Tropical Storm Harvey restrengthened slightly today as it has emerged into the extreme northwestern Gulf of Mexico, but remains poorly organized and most of the convection is to the northwest of the center. Harvey is likely to make a second landfall in extreme eastern Texas or even western Louisiana early on Wednesday. Although Harvey is centered over water, the flood threat remains for Southeastern Texas.

Potential Tropical Cyclone Ten has failed to develop a well-defined center of circulation today, and its chances of becoming a tropical storm are decreasing as it is expected to acquire extratropical characteristics on Wednesday. Even though PTC Ten is becoming less likely to develop into a tropical storm, heavy rains are possible along the Carolinas coast tonight and Tuesday.

Disorganized Harvey re-emerges over the Gulf of Mexico, flooding threat continues

As of 10:00 p.m. CDT (11:00 p.m. EDT), Tropical Storm Harvey was centered near, and was moving. Maximum sustained winds were 40 knots (45 mph), with an estimated minimum pressure of 997 mb. Although Harvey is slightly stronger than yesterday, its appearance on satellite is unimpressive, with all of the convective activity north of the exposed low-level center, possibly due to some southerly shear. Harvey’s unimpressive appearance does not lessen the flood threat for Southeastern Texas and Southwestern Louisiana. Catastrophic flooding has continued today in the Houston area. Do not attempt to travel on flooded roadways! Rainfall amounts of 15-25 inches remain likely with isolated amounts of over 50 inches.

Harvey is expected to make it second landfall near the Texas-Louisiana border (not far from where Tropical Storm Cindy made landfall in June) on Wednesday. A Tropical Storm Warning is in effect from Mesquite Bay to Intracoastal City, and a Storm Surge Watch is in effect from Port Bolivar to Morgan City. After landfall, Harvey should begin to weaken as it continues north-northeastward. Harvey should finally weaken to a post-tropical remnant low by Friday or Saturday, but the rainfall threat is likely to continue throughout the Southeastern United States through Saturday.

Potential Tropical Cyclone Ten still lacks a well-defined circulation, becoming less likely to develop

As of 11:00 p.m. EDT, Potential Tropical Cyclone Ten was centered near 32.5°N 80.0°W, and was moving north-northeast at about 7 mph. Maximum sustained winds were 35 knots (40 mph), with an estimated minimum pressure of 1005 mb. The National Hurricane Center (NHC) gives PTC Ten a 50 percent chance of developing into a tropical cyclone during the next 48 hours (and five days), but this could be a little generous. An Air Force Hurricane Hunter Aircraft investigated PTC Ten Monday afternoon, and was unable to find a well-defined center of circulation. The aircraft found a sharp trough of low pressure with multiple swirls, with tropical storm force winds on the eastern side of the disturbance. Deep convection has, however, increased with PTC Ten during the past few hours, but it is still unlikely that a well-defined center of circulation exists based on recent surface observations. Another reconnaissance aircraft is scheduled to visit PTC Ten early tomorrow morning, if necessary. If PTC Ten does manage to develop a well-defined circulation in the next 24 hours, it will be named Tropical Storm Irma, as it is already producing winds to tropical storm force. Even though PTC Ten is becoming less likely to develop, impacts will remain the same, with heavy rainfall possible along the coast of the Carolinas along with isolated tropical storm force winds. A Tropical Storm Warning remains in effect for North of Surf City to Duck, as well as the Ablemarle and Pamlico Sounds. A Tropical Storm Watch is in effect from South Santee River, SC to Surf City, NC. PTC Ten is then likely to turn to the northeast out to sea as an extratropical cyclone, and could become a hurricane-strength extratropical cyclone by late this week.

93L likely to develop over the eastern Atlantic – future track uncertain

A tropical wave located over the far eastern Atlantic – designated Invest 93L – has a high chance of developing into a tropical depression during the next five days. As of 00:00 UTC Tuesday, Invest 93L was centered near 12.2°N 22.5°W, and was moving westward at about 15 to 20 mph. Maximum sustained winds were 25 knots (30 mph), with an estimated minimum pressure of 1008 mb. Nearly all global models develop 93L into a tropical depression during the next five days, but have trended weaker in the short term. 93L is currently located in an environment of moderate to strong wind shear (near 25 knots), but the shear is likely to decrease to below 10 knots in about 24 hours and remain low throughout the next five days. Sea surface temperatures are currently warm, near 28°C (84.2°F), but are likely to decrease to under 27°C (82.4°F) by late tomorrow and remain around 27°C for the next several days. Mid-level relative humidity values are currently high, near 75 percent, but are likely to decrease to an adequate 55-60 percent over the next several days. Overall, 93L is in a conducive environment for gradual consolidation and development, and the NHC gives 93L a 40 percent chance of development in the next 48 hours and an 80 percent chance within the next five days.

As a well-defined center of circulation has not yet formed, it is too soon to determine the future track and intensity of 93L. There is a low chance that it could be near the Northern Leeward Islands in eight to nine days.

I will be back with another post tomorrow.