Updated  130pm Wednesday / 15 February 2012

…. Clearing Skies as Cooler and Drier Air Mass Moves into the Area ….
…. Another Storm System and Cold Front Brings Rain Chances Friday Night ….
…. Clearing Again On Sunday But Clouds Pick Up Again by Early Next Week ….

On this Wednesday… a surface high pressure area is over the Appalachians and eastern seaboard while a low pressure area is over southern Kansas with a cold front extending southward into Texas. As a result of this surface pressure pattern, a southerly wind is becoming northwesterly across our area as the front passes.

In the upper levels of the atmosphere… a broad trough.. or line.. of upper air low pressure is over the western third of the USA. Embedded within that flow, there are strong upper air disturbances over northwest Texas (it’s moving east northeastward) and another over eastern California and western Nevada (it’s diving southeastward). As a result of this pressure pattern, the upper air winds over our area of Texas are, in general, southwesterly across Texas and our local area.

As the cold front passes the area today, the skies will quickly clear from west to east with a drier and more stable air mass taking hold for tonight into Thursday.

Another upper air disturbance combined with a quick turn around to a south southeasterly surface wind flow and increased atmospheric moisture will result in increased clouds by tomorrow night into Friday with a return to rain chances again Friday night and into early Saturday. The disturbance will trigger the development of a surface low over south Texas which will move eastward into the Gulf of Mexico.

As that surface low moves eastward across the northern Gulf (and away from us), 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 as yet another weather system.. in a progressive (quick moving) series of disturbances.. affects Texas by the first part of next week. I’ve removed rain chances from this part of the forecast.

My forecast confidence through this week is high to very high (timing in progressive/fast moving weather patterns, like we’re in, can be problematic, though). 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 and Tuesday’s clouds and any rain chances being the main questions) .

For Austin and south central Texas… tonight will see a mostly clear sky. Lows in the 40s with a northwesterly wind. For tomorrow, mostly sunny. Highs in the 60s with a northerly wind.

Have a good Wednesday night and Thursday…
Meteorologist Troy Kimmel

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