February 2017- Spring Like Weather Returns

[StormOne]

if it holds together and the cape stays strong - have to wait and see.

CAPE is the weakest part of this whole thing atm. If SE TX sees CAPE values of >1000 J/kg in the morning, that may be sufficient for a moderate risk IMO. GFS and NAM are quarreling on intensity as always, so a ton of uncertainty still exists, and wouldn't be surprised to see uncertainty even beyond the 13z SPC outlook.

[Andrew]

if it holds together and the cape stays strong - have to wait and see.

CAPE is the weakest part of this whole thing atm. If SE TX sees CAPE values of >1000 J/kg in the morning, that may be sufficient for a moderate risk IMO. GFS and NAM are quarreling on intensity as always, so a ton of uncertainty still exists, and wouldn't be surprised to see uncertainty even beyond the 13z SPC outlook.

I would be surprised to see a moderate risk come out of this. Just too many uncertainties in respect to storm mode and overall evolution. I feel like the enhanced risk with the 10% risk is a good forecast. Helicity, especially at the lowest 1km looks promising but lack of instability (especially at the mid to lower levels) really indicates it could be difficult to get a widespread outbreak. With that said, if surface temperatures are a little warmer and we can get just a little cooling aloft who knows. I would keep an eye on the HRRR overnight, it has been producing some rather interesting results south of I-10.

[Katdaddy]

Tornado Watch likely for S Central and SE TX shortly.

Mesoscale Discussion 0178
NWS Storm Prediction Center Norman OK
0357 AM CST Tue Feb 14 2017

Areas affected...South-central and Southeast Texas

Concerning...Severe potential...Watch possible

Valid 140957Z - 141230Z

Probability of Watch Issuance...60 percent

SUMMARY...A severe threat is likely to develop across south-central
Texas over the next hour or two. A tornado threat along with
isolated large hail and wind damage will be possible as a linear
convective system organizes and moves from eastern parts of the
Texas Hill Country eastward into southeast Texas this morning.
Weather watch issuance will need to be considered once the exact
corridor with the greatest severe threat becomes apparent.

DISCUSSION...The latest surface analysis shows a cold front
extending southward from the Dallas/Fort Worth Metro along and just
east of the I-35 corridor to near Austin where a mesolow is
analyzed. The front extends southwestward from this surface low to
near San Antonio where a second surface low is analyzed. A warm
front extends eastward from this surface low into the Houston area
with surface dewpoints south of the front across the Texas Coastal
Plains mainly in the 65 to 70 F range.

In addition, water-vapor imagery shows an upper-level trough
approaching the lower Rio Grande Valley. Increasing large-scale
ascent ahead of the shortwave trough along with lift associated with
a developing low-level jet in south Texas will likely result in a
gradual expansion of thunderstorm activity across south-central
Texas over the next couple of hours. RAP forecast soundings near and
to the south of San Antonio early this morning gradually weaken a
capping inversion near 700 mb which will make conditions
increasingly favorable for surface-based development. The latest
HRRR forecast suggests that surface-based storms will first initiate
along the cold front to the south of San Antonio with this
convection expanding northward and organizing into a line. MLCAPE
estimated to be from 1000 to 1200 J/kg along with 40 to 50 kt of 0-6
km shear will support supercell development with the stronger cells
embedded in the line. Storm relative helicities of 300 to 325 m2/s2
evident on forecast soundings will be sufficient for a tornado
threat associated with supercells. The line of storms is forecast to
move eastward into the Houston area by late morning where a threat
for tornadoes, wind damage and hail will be possible.

[srainhoutx]

@NWSWPC
Here's a look at today's National Forecast. Severe weather will be possible along the western and central Gulf Coast.

[srainhoutx]

Special Weather Statement
National Weather Service Austin/San Antonio TX
455 AM CST TUE FEB 14 2017

Guadalupe TX-Karnes TX-Bexar TX-Caldwell TX-Gonzales TX-Wilson TX-
455 AM CST TUE FEB 14 2017

...SIGNIFICANT WEATHER ADVISORY FOR CALDWELL...GUADALUPE...CENTRAL
KARNES...GONZALES...WILSON AND EAST CENTRAL BEXAR COUNTIES UNTIL 530
AM CST...

