| NHC sure is busy. Forecast as of posting this is to strengthen to 110mph. Some storms are really able to strengthen in Bay of Campeche. Track: http://www.nhc.noaa.gov/refresh/graphics_at3+shtml/?cone#contents Satellite: Floater: http://www.ssd.noaa.gov/PS/TROP/floaters/13L/13L_floater.html Gulf: http://www.ssd.noaa.gov/imagery/gmex.html Other areas of Atlantic: http://www.ssd.noaa.gov/PS/TROP/trop-atl.html Hurricane Katia Discussion Number 6 NWS National Hurricane Center Miami FL AL132017 1000 PM CDT Wed Sep 06 2017 Satellite images indicate that Katia has a small symmetric central dense overcast with very deep convection near the center. Subjective and objective Dvorak estimates have risen since the past advisory and, after accounting for the low bias earlier, support an initial wind speed of 70 kt. With wind shear forecast to drop while the hurricane remains over very warm waters, it is puzzling to see that most of the regional hurricane guidance is only showing a small increase in wind speed. Although this area of the Gulf of Mexico is known for significant upwelling, Katia is a rather small tropical cyclone that shouldn't stir up as much cool water from below as most hurricanes would. After considering the potential upwelling and the extremely favorable upper-level environment, the intensity forecast is raised from the previous one, but could be conservative since the SHIPS RI index is showing roughly a 50 percent of rapid intensification during the next 24 hours. Katia is drifting east-southeastward, caught in a light steering area between two ridges. The hurricane should gradually turn southwestward during the next 24 hours, then accelerate after that time due to a strengthening ridge over the northwestern Gulf of Mexico. The official forecast is very similar to the previous one, on the south side on the dynamical model consensus TVCN in the direction of the corrected consensus. Given the latest wind radii forecast, the government of Mexico has extended the hurricane watch northward to Cabo Rojo. FORECAST POSITIONS AND MAX WINDS INIT 07/0300Z 21.7N 94.8W 70 KT 80 MPH 12H 07/1200Z 21.5N 94.6W 80 KT 90 MPH 24H 08/0000Z 21.3N 94.8W 90 KT 105 MPH 36H 08/1200Z 21.1N 95.4W 95 KT 110 MPH 48H 09/0000Z 20.6N 96.4W 95 KT 110 MPH 72H 10/0000Z 19.0N 98.5W 20 KT 25 MPH...POST-TROP/INLAND 96H 11/0000Z...DISSIPATED $$ Forecaster Blake Hurricane Katia Advisory Number 6 NWS National Hurricane Center Miami FL AL132017 1000 PM CDT Wed Sep 06 2017 ...KATIA STRENGTHENING SLOWLY... ...HURRICANE WATCH EXTENDED NORTHWARD TO CABO ROJO... SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...21.7N 94.8W ABOUT 200 MI...325 KM E OF TAMPICO MEXICO ABOUT 195 MI...315 KM NNE OF VERACRUZ MEXICO MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...ESE OR 105 DEGREES AT 2 MPH...4 KM/H MINIMUM CENTRAL PRESSURE...989 MB...29.21 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has extended the Hurricane Watch northward along the coast of Mexico to Cabo Rojo. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Watch is in effect for... * Cabo Rojo to Laguna Verde 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. Hurricane warnings will likely be issued on Thursday morning for a portion of the watch area. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 1000 PM CDT (0300 UTC), the center of Hurricane Katia was located near latitude 21.7 North, longitude 94.8 West. Katia is moving toward the east-southeast near 2 mph (4 km/h). Little overall motion is anticipated through late Thursday, but then the hurricane is forecast to turn southwestward and be approaching the coast within the watch area late Friday or early Saturday. Maximum sustained winds are near 80 mph (130 km/h) with higher gusts. Some strengthening is forecast during the next 48 hours and Katia could be near major hurricane strength at landfall. Katia is a small tropical cyclone. Hurricane-force winds extend outward up to 10 miles (20 km) from the center and tropical-storm- force winds extend outward up to 45 miles (75 km). The estimated minimum central pressure is 989 mb (29.21 inches). HAZARDS AFFECTING LAND ---------------------- STORM SURGE: A dangerous storm surge will raise water levels by as much as 5 to 7 feet above normal tide levels along the immediate coast within portions of the hurricane watch area. Near the coast, the surge will be accompanied by large and destructive waves. RAINFALL: Katia is expected to produce total rain accumulations of 5 to 10 inches over northern Veracruz, and 2 to 5 inches over far southern Tamaulipas, northeast Puebla, and southern Veracruz through Saturday morning. Isolated maximum amounts of 15 inches are possible in northern Veracruz. This rainfall may cause life-threatening flash floods and mudslides, especially in areas of mountainous terrain. WIND: Hurricane conditions are possible within the watch area by late Friday, with tropical storm conditions possible early Friday. SURF: Swells generated by Katia are expected to affect portions of the coast of southeastern Mexico on 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 100 AM CDT. Next complete advisory at 400 AM CDT. $$ Forecaster Blake |