Friday Severe Threat

Weather Set Up

A potent and far southward-digging upper level storm system (trough of low pressure) and its attendant surface cold front will approach and move across the state of Texas on Friday. Ahead of this strong storm system, strong south southeasterly winds have developed. Those winds off of the Gulf of Mexico are pumping in lots of Gulf of Mexico moisture for the approaching storm system to work with to generate thunderstorms, some of which are likely to be strong/severe, Friday afternoon/evening/night across central, south central, north, southeast and east Texas. 

Threat Level by City

Austin Threat Level: Enhanced

San Antonio Threat Level: Slight

Houston Threat Level: Enhanced

Dallas/Fort Worth Threat Level: Enhanced

Central Texas Severe Outlook

Graphic courtesy of Meteorologist Avery Tomasco at CBS Austin News

Texas Severe Outlook

What does an enhanced risk of severe storms mean? Let’s take a look – plus I've added our threat levels for Friday's forecast

   

Numerous severe storms possible. The severe storms that develop will be more persistent and/or widespread and a few may be intense

      A few tornadoes possible – LOW THREAT

Several reports of wind damage – MODERATE THREAT

 Damaging hail 1-2 inches in diameter – LOW THREAT

***Widespread severe weather is NOT expected, however, there is the potential for some areas to receive some severe weather

Friday Weather Timeline

As it looks right now, passing showers and perhaps a thundershower will be possible Friday morning through early afternoon across central Texas (I think a lot of that activity will be limited by a layer of warmer air aloft) with the more organized activity developing late afternoon into Friday evening along and just west of the I-35 corridor as the main upper level energy and a cold front begin to move in. Based on the latest high resolution forecast model data, it appears that there is the potential for a rapidly developing squall line (line of thunderstorms) to initiate along and possibly just west of the I-35 corridor between 4-8 p.m. CST Friday evening. The greatest severe threat from these developing storms will be damaging winds in excess of 60-75 mph. Once this line of storms initiates, it will continue to march east with the cold front and upper level storm system. The severe threat looks to ramp up once the line of storms pushes east of the I-35 corridor.

Tornadoes??
There is a low-end tornado threat across the area tomorrow evening, however, the best dynamics for tornadoes appears to remain east and especially well to the northeast of the I-35 corridor into east Texas and northeast Texas (red shaded area on the Texas map above). Damaging wind gusts still appear to be the biggest threat from storms that develop locally. Additionally, all storms that develop will have the potential to produce brief heavy downpours and dangerous cloud to ground lightning.

I do need to mention that if the forecast line of storms remains broken (rain free areas in between the forecast line of storms) and if isolated storms are able to develop ahead of the forecast line of storms, those discrete thunderstorm cells will have the best potential to rotate and perhaps produce a tornado. This will need to be watched closely and it is by no means likely or a sure thing. 

Along with all that I’ve mentioned above, it’s possible that we only see garden variety showers and storms in Austin with the worst of the weather potentially staying off to our east.

Rainfall Accumulation
A quick 0.5-1.5 inches of rain will be possible...some may receive more and some may receive less. Rainfall is very welcome at this time and flash flooding does NOT look to be an issue on Friday.

With all that noted, we will all need to remain weather aware Friday afternoon/evening. With the potential for severe weather, it is always a good idea to turn on emergency alert notifications on your cell phone.

How to enable emergency alerts on iPhone

Open settings à notifications à scroll down to the bottom of notifications tab to where it says “Government Alerts” and turn on “Emergency Alerts”

Should and if a tornado or flash flood warning were to be issued, you would receive notification on your phone

What to Expect behind the Storms & the Weekend

Behind the line of storms, lingering showers and thundershowers may persist for 2-3 hours before conditions rapidly clear from west to east behind the storm system as a much drier and cooler air mass infiltrates the region.

Highs Saturday despite a sunny sky will only manage the 50s to lower 60s (near normal for this time of year) with a breezy northwest wind. As winds relax Saturday evening under a clear sky, temperatures will plummet into the 20s to middle 30s across the area by early Sunday morning. Low-lying, out-lying locations will likely receive a freeze with areas like downtown Austin staying a few degrees above 32°F.