At 452 AM CST, Doppler radar was tracking thunderstorms extending
from eastern Atascosa County to Caldwell County. Movement was east
at 30 mph.

Periodic wind gusts up to 50 mph will be possible with these storms.

Locations impacted include...
New Braunfels, San Marcos, Schertz, Seguin, Cibolo, Lockhart,
Gonzales, Floresville, Luling, Karnes City, Poth, Stockdale,
Kosciusko, Nixon, St. Hedwig, Martindale, Marion, Waelder, La Vernia
and Santa Clara.

[srainhoutx]

TORNADO WATCH OUTLINE UPDATE FOR WT 32
NWS STORM PREDICTION CENTER NORMAN OK
505 AM CST TUE FEB 14 2017

TORNADO WATCH 32 IS IN EFFECT UNTIL 100 PM CST FOR THE
FOLLOWING LOCATIONS


TX
. TEXAS COUNTIES INCLUDED ARE

ARANSAS AUSTIN BEE
BRAZORIA CALHOUN CHAMBERS
COLORADO DEWITT FAYETTE
FORT BEND GALVESTON GOLIAD
GONZALES GRIMES HARRIS
JACKSON KARNES LAVACA
LIBERTY MATAGORDA MONTGOMERY
POLK REFUGIO SAN JACINTO
SAN PATRICIO VICTORIA WALKER
WALLER WASHINGTON WHARTON
$$

[Katdaddy]

Some strong wording from the Houston-Galveston's morning AFD:

Significant tornado parameters from SPC Mesoanalysis as well as the Texas Tech WRF are also highlighting this
increasing tornado threat and have concerns that a significant tornado (EF2 or greater) could be observed today.

Remain very weather aware today across S Central TX, SE TX, and the Middle and Upper TX Coast. A Tornado Watch has just been issued until 1:00PM this afternoon The main area of concern are areas S of I-10 to the coast.

Parameters are in place for the tornado potential to increase later this morning as storms intensify betweenVictoria and San Antonio and push into SE TX ahead of the of squall line. Any of these discreet cells will have the potential to produce tornadoes.

A very busy weather day ahead for this Valentines Day.

[srainhoutx]

Tuesday morning briefing from Jeff:

***Tornado Watch issued for all of SE TX except Brazos and Burleson Counties until 100pm***

Significant tornado parameters will be in place by mid morning.

Powerful upper level trough is moving into SC TX with strong lift spreading into the western sections of an increasingly moist and unstable warm sector. Surface low is forming along a trough axis from roughly College Station to near Victoria and within the last hour discrete cells have started to develop over the warm sector north of Victoria. Aircraft ascents out of HOU and IAH this morning show a mid level warm layer (cap) in place, but expect this feature to rapidly erode this morning with development of discrete supercells across the warm sector.

Parameters really begin to increase for supercells and tornado production by mid morning as a 90kt mid level jet plows across a 35kt low level jet helping to greatly enhance low level shear values. Reservoir of high CAPE (instability) over the western Gulf of Mexico with values of 1000-2000 J/kg will expand NNE on the low level jet into at least the SW ½ of SE TX by mid morning. Given a very moist air mass, strong low level shear, and building instability the threat for severe weather and tornadoes will greatly increase by mid morning and continue into the mid afternoon hours. Latest HRRR suggests that some sort of meso low may form within the convective lines just west of Houston along I-10 late this morning and this would enhance low level shear even more along and S of I-10. Significant tornado parameters will be in place by mid morning and the potential for a few strong or violent tornadoes (EF2 or higher) is possible today over SE TX. Additionally strong wind energy aloft will likely be transported to the surface in any supercells or along the main line of thunderstorms with wind damage possible. Maximum tornado threat will be found in cells ahead of the main line or supercells embedded within the line.

Morning meso analysis shows pool of 1.6 inch PWS have surged into SC TX overnight and 850mb moisture transport will bring this NE into SE TX this morning. LCRA gages overnight have shown some impressive short term rainfall rates with cells and the heavy rainfall/flash flood threat will increase this morning into the early afternoon. No significant changes to the rainfall amounts of 1-3 inches with isolated totals up to 5 inches. High hourly rainfall rates within HP supercells of 2-3 inches will be possible which can lead to rapid onset urban flash flooding.

