Debby continues to weaken this afternoon, but remains a tropical storm with maximum sustained winds of 40 mph. The storm’s center of circulation made landfall this afternoon near Steinhatchee, Florida. Hurricane hunters continue to find surface wind speeds that just meet tropical storm criteria and surface buoys on Wundermap are all clocking in at or below 30 mph. The storm’s upper-level circulation is being stretched out into the Atlantic by the same steering forces that will transport it to the other side of Florida, and this combined with dry air has led to a messy-looking tropical cyclone over the past couple of days. Though there was no lack of rain yesterday in the Florida panhandle, Debby has certainly been weakened by the dry air that has wrapped into its center (figure 1). Water vapor imagery from satellite shows Debby’s center is almost completely void of moisture, though rain continues to fall on the northeast side of the storm where moisture is still available. A 6 foot wide, 12-15 foot deep sinkhole swallowed a small portion of I-10 in Madison County west of Jacksonville, Florida, this morning, where heavy rain continues, though this hole will likely be filled and the lane reopened by tomorrow morning. Wind shear around 20 knots is also keeping Debby at bay, but the real disrupter is the lack of moisture.

Figure 1. Where’s Debby? On the left: visible satellite imagery. On the right: water vapor satellite imagery, where the dry air ranges from black to rusty orange. Debby’s center is almost completely void of moisture. These images were captured around 1pm EDT.

Forecast for Debby
The forecast for Debby continues to be similar to previous forecasts. The storm will likely continue to lose strength as it moves over Florida this evening and Wednesday, but could gain some momentum again when it reaches the yet untapped Atlantic water. There’s a high chance Debby will be downgraded to tropical depression status this evening. The HPC continues to forecast up to 8 inches of rain for far northeast Florida over the next 5 days, likely because of the slight strengthening forecast to occur on Thursday and beyond. Debby’s center will most likely be over Atlantic water Wednesday night.

Figure 2. Advisory map for the U.S. Tuesday afternoon. Heat advisories (pink) blanket the central U.S. This heat is expected to move eastward over the next few days as the ridge of high pressure advances.

The Heat Continues

Record highs continue to fall Tuesday afternoon in the central U.S., where Denver, Colorado had its fifth consecutive day of triple-digit heat after it reached 100°F at 1pm MDT, and could continue to rise this afternoon. This ties the all-time record for consecutive 100°F+ days. Nebraska and Kansas are particularly toasty this afternoon; McCook, Nebraska has reached 113°F so far, and Hill City, Kansas is up to 112°F. Though, to put that in perspective, the state record for Nebraska is 118°F, and the state record for Kansas is 121°F.

The heat moves east tomorrow, and by Thursday, many of the major Midwest cities are forecast to be in the triple-digits, including Chicago, St. Louis, and Indianapolis. By Friday the heat will be beating down on the East Coast. In the meantime out west, the forecast high in Fresno for this weekend is 82°F, which would tie as the coolest final weekend in June on record, according to the Hanford forecast office.

Angela