Bob Peters Forecast

Thursday looks to be the last dry day for a while, with a turn to cooler and unsettled weather likely beginning Friday afternoon.

Thursday's temperatures ran slightly warmer than Wednesday's, and were still about 2 degrees below normal. Friday readings should be similar, with readings running about 5 degrees below normal beginning Saturday.

The culprit is an upper air low pressure area, which was dropping southward out of South Central Canada Thursday afternoon, and heading for a position somewhere over Northwest Texas or Northeast New Mexico by Saturday morning. The low is pulling a weak cold front southward into the area.

On Thursday, this front caused showers as far south as Oklahoma City. It should reach East Texas Friday afternoon, with an increasing likelihood for showers and thunderstorms beginning then. The activity should peak Saturday, and then decrease again Saturday night and Sunday, before increasing again beginning Sunday night.

The track of the upper air low is farther west than had been earlier forecast. This means it will be slower coming out across the Plains, and hence slower to eject northeastward out of range.

That probably won't happen until Wednesday or Wednesday night.

There is the risk for more heavy and potentially flooding rains over East Texas, with Sunday night and Monday looking to be the time for the heaviest rainfall.

Rainfall through Sunday afternoon should run between one-half inch and one inch, with one to three inches likely Sunday night and Monday.

In both instances, amounts will increase from south to north.

Areal coverage should run about 90 percent through Sunday afternoon, with coverage the highest on Saturday. Coverage should run near 100 percent early next week.

Low temperatures in the area Thursday morning were from the middle 60s in the north to the middle 70s in the south. The lower readings were the result of the dry and stable air mass associated with high pressure, which built in behind Tuesday's cold front.

Afternoon high readings, under the dry air and nearly full sun, climbed into the 90s region-wide, with near 100-degree readings over the southwest. Crockett reported a maximum heat index value of 103.

Low temperatures Friday through Sunday morning should run in the 70s. Daytime high readings will be in the lower to middle 90s Friday slightly lower than on Thursday because of increased clouds and showers.

High temperatures from Saturday through mid-week should run in the 80s.

Winds were light and easterly Thursday morning, and became light and southeasterly as the surface high went east of the region Thursday afternoon.

Tyler's highest sustaining wind Thursday was northeasterly at 10 mph with a peak gust of 13 mph and an average velocity of 2.6 mph. Wednesday's average wind velocity was 3.9 mph.

Thursday's average relative humidity was 64 percent, with higher values likely Friday through Sunday. Wednesday's average was 69 percent. Tyler's high temperature of 94 came at 4:04 p.m., following the morning's low of 69 at 6:52 a.m.

Measurable rain fell nowhere in the area Thursday.