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By: angelafritz, 11:29 PM GMT on June 29, 2011
Tropical Storm Arlene hasn't intensified much on paper, but thunderstorm activity has increased, and it looks impressive on satellite considering it was just named 24 hours ago. In a 5:30pm EDT special update, the National Hurricane Center said the tropical storm had winds of 60 mph. Thunderstorm activity increased on the southern end of the storm this afternoon, and there is some suggestion that these stronger thunderstorms could begin to wrap around the storm, if it only had more time over the warm, conducive waters of the Bay of Campeche. Tampico, Mexico has sustained winds up to 20 mph out of the north-northeast this evening. Radar indicates the heaviest rainfall is occurring on the southern side of the storm in association with the coldest cloud tops on satellite. Although flooding is expected, this storm is bringing some much needed rain to central Mexico, assuming it can be absorbed into the very dry soil.
Figure 1. Visible satellite image of Tropical Storm Arlene at 5:32pm CDT on June 29, 2011. The strongest convection is to the south of the center of the storm.
An Air Force hurricane hunter reconnaissance mission was in Arlene this afternoon/evening, and found slightly stronger winds than expected. The circulation is broad and surface winds near the center of the storm are only around 35-40 mph. The highest wind speeds were found displaced from the center, associated with the strongest convection. The recon mission measured a minimum central pressure of 996 millibars, which is down from 1000 millibars in the 5pm advisory.
Arlene is having an impact on the U.S., as well. Brownsville, Texas saw a line of heavy showers earlier, and will continue to get rain throughout the evening from the outer rain bands of the storm. Coastal flood statements and rip current statements have been issued from South Padre Island to Port Lavaca, Texas. Strong rip currents and tidal overflow is expected during the next few days as lingering effects of Arlene.
Figure 2. Brownsville, Texas radar at 5:37pm CDT on June 29, 2011. The outer bands of Tropical Storm Arlene are reaching as far north as Brownsville, and coastal flood/rip currents are expected along the southern Texas coast for the next few days.
The forecast for Arlene remains almost the same as this morning. Slight strengthening (to 65 mph) is expected over the next few hours before landfall, though the National Hurricane Center admits there's a small chance winds could exceed hurricane strength. The tropical storm will come ashore south of Tampico, Mexico, just after 2am EDT, and likely will have just missed being 2011's first hurricane by few more hours over water.
Updated: 1:20 AM GMT on June 30, 2011