Late-day thunderstorms erupted in parts of Southeast Texas this July 5th drenching some and leaving others longing for the sound of falling rain. It all started around 4 pm as isolated storms drifted in from Louisiana and north of Walker county. Then something happens that often happens in the summer-time. As the storms wind down, they send out a rush of cool air. This looks like a thin blue line on HD Doppler and its called an outflow boundary. That rush of cool air collides with very hot and humid air causing that air to rise quickly and produce a new thunderstorm. Sometimes, this can cause a chain-reaction of storms that blossom. This evening, one of those storms produced some hail. Here's a progression of events starting at 6 pm tonight:
A strong thunderstorm with gusty winds in eastern Liberty and northern Chambers county sends an outflow boundary between Baytown and just east of Humble. Another outflow is seen just north of Spring from a smaller thunderstorm near Conroe.
An hour later, a storm grows near Spring from the two prior outflow boundaries and it produces and outflow that heads toward Tomball.
That final outflow generates a severe thunderstorm that towered to 45 thousand feet and produced small hail in Northwest Harris county west of Tomball to Hempstead. You can also see how the lightning count jumped from 7:00 pm to 7:30 pm as the Tomball storm grew.
For the most part, rain today was sporadic; here's a look at Weather Bug stations recording rain:
There's hope for a more widespread smattering of rain tomorrow as today's boundaries are re-activated with heating tomorrow. Additionally, an upper-level low wobbling in the Gulf will push surges of tropical moisture our way, increasing the chance of rain. Keep your fingers crossed and your umbrellas ready...