Updated 600am CT – Tuesday / 15 July 2014
…. An Unstable Weather Pattern ….
…. A Unusual Summer Cold Front Moving Southward Through Texas ….
…. Rain and Thunderstorm Chances On and Off Over the Next Few Days ….
On this Tuesday morning…. a southward moving cold front extends westward from middle Tennessee and northern Mississippi to near Shreveport and toto near Abilene then northwestward into northeastern New Mexico. As a result of this surface weather pattern, our local surface winds are light southerly.
In the upper levels of the atmosphere… an area of upper level high pressure continues over the western USA with a deepening and unseasonably strong upper level low pressure trough (or line) extending from southeast of Hudson Bay southward through the Mississippi Valley. As a result of this pattern, the upper level winds over south central Texas and the Austin metro area, about 18,000 feet above the ground, are becoming more northwesterly at 10 to 20 mph.
The upper level high pressure area continues far to our west and northwest as the unseasonably strong trough, or line, of upper air low pressure – and its counterclockwise circulation – deepens from the Great Lake states through the Mississippi Valley. At the surface, the cold front is moving southward in the increasing northwesterly wind flow aloft and will settle southward into our area as it weakens over the next day or so. As a result of this surface and upper air wind pattern in addition to good low level moisture being available, an unstable air mass is in place across our area.
Through the balance of this week, widely scattered to scattered rain showers and thunderstorms are expected to continue across our area. At this point, I expect the best rain chances today into tonight and again Thursday into Friday. Through the period, National Weather Service guidance suggests we could see 1/2 to 1 inch of rain over our area.
Temperatures, which have been a little above average of late (101 yesterday at Camp Mabry), with more clouds and the chance of rain, I expect temperatures to be closer to seasonal averages over the next few days.
Regarding my forecast, my local forecast confidence: My forecast confidence is high over the balance of the week (rainfall timing and amounts still being the issues) then very high Saturday into early next week.
Have a good Tuesday….
Meteorologist Troy Kimmel