| Track: https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/?cone#contents Satellite: https://rammb-data.cira.colostate.edu/tc_realtime/storm.asp?storm_identifier=al202020 https://www.star.nesdis.noaa.gov/GOES/floater.php?stormid=AL202020#homePageLink Hurricane Teddy Discussion Number 34 NWS National Hurricane Center Miami FL AL202020 500 PM AST Sun Sep 20 2020 Satellite images show that Teddy is continuing to maintain a central core, albeit eroded on the western side due to shear and dry air. However, the latest microwave data show a more distinct eye than conventional data would indicate, along with an open eyewall. The initial intensity is held at 90 kt, pending Air Force Reserve Hurricane Hunter aircraft data this evening. The hurricane has turned north-northwestward and is likely to turn northward tonight and north-northeastward tomorrow due to an approaching large mid-latitude trough. By early Tuesday, the cyclone should turn back to the north-northwest as it rotates around the same trough, then turn northeastward early Wednesday ahead of yet another trough moving into from eastern Canada. Track model guidance remains in very good agreement, and only a slight westward adjustment was made to the forecast. The global models are in excellent agreement on Teddy transitioning into a large non-tropical low between Bermuda and Nova Scotia in about 2 days. In many respects, the upcoming trough interaction reminds me of an extratropical transition like Sandy 2012, thankfully happening at a good distance from land, with the GFS/ECMWF models showing pressures into the 940s tomorrow, a slight increase in maximum winds, and a large increase in the size of the tropical-storm-force winds. Beyond Tuesday, the hurricane should become post-tropical near or south of Nova Scotia and be absorbed by a larger extratropical low after day 4 to the northeast of Newfoundland. Little change was made to the official forecast, other than show a small increase tomorrow as the peak extratropical forcing deepens the cyclone. It is still worth noting every model has a rather large and strong post-tropical cyclone near Nova Scotia in 2-3 days, with hazards that will extend a very long way from the center. Extremely dangerous surf conditions with 20-ft waves have been reported on the south shore of Bermuda, and officials are encouraging residents to avoid going into or near the water. Key Messages: 1. The center of Teddy is forecast to move east of Bermuda on Monday. Tropical storm conditions are likely on the island beginning this evening and could continue into Monday evening. 2. Teddy is expected to transition to a powerful post-tropical cyclone as it moves near or over portions of Atlantic Canada late Tuesday through Thursday, where there is an increasing risk of direct impacts from wind, rain, and storm surge. A Tropical Storm Watch has been issued for portions of Nova Scotia, and heavy rain is also expected across sections of Atlantic Canada. 3. Large swells produced by Teddy are expected to affect portions of Bermuda, the Leeward Islands, the Greater Antilles, the Bahamas, the east coast of the United States, and Atlantic Canada during the next few days. These swells could cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 29.0N 63.4W 90 KT 105 MPH 12H 21/0600Z 30.1N 63.5W 85 KT 100 MPH 24H 21/1800Z 32.8N 62.6W 90 KT 105 MPH 36H 22/0600Z 36.9N 63.0W 90 KT 105 MPH 48H 22/1800Z 40.0N 64.0W 85 KT 100 MPH 60H 23/0600Z 42.7N 63.5W 75 KT 85 MPH...POST-TROP/INLAND 72H 23/1800Z 46.0N 61.3W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 24/1800Z 54.5N 50.5W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 25/1800Z...DISSIPATED $$ Forecaster Blake Hurricane Teddy Advisory Number 34 NWS National Hurricane Center Miami FL AL202020 500 PM AST Sun Sep 20 2020 ...TROPICAL STORM WATCH ISSUED FOR PORTIONS OF NOVA SCOTIA... ...DANGEROUS RIP CURRENTS FORECAST ALONG WESTERN ATLANTIC BEACHES FOR SEVERAL DAYS... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...29.0N 63.4W ABOUT 245 MI...390 KM SSE OF BERMUDA MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H PRESENT MOVEMENT...NNW OR 330 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...964 MB...28.47 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Canadian Hurricane Centre has issued a Tropical Storm Watch for the coast of Nova Scotia from Lower East Pubnico to Canso. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Bermuda A Tropical Storm Watch is in effect for... * Lower East Pubnico to Canso Nova Scotia A Tropical Storm Warning means that tropical storm conditions are expected within the warning area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere in Atlantic Canada should closely monitor the progress of Teddy. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 500 PM AST (2100 UTC), the center of Hurricane Teddy was located near latitude 29.0 North, longitude 63.4 West. Teddy is moving toward the north-northwest near 9 mph (15 km/h). A turn toward the north is expected tonight, and Teddy is then forecast to continue generally northward for another couple days. On the forecast track, Teddy will approach Bermuda tonight, and the center should pass east of the island Monday morning. Teddy is forecast to be approaching Nova Scotia late Tuesday or Wednesday. Maximum sustained winds are near 105 mph (165 km/h) with higher gusts. Little change in strength is forecast, and the system is expected to remain a large and powerful hurricane through Tuesday, then become a strong post-tropical cyclone on Wednesday. Teddy is a large hurricane. Hurricane-force winds extend outward up to 80 miles (130 km) from the center and tropical-storm-force winds extend outward up to 230 miles (370 km). The estimated minimum central pressure is 964 mb (28.47 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Teddy can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT5 and WMO header WTNT45 KNHC and on the web at www.hurricanes.gov/text/MIATCDAT5.shtml. WIND: Tropical storm conditions are expected to affect Bermuda tonight and could continue into Monday night. Tropical storm conditions could begin over Nova Scotia on Tuesday afternoon. SURF: Large swells generated by Teddy are affecting Bermuda, the Lesser Antilles, the Greater Antilles, the Bahamas, the east coast of the United States, and Atlantic Canada. These swells are likely to cause life- threatening surf and rip current conditions. Please consult products from your local weather office. RAINFALL: From Tuesday through Thursday, Teddy is expected to produce rainfall accumulations of 2 to 4 inches (50 to 100 mm) with isolated totals of 6 inches (150 mm) across sections of Atlantic Canada. NEXT ADVISORY ------------- Next intermediate advisory at 800 PM AST. Next complete advisory at 1100 PM AST. $$ Forecaster Blake |