While Galvestonians have been grateful for the heavy rains that brought some relief to the Island this past week, the prolonged heat and drought means that more rain is definitely needed to restore conditions back to normal.

In the short-run, a weak cool front stalled to the north of Houston may bring some thundershowers to our area this afternoon (Thursday, July 23). However, if we fail to get rainfall today, then are chances are likely to decrease to the widely scattered category as we finish out the week and move through the weekend. Essentially, we will be left with ample heat and moisture, but no real triggering mechanism to set off any widespread storm activity.

Some models are suggesting that chances for rain could improve dramatically by the middle of next week. It all depends on how pressure patterns evolve over the coming 5-6 days. The ECMWF (European Center for Medium-Range Weather Forecasts), which has been fairly accurate so far this summer is optimistic about the possibility for decent rains next week. On the other, hand the GFS model (Global Forecast System) is much less optimistic about our chances then. Which model proves to be most accurate will determine whether we make good progress in overcoming our drought or continue to suffer from a substantial rain deficit.

At any rate, the ECMWF is predicting that a closed upper-level low will develop over south Texas as the persistent high pressure center over the west sinks south into Mexico. This will open the door for additional moisture to flow into Texas. Then, it hints that a deep low pressure trough will extend southwest into Texas. This, along with a southward moving cool front, could provide the trigger for some substantial rainfall. At least, that is the hope for those of us tending our yards and gardens and worrying about the fate of our Ike-stressed trees.

Below are a couple of forecast maps, showing the potential weather pattern for the middle of next week. The first, shows rainfall potential heading into next Tuesday and the second shows the forecast map for Wednesday, which could be the wettest day if the model proves to be correct. It shows the low pressure area and trough that could trigger our mid-week rains.