Debby lingers in the Gulf, bringing heavy rain, flooding to Florida

Debby remains a raggedy-looking tropical storm with maximum sustained winds of 45 mph. The hurricane hunter mission that ended around 1pm ET found a minimum central pressure of 995 mb and much weaker winds that it had found on previous missions. Despite Debby's less-than-organized appearance, the storm is still managing to dump buckets on Florida, and in particular today, the panhandle. A burst of thunderstorm activity has exploded on the northern side of Debby, and Tallahassee, Florida and it's southern neighbors are getting the worst of the storm's rain this afternoon as it rotates in place. Weather stations near Tallahassee have recorded anywhere from 2 to 9 inches of rain so far today. The strongest wind speeds reported from buoys are around 30 mph this afternoon. The storm's moisture is still confined to the north and east of the center, as a region of dry air continues to wrap in from the south and west. Visible satellite imagery illustrates just how dry Debby is on the southwest, as well as the strong thunderstorm activity that is expected to continue over Florida for the next couple of days. Debby has begun to create a bit of storm surge in the Apalachee Bay area, with reports from St. Marks, Florida that the storm surge has reached the town, though high tide is not for another 2 hours.


Figure 1. Monday afternoon visible satellite imagery of Tropical Storm Debby.


Figure 2. 5-day forecast rainfall from the Hydrometeorological Prediction Center. Rainfall in excess of 15 inches is expected in northern Florida as Debby makes its slow way across the state and into the Atlantic.

Forecast for Debby
Debby continues to drift to the northeast this afternoon, a track that will continue, slowly, over the next couple of days, before it finally crosses Florida, which will likely happen Wednesday and Thursday of this week. The National Hurricane Center's 5pm forecast track is similar to the tracks from earlier today, though the timing has sped up a bit, with landfall occurring Wednesday afternoon. All of the models now agree that Debby will continue moving northeast and gradually turn to the east as it crosses over Florida into the Atlantic. In terms of intensity, the Hurricane Center is predicting that the storm will remain a storm through Wednesday, after which it will likely diminish to tropical depression status. Given the current state of the storm and the dry air that continues to wrap in, it's possible this could happen earlier than Wednesday. Interestingly, the GFDL is suggesting Debby could gain some strength as it crosses Florida, and the ECMWF's earlier run actually thinks Debby will rapidly intensify when it reaches the yet untapped warm waters of the Gulf Stream in the Atlantic and tracks northeast. It's worth nothing that the ECMWF is the only model suggesting this intensity outcome, though all the models have a similar track. In any case, Debby will remain a rainmaker for the rest of the week, and some storm surge is possible, especially in the Big Bend. The SLOSH model, which predicts storm surge heights, suggests this area could see up to a 6 foot storm surge. The coastal flooding will be the worst in the Apalachee Bay region, where high tide occurs from around 7am to 9am EDT.

Angela