Tornado Safety:

· Have a way to receive weather warnings today…if you have turned off the alerts on your cell phone…turn it back on for today

· A tornado warning means that a tornado is occurring or likely and immediate action should be taken

· The safest place in a tornado is in an interior room on the lowest floor of the structure away from windows

· The safest place in a tornado at school or in an office building is a stairwell or against a concrete reinforced interior wall

· Do NOT open windows

· Do NOT shelter from a tornado under freeway overpasses/underpasses

Tornado Watch Outline:

[unome]

https://twitter.com/NWStornado/status/8 ... 9164494852

http://forecast.weather.gov/wwamap/wwat ... %20warning

Tornado Warning
TXC025-175-391-409-141300-
/O.NEW.KCRP.TO.W.0001.170214T1224Z-170214T1300Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Corpus Christi TX
624 AM CST TUE FEB 14 2017

The National Weather Service in Corpus Christi has issued a

* Tornado Warning for...
Northern San Patricio County in south central Texas...
South central Goliad County in south central Texas...
Southwestern Refugio County in south central Texas...
Southeastern Bee County in south central Texas...

* Until 700 AM CST

* At 623 AM CST, a thunderstorm capable of producing a tornado was
located near Tynan, or near Skidmore, moving east at 50 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.

* This dangerous storm will be near...
Skidmore around 630 AM CST.
Papalote around 635 AM CST.
Blanconia around 650 AM CST.
Woodsboro around 655 AM CST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 2802 9727 2811 9782 2817 9783 2818 9781
2828 9786 2856 9735
TIME...MOT...LOC 1223Z 257DEG 43KT 2822 9776

TORNADO...RADAR INDICATED
HAIL...<.75IN

[Katdaddy]

Severe Thunderstorm Warning
Severe Thunderstorm Warning
TXC015-039-089-157-239-321-481-141430-
/O.NEW.KHGX.SV.W.0013.170214T1325Z-170214T1430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Houston/Galveston TX
725 AM CST TUE FEB 14 2017

The National Weather Service in League City has issued a

* Severe Thunderstorm Warning for...
Wharton County in southeastern Texas...
Southeastern Colorado County in southeastern Texas...
Matagorda County in southeastern Texas...
Western Brazoria County in southeastern Texas...
Southeastern Austin County in southeastern Texas...
Fort Bend County in southeastern Texas...
Jackson County in south central Texas...

* Until 830 AM CST.

* At 724 AM CST, severe thunderstorms were located along a line
extending from near Wallis to near Lolita, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
Southern Sugar Land, southern Missouri City, Matagorda, Rosenberg,
Alvin, Bay City, Richmond, El Campo, Wharton, Edna, Manvel,
Palacios, West Columbia, Sweeny, Eagle Lake, Fresno, First Colony,
South Texas Nuclear Plant, Pecan Grove and Brazoria.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

[srainhoutx]

The attachment 02142017 SPC day1otlk_20170214_1300_prt.gif is no longer available

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0647 AM CST Tue Feb 14 2017

Valid 141300Z - 151200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS MORNING
OVER A SMALL PART OF THE MIDDLE-UPPER TX COASTAL AREA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS INTO
AFTERNOON...ELSEWHERE FROM THE TX COASTAL BEND TO EAST TX AND
WESTERN LA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS
IMMEDIATE COASTAL AREAS FROM THE MS RIVER MOUTH TO THE WESTERN FL
PANHANDLE...

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE WESTERN
SLIGHT-RISK AREA ACROSS PORTIONS OF CENTRAL/SOUTHERN MS AND AL...

...SUMMARY...
Severe thunderstorms are expected to shift eastward over southeast
Texas toward the Sabine River region through early afternoon, with a
few tornadoes and damaging winds possible. After a relative lull
when the risk becomes marginal, the threat of severe weather will
increase conditionally tonight into Wednesday morning, from the
mouth of the Mississippi River to the coastal Florida Panhandle.

...Synopsis...
A high-amplitude large-scale pattern will persist over North
America, characterized by troughing from eastern Canada across the
Great Lakes to the central Appalachians, and a sharp ridge from
Yukon and the NW Territories across the northern Rockies and CA.
East of that ridge, a strong/southern-stream shortwave trough was
evident in moisture-channel imagery from western KS southward across
the southern High Plains to the TX Big Bend region and adjoining
parts of northern MX. As a basal vorticity max aloft, now near the
Big Bend, ejects northeastward, the shortwave trough as a whole will
deamplify gradually, but still remain strong through most of the
period. By 00z, the 500-mb trough should reach eastern OK and
central TX, with a transient closed low possibly developing over
eastern OK. Thereafter the perturbation will enter a broader-scale
confluent-flow regime, reaching the Mid-South and lower Mississippi
Valley near the end of the period.