Sunny and near perfect conditions expected for your Sunday with highs rebounding into the lower 60s under a mainly sunny sky.

BIG Temperature Drop & Rain Tomorrow

Record Warmth ahead of Strong Cold Front

As of 3pm, temperatures have soared into the upper 70s and lower 80s across central Texas in advance of a strong cold front that will bring a temperature shock by the time we wake up Tuesday morning. Both Austin's Camp Mabry and Austin Bergstrom International Airport have tied (and possibly broken) their record highs for this date both at 81°F.

Where is the Front Now?

While this front is going to be bringing a significant drop in temperatures, the really cold air is lagging well behind the leading edge, or wind shift line. The leading edge of this modified Arctic Air has already pushed through the Dallas Metroplex and and is currently located in the extreme northwestern Hill Country. Temperatures behind the front have cooled into the 50s and 60s while areas out ahead of the front are still mild in the 70s and 80s.

3:45 PM Temperature Analysis (state of Texas)

The cold front will move through the I-35 corridor later this evening and bring with it the possibility for some rain, but the better rain chances for widespread more persistent rain will hold off until late tonight into Tuesday morning as an upper level disturbance moves across the state from west to east and generates lift in our atmosphere. The energy with this disturbance will create the widespread rain we are expecting for tomorrow morning into the early afternoon hours. The progressive, or fast-moving, nature of this disturbance will help to quickly dry us out by late Tuesday afternoon into Tuesday evening as the coldest temperatures begin settling into central Texas, but not before giving us on average a quarter to as much as half an inch of rainfall in spots (we will take every drop!).

What to Expect on Tuesday?

Significantly colder conditions & rain! Some 40 degrees colder than today! You won't want to walk out the door Tuesday morning without a jacket and an umbrella because you will want both! Temperatures on Tuesday will stay in the 40s all day with breezy north winds and rain making it feel even colder in the 30s. Rain, mainly light with some pockets of moderate to isolated pockets of heavy rain will develop overnight tonight and persist through 2-3pm Tuesday afternoon before conditions begin to clear by late afternoon into the evening.Air temperatures will drop into the 30s late Tuesday into Wednesday morning and drop to near or below the freezing mark by Wednesday morning. Luckily for us, conditions are expected to be dry by the time temperatures near the freezing mark.

Beyond Tuesday

After a cold start to the day on Wednesday, afternoon highs under sunny skies will rebound nicely into the 50s, but those clear skies will allow for another chilly night Wednesday night with temperatures dipping into the 30s (light freeze for out-lying, low-lying locations) and warming back into the 50s for Thursday afternoon under a mostly sunny sky. Temperatures continue to moderate into the weekend with highs returning quickly into the 60s and 70s with the return of southerly winds and mostly sunny/mostly clear skies.   

Unseasonably Cold Weather & Rain Chances

Forecast Discussion

A shallow wedge of cold air snuck into the area yesterday evening and has left us with a cloudy, chilly, and dreary day with temperatures ranging from as cold as the 40s to as warm as the lower 60s across the area. Light and patchy areas of rain, mist, and drizzle will continue through the evening before increasing in coverage and intensity overnight and into the day on Wednesday ahead of a strong upper level low pressure system that will send a second, more significant push of colder air into the area Wednesday afternoon. Highs on Wednesday will occur early in the day with falling temperatures expected into the afternoon and evening thanks to gusty northerly winds.

Tuesday 5pm Temperatures across the state 

(check out the spread between Amarillo and South Texas)

Severe Threat???

The Storm Prediction Center has placed the majority of the area under the MARGINAL RISK category for potential severe weather on Wednesday. What does that mean? It means an isolated storm or two has the potential to briefly become severe and produce damaging winds in excess of 58 mph. The majority of the storms that develop over the next 24-36 hours will be non-severe, but a few may be strong. All storms will pose a risk from brief locally heavy rainfall and dangerous cloud to ground lightning. On average, an additional 0.25 to 1 inch of rain will be possible across the area between now and tomorrow evening with some areas potentially receiving a little more from scattered strong downpours/thunderstorms.

