENTRAL APPALACHIANS AND SHOULD BECOME POST-TROPICAL TODAY... ...WIDESPREAD HEAVY RAIN AND AREAS OF LIFE THREATENING FLASH FLOODING ARE LIKELY TODAY AND TONIGHT NEAR THE TRACK OF IDA... ...ENHANCED RISK FOR SEVERAL TORNADOES ACROSS PARTS OF THE MID-ATLANTIC ON WEDNESDAY... SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...37.3N 82.5W ABOUT 135 MI...220 KM W OF ROANOKE VIRGINIA ABOUT 135 MI...215 KM NE OF KNOXVILLE TENNESSEE MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H PRESENT MOVEMENT...NE OR 55 DEGREES AT 24 MPH...39 KM/H MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES WATCHES AND WARNINGS -------------------- Flood and Flash Flood Watches are in effect for portions of the central Appalachians, Mid-Atlantic, and into southern New York and southern New England. A Tornado Watch is in effect until 8 AM EDT Wednesday across the District of Columbia, central and northern Maryland, and northeastern Virginia. For the latest severe weather outlooks and status of watches, including Tornado Watches, please refer to the Storm Prediction Center. DISCUSSION AND OUTLOOK ---------------------- At 500 AM EDT (0900 UTC), the center of Tropical Depression Ida was located near latitude 37.3 North, longitude 82.5 West. The depression is moving toward the northeast near 24 mph (39 km/h) and this motion is expected to continue over the next couple days. Maximum sustained winds are near 30 mph (45 km/h) with higher gusts. Some strengthening is forecast later today and tonight as Ida becomes extratropical. The estimated minimum central pressure is 1000 mb (29.53 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Tropical Depression Ida will produce the following rainfall totals: Mid Atlantic to Southern New England: 3 to 8 inches with isolated higher amounts through Thursday. Significant and life-threatening flash flooding is likely from the Mid-Atlantic into southern New England, especially across highly urbanized metropolitan areas and areas of steep terrain. Widespread moderate and major river flooding impacts are forecast from northern West Virginia and western Maryland into southern Pennsylvania and New Jersey, particularly in the Monongahela, Potomac, Susquehanna, Delaware, and lower Hudson river basins. Widespread minor to isolated major river flooding is occurring or forecast from the Lower Mississippi Valley into far western Alabama and northeast Georgia. 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: www.wpc.ncep.noaa.gov/discussions/nfdscc4.html TORNADOES: Several tornadoes are probable across portions of the Mid Atlantic today, mainly during the afternoon and evening hours. NEXT ADVISORY ------------- Next complete advisory at 1100 AM EDT. $$ Forecaster Lamers FORECAST POSITIONS AND MAX WINDS INIT 01/0900Z 37.3N 82.5W 25 KT 30 MPH...INLAND 12H 01/1800Z 38.9N 79.1W 30 KT 35 MPH...POST-TROP/INLAND 24H 02/0600Z 41.2N 73.7W 35 KT 40 MPH...POST-TROP/INLAND 36H 02/1800Z 43.8N 68.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 48H 03/0600Z 46.1N 65.1W 35 KT 40 MPH...POST-TROP/EXTRATROP NNNN