Bob Peters Forecast

Clouds and a northeast wind held temperatures unseasonably low over the northern two-thirds of the region, with afternoon high temperatures running near 80 some 15 degrees below normal for mid-August.

Temperatures on Sunday and Monday should be a few degrees warmer, but below normal temperatures are likely all this week.

There is also an increasing likelihood for rain and thunderstorms. The very slow movement of an upper air low pressure area over the Southern Rockies has pushed back the expected onset of significant rainfall to Monday night and Tuesday from an initial forecast of Saturday night and Sunday.

An unseasonably strong surface high pressure ridge was centered near Sioux City, Iowa, and it extended southward to a cold front, which had become stationary along the Texas Gulf Coast.

There were some light showers Saturday morning over the southeastern counties, generally east of a Lufkin-Shreveport line. These had moved out of the state by noon, and were what was left of an earlier thunderstorm complex to the west.

The clouds were the remnant of the same complex which brought significant rains to parts of West and Central Texas overnight and early Saturday morning.

A northeast wind at 5-10 mph brought mild and slightly drier air into the region. Decreased clouds on Sunday should send high readings into the middle to high 80s in much of the region still well below the lower to mid-90 degree normal.

The upper air low is forecast to begin crossing the Plains Monday night and Tuesday. At the same time, the cold front will come back northward as a warm front, and a strong flow of moist air in the lower and middle atmosphere should be present.

The result is still forecast to be general rain and thunderstorms with the risk for heavy rainfall. The most likely period appears to be from late Monday for about 48 hours into late Wednesday.

Rainfall amounts are expected to range between two and five inches in East Texas, with amounts increasing from northeast to southwest. If the five-inch rains materialize over the southwest, urban flooding and small stream rises could become a problem in such places as Athens and Corsicana.

In the immediate Tyler area, heavy rainfall could trigger rises because of the nearly seven inches of rain which fell in parts of the city last week.

Areal coverage this week is forecast to be near 100 percent. A few showers could develop in the area Sunday. Another thunderstorm complex was forming over West Texas Saturday afternoon. It will move eastward overnight, and will probably behave as the Thursday night/Friday and Friday night/Saturday ones did: weaken before reaching East Texas, but leaving behind an outflow boundary of rain-cooled air which could serve as the focus for shower development during the day.

Tropical Storm Fay has formed in the Caribbean Sea. The presence of the slow-moving low over the Plains this week should steer fay inland over the Florida Panhandle, with landfall likely some time Tuesday night as a minimal hurricane.

Low temperatures Saturday morning were from the middle 60s in the north to the middle 70s in the south. Near to mid-70 overnight readings are forecast through Tuesday morning.

Tyler's high temperature of 81 a record low maximum for the date was reached at 5:33 p.m. The previous record low maximum of 83 dates to 1992.

The day's low of 72 came at 5:56 a.m. Saturday's temperatures were 8 degrees below normal.

Tyler's highest sustaining wind Saturday was northeasterly at 14 mph with a peak gust of 18 mph, and an average velocity of 7.5 mph. Friday's average wind velocity was 6.2 mph.

Saturday's average relative humidity was 78 percent, with slightly reduced values for Sunday, and increased values for Monday and Tuesday. Friday's average was 74 percent.