Texas Spring 2016

[Brent]

The hrrr has a squall line/MCS moving through the metroplex for rush hour in the morning

[StormChaser75]

Made sure my garden plants were tied down ,especially since I am close to the enhanced possibility area for severe storms

[CajunMama]

The hrrr has a squall line/MCS moving through the metroplex for rush hour in the morning

And guess whose flight is due to land at DFW at 7:45. I am NOT liking this scenario.

[EF-5bigj]

There is a enhanced risk in TX today. I don't know much about the tornado threat though.

[Ntxw]

We need to watch this evening closely. HRRR is developing big supercells near DFW while cape values 3000-4000 k/g. That is a hotbed for tornado potential. Be on alert and hopefully the MCS later this morning can work the atmosphere over.

[KatDaddy]

Lots of action in SE TX on the way today, tonight, and through Wednesday afternoon as significant flood and severe weather event develops across S and SE TX. Severe storms ongoing across W Central TX and beginning to develop along the Coastal Bend and Hill Country. A busy 24-36 hours ahead From this morning's Houston-Galveston AFD:

A POTENT UPPER LEVEL STORM SYSTEM WILL BRING THE POTENTIAL FOR A DANGEROUS FLOOD EVENT ACROSS SE TEXAS TONIGHT AND WEDNESDAY.

Severe weather is a concern from late this morning through the overnight hours with a very strong 45-60kt low level jet and helicity values near 600. Tornadoes and damaging winds will be possible. The SPC has an enhanced area for S, S Central, and SE TX.

In addition Coastal Flood Warnings have been issued for the Upper TX Coast due to strong S winds of 25-30kts with gusts of 40-45kt bringing tides of 3-4ft above MSL. Gale Warnings have also been issued for the coastal waters for this evening and tonight

Flash Flood Watch remains in effect with the 4-8" rains likely and even higher amounts up 12" through Wednesday afternoon. The Wednesday morning commute could be dangerous so remember the phrase "turn around don't drown" should you encounter high water.

[TheProfessor]

We need to watch this evening closely. HRRR is developing big supercells near DFW while cape values 3000-4000 k/g. That is a hotbed for tornado potential. Be on alert and hopefully the MCS later this morning can work the atmosphere over.

Yeah you really don't want that line to weaken.

Part of the Early morning AFD says it best.

THE AFTERNOON FORECAST IS UNCERTAIN DUE TO CONFLICTING SIGNALS IN
THE ATMOSPHERE. ON ONE HAND...RATHER STRONG UPPER LEVEL SUBSIDENCE
ON THE SYNOPTIC SCALE IS EXPECTED AND IT WOULD CERTAINLY SUPPRESS
CONVECTIVE POTENTIAL THIS AFTERNOON...BUT IT WOULD BUILD UP A
TREMENDOUS AMOUNT OF SURFACE BASED INSTABILITY. MODEL GUIDANCE IS
UNANIMOUSLY SHOWING CAPE VALUES OF AT LEAST 2000 J/KG WITH SOME
INDICATING 3500 J/KG. THIS INSTABILITY WOULD BE UNCAPPED...BUT IF
THE SUBSIDENCE IS DOMINANT...CONVECTION WOULD HAVE A TOUGH TIME
FORMING. ON THE OTHER HAND...SOME OF THE HI-RES GUIDANCE SHOWS
MESOSCALE FEATURES WHICH COULD RESULT IN LOCALIZED UPWARD FORCING
THAT WOULD ALLOW THUNDERSTORMS TO DEVELOP. ONE OF THESE MAY BE A
DRY LINE THAT ACTUALLY MOVES UP FROM THE SOUTH FROM THE HILL
COUNTRY INTO THE SOUTHWEST ZONES TODAY. THIS IS CERTAINLY NOT A
NORMAL OCCURRENCE HERE AND IS ATTRIBUTED TO THE UNUSUAL SOUTHERLY
TRACK OF THE UPPER LOW. THE SECOND FEATURE OF INTEREST IS FORECAST
BY THE RAP...WHICH SUGGESTS THIS MORNING/S CONVECTION WILL LEAVE
AN OUTFLOW BOUNDARY SOMEWHERE ACROSS THE NORTHWEST ZONES. STRONG
SOUTH WINDS IN THE LOW LEVELS WOULD INDUCE STRONG WARM ADVECTION
AND LIFT OVER THE TOP OF THIS BOUNDARY AND COULD RESULT IN
CONVECTIVE INITIATION. IF ANY STORMS DEVELOP ALL FACETS OF SEVERE
WEATHER WOULD BE POSSIBLE DUE TO THE HIGH INSTABILITY AND DEEP
SHEAR. THE MOST LIKELY REGION WHERE AFTERNOON STORMS WOULD DEVELOP
IS WEST OF I-35...BUT DUE TO LOW CONFIDENCE/COVERAGE WILL KEEP
AFTERNOON POPS AT 30 PERCENT OR LESS.

