A strong cold front, combining with an upper level system, caused some rough weather on Saturday morning. The system has cleared the area allowing for more stable weather conditions and cooler temperatures.
1:40pm Final Update
The line of storms has pushed far enough east that it is safe to say that the chance for severe weather in the Brazos Valley has diminished. Dry cool air is expected to sink in through the rest of the afternoon allowing for scattered showers to clear out by this evening. As weather conditions become more stable we are anticipating the Tornado Watch to be dropped from our counties earlier in the afternoon.
Severe Thunderstorm Watch has been CANCELLED for Lee County. The bulk of the storm activity continues to move further west. Currently we are monitoring an isolated cell moving towards Bryan/College Station. At this time the storm continues to weaken as it becomes less organized.
Line of showers / storms has become slightly unorganized over the past hour. However, multiple embedded thunderstorms are associated with this line and could cause damaging winds, frequent lightning and heavy downpours as it moves through the Brazos Valley.
Strong line of showers is moving in from the west. The main threat is high wind, frequent lightning and heavy rainfall. There is a possibility for an isolated thunderstorm to be embedded within the line.
A Severe Thunderstorm Watch has been issued for Lee county until 3pm this afternoon. It is possible to see some severe thunderstorms throughout the Brazos Valley, but in our western counties especially.
A Tornado Watch has been issued for multiple counties across the Brazos valley through 6PM. The chances for a tornado to develop are very slim but there is a small possibility for a brief tornado.
We are in a small break of showers with just a few light showers moving through the Brazos Valley. We are expecting another line of rain to eventually push in from the west. There is a chance for isolated thunderstorms within this line.
Scattered showers dominate the southeastern half of the Brazos Valley, with an embedded strong thunderstorm located just Northeast of Navasota.
Still keeping a close eye on strong thunderstorms, just west of the I-35 corridor. Some energy could be lost well before they make their way to the ENE.
Another strong isolated storm flaring up north of Daniels, heading Northeast towards Navasota & Courtney.
Strongest embedded storms extend from Madisonville, down through Navasota. Nothing severe at this time, just frequent lightning and brief heavy downpours.
Cooler temperatures continue filtering in behind front, while southern counties still feeling those mild 70s. However, with temperatures already falling overnight, we could be in store for a rather chilly afternoon than originally anticipated. Scattered showers dominate the area, with a few strong embedded storms off to our northern and northeastern counties.
Cold front continues to drop to the south -- moving into southern portions of Lee, Burleson, Brazos, and Madison Counties.
On one hand, this is good news, as it is stabilizing the northern half of the Brazos Valley's atmosphere -- to keep severe weather at bay.
The downside, is that those to the south of the front are not entirely out of the way to possibly see a stray severe thunderstorm or two.
An upper-level low is spinning towards El Paso from the west -- this is the weather system responsible for the rain and thunderstorms moving into the area.
Due to a counter-clockwise rotation around that low, we expect the cold air to be shoved back to the north later this morning as south to southwest winds take back over across the region. Rain chances will end and that should lead to a warmer end to the afternoon.
It is still expected that the front will re-arrive on Sunday...and this time stick around / leave the cold air in place.
Our first wave of rain and thunderstorms is moving across the Brazos Valley. Currently, non-severe -- but strong -- storms are pushing east across Leon County, towards I-45.
Occasional lightning, thunder and winds in excess of 15mph to 30mph are possible on the leading edge of these storms as they approach the interstate from the west and then move into the eastern half of the county.
The cold front we talked about below, has managed to nose its way south of Hwy. 21 into Caldwell and Bryan / College Station.
While the front is more south than expected, the cold air helps to settle the atmosphere. That said, anybody south of the cold front still has the chance to find a touch of possible severe weather.
A line of non-severe thunderstorms has managed to take shape across Western & Central Robertson County, stretching into Brazos County -- just north and west of Bryan.
While not severe, heavy rain, thunder, lightning, and wind gusts -- on the leading edge of this line -- in excess of 15mph to 30mph will be possible.
On a side note, latest word from the National Weather Service in Fort Worth: A tornado warning will not be issued for Milam, Robertson or Leon Counties due to the fact that a cold front has slide into that area. We could still see other parts of the Brazos Valley fall into that watch if it is issued.
The Storm Prediction Center has released its latest Mesoscale Discussion. There currently is a 60% chance that a Tornado Watch could be issued before sunrise, for anywhere inside the red oval:
If that watch is issued, it could include parts of the East & Northeastern Brazos Valley.
The cold front that was sitting to the north of the Brazos Valley has managed to slip into Milam and Robertson Counties. Winds behind the front are blowing from the north at 15-20mph.
Scattered showers have developed along the front across the Nothern Brazos Valley, while areas of rain and a few embedded (non-severe) thunderstorms continue to work into the Western Brazos Valley.
Latest run of the 4km WRF Computer Forecast Model shows the cold front stalling just north of Hwy. 21 through sunrise (~6am to 7am). Temperatures behind the front sit in the 50s, ahead of the front remain in the 70s.
Depending on where that cold front sets up, there could be additional shower and thunderstorm activity fire up -- especially after sunrise.
