Although rain chances will increase later today across parts of Southeast Texas with heavy rain possible, significant rainfall amounts are likely to remain north of Galveston County. The rain will be in conjunction with an upper-level disturbance moving into North Texas associated with a low pressure trough developing over the West.
This is consistent with a pattern that has lingered for the past month or so with parts of East Texas receiving copious amounts of rain with areas close to the coast missing out on much of the rain (as well as most of the severe weather as well).
In April, Galveston received only 0.99” of rain, which is 2.06 inches of rain less than would be expected for the month. League City fared a little better with 1.91 inches of rain during April, but that was still 1.40 inch less than normal for the month. Essentially, precipitation continues to be suppressed by a spring-time atmospheric cap which has been suppressing storm formation along the Texas coast.
We will have another chance of precipitation Friday night into Saturday as another upper-level disturbance combines with a weak frontal boundary expected to reach the coast Saturday before stalling offshore on Sunday. The frontal boundary may provide enough extra lift to promote thunderstorm activity closer to the coast. Still, at the present time, precipitation amounts are not expected to be too impressive over the County.
Looking further ahead, there are indications that an even more potent upper-level system will move into the region by next Tuesday or Wednesday. This may provide yet another chance for substantial rainfall in the area. Currently we are a little too far out in time to get a good projection on rainfall rates and/or severe weather potential. But it will be something to monitor as we move through this coming weekend. As is typical for this time of year, however, the greatest chance for storms will probably be off to our north.