A HEAT ADIVSORY continues until 7 p.m. tonight. These are issued by the National Weather Service when the HEAT INDEX tops 105°. They have NOT extended this advisory into Thursday or Friday as of mid-day. This might come as a surprise to you when you see the forecasted temperatures all the way through the weekend:
We are expecting some mixing in the lower levels of the atmosphere to allow for the afternoon humidity to drop, keeping the heat index below that 105° threshold. So while the actual temperature is about the same each afternoon, the humidity will be SLIGHTLY lower. We’ll also enjoy a nice southern breeze, another sign that there is a chance the humidity will lower slightly during the heat of the day.
Now in July, these temperatures are no surprise. Yet, it hasn’t been THAT hot so far this year. July is running a few degrees below average, June did as well. Last year we suffered a total of 17 days where the daily high at DFW (the official weather site for the Metroplex) hit at least 100° during July. We have yet to hit 100° at DFW ONCE so far this summer.
Now I have even better news. Yesterday the long range forecast models started to show a big shift in the weather pattern starting next week. The high pressure ridge slides off to the west and allows a trough to build in the east. This is shown in the animation at top. What this allows is for a rare event in July to take place: an actual cold front from the upper mid-west to make its way down to Texas. This breaks the heat wave and gives us some much needed rain. It has been just over 30 days since the last big rain at DFW (over 1″).
The QPF Forecast by issued the Weather Prediction Center shows NO RAIN thru the weekend but by Tuesday/Wednesday as much as in inch of rain possible over much of Texas.
Let’s hope the forecast holds. Such weather pattern shifts are rare this time of year…and very welcomed!