| NHC: https://www.nhc.noaa.gov/ Satellite floaters: https://www.star.nesdis.noaa.gov/GOES/floater.php?stormid=AL132023 https://rammb-data.cira.colostate.edu/tc_realtime/storm.asp?storm_identifier=al132023 U.S. East Coast satellite view: https://www.star.nesdis.noaa.gov/GOES/sector_band.php?sat=G16§or=eus&band=13&length=12 Canada satellite view: https://www.star.nesdis.noaa.gov/GOES/sector_band.php?sat=G16§or=eus&band=13&length=12 SLIDER display from Colorado State: https://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=full_disk&x=11600&y=1880&z=2&angle=0&im=12&ts=1&st=0&et=0&speed=130&motion=loop&maps%5Bborders%5D=white&p%5B0%5D=band_13&opacity%5B0%5D=1&pause=0&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&draw_color=FFD700&draw_width=6 Post-Tropical Cyclone Lee Discussion Number 44 NWS National Hurricane Center Miami FL AL132023 500 AM AST Sat Sep 16 2023 Lee appears to have completed its transition to a post-tropical cyclone. The cloud pattern is comma shaped, and there has been no significant central deep convection for the past 12 hours or so. The cyclone is now frontal but likely still has a warm core, indicating that it is a warm seclusion-type of extratropical cyclone. Despite this transition, it remains a potent cyclone, and the initial intensity remains 70 kt since the Air Force Reserve Hurricane Hunters measured SFMR winds as high as 66 kt about 110 n mi southwest of the center. Lee accelerated more than expected during the past 6-12 hours, and the current motion is estimated to be northward (355 degrees) at 22 kt. The aircraft fixes and recent satellite imagery indicate that the center has bent back to the west by just a bit, which was expected, likely due to interaction with a mid-level trough which moved off the U.S. Mid-Atlantic coast. A general northward motion, but at a slower forward speed, is expected today, and Lee's center is now forecast to reach western Nova Scotia around midday. The cyclone is then expected to turn toward the north-northeast and then northeast, moving across Atlantic Canada and the Gulf of St. Lawrence tonight through Sunday. Due to the recent acceleration, the new NHC track forecast is faster than, but still otherwise on top of, the previous prediction. Lee's center has moved north of the Gulf Stream, and water temperatures along the cyclone's path are down to 20 degrees Celsius and decreasing. Intensity models indicate that Lee should begin gradually weakening very soon, although the maximum winds are likely to still be at or just below hurricane strength (mainly over water) when Lee's center reaches Nova Scotia later today. The NHC intensity forecast closely follows the GFS and ECMWF solutions, and Lee is expected to continue producing gale-force winds while it moves across Atlantic Canada tonight through Sunday. KEY MESSAGES: 1. Hurricane conditions are possible across portions southern New Brunswick and Nova Scotia later today within the Hurricane Watch areas. Tropical storm conditions and coastal flooding are occurring across portions of coastal New England and Atlantic Canada, and will continue to spread northward within the Tropical Storm Warning areas. The strong winds are likely to lead to downed trees and potential power outages. 2. Heavy rainfall from Lee may produce localized urban and small stream flooding in portions of far eastern Massachusetts, eastern Maine, New Brunswick, and western Nova Scotia today. 3. Dangerous surf and life-threatening rip currents will continue to affect the U.S. East Coast, Atlantic Canada, Bermuda, the Bahamas, the Turks and Caicos Islands, Hispaniola, Puerto Rico, the Virgin Islands, and the northern Leeward Islands through the weekend. FORECAST POSITIONS AND MAX WINDS INIT 16/0900Z 41.8N 66.0W 70 KT 80 MPH...POST-TROP/EXTRATROP 12H 16/1800Z 44.1N 65.6W 55 KT 65 MPH...POST-TROP/EXTRATROP 24H 17/0600Z 46.8N 64.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 36H 17/1800Z 49.5N 60.1W 40 KT 45 MPH...POST-TROP/EXTRATROP 48H 18/0600Z 52.3N 53.4W 40 KT 45 MPH...POST-TROP/EXTRATROP 60H 18/1800Z...ABSORBED BY ANOTHER LOW $$ Forecaster Berg Post-Tropical Cyclone Lee Advisory Number 44 NWS National Hurricane Center Miami FL AL132023 500 AM AST Sat Sep 16 2023 ...LEE BECOMES POST-TROPICAL AS IT APPROACHES NOVA SCOTIA, BUT IT IS STILL PRODUCING HURRICANE-FORCE WINDS... ...NHC ADVISORIES WILL CONTINUE... SUMMARY OF 500 AM AST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...41.8N 66.0W ABOUT 230 MI...365 KM SSW OF HALIFAX NOVA SCOTIA ABOUT 220 MI...355 KM SSE OF EASTPORT MAINE MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...N OR 355 DEGREES AT 25 MPH...41 KM/H MINIMUM CENTRAL PRESSURE...965 MB...28.50 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Watch is in effect for... * New Brunswick from the U.S./Canada border to Point Lepreau, including Grand Manan Island * Nova Scotia from Digby to Ecum Secum A Tropical Storm Warning is in effect for... * Westport Massachusetts northward to the U.S./Canada border * Martha's Vineyard * Nantucket * New Brunswick from the U.S./Canada border to Fort Lawrence, including Grand Manan Island * New Brunswick from Shediac to Tidnish * Nova Scotia from Fort Lawrence to Point Tupper A Tropical Storm Watch is in effect for... * Prince Edward Island * Magdalen Islands * New Brunswick from Belledune to Shediac * Nova Scotia from Tidnish to Aulds Cove * Nova Scotia from Aulds Cove to Meat Cove to Point Tupper A Hurricane Watch means that hurricane conditions are possible within the watch area, in this case later today. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning, in this case today through Sunday. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 500 AM AST (0900 UTC), the center of Post-Tropical Cyclone Lee was located near latitude 41.8 North, longitude 66.0 West. Lee is moving toward the north near 25 mph (41 km/h). A northward motion but at a slower forward speed is expected later today, and the center of Lee is forecast to reach western Nova Scotia around midday. Lee is then expected to turn toward the north-northeast and northeast and move across Atlantic Canada tonight and Sunday. Data from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds remain near 80 mph (130 km/h) with higher gusts. Lee is expected to be at or just below hurricane strength when it reaches Nova Scotia later today. Weakening is forecast tonight and Sunday while Lee moves across Atlantic Canada. Hurricane-force winds extend outward up to 140 miles (220 km) from the center and tropical-storm-force winds extend outward up to 390 miles (630 km). A sustained wind of 47 mph (76 km/h) and a gust to 56 mph (91 km/h) was recently reported at Brier Island, Nova Scotia. A sustained wind of 43 mph (69 km/h) and a gust to 59 mph (94 km/h) were recently measured at Dennis, Massachusetts. The minimum central pressure based on dropsonde data is 965 mb (28.50 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Lee can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC and on the web at hurricanes.gov/text/MIATCDAT3.shtml WIND: Hurricane conditions are possible in the Hurricane Watch areas in Atlantic Canada later today. Tropical storm conditions are occurring along the coasts of New England and Nova Scotia and will spread northward within the Tropical Storm Warning areas today and tonight. The strong winds are likely to lead to downed trees and potential power outages. SURF: Swells generated by Lee are affecting the U.S. Virgin Islands, Puerto Rico, Hispaniola, the Turks and Caicos Islands, the Bahamas, Bermuda, 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: Through tonight, Lee is expected to produce rainfall amounts of 1 to 4 inches (25 to 100 millimeters) over far eastern Massachusetts, eastern Maine, western Nova Scotia, and New Brunswick. This may produce localized urban and small stream flooding. STORM SURGE: The combination of storm surge and 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... Watch Hill, RI to the U.S./Canada border...1-3 ft Cape Cod...1-3 ft Martha's Vineyard and Nantucket...1-3 ft Boston Harbor...1-3 ft The deepest water will occur along the immediate coast where the surge will be accompanied by large and destructive waves. 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. A dangerous storm surge will produce coastal flooding within the wind warning areas in Atlantic Canada in areas of onshore winds. Near the coast, the surge will be accompanied by large and destructive waves. NEXT ADVISORY ------------- Next intermediate advisory at 800 AM AST. Next complete advisory at 1100 AM AST. $$ Forecaster Berg Post-tropical Lee now has a tropical storm force wind field 644 to 702 miles wide according to the 5am EDT Saturday NHC forecast advisory. U.S. Tides: https://tidesandcurrents.noaa.gov/ Canada Tides (red triangles on map have real time data): https://www.tides.gc.ca/en/stations Canadian Hurricane Centre: forecasts and products: https://www.canada.ca/en/environment-climate-change/services/hurricane-forecasts-facts/products.html U.S. Radar: https://mrms.nssl.noaa.gov/qvs/product_viewer/index.php?time_mode=update&zoom=6&clon=-71.3&clat=43.5&product_type=crefls&product=CREF&looping_active=on Canada Radar: https://weather.gc.ca/?layers=,radar Maine River Levels: https://water.weather.gov/ahps/region.php?state=me Quantitative Precipitation Forecasts from the Weather Prediction Center for estimated forecast rain totals: https://www.wpc.ncep.noaa.gov/#page=qpf Recon is still occurring: https://hurricanecity.com/recon/ Not often they are that far north. Air Force mission left the storm hours ago and now NOAA mission is approaching. Air Force mission went all the way from Biloxi and took over four and a half hours to fly to the center of the storm, did part of a pattern, went back through the center and are now on the way home to Biloxi. They sure work hard. |