That same run of the WRF model, shows our cold front retreating back to the northwest by 9am. Temperatures could be left on the chilly side across Milam and Northwestern Robertson County through the day.
There is a chance that this cold front could graze Bryan / College Station / North Brazos County briefly by late morning / midday. That said, southwesterly winds look to take back over for the afternoon, pushing temperatures back into the low 70s by late in the day.
A line of showers and embedded pockets of moderate to heavy rain / thunder has come together and is racing across I-35 at 45mph.
While this activity is not severe, lightning activity is starting to pick up just east of I-35, near Georgetown and Hutto. Should this activity continue to strengthen, it will likely move into Milam County.
For now, expect rain to push into Thorndale by 1:45am and Cameron by 2am.
Midnight Saturday Update
An area of light showers has managed to form from Leon County, across I-45 south towards Normangee and Madisonville, to Bryan / College Station, and south towards Somerville / Lake Somerville. All activity across the area remains light showers, as of the time being.
The Storm Prediction Center put out a Mesoscale Discussion earlier this evening, as strong thunderstorms started to develop north and east of the Brazos Valley -- near Athens.
While the threat isn't very large for now, they have put out a 40% chance of a watch being issued for parts of the area later tonight. Main concern will be when activity out in West Texas starts to cross over I-35.
Latest run of the WRF Model (Hi-Res short-range model) shows a decent line of thunderstorms / moderate to heavy rain still possible by Saturday morning. Here's it's thoughts as of 8am:
One thing to note -- not much lightning activity is showing up with rain moving in from the western side of the state. That said, dynamics will become better as we approach sunrise for thunderstorm development to take shape. Still a watch and wait game as of this point...
Strong, southerly winds are blowing in from the north this evening -- in response to the wide temperature spread across the State of Texas. As of 10pm, temperature range from 72° to 77° across the Brazos Valley, while they are in the 40s in Waco and 30s from Dallas / Fort Worth to points north (all behind a strong cold front).
10:30pm wind gusts
Good and bad with winds at this speed -- if they stay strong through the time storms try to develop.
The Good: Strong winds at the surface, and in the upper-levels of the atmosphere, make it hard for storm structures to build. That means, any severe thunderstorms that tries to develop will have a chance of being knocked over by those winds -- which helps keep the severe threat at bay.
The Bad: Should a thunderstorm manage to develop and take shape, those strong, southerly winds can help create a brief, weak tornado threat. That southerly wind would essentially "notch" out the storm -- meaning help create a possible area of rotation. Should this happen, they typically do not last long, but could prompt tornado warnings to be issued.
We'll keep an eye on things through the evening and into tomorrow.
Updates as needed will continue to be posted here.
What is a SLIGHT RISK for Severe Weather?
The Storm Prediction Center (SPC) issues outlooks for possible thunderstorms, along with if they could be severe, for a three day period across the United States.
The three risk types are SLIGHT, MODERATE, and HIGH.
--A SLIGHT RISK is issued when severe thunderstorms are not out of the question, but typically the chance is 30% or less.
-A MODERATE RISK is when conditions are favorable for a decent chance of severe weather to break out -- roughly a 45% to 50% chance.
--A HIGH RISK is rarely issued, but when it is it typically means there is a chance for highly dangerous thunderstorms that could produce life threatening tornadoes and damage.
Here is the outlook for Saturday, as of the latest update from the SPC Friday evening
Main Concern for Storms Saturday Morning
While the severe threat is marginal -- there is the potential that a few storms could bring the potential for damage to the Brazos Valley as the weekend begins.
Any storm that manages to build on Saturday could bring:
--50mph to 60mph+ wind
--Brief, isolated, weak tornado threat
--Heavy, blinding rainfall
The biggest concern lies in individual storms that manage to fire up ahead of our expected line of showers and thunderstorms. That line is expected to move into the Brazos Valley around sunrise Saturday -- any storm between 3am and 5am could become a cause for concern.
Timing of Rain & Storms
As of Friday evening, it looks like our main storm "window" will fall between 3am and Noon Saturday.
Below is a look at the Friday Afternoon Run of the PinPoint Computer Forecast Model. This computer model is trying to predict what the radar may look like as shower and thunderstorms develop and move across the area. Still images are available at the top of this story)
Best bet for thunderstorms in the Western and Central Brazos Valley falls between 7am and 10am. For the Eastern Brazos Valley, we'll look for that chance to run between 10am and Noon.
Colder Air Arrives Sunday
This rain & storm chance / severe thunderstorm potential all exists ahead of a strong cold front -- scheduled to blow into the Brazos Valley on Sunday.
That same cold front had already reached Texas as of Friday afternoon. However, the cold air will remain to the north of the area during the day on Saturday, before a secondary push from the upper atmosphere helps nudge it into the area to wrap up the weekend.
The muggy, spring-like feel will be erased as colder than average temperatures blow back into the Brazos Valley.
Overnight lows will drop back down around freezing by Monday morning, while afternoon highs struggle to reach the 50s through, and beyond, Christmas Day.
Stay Up-To-Date with the Latest
The PinPoint Weather Team will be monitoring the situation closely as long as the severe weather threat persists.
You can always check the latest by using Interactive PinPoint Radar.
More updates as needed to come.