Tuesday, June 16, 2015 10:47 PM

Southeast Heat Ridge and Tropical Storm Bill

Matthew Holliday

In this article, I just want to briefly touch on the highlights of this week. The majority of my long-range forecasts were put out back in May for this month, so it’s just been a matter of making some very small adjustments and getting into the nitty gritty details on Tropical Storm Bill. My next cycle of medium/long-range forecasts will be coming out in a few days.

The heat has been relentless across the Southeastern U.S. over the past few days. As I mentioned earlier, the heat has occurred as a result of a heat ridge that has been stuck over the region, and it has made the air stagnant and unfavorable for much, if any, thunderstorm development, unlike what occurred earlier this month. Isolated to scattered thunderstorm development could occur over the region as the week progresses, but the high pressure ridge is going to have to break down some with a more favorable moist flow returning. As Tropical Storm Bill makes its way northward on the outskirts of this ridge, the ridge will break down some and should flatten out, but the heat will likely stay in place. A few degrees cooler is possible, however the increase in humidity will make things seem just as hot, if not hotter!

HRRR Model Temperature Forecast For Noon Tomorrow in Southeast:
HRRR forecast

Tropical Storm Bill made landfall today, and it has already been pushing its outer bands well into Texas and Oklahoma. The mid/upper-level atmosphere is very favorable for this system to maintain it’s overall strength, and the recent floods in Texas/Oklahoma from last month could aid in keeping Bill from weakening too quickly. The outer rain bands have re-saturated the top layer of soil today over the area also.

Tropical Storm Bill is basically moving between a Southwestern U.S. ridge and the ridge over the Southeast that I discussed above. These tropical systems just follow the path where the wind flow steers them. Eventually, a northern trough is supposed to grab up Bill and pull it around the Southeast ridge, but it may actually try to stall a while over northern Texas/Oklahoma. Hopefully it gets pulled out fast, because the longer it stays around, the more rain those already saturated areas will get. Christopher Nunley (the newest meteorologist on Firsthand Weather) is going to detail all of this a bit more and will explain everything more clearly in a future article.

Latest 5-Day Rainfall Forecast By WPC (for the most part, I agree):

Rainfall Forecast

The rain will not be exclusive to Texas/Oklahoma and will continue to wrap into parts of Arkansas/Missouri and eventually into the Ohio Valley. Again, this system is going to be a slow-mover, so many of you are about to get A LOT of rain. Exact timing/track is pretty much key as to who gets what, and that’s what we’ll be covering at Firsthand Weather over the coming days.

Again, I’ll get back to putting out medium and long-range forecasts soon. Right now, the focus is on the very hot weather and Bill.