A complex surface pattern was evident in an 11Z analysis in and near
the outlook region, with a weak low between CLL-CRS and a wavy cold
front from there southwestward across the western part of the lower
Rio Grande Valley region. A diffuse warm front was drawn from the
low southeastward across the HOU metro area and over shelf waters
just off the LA coast. The surface low pressure should consolidate
better through this afternoon over southeast and east TX, with a
fairly well-defined low crossing the Sabine River valley near Toledo
Bend Reservoir mid-late afternoon. By 00z, the surface low should
be located over central or northern LA, with the cold front
southwestward across southern LA and the northwestern Gulf. Through
the overnight hours, the surface low should weaken and accelerate
east-northeastward toward west-central AL. By 12Z, the cold front
should extend from there southwestward over southeastern MS,
southeastern LA and the west-central Gulf.

...South-central/southeast TX to western LA...
A gradually organizing complex of strong-severe thunderstorms is
forecast to continue shifting eastward to east-northeastward across
the outlook area into at least early-mid afternoon, noticeably
faster than progged by most convection-allowing model solutions from
the 00Z-09Z initialization cycles. This activity still will cross
an area of enhanced low-level SRH favorable for embedded supercells
and QLCS circulations supporting tornado/wind risk. By mid-late
afternoon, we currently anticipate a general decrease in both
large-scale upper support and inflow-layer instability for most of
the complex as it proceeds deeper into LA, though isolated severe
and a persistent supercell or two cannot be ruled out.

In the meantime, lateral expansion of the MCS is possible both
northward and southward; however, the extent of that is uncertain
due to:
1. Capping on the south end (evident in the 12Z CRP RAOB) versus
both frontal forcing and the glancing influence of large-scale
DCVA/cooling aloft on the inversion layer sampled around 700 mb.
2. Northern extent of favorable near-surface destabilization/
effective-inflow parcels, amidst the rather lax thermal/theta-e
gradient represented by the warm-frontal zone.
In between, the area around I-10 and southward to the middle/upper
TX coast, near the axis of SPC tornado watch 32, represents the most
favorable severe-weather corridor through early afternoon.

For additional information and nowcast updates, refer to watch-based
mesoscale discussions, to be issued as needed through the morning
hours.

...Southeast LA to coastal FL Panhandle...
A conditional slight risk for tornadoes and marginal
thunderstorm-wind threat remains apparent over this region
overnight, as the surface low tracks eastward across MS. Related
isallobaric forcing should help to maintain generally southerly
surface winds beneath an eastward-shifting, 45-55-kt southwesterly
LLJ. The net effect will be to strengthen low-level bulk shear and
hodograph sizes with time in any given spot, while deep shear also
increase as the shortwave trough crosses the MS River and height
gradients tighten to its south and southeast. Forecast hodographs
accordingly show an eastward spread of effective SRH in the 250-450
J/kg range and effective-shear magnitude near 50 kt along the coast
where moisture and instability will be most favorable.

Thermodynamically, lapse rates aloft will be rather weak for much of
the period. However, subtle large-scale ascent from both low-level
warm advection and weak DCVA should steepen lapse rates overnight
enough, in tandem with surface dew points mid 60s F near the
northern rim of the most substantial Gulf return flow, to remove
CINH and support 500-1000 J/kg MLCAPE. Buoyancy will diminish
substantially inland, making the potential even more isolated and
conditional northward. The main uncertainty at this time involves
low-level/pre-frontal forcing for convective-scale lift, and
resulting coverage/mode of storms in an environment otherwise
favorable for supercells. Any sustained cells will have the
potential to generate cyclic mesocyclones with attendant tornado
threat and potential for at least isolated nontornadic wind damage.

..Edwards/Broyles.. 02/14/2017

[srainhoutx]

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Houston/Galveston TX
729 AM CST TUE FEB 14 2017

The National Weather Service in League City has issued a

* Tornado Warning for...
East central Wharton County in southeastern Texas...
North central Matagorda County in southeastern Texas...
West central Brazoria County in southeastern Texas...
Southwestern Fort Bend County in southeastern Texas...

