| "Helene has maintained deep convection this afternoon though only in the northern semicircle." "The Government of Portugal has issued a Tropical Storm Watch for all of the Azores Islands." Floater: https://www.ssd.noaa.gov/PS/TROP/floaters/08L/08L_floater.html Track: https://www.nhc.noaa.gov/refresh/graphics_at3+shtml/?cone#contents I thought I would mention it since watches went up. Tropical Storm Helene Advisory Number 26 NWS National Hurricane Center Miami FL AL082018 500 PM AST Thu Sep 13 2018 ...TROPICAL STORM WATCHES ISSUED FOR THE AZORES ISLANDS FOR HELENE... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...26.3N 37.0W ABOUT 1035 MI...1670 KM SW OF LAJES AIR BASE IN THE AZORES MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...N OR 5 DEGREES AT 21 MPH...33 KM/H MINIMUM CENTRAL PRESSURE...993 MB...29.33 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Government of Portugal has issued a Tropical Storm Watch for all of the Azores Islands. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Watch is in effect for... All of the Azores Islands A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. DISCUSSION AND OUTLOOK ---------------------- At 500 PM AST (2100 UTC), the center of Tropical Storm Helene was located near latitude 26.3 North, longitude 37.0 West. Helene is moving toward the north near 21 mph (33 km/h). The system is expected to accelerate and turn toward the northeast by Monday. On this forecast track, Helene will be crossing over or near the Azores late Saturday or Sunday. Maximum sustained winds are near 65 mph (100 km/h) with higher gusts. Little change in strength is forecast during the next 48 hours. Tropical-storm-force winds extend outward up to 140 miles (220 km) from the center. The estimated minimum central pressure is 993 mb (29.33 inches). HAZARDS AFFECTING LAND ---------------------- WIND: Tropical storm conditions are possible within the watch area by late Saturday. RAINFALL: Helene is expected to produce total rainfall amounts of 2 to 4 inches across the Azores, with isolated amounts up to 8 inches across the western Azores. This rainfall may cause life-threatening flash flooding. SURF: Swells generated by Helene are affecting portions of the Azores. 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 800 PM AST. Next complete advisory at 1100 PM AST. $$ Forecaster Landsea Tropical Storm Helene Discussion Number 26 NWS National Hurricane Center Miami FL AL082018 500 PM AST Thu Sep 13 2018 Helene has maintained deep convection this afternoon though only in the northern semicircle. Dvorak estimates from TAFB and SAB are continuing to drop, and a blend of these with the CIMSS SATCON supports lowering the intensity to 55 kt. Strong tropospheric vertical shear along with only lukewarm waters are likely contributing toward Helene's weakening. The shear should further increase during the next two days, though the sea surface temperatures will rebound up to 27C along with an increase in low-level moisture. Helene is expected to be either slowly weakening or steady state during this time. Beginning in about three days, Helene will commence baroclinic transition, and it is expected to become an extratropical cyclone by 96 hours. The baroclinic forcing should preclude any additional weakening through the remainder of the forecast period, and the official intensity forecast is nearly the same as the last advisory. This prediction is based on a blend of the stronger HWRF/COAMPS dynamical models and the weaker SHIPS/LGEM statistical schemes for the next couple of days, and is based on a blend of the GFS/ECMWF/UKMET global models at the extended lead times. Helene is moving northward at about 12 kt between the subtropical ridge to its east and a deep-layer trough to its west. The system should accelerate and turn toward the northeast over the next few days as it rounds the subtropical ridge and starts getting picked up by the mid-latitude westerlies. The official track forecast is based upon the tightly clustered variable consensus technique (TVCN) and is nearly the same as the previous forecast. FORECAST POSITIONS AND MAX WINDS INIT 13/2100Z 26.3N 37.0W 55 KT 65 MPH 12H 14/0600Z 28.8N 36.7W 50 KT 60 MPH 24H 14/1800Z 32.3N 35.8W 50 KT 60 MPH 36H 15/0600Z 35.5N 34.2W 50 KT 60 MPH 48H 15/1800Z 37.9N 31.7W 50 KT 60 MPH 72H 16/1800Z 40.6N 24.4W 50 KT 60 MPH 96H 17/1800Z 44.0N 17.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 18/1800Z 51.0N 7.5W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Landsea |