Monday, January 7, 2013

A Texas Sized Rain Storm, Severe Storms Too

If you remember around this time last year, the drought was so bad, that even if you watered your lawn, it would stay brown. However, a storm late in January 2012 brought tremendous rainfall, flooding and even severe weather. It was this storm that began a chain of wet weather events to helping to turn the brown into a beautiful lush green. Another event is setting us as I write this that will hammer the entire viewing area, and in fact most of Texas with a wall of water.

At the moment, there are two main features with this next storm, a low-pressure center at the surface, and another in the upper levels. During this blog, we will concentrate on the low-pressure center at the surface. As of Monday afternoon, the center of low pressure resides in north Mexico with a movement towards the east. By Tuesday afternoon, the center of this storm will slide into south Texas. At this time, intense strengthening will take place, and widespread rain will take shape. 

Along the east side of this storm, a warm front will extend from south Texas to the upper Texas coastline. Ahead of the front there will be a shield of widespread rain with several embedded thunderstorms. In the meteorological world, we call this type of set up, "overrunning precipitation." Where the warm air aloft runs over the cooler air at the surface. Therefore the air lifts, condenses and creates precipitation. During this time, you will notice pockets of light rain early in the day Tuesday, with steadier, heavier rainfall by the afternoon and evening. But here is where the scenario gets interesting. The body of low pressure will move basically due north.

As the low moves north from Tuesday night and into Wednesday morning, we will be in an area called the "warm sector." This is an area between the warm and cold front. Temperatures will rise though Wednesday morning, but this also puts the Brazos Valley in a location favorable for severe thunderstorms. Within this region, winds at the ground and aloft tend to have different speeds and directions, plus there tends to be additional instability. In other words, there could be a few storms that create winds greater than 58mph, large hail, and even a tornado. Furthermore, in this zone, rain will come down even harder on Wednesday than what we experience ahead of the warm front on Tuesday.

When it comes to the risk of tornadoes, data shows that the tornado risk will be small. I cannot rule out a few isolated weak tornadoes, but the dynamics of this particular storm do not favor a huge outbreak. Nonetheless, I will keep my eyes peeled throughout the entire storm and keep you in the loop on Twitter, Facebook and On-air.

What we will all remember from this event will be the tremendous rainfall and possible flooding. Because the center of low pressure will move due north from south Texas from Tuesday to Wednesday, rain will fall over the same areas for a 36 hour period. By the end of this, some locations could pick up nearly 6"-7" of rain. Below is one computer models projection on general rainfall amounts from Tuesday to Wednesday.


Again, this will be the general amounts received with pockets of higher totals. Due to the strong confidence in  this rain event, the National Weather Service out of Houston decided to slap on a FLASH FLOOD WATCH for all of southeast Texas from 12PM Tuesday until 12AM Thursday.


Considering the extend of heavy rainfall, I would not be surprised if this WATCH were to be extended into portions of north and central Texas. 

Overall, the simplify things, here is what you need to know:

Tuesday: Light rain becomes heavy during the evening and several thunderstorms will be around.

Wednesday Morning: Rain becomes heavier, thunderstorms could be severe with a small threat of tornadoes.

Wednesday Evening: The storm lifts north and we gradually dry out.

Impacts: Widespread 3"-5" rainfall total with a few locations picking up nearly 7". Flooding will be a concern, along with isolated severe thunderstorms.

For more news and weather you can log onto: www.facebook.com/plushnickweather or www.facebook.com/KAGSTV. You can also check out our twitter feeds: @KAGSweather and @KAGSnews. Furthermore, you can download our new weather app. Search: KAGS Weather, in the Apple App Store or Google Play for Android.

No comments:

Post a Comment