Track: http://www.nhc.noaa.gov/refresh/graphics_at1+shtml/025127.shtml?5day?large#contents Satellite: http://www.ssd.noaa.gov/PS/TROP/floaters/11L/11L_floater.html http://rammb.cira.colostate.edu/products/tc_realtime/storm.asp?storm_identifier=AL112015 HURRICANE JOAQUIN DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015 1100 PM EDT WED SEP 30 2015 Joaquin has rapidly intensified during the past 24 hours with the satellite presentation continuing to improve this evening. The eye has recently become apparent near the center of the very symmetric central dense overcast. An Air Force Reserve Hurricane Hunter aircraft that has been investigating the hurricane this evening has measured peak 700 mb flight-level winds of 113 kt and 102 kt surface winds from the SFMR. These data support an initial intensity of 100 kt, making Joaquin the second major hurricane of the 2015 Atlantic hurricane season. NOTE: Communications problems have delayed the public release of the Air Force reconnaissance data. Joaquin continues to move slowly southwestward with an initial motion estimate of 220/5 kt. The hurricane is forecast to move slowly southwestward or west-southwestward for another 24 hours or so while it remains to the south of a narrow northeast to southwest oriented ridge. This ridge is expected to weaken by Friday as a trough deepens and cuts off over the southeastern United States. This should cause Joaquin to turn northward within 48 hours. The 18Z runs of the GFS and HWRF remain in general agreement with the 12Z UKMET and Canadian models moving Joaquin around the northeastern portion of the cut-off low and bring the hurricane inland over the Carolinas or mid-Atlantic states. The 12Z ECMWF remains the outlier by showing a track toward the northeast out to sea. The NHC forecast continues to follow the trend of the bulk of the guidance and takes Joaquin toward the U.S east coast. The NHC track is similar to the previous advisory and is once again east of the multi-model consensus. The NOAA G-IV aircraft has recently completed its synoptic surveillance flight, and data collected during this mission should be assimilated into the 0000 UTC models, hopefully reducing the spread of the track guidance. The upper-level wind pattern over the hurricane is forecast by the global models to become even more conducive during the next couple of days. This favors additional intensification, with the only possible limiting factors being upwelling of cool SSTs beneath the slow-moving hurricane and eyewall cycles which could cause some fluctuations in intensity. By 72 hours, increasing southwesterly shear, dry air intrusion, and lower SSTs are expected to cause gradual weakening. The updated NHC intensity forecast has been significantly increased from the previous advisory primarily due to the higher initial intensity. The official forecast is between the lower statistical guidance and the higher HWRF during the first 36-48 hours, and is near the SHIPS/LGEM guidance after that time. KEY MESSAGES: 1. Preparations to protect life and property within the warning areas in the Central Bahamas should be completed now. 2. Confidence in the details of the forecast after 72 hours remains low, since we have one normally excellent model that keeps Joaquin far away from the United States east coast. The range of possible outcomes is still large, and includes the possibility of a major hurricane landfall in the Carolinas. 3. Every effort is being made to provide the forecast models with as much data as possible. The NOAA G-IV jet has begun a series of missions in the storm environment, and the National Weather Service has begun launching extra balloon soundings. 4. Because landfall, if it occurs, is still more than three days away, it's too early to talk about specific wind, rain, or surge impacts from Joaquin in the United States. Regardless of Joaquin's track, strong onshore winds will create minor to moderate coastal flooding along the coasts of the mid-Atlantic and northeastern states through the weekend. 5. A hurricane watch for a portion of the U.S. coast could be required as early as Thursday evening. 