Marginal Risk Area (dark green shading)

Unseasonably Cold Air

Freeze likely for many early Thursday (Halloween) Morning with even more locations dipping to near and below the freezing mark on Friday morning under clear and calm conditions. The average high/low for this time of year in Austin is 78/57. 

What to Expect for the Rest of the Week

You’ll need a jacket and an umbrella as you head out the door on Wednesday…by Wednesday evening, showers and storms will begin to come to an end as drier and much colder air moves into the region on gusty north winds.

Halloween (Thursday) Morning we will wake up to temperatures in the 30s area wide (some spots at the freezing mark north and west of Austin) with wind chills in the 20s to lower 30s area wide. Despite sunny skies on Thursday, temperatures will struggle into the 50s thanks north winds streaming in cold air across the area. Thursday night as winds go calm and skies are clear, temperatures are expected to dip into the upper 20s in the coldest spots to mid-30s in the warmest spots (i.e. downtown Austin). A gradual warming trend takes us into the upcoming Formula One weekend with sunny skies, highs in the 60s and lows in the 30s/40s.

Forecast Wind Chills Thursday morning (NAM Model)

Showers & Storms Ahead of Strong Cold Front

Good Afternoon, folks!

Warm and balmy conditions in the 80s right now will shortly be a thing of the past. A strong fall cold front is currently positioned west of the IH-35 corridor along a line from southeast Oklahoma through the Dallas Metroplex and into the northwestern Hill Country. Along and immediately behind the frontal boundary, heavy showers and isolated thunderstorms have developed. To give you an idea of the strength of this cold front, as of 4pm, it is 82°F at Austin’s Camp Mabry and 50°F in Brady, TX (northwestern Hill Country). Farther to the northwest it is 31°F and snowing in Amarillo.

Temperatures across Central Texas as of 4:15 p.m. CDT Thursday (24 Oct 2019)

Weather Setup 

A potent upper level low pressure system moving into the area from the northwest is pushing a strong cold front southeast through the state of Texas this afternoon. Ahead of the front, warm and humid conditions have developed (temperatures in the 70s, 80s and even 90s in south Texas), compared to 30s, 40s, and 50s behind the front.

Severe Risk?

The Storm Prediction Center has placed all of central, north central and south central Texas under the Marginal risk category for potential severe thunderstorms this afternoon and evening. By no means does this mean that widespread severe weather is going to occur, rather it means that an isolated storm or two has the potential to become briefly severe and produce hail up to the size of quarters along with isolated wind gusts in excess of 58mph.

As the front traverses the area from northwest to southeast through the evening, shower and thunderstorm chances will increase and persist into the wee hours of Friday morning with rain chances coming to an end across the area (from west to east) before sunrise Friday morning.

Marginal Risk for Isolated Severe Storms (dark green shaded area)

Rainfall Accumulation

Forecast rainfall accumulation may exceed as much as 1-2 inches in some locations from this rain event, but it appears that the majority of the area (especially west of Austin) may receive less than 0.50 inches. High resolution forecast models continue to indicate the possibility of greater than an inch of rain falling for portions of the IH-35 corridor and points east. We will take every drop given the severe to extreme drought ongoing across the area.

What can we expect on Friday/Saturday??

Sharply colder and windier weather will push in behind the front for Friday with all of the area experiencing temperatures in the 40s (mid to upper 40s along and east of the Interstate and upper 30s to lower 40s across the Hill Country) with wind chills in the 30s to lower 40s across the majority of the area. Despite clearing skies on Friday, strong north winds will only allow for temperatures to recover in the 50s and lower 60s (south of Austin) on Friday afternoon. Those strong north winds will continue to transport cold air into the area from the north. Everyone drops back down into the 40s Friday night/Saturday morning with temperatures expected to rebound nicely Saturday afternoon with plenty of sunshine into the 60s to lower 70s across the area.

