ZCZC NFDTCPAT4 ALL TTAA00 KWNH DDHHMM BULLETIN Post-Tropical Cyclone Nicholas Advisory Number 18 NWS Weather Prediction Center College Park MD AL142021 1000 AM CDT Thu Sep 16 2021 ...POST-TROPICAL CYCLONE NICHOLAS ON THE CENTRAL LOUISIANA COAST... ...FLASH FLOODING REMAINS A POSSIBILITY ACROSS PORTIONS OF THE CENTRAL GULF COAST OVER THE NEXT COUPLE OF DAYS... SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...29.8N 91.7W ABOUT 115 MI...185 KM SSE OF ALEXANDRIA LOUISIANA ABOUT 35 MI...55 KM SSE OF LAFAYETTE LOUISIANA MAXIMUM SUSTAINED WINDS...25 MPH...35 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 2 MPH...4 KM/H MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES WATCHES AND WARNINGS -------------------- Flash Flood Watches are in effect along the central Gulf Coast from portions of southeast Louisiana, across southern Mississippi and Alabama, to the Florida Panhandle. DISCUSSION AND OUTLOOK ---------------------- At 1000 AM CDT (1500 UTC), the center of Post-Tropical Nicholas was located near latitude 29.8 North, longitude 91.7 West. The circulation associated with Nicholas was moving slowly to the north around 2 mph (4 km/h) and this motion is expected to continue through Friday. The heaviest rainfall associated with the post-tropical low will continue to be well removed to the east of the circulation today. However, there is some chance for thunderstorm development closer to the cyclone center, and these thunderstorms could pose a risk of locally heavy rainfall, while additional thunderstorms continue to move northeast from the Gulf of Mexico across southeast Louisiana, southern Mississippi and Alabama, to the Florida Panhandle. Maximum sustained winds are near 25 mph (35 km/h) with higher gusts. The system is forecast to remain relatively weak through 48 hours. The estimated minimum central pressure is 1007 mb (29.74 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Nicholas is expected to produce additional rainfall of 2 to 4 inches across the central Gulf coast Friday, with isolated amounts of 6 inches possible. Flash flooding impacts, especially in urban areas, are possible across these regions. Widespread minor river flooding is expected, while scattered moderate river flooding is possible, across portions of southeastern Louisiana, southern Mississippi, southern Alabama, and the Florida Panhandle. For the latest rainfall reports and wind gusts associated with Post-Tropical Cyclone Nicholas see the companion storm summary at WBCSCCNS4 with the WMO header ACUS44KWBC or at the following link: https://www.wpc.ncep.noaa.gov/discussions/nfdscc4.html NEXT ADVISORY ------------- Next complete advisory at 400 PM CDT. $$ Forecaster Carbin FORECAST POSITIONS AND MAX WINDS INIT 16/1500Z 29.8N 91.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 12H 17/0000Z 30.1N 91.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 24H 17/1200Z 31.1N 91.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 18/0000Z 32.4N 91.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 18/1200Z 33.1N 91.9W 20 KT 25 MPH...POST-TROP/REMNT LOW NNNN