July 27, 2011 - 8:40 PM CDT

As expected, Invest 90L continued to organize this morning and when the Hurricane Hunters arrived they found a developed low level circulation and enough data to upgrade Invest 90L to Tropical Storm Don, the fourth atlantic tropical system this year. Hurricane Hunters found winds of 40 MPH when they were in the system earlier this afternoon. Since that time, the convection of Tropical Storm Don has degraded. This may be due to the proximity of the system to the Yucatan Peninsula and the late afternoon hours, in which convection in weak systems can falter. The majority of convection right now is located over the Yucatan Peninsula and is being generated by the heat of the afternoon. There is really very little in the way of convection associated with the center of Tropical Storm Don at this point. While this is indicative of a poorly organized tropical system, convection normally increases during the overnight hours. We’ll be monitoring this trend tonight to see if Don fires off more convection. If it does not, then it is possible that Don could weaken back to a Tropical Depression. We’ll continue to watch for that possibility tonight, otherwise lets get down to the latest information on Don.

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