Forecast Wind Chills 9 a.m. Friday Oct 25 2019 (HRRR Model)

This is what it will feel like when you combine air temperature and wind speed

WIND ADVISORY in effect for all of central Texas from 7 p.m. Thursday evening through 4 p.m. Friday afternoon. Sustained winds of 20-30 mph with gusts in excess of 35-40 mph will be possible across the area behind a strong cold front. Gusty winds could blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. Travel could be difficult for high profile vehicles on east to west oriented roads.

Summer to winter within 24 hours

Record Heat Today ahead of STRONG cold front

Good Evening, Folks!

What a roller coaster ride this week has been so far. We approached the top of the roller coaster today with a new record high temperature of 99°F at Austin’s Camp Mabry beating the previous record of 97°F set back in 1926. Austin Bergstrom International Airport also crushed their previous record high of 93°F set back in 2014 by 4 degrees coming in at 97°F this afternoon.

Today’s summer-like heat is about to take a big drop for our Friday as an unseasonably strong cold front sweeps through the area early tomorrow morning. 

Current Temperatures across the southern Plains (as of 6:45 pm Thursday)

The leading edge of the colder air is currently approaching the I-20 corridor in northwest Texas and has prompted the Storm Prediction Center to issue a SEVERE THUNDERSTORM WATCH for portions of north and north central Texas, including the DFW Metroplex, until 1:00 AM CDT Friday. The biggest threats from the storms that develop in those areas this evening and early Friday morning will be scattered large hail and isolated very large hail events up to 2 inches in diameter along with scattered damaging winds gusts to 70 mph. By the time those storms reach central Texas early Friday morning, the storms should be below severe levels, but one or two strong storms cannot be ruled out (especially north and west of Austin).

Severe Thunderstorm Watch

Counties shaded in yellow on the map below are included in the SEVERE THUNDERSTORM WATCH until 1:00 AM CDT Friday…a watch means conditions are favorable for the development of severe weather…a warning means severe weather is imminent and/or occurring and that it is time to seek shelter

Cold Front Timeline

According to high resolution forecast model data, the front will be moving into the far northwestern Hill Country between midnight and 1 a.m. with showers and thunderstorms and moving into the Austin Metro Area between 3:30-4:30 a.m. Friday morning with gusty winds, scattered showers and thunderstorms and rapidly falling temperatures. By 7 a.m. the leading edge of the cold front will be south of San Antonio and pushing south southeast towards the extreme northwest portions of the Houston Metro Area. Rain may stick around behind the front through noon Friday. High temperatures Friday will occur early Friday morning and drop drastically behind the front into the 40s and 50s across the area. Afternoon highs on Friday will struggle to rebound into the mid to upper 50s in Austin with cloudy skies, rain showers (in the morning), and gusty north winds will make it feel like it’s in the 40s!

1:00 a.m. Friday (forecast radar/forecast surface temperatures)

4:00 a.m. Friday (forecast radar/forecast surface temperatures)

7:00 a.m. Friday (forecast radar/forecast surface temperatures)

9:00 a.m. Friday (forecast radar/forecast surface temperatures)

Roller Coaster Temperatures

After setting a record breaking high of 99ºF this afternoon, beating the previous record of 98ºF set all the way back in 1912, relief is on the way. The leading edge of our first fall cold front is currently pushing through northwest Texas and is already dropping temperatures into the 60s across Oklahoma and the Texas Panhandle. Ahead of the front scattered showers and thunderstorms have developed across northwest Texas and are beginning to push south into portions of the northwestern Hill Country on this Sunday evening.