6. Many portions of the eastern U.S. are currently experiencing heavy rains and gusty winds associated with a frontal system. These heavy rains are likely to continue for the next few days, even if the center of Joaquin stays offshore. The resulting inland flood potential could complicate preparations for Joaquin should it head toward the coast, and even more substantial inland flooding is possible if Joaquin later passes near or over these same areas. FORECAST POSITIONS AND MAX WINDS INIT 01/0300Z 23.8N 73.1W 100 KT 115 MPH 12H 01/1200Z 23.5N 73.8W 110 KT 125 MPH 24H 02/0000Z 23.6N 74.5W 120 KT 140 MPH 36H 02/1200Z 24.7N 74.8W 120 KT 140 MPH 48H 03/0000Z 26.6N 74.7W 110 KT 125 MPH 72H 04/0000Z 31.6N 74.7W 95 KT 110 MPH 96H 05/0000Z 36.2N 75.6W 85 KT 100 MPH 120H 06/0000Z 38.5N 76.5W 55 KT 65 MPH $$ Forecaster Brown HURRICANE JOAQUIN ADVISORY NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015 1100 PM EDT WED SEP 30 2015 ...JOAQUIN BECOMES A CATEGORY 3 HURRICANE AS IT MOVES TOWARD THE CENTRAL BAHAMAS... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...23.8N 73.1W ABOUT 90 MI...145 KM E OF SAN SALVADOR ABOUT 170 MI...275 KM E OF THE CENTRAL BAHAMAS MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H PRESENT MOVEMENT...SW OR 220 DEGREES AT 6 MPH...9 KM/H MINIMUM CENTRAL PRESSURE...951 MB...28.09 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of the Bahamas has issued a Tropical Storm Warning and a Hurricane Watch for Andros Island. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Central Bahamas including Cat Island, the Exumas, Long Island, Rum Cay, and San Salvador * Northwestern Bahamas including the Abacos, Berry Islands, Eleuthera, Grand Bahama Island, and New Providence A Hurricane Watch is in effect for... * Bimini * Andros Island A Tropical Storm Warning is in effect for... * Southeastern Bahamas including the Acklins, Crooked Island, Long Cay, the Inaguas, Mayaguana, and the Ragged Islands, but excluding the Turks and Caicos Islands. * Andros Island A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. Preparations to protect life and property should have already been completed in the Central Bahamas. A Hurricane Watch means that hurricane conditions are possible within the watch area. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 1100 PM EDT (0300 UTC), the center of Hurricane Joaquin was located near latitude 23.8 North, longitude 73.1 West. Joaquin is moving toward the southwest near 6 mph (9 km/h) and this general motion is expected to continue over the next 24 hours. A turn toward the northwest and north is forecast Thursday night or Friday. The center of Joaquin is expected to move near or over portions of the central Bahamas overnight and Thursday, and be near or over portions of the Northwestern Bahamas Thursday night or Friday. Data from an Air Force Reserve Hurricane Hunter Aircraft indicate that maximum sustained winds have increased to near 115 mph (185 km/h) with higher gusts. Joaquin is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Additional strengthening is forecast during the next day or so. Some fluctuations in intensity are possible Thursday night and Friday. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). The latest minimum central pressure estimated from reconnaissance data is 951 mb (28.09 inches). HAZARDS AFFECTING LAND ---------------------- WIND: Hurricane conditions are expected to reach portions of the Central Bahamas by early Thursday morning. Winds are expected to first reach tropical storm strength in the warning area tonight, making outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. Tropical storm conditions are expected in the southeastern Bahamas beginning tonight. Hurricane conditions are expected over portions of the Northwestern Bahamas Thursday night or Friday. STORM SURGE: A dangerous storm surge will raise water levels by as much as 5 to 8 feet above normal tide levels in the Central Bahamas in areas of onshore flow. A storm surge of 2 to 4 feet above normal tide levels is expected in the Northwest Bahamas within the Hurricane Warning area, and 1 to 2 feet is expected in the Southeast Bahamas. Near the coast, the surge will be accompanied by large and dangerous waves. RAINFALL: Joaquin is expected to produce total rain accumulations of 10 to 15 inches over the central Bahamas and 5 to 10 inches over the northwestern Bahamas and southeastern Bahamas. Isolated maximum amounts of 20 inches are possible in the central Bahamas. This rainfall could result in life-threatening flash floods. SURF: Swells generated by Joaquin will affect portions of the Bahamas during the next few days, and will begin to affect portions of the southeastern coast of the United States by Thursday. 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 EDT. Next complete advisory at 500 AM EDT. $$ Forecaster Brown/Stewart |