BOCA RATON, FL (BocaNewsNow.com) — Isaias remains a strong tropical storm at 11 p.m., but the National Hurricane Center says a return to hurricane strength is likely overnight. The storm is expected to affect Palm Beach County over the next several hours into mid-day Sunday.
Here’s the 11 p.m. update from the National Hurricane Center:
BULLETIN Tropical Storm Isaias Advisory Number 20 NWS National Hurricane Center Miami FL AL092020 1100 PM EDT Sat Aug 01 2020 ...ISAIAS CONTINUES TO SLOWLY APPROACH THE SOUTHEAST FLORIDA COAST... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...25.5N 79.1W ABOUT 80 MI...130 KM ESE OF FORT LAUDERDALE FLORIDA ABOUT 105 MI...165 KM SE OF WEST PALM BEACH FLORIDA MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Boca Raton to the Volusia/Flagler County Line Florida * Bimini, the Berry Islands, and Grand Bahama Island A Storm Surge Watch is in effect for... * Jupiter Inlet to Ponte Vedra Beach Florida A Tropical Storm Warning is in effect for... * North of Ocean Reef to south of Boca Raton Florida * Lake Okeechobee * Volusia/Flagler County Line to Ponte Vedra Beach Florida A Tropical Storm Watch is in effect for... * North of Ponte Vedra Beach Florida to South Santee River South Carolina Interests elsewhere along the southeast and mid-Atlantic coasts of the United States should monitor the progress of Isaias. Additional watches or warnings may be required tonight or Sunday. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. Preparations to protect life and property should be rushed to completion. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. 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 1100 PM EDT (0300 UTC), the center of Tropical Storm Isaias was located near latitude 25.5 North, longitude 79.1 West. Isaias is moving toward the northwest near 9 mph (15 km/h). A general northwestward motion with some decrease in forward speed is expected for the next day or so, followed by a north-northwestward motion by late Sunday. A turn toward the north and north-northeast is anticipated on Monday and Tuesday with an increase in forward speed. On the forecast track, the center of Isaias will approach the southeast coast of Florida tonight and early Sunday and move near or along the east coast of Florida Sunday and Sunday night. On Monday and Tuesday, the center of Isaias will move from offshore of the coast of Georgia into the southern mid-Atlantic states. Maximum sustained winds are near 70 mph (110 km/h) with higher gusts. Some restrengthening is possible, and Isaias could regain hurricane strength early Sunday. Slow weakening is expected to begin Sunday night and continue through Monday. Tropical-storm-force winds extend outward up to 115 miles (185 km) from the center. A Weatherflow site in Morningside Park in Miami recently reported a wind gust to 41 mph (66 km/h). An unofficial observing station on Great Harbour Cay recently reported a wind gust of 40 mph (64 km/h). The minimum central pressure estimated from Air Force Hurricane Hunter observations is 995 mb (29.39 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Isaias can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT4.shtml. STORM SURGE: The combination of a dangerous storm surge and the 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... Jupiter Inlet to Ponte Vedra Beach FL...2-4 ft North Miami Beach to Jupiter Inlet FL...1-3 ft The deepest water will occur along the immediate coast near and to the right of the center, where the surge will be accompanied by large 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 raise water levels by as much as 3 to 5 feet above normal tide levels in areas of onshore winds in the Northwestern Bahamas. WIND: Hurricane and tropical storm conditions will continue over portions of the Northwestern Bahamas through Sunday morning. Hurricane conditions are expected to reach the coast within the hurricane warning area in Florida Sunday morning and will spread northward through Sunday night. Winds are expected to first reach tropical storm strength later tonight, making outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. Tropical storm conditions are expected within the tropical storm warning area in South Florida Sunday morning. Tropical storm conditions are expected in the warning area in northeast Florida by Sunday night, and are possible in the watch area from northeast Florida to South Carolina on Monday. RAINFALL: Isaias is expected to produce the following rain accumulations: Bahamas: 4 to 8 inches, with isolated maximum totals of 12 inches. Cuba: 1 to 2 inches, with isolated maximum totals of 4 inches. Eastern Florida: 2 to 4 inches, with isolated maximum totals of 6 inches. Northeast Florida and coastal Georgia: 1 to 3 inches. Carolinas and the mid Atlantic, including the southern and central Appalachians: 2 to 5 inches, with isolated maximum totals of 7 inches. Southeast New York and much of New England: 2 to 4 inches, with isolated maximum totals of 6 inches. Heavy rainfall from Isaias could result in potentially life-threatening flash flooding in the Bahamas and flash and urban flooding along the East Coast of the United States. Minor river flooding and isolated moderate river flooding is possible across portions of the Carolinas and mid Atlantic. SURF: Swells generated by Isaias are affecting portions of Hispaniola, eastern Cuba, the Turks and Caicos, and the Bahamas. These swells will spread along the east coast of Florida and the southeastern United States coast through Sunday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.