[Ntxw]

I'm thinking the line will hold. There is embedded showers ahead of it and even they are putting on and off moderate to heavy rain. I drove through one and it was huge drops. Very juiced at atmosphere.

[Garnetcat5]

What will help Houston avoid tornados? Is it better if it storms today to use up the energy? Ahh what to pray and watch for?!

[Ntxw]

What will help Houston avoid tornados? Is it better if it storms today to use up the energy? Ahh what to pray and watch for?!

Houston's biggest threat will be flooding. Not to say tornado's are not a risk they could occur in embedded storms but the guidance overall are not showing supercell type development that way. Central and N Tx are more likely to see the singular development mode. At least for today.

[jasons2k]

Yes our primary threat down here is flooding but we have a tremendous amount of shear. Helicity values on the forecast soundings are pretty impressive. We will probably be under a tornado watch sometime this evening.

[Ntxw]

Tornado watch for central Texas, lower part of the MCS crossing NTx, including Austin, college station areas.

[weatherdude1108]

Tornado watch for central Texas, lower part of the MCS crossing NTx, including Austin, college station areas.

I saw that. It popped up on my phone. I'm at work and we went to the training room back in October, which is inside the building. Maybe this line will work over the atmosphere down here for later tonight(?). I can pray and hope. I don't like tornado threats, especially close to home. I get recurring storm anxiety with just a threat of tornadoes.

The ironic thing is I used to imagine being a storm chaser, and have watched TWISTER I don't know how many times. It changed when I had a close call by myself, with siren going off in distance. That affected me on a personal level. Now I prefer them in pictures/videos.

This is the SPC MD:

MESOSCALE DISCUSSION 0184
NWS STORM PREDICTION CENTER NORMAN OK
0706 AM CST TUE MAR 08 2016

AREAS AFFECTED...MUCH OF E CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 081306Z - 081530Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SCATTERED STORMS ARE EXPECTED TO AFFECT MUCH OF E CNTRL TX
THROUGHOUT MUCH OF THE DAY. DAMAGING WINDS, HAIL AND A BRIEF TORNADO
OR TWO WILL ALL BE POSSIBLE.

DISCUSSION...A LINE OF STORMS...CONTAINING PERIODIC EMBEDDED
CIRCULATIONS AS WELL AS HAIL CORES...CONTINUES TO MOVE EWD ACROSS N
CNTRL INTO CNTRL TX. ALTHOUGH THIS SYSTEM IS LARGELY LINEAR...AREAS
OF ROTATION HAVE BEEN NOTED AT TIMES. ALSO...NEW CELLS ARE
CURRENTLY DEVELOPING AWAY FROM THE LINE ACROSS CNTRL TX. RADAR ALSO
SHOWS SHALLOW SHOWERS OVER MUCH OF THE WARM SECTOR E OF THE
STORMS...SUGGESTING OTHER PRE-LINE DEVELOPMENT IS POSSIBLE.

ALTHOUGH WIND AND HAIL IS THE MAIN THREAT CURRENTLY...THE TORNADO
THREAT MAY INCREASE AS STORMS EVOLVE FARTHER EWD WHERE LOW-LEVEL
SHEAR IS STRONGER AND AS MOISTURE CONTINUES TO INCREASE BENEATH
RELATIVELY STEEP MIDLEVEL LAPSE RATES.

[Ntxw]

Tornado warning embedded in the line coming into FW

[gboudx]

Update from jeff:

**High impact…potentially dangerous…weather event this afternoon-Wednesday***

Tornado Watch issued for the NW 1/3rd of SE TX until 100pm

Flash Flood Watch all counties from noon today until 600pm Wednesday

Coastal Flood Warning Harris, Galveston, Brazoria, Chambers Counties from noon today to noon Wednesday.

