| Track: https://www.nhc.noaa.gov/refresh/graphics_at3+shtml/?cone#contents Some highlights from the 11pm AST Sunday advisory: "Hurricane and Tropical Storm Watches have been issued for the Azores, and these winds could start late Tuesday or early Wednesday." "The Portuguese Institute for the Sea and the Atmosphere has issued a Hurricane Watch for the central and western Azores, including the islands of Flores, Corvo, Faial, Pico, Sao Jorge, Graciosa, and Terceira. The Institute has also issued a Tropical Storm Watch for the eastern Azores, including the islands of Sao Miguel and Santa Maria." "It should be emphasized that even though the peak winds are down since yesterday, the area of the hurricane-force winds has more than doubled during that time." "Lorenzo is forecast to remain a large and powerful hurricane while it passes near the Azores." "Lorenzo is likely to be a category 1 or 2 hurricane near the Azores." "Large swells generated by Lorenzo will continue to spread across much of the north Atlantic basin during the next few days. These swells will produce life-threatening surf and rip currents." GFS: https://www.tropicaltidbits.com/analysis/models/?model=gfs®ion=atl&pkg=mslp_uv850 Euro: https://www.tropicaltidbits.com/analysis/models/?model=ecmwf®ion=atl&pkg=mslp_uv850 Satellite: http://rammb.cira.colostate.edu/products/tc_realtime/storm.asp?storm_identifier=AL132019 https://www.star.nesdis.noaa.gov/GOES/floater.php?stormid=AL132019 https://rammb-slider.cira.colostate.edu/?sat=goes-16&z=2&im=12&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=full_disk&p%5B0%5D=band_13&x=15616&y=4040 Hurricane Lorenzo Discussion Number 31 NWS National Hurricane Center Miami FL AL132019 1100 PM AST Sun Sep 29 2019 There haven't been a lot of changes with Lorenzo this evening, with a small cloud-filled eye remaining visible and an enormous cloud shield expanding in the northern semicircle. Satellite intensity estimates support a somewhat lower intensity than the previous advisory, so the initial wind speed is set to 95 kt. It should be emphasized that even though the peak winds are down since yesterday, the area of the hurricane-force winds has more than doubled during that time. Earlier aircraft data indicated that the large hurricane is upwelling a significant amount of cooler waters under the storm, and this is anticipated to cause Lorenzo to slowly weaken during the next couple of days. While the SSTs drop off considerably after late tomorrow, which would normally cause faster weakening, most of the guidance is showing a favorable trough interaction at that time with strong upper-level divergence. These effects are expected to offset, and Lorenzo is likely to be a category 1 or 2 hurricane near the Azores. Little change was made to the previous forecast, except to raise the intensity a little higher near the Azores after more heavily weighting the global models, which have been good performers for this cyclone. The guidance is in very good agreement on Lorenzo becoming an extratropical cyclone in about 72 hours, and that is reflected in the latest forecast. Lorenzo continues north-northeastward at 9 kt through a break in the subtropical ridge. The forecast track confidence remains very high through 48 hours as the hurricane is accelerated toward the northeast ahead of a mid-latitude trough, and the new forecast is essentially an update of the previous one. After that time, however, there is a very large spread in the guidance caused by whether Lorenzo is captured by the mid-latitude trough or if it remains separate. There isn't much change in the newest guidance, although it should be noted that the 12Z ECMWF solution is pretty far east of its ensemble mean. The forecast track confidence is extremely low beyond 72 hours, and the new NHC track was nudged just a little to the left from the previous advisory, slightly east of the various consensus aids. Key Messages: 1. Lorenzo is a large and powerful hurricane, and its hurricane- and tropical-storm-force wind fields are expected to expand further during the next several days. Hurricane and Tropical Storm Watches have been issued for the Azores, and these winds could start late Tuesday or early Wednesday. 2. Large swells generated by Lorenzo will continue to spread across much of the north Atlantic basin during the next few days. These swells will produce life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 30/0300Z 27.6N 43.5W 95 KT 110 MPH 12H 30/1200Z 28.9N 42.9W 90 KT 105 MPH 24H 01/0000Z 31.0N 41.5W 90 KT 105 MPH 36H 01/1200Z 33.9N 38.6W 85 KT 100 MPH 48H 02/0000Z 37.5N 34.2W 85 KT 100 MPH 72H 03/0000Z 48.0N 22.5W 70 KT 80 MPH...POST-TROP/EXTRATROP 96H 04/0000Z 53.0N 17.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 05/0000Z 54.0N 17.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Blake Hurricane Lorenzo Advisory Number 31 NWS National Hurricane Center Miami FL AL132019 1100 PM AST Sun Sep 29 2019 ...HURRICANE WATCH ISSUED FOR THE WESTERN AND CENTRAL AZORES... SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...27.6N 43.5W ABOUT 1195 MI...1920 KM WSW OF THE AZORES MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H PRESENT MOVEMENT...NNE OR 20 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...952 MB...28.12 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Portuguese Institute for the Sea and the Atmosphere has issued a Hurricane Watch for the central and western Azores, including the islands of Flores, Corvo, Faial, Pico, Sao Jorge, Graciosa, and Terceira. The Institute has also issued a Tropical Storm Watch for the eastern Azores, including the islands of Sao Miguel and Santa Maria. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Watch is in effect for... Flores, Corvo, Faial, Pico, Sao Jorge, Graciosa, Terceira A Tropical Storm Watch is in effect for... Sao Miguel, Santa Maria A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. A Hurricane Warning will likely be issued for some of these areas on Monday morning. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM AST (0300 UTC), the center of Hurricane Lorenzo was located near latitude 27.6 North, longitude 43.5 West. Lorenzo is moving toward the north-northeast near 10 mph (17 km/h). A turn to the northeast is expected on Monday with a gradual increase in forward speed through Wednesday. On the forecast track, the center of Lorenzo is expected to pass near the Azores early on Wednesday. Maximum sustained winds are near 110 mph (175 km/h) with higher gusts. Some weakening is forecast during the next 48 hours, but Lorenzo is forecast to remain a large and powerful hurricane while it passes near the Azores. Hurricane-force winds extend outward up to 90 miles (150 km) from the center and tropical-storm-force winds extend outward up to 255 miles (405 km). The estimated minimum central pressure is 952 mb (28.12 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Lorenzo can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC and on the web at www.hurricanes.gov/text/MIATCDAT3.shtml WIND: Hurricane conditions are possible within the hurricane watch area by early Wednesday, with tropical storm conditions possible by late Tuesday in the Azores. RAINFALL: Lorenzo is expected to produce total rain accumulations of 3 to 6 inches over much of the western Azores and 1 to 2 inches over the central Azores Tuesday and Wednesday. This rainfall could cause life-threatening flash flooding in the western Azores. SURF: Swells generated by Lorenzo are spreading across much of the North Atlantic basin. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 200 AM AST. Next complete advisory at 500 AM AST. $$ Forecaster Blake |