Temperatures as of 7pm Sunday Evening (courtesy of Wright-Weather) 

The much anticipated cold front will arrive in Austin around midnight. There is the possibility for a shower or brief storm to accompany the frontal passage, but the best chance for rain will remain north and west of Austin. Breezy northerly winds behind the front will usher in the coolest air we have seen since early May. We will wake up to temperatures in the 60s area wide with afternoon highs only managing the 70s for most locations, lower 80s for some, on Monday afternoon. Temperatures early Tuesday morning will be able to drop even further into the upper 50s to lower 60s across the area before temperatures begin to quickly heat up by mid-week back into the 90s, record territory, ahead of a second stronger cold front that will approach the area late Thursday evening and arrive early Friday. This front looks to bring an even more significant and longer lasting cool down along with a slightly better chance for precipitation. Afternoon highs in the 60s will be possible on Friday with a gusty north wind, clouds and rain showers making it feel even colder with overnight lows dropping into the 50s by Saturday morning with afternoon highs remaining quite comfortable in the 70s for next weekend and morning lows in the 40s and 50s. Ahhhh!! We definitely deserve that! 

While these fronts will be bringing us some heat relief, unfortunately they do not look to bring us widespread, significant rainfall to relieve ongoing drought conditions across the area. Many areas across the state have slipped into severe to extreme drought conditions. 

Latest Drought Monitor (as of October 3rd)

Flash Flood Watch/Severe Weather Risk

Hello, folks! The fourth storm system this month has its eyes set on Texas and we're already feeling its effects. The upper level low is currently located in northern Mexico south of Arizona and is pushing disturbances across the state of Texas out ahead of it. These disturbances generate lift in our atmosphere. That lift helps to promote the development of showers and thunderstorms.

Image above courtesy of earth wind map and is depicting upper level winds over Mexico and the United States

Gulf moisture has already made a big return to the area as of Wednesday afternoon as evidenced by dew point temperatures in the upper 60s. At the surface a cold front is currently draped along the I-20 corridor across West Texas and is the focus for thunderstorm development this afternoon. Yellow shaded area north west of south central Texas is under a SEVERE THUNDERSTORM WATCH until 11pm CDT this evening. The storms outlined in red boxes are severe.

Texas Radar Update as of 5:20 pm CDT Tuesday evening

What should we expect in central Texas?

This evening/overnight:Widespread shower and thunderstorm activity will remain well to the north and west of our region tonight. A few thunderstorms may try and creep into northwestern areas of the Hill Country, but the storms will hold off for the I-35 corridor until Wednesday and especially Wednesday afternoon and evening. With that being said, a brief passing shower or downpour cannot be ruled out overnight and early Wednesday morning. Lows tonight will only manage the 60s area wide thanks to a persistent moist southerly breeze off of the Gulf of Mexico.

Wednesday Morning: Showers and storms may be ongoing across portions of the northwestern Hill Country and a large portion of west Texas slowly spreading south and east into the Hill Country during the early afternoon hours.

Wednesday afternoon/evening: Scattered showers and thunderstorms will begin to pop up along the I-35 corridor, becoming more widespread as a line of storms develops across the Hill Country and pushes slowly east through the I-35 corridor during the early evening hours. This is when the worst of the storms are expected in Austin/IH-35 corridor. In addition to the threat of locally heavy rainfall and dangerous cloud to ground lightning, the Storm Prediction Center based in Norman, Oklahoma has placed a large swath of central, south central, south, and southeast Texas under a SLIGHT RISK area for potential severe weather on Wednesday. This is a threat level 2 out of 5 and indicates that scattered severe storms will be possible, but the severe storms that develop will be short-lived and/or not widespread; however, an isolated intense storm or two is possible.

Forecast Radar Graphic (this is what one model believes the radar will look like at different times of the day on Wednesday)

Wednesday Severe Weather Threats

Flash Flood Watch (counties shaded in green)
in effect for the following counties: Travis, Williamson, Hays, Burnet, Blanco, Llano, and Gillespie from 7 am CDT Wednesday until midnight Thursday. Widespread amounts of 2-4 inches of rain will be possible in these locations with isolated higher amounts of up to 6 inches possible.

Images above courtesy of the Austin/San Antonio National Weather Service Forecast Office

Please remember, IF YOU COME ACROSS A FLOODED ROADWAY, TURN AROUND, DON'T DROWN!!!