Discussion:
Monster of an upper level storm system dropping SE into NW MX this morning and will continue to dig SE deeper into MX today and tonight. Low level jet is already howling across coastal TX with 925mb winds of 45kts transporting deep tropical moisture into the region. Short wave within the flow on the far eastern flank of this storm system is current approaching SE TX and meso scale models show scattered showers currently from Matagorda Bay to College Station erupting into thunderstorms this morning. Backed low level winds will support a tornado threat with these storms…enhance the issuance of the tornado watch for the College Station area.

Main event will be this evening into Wednesday as ingredients are coming together to produce a dangerous flash flood event across SE TX. Development of a nearly stalled low level boundary this evening, increase in the low level jet after dark, increasing large scale lift, and storms developing nearly parallel to the upper level flow (SSW to NNE) support a high flash flood threat. Moisture levels surge to near 1.9 inches (1.92 on the NAM forecast soundings) which is +2 SD above normal and at or above expected maximum levels for early March. This combined with the prolonged and sustained lift points toward a major rainfall event with flash flooding. I am very worried that storms will anchor at some point tonight in the low level flow and dump hour after hour on the region…but where this may happen is impossible to predict. Given everything in place would not be surprised to see a few 12 inch totals in the next 24 hours over SE TX.

Rainfall:
Widespread: 4-6
Isolated: 8-10

Flood Threat:
Rainfall of this magnitude will cause flooding especially in urban areas with the high hourly rainfall rates. Concern is certainly there for mainstem river flooding on the San Jacinto and Trinity basins given the very high totals and widespread nature of the event. Within Harris County rapid rises on area watershed seem likely and depending on where the greatest rain falls some watersheds may exceed their banks.

Severe:
Threat is already increasing over the NW part of the area and will continue to increase today into tonight. Low level shear values increase this evening as surface winds back more to the ESE and SE with oncoming height falls forcing surface low pressure over SW TX. This will increase the shear effect on updrafts. Really focusing in on the area around Matagorda Bay WSW toward the Rio Grande where the air mass will become most unstable this afternoon. Storms may initiate as supercells in this region with a higher tornado threat before transitions into a more damage wind threat over most of SE TX. Will not tone down the tornado potential over SE TX as any sustained cells with all the shear could rotate and produce a tornado this afternoon-Wednesday morning. This will be a prolonged severe threat for almost 24 hours for the region.

Tides:
Coastal water levels are running 1.0-1.5 ft above normal currently in Galveston Bay and NE of Freeport. Strong onshore flow will continue to push water toward the coast along with wave run-up and tidal trapping in the NW portion of Galveston Bay. Winds really ramp up this afternoon and evening which may require a short fused Gale Warning. This will likely push total water levels to near warning criteria on the Gulf beaches along Bolivar and the west end of Galveston Island where overwash is looking increasing likely. Could see some problems on the west side of Galveston Bay also, but wave run-up is not as great in this area compared to the Gulf beaches. Tides in Matagorda Bay will run 1-2 ft above normal.

Wednesday afternoon-Friday:
Will maintain additional period of thunderstorms as the main upper low rotates into and across the region. Hard to time rain and dry period at this point and main focus right now is getting through tonight and Wednesday morning.

Actions:
Residents across the region should be prepared for rapidly changing weather conditions over the next 24 hours. Plan for excessive rainfall and flooding along with severe weather potential. Know what you will do if faced with one of these threats or a warning is issued for your area. Do not drive into high water…the majority of all flash flood fatalities are from persons who drive into high water and are swept away.

[EF-5bigj]

There is a nasty looking cell near gatesville.

[gboudx]

Anyone experience the bowing segment of this DFW MCS? Looks potent and heading right for me.

[Ntxw]

Anyone experience the bowing segment of this DFW MCS? Looks potent and heading right for me.

Its pretty intense, wind whipped rain going on. Looking out the window a lot of cars have stopped waiting for it to pass

[WeatherNewbie]

Anyone experience the bowing segment of this DFW MCS? Looks potent and heading right for me.

Yep. On the border of Carrollton and Addison and it is nasty. This is the darkest and windiest I have seen in a long time. Easily 50+ mph gusts.

[Tireman4]

The winds are howling from the SE. 22 MPH with gusts near 30. I mean howling in Humble. I had my battery die today and took it to get warrantied out at Firestone. I am walking across the parking lot and the gusts are moving me...this is some wind. This may not be good for the folks in Central Texas...