Updated 130pm Tuesday / 14 February 2012
…. Clouds Increase Rapidly by Tonight with Rain Chances by Later Tonight ….
…. A Cold Front with a Chance of Rain and Thunderstorms Tomorrow ….
…. Clearing Again Later Tomorrow Into Thursday Before Clouds Again on Friday ….
On this Tuesday… a surface high pressure area is off the southeastern USA over the southwest north Atlantic Ocean. A trough.. or line.. of low pressure is located over west Texas and eastern New Mexico with a warm front extending southeastward into the lower Mississippi valley. As a result of this surface pressure pattern, a light and variable surface wind has become southerly across our area.
In the upper levels of the atmosphere… a deepening area of low pressure is situated over southern Nevada. As a result of this pressure pattern, the upper air winds over our area of Texas are, in general, westerly across Texas but should become more southwesterly as the upper low out est moves eastward.
After a sunny day today, clouds will be on the increase tonight in advance of the upper level low pressure area and as associated eastward moving cold front which will cross our local area in the midday hours on Wednesday. Low level moisture and atmospheric instability will have increased enough for scattered rain showers and thunderstorms along and ahead of the front.
After the front passes on Wednesday, skies will quickly clear with a drier and more stable air mass taking hold for Wednesday night into Thursday.
Another disturbance combined with a quick turn around to a south southeasterly surface wind flow and increased atmospheric moisture will result in increased clouds and rain chances again Friday through Friday night and into Saturday. The disturbance will trigger the development of a surface low over south Texas which will move eastward into the Gulf of Mexico.
Rain chances will drop and a more stable atmosphere will return by late Saturday through Sunday. As a result, sunshine will increase as we wrap up the weekend.
Clouds will increase again with a slim chance of rain as yet another weather system.. in a progressive (quick moving) series of disturbances.. affects Texas.
My forecast confidence through this week is high to very high. My confidence for the forecast for next weekend into next week is medium (with exact rain chances and time of clearing on Saturday as well as Monday’s rain chances being the main questions) .
For Austin and south central Texas… tonight will see a quick increase of clouds resulting in a cloudy sky with isolated rain showers late. Lows around 60 with a southerly wind. For tomorrow, expect scattered to numerous rain showers and thunderstorms in the morning with clearing by midday into the afternoon. Highs in the 70s and southwesterly wind shifting northwesterly by afternoon.
Have a good Tuesday night and Wednesday…
Meteorologist Troy Kimmel