| Track: http://www.nhc.noaa.gov/refresh/graphics_at3+shtml/?cone#contents Floater: http://www.ssd.noaa.gov/PS/TROP/floaters/13L/13L_floater.html Tropical Storm Katia Advisory Number 3 NWS National Hurricane Center Miami FL AL132017 400 AM CDT Wed Sep 06 2017 ...DEPRESSION BECOMES TROPICAL STORM KATIA... SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...22.1N 96.3W ABOUT 105 MI...165 KM E OF TAMPICO MEXICO MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...ESE OR 110 DEGREES AT 2 MPH...4 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. A tropical storm watch could be required for portions of the Mexican state of Veracruz later today. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 400 AM CDT (0900 UTC), the center of Tropical Storm Katia was located near latitude 22.1 North, longitude 96.3 West. Katia is moving toward the east-southeast near 2 mph (4 km/h), and the system should gradually turn southeastward during the next 24 hours and continue moving in this general direction through Thursday. A turn toward the southwest is forecast on Friday. On the forecast track, the center of Katia is expected to remain offshore of Mexico through Friday morning. Maximum sustained winds have increased to near 40 mph (65 km/h) with higher gusts. Some strengthening is forecast during the next 48 hours. Tropical-storm-force winds extend outward up to 45 miles (75 km) from the center. The estimated minimum central pressure is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- None NEXT ADVISORY ------------- Next complete advisory at 1000 AM CDT. $$ Forecaster Roberts Tropical Storm Katia Discussion Number 3 NWS National Hurricane Center Miami FL AL132017 400 AM CDT Wed Sep 06 2017 Conventional satellite imagery shows improved organization of the cloud pattern during the past several hours, with recent cold cloud top of -80C associated with deep convective bursts near the surface center. An earlier SSMI/S microwave pass also revealed a developing curved band feature in the eastern portion of the cyclone. Additionally, a 0306 UTC ASCAT-B overpass indicated winds of 35 kt in the aforementioned rain band. A Dvorak satellite intensity estimate of 35 kt from TAFB and the scatterometer wind data support upgrading the depression to Tropical Storm Katia at this time. The SHIPS model and the CIMSS shear analysis indicate westerly shear impinging the western side of Katia, but the flow aloft appears to be more diffluent now, indicative of the recent deep convective outbreak. Guidance continues to suggest that the shear will relax in about 36 hours which should allow Katia to strengthen, possibly to a hurricane as indicated in the HWRF forecast. There are no changes to the intensity forecast from the previous advisory, and it's based on the IVCN multi-model. The initial motion is estimated to be east-southeastward, or 110/2 kt. Katia has been drifting generally in this direction during the past several hours within weak steering currents associated with a mid-tropospheric trough digging southwestward from the Mississippi Valley. Later today, Katia should begin a gradual turn southeastward and southwestward around the 36 hour period as a mid-level ridge builds over the western gulf from Texas. The official forecast basically splits the guidance envelope and is hedged toward the HFIP Corrected Consensus Model. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 22.1N 96.3W 35 KT 40 MPH 12H 06/1800Z 21.9N 96.0W 40 KT 45 MPH 24H 07/0600Z 21.6N 95.6W 50 KT 60 MPH 36H 07/1800Z 21.3N 95.4W 55 KT 65 MPH 48H 08/0600Z 21.1N 95.6W 60 KT 70 MPH 72H 09/0600Z 20.4N 96.7W 60 KT 70 MPH 96H 10/0600Z 19.2N 98.7W 25 KT 30 MPH...POST-TROP/INLAND 120H 11/0600Z...DISSIPATED $$ Forecaster Roberts |