Upper level ridge of high pressure currently located over the SW US will back westward slightly today and weaken on the eastern flank. This will allow a trough over the southern US to move westward a bit. Local radars over LA this morning show a complex of thunderstorms east of the central LA area moving westward and convection allowing models (CAMs) are in general agreement that this complex and its associated outflow boundary will continue westward toward the Sabine River today and then into east Texas this afternoon and toward the I-45 corridor by mid to late afternoon.

With the subsidence from the ridge weakening over the area and moisture increasing from the east, expect the complex of storms or new storms to form along the leading westward moving outflow boundary. Best chances of rainfall will be east of I-45, although CAMs are suggesting areas of northern Harris, Liberty, San Jacinto, Walker, and Montgomery Counties may see the best chances this afternoon. Rainfall will be scattered and mainly focused east of I-45, so while there is about a 30% chance this afternoon, not everyone will see rain.

Ridge starts to shift back eastward this weekend, but still think there will be a chance for scattered showers and thunderstorms on Saturday with the seabreeze front and continued decent moisture levels before subsidence overruns the region again by Sunday. Ridge looks to never fully gain a foot hold over SE TX compared to the recent weeks and is based more north of the area so temperatures into next week look more like the mid to upper 90’s with 100’s over the Brazos Valley instead of the widespread 100’s of late. Additionally with the ridge axis just enough to the north this will open the door for westward moving tropical waves to move into the TX coast. The first should arrive around Tue/Wed with increased rain chances followed by another around next Friday. This slight pattern shift may be able to bring some drought and heat relief to the region.

Fire Weather:

Afternoon humidity values have not been mixing out as much as earlier this week and winds have returned to a more typical summer pattern of mainly light southerly and this has helped to reduce the critical fire weather concerns from earlier in the week. Fuel loads are extremely dry through the entire column and will remain dry until widespread wetting rains occur.

There is some concern this afternoon that storms in the area could produce lightning starts and may not produce rainfall over any new starts. Additionally, outflow winds of 40-50mph could quickly fan any new starts. Generally these would be short lived conditions, but similar activity and conditions in north Texas earlier this week produced several wildfires due to lightning followed by little or no rainfall at the ignition site.