Here is the 11 p.m. “discussion” from the National Hurricane Center.
Tropical Storm Isaias Discussion Number 20 NWS National Hurricane Center Miami FL AL092020 1100 PM EDT Sat Aug 01 2020 Deep convection has increased this evening in a cluster to the east and northeast of the aircraft-observed center position. Radar data suggests a mid-level center or vorticity maximum in that area, which is between Grand Bahama and Andros Island. Observations from the Air Force Hurricane Hunters indicate that Isaias has not restrengthened thus far, but there is still a small window of opportunity for it to regain hurricane intensity Sunday while passing over the Gulf Stream waters. Synoptic surveillance data from the NOAA Gulfstream-IV aircraft indicate that the upper-level west-southwesterly flow over Isais will begin to increase by late Sunday. The resulting increase in shear and interaction with land should cause weakening beyond 24 hours, and the official intensity forecast is near or above the intensity model consensus. Assuming that the aforementioned mid-level feature is not the dominant center of circulation, the aircraft fixes give a motion estimate of about 310/8 kt. Isais has been moving northwestward along the southwestern periphery of a mid-level high pressure area. An approaching trough near the Ohio Valley is expected to cause the tropical cyclone to turn northward within 48 hours. After that, Isaias should accelerate north-northeastward to northeastward ahead of the trough, and move near or over the east coast of the United States. The official track forecast remains close to both the simple and corrected dynamic model consensus tracks, TVCN and HCCA respectively. Key Messages: 1. Hurricane conditions and dangerous storm surge will continue in portions of the northwest Bahamas through Sunday morning. 2. Hurricane conditions are expected along portions of the Florida east coast on Sunday with tropical storm conditions expected to begin late tonight. Preparations to protect life and property should be rushed to completion. 3. Dangerous storm surge is possible along the Florida east coast from Jupiter Inlet to Ponte Vedra Beach where water rises of 2 to 4 feet above ground level are possible along the immediate coastline and adjacent waterways. Residents there should follow advice given by local emergency officials. 4. Isaias will produce heavy rains and potentially life-threatening flash flooding in the Bahamas, and flash and urban flooding, especially in low-lying and poorly drained areas, along the east coast of the United States. Minor river flooding and isolated moderate river flooding is possible across portions of the Carolinas and mid Atlantic early next week. 5. Tropical storm watches and warnings are in effect for portions of the United States East Coast from northeast Florida to South Carolina. Additional watches and warnings will likely be issued on Sunday as Isaias is expected to move northward near or over the southeast and mid-Atlantic coasts early next week. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 25.5N 79.1W 60 KT 70 MPH 12H 02/1200Z 26.6N 79.9W 65 KT 75 MPH 24H 03/0000Z 28.0N 80.5W 65 KT 75 MPH...ON COAST 36H 03/1200Z 29.7N 80.8W 60 KT 70 MPH 48H 04/0000Z 32.0N 80.0W 55 KT 65 MPH 60H 04/1200Z 35.3N 78.1W 50 KT 60 MPH...INLAND 72H 05/0000Z 39.7N 74.8W 40 KT 45 MPH...INLAND 96H 06/0000Z 47.0N 66.0W 35 KT 40 MPH...POST-TROP/INLAND 120H 07/0000Z 51.5N 57.5W 30 KT 35 MPH...POST-TROP/INLAND
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