* Until 800 AM CST.

* At 728 AM CST, a severe thunderstorm capable of producing a tornado
was located near Pierce, or near Wharton, moving east at 45 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.

* Locations impacted include...
El Campo, Wharton, Needville, Pleak, Kendleton, Pierce, Boling-Iago
and Hungerford.

[Katdaddy]

Tornado Warning
TXC039-157-321-481-141400-
/O.NEW.KHGX.TO.W.0015.170214T1329Z-170214T1400Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Houston/Galveston TX
729 AM CST TUE FEB 14 2017

The National Weather Service in League City has issued a

* Tornado Warning for...
East central Wharton County in southeastern Texas...
North central Matagorda County in southeastern Texas...
West central Brazoria County in southeastern Texas...
Southwestern Fort Bend County in southeastern Texas...

* Until 800 AM CST.

* At 728 AM CST, a severe thunderstorm capable of producing a tornado
was located near Pierce, or near Wharton, moving east at 45 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.

* Locations impacted include...
El Campo, Wharton, Needville, Pleak, Kendleton, Pierce, Boling-Iago
and Hungerford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

[srainhoutx]

HGX reports some "preliminary" reports of damage in Wharton County near El Campo.

[srainhoutx]

Update from Jeff:

Severe weather and tornado event underway.

Line of severe thunderstorms capable of producing tornadoes moving across SE TX. Currently supercells over Fort Bend County showing off and on strong rotation couplets with current cell between East Bernard and Kendleton showing the strongest rotation.

Parameters in place for tornadoes. Tornadoes may be wrapped in rain and impossible to see so take warnings seriously.

[Katdaddy]

Tornado Warning
TXC039-157-201-481-141445-
/O.NEW.KHGX.TO.W.0017.170214T1355Z-170214T1445Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Houston/Galveston TX
755 AM CST TUE FEB 14 2017

The National Weather Service in League City has issued a

* Tornado Warning for...
Northeastern Wharton County in southeastern Texas...
Northwestern Brazoria County in southeastern Texas...
South central Harris County in southeastern Texas...
Fort Bend County in southeastern Texas...

* Until 845 AM CST.

* At 754 AM CST, a severe thunderstorm capable of producing a tornado
was located near Kendleton, or near Wharton, moving east at 30 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely. Valentines day tents may be upended.

* Locations impacted include...
Sugar Land, Missouri City, Rosenberg, Stafford, Richmond,
southwestern Manvel, Fresno, First Colony, Pecan Grove, Meadows
Place, Needville, East Bernard, Arcola, Iowa Colony, Pleak,
Fairchilds, Beasley, Kendleton, Thompsons and Brazos Bend State
Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

[srainhoutx]

Heads up Wharton and Fort Bend Counties. Cyclonic signature and increased rotation noted on radar.

[srainhoutx]

Heads up in NW Harris County. Cell starting to show rotation and possibly taking on Super Cell characteristics

[houstonia]

Waiting patiently in far southwest Houston... I'm gong to wait for the storm to pass before trying to head downtown. So far we are just getting occasional lighting/thunder, off and on wind and only a few drops of rain.

Did any of you catch the major red sky at sunrise this morning? I couldn't get a good picture of it.

Stay safe everyone!

[srainhoutx]

Reports from spotter of a brief tornado touchdown SSW of Rosenberg...

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Houston/Galveston TX
816 AM CST TUE FEB 14 2017

The National Weather Service in League City has issued a

* Severe Thunderstorm Warning for...
Southwestern Harris County in southeastern Texas...
Southeastern Walker County in southeastern Texas...
Montgomery County in southeastern Texas...
North central Brazoria County in southeastern Texas...
Northeastern Fort Bend County in southeastern Texas...

* Until 900 AM CST.

* At 816 AM CST, severe thunderstorms were located along a line
extending from 8 miles southwest of Huntsville State Park to 7
miles southwest of Lake Conroe Dam to 6 miles southwest of Cypress
to near Cumings, moving east at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
Northwestern Pasadena, Pearland, Sugar Land, Missouri City, Conroe,
Stafford, South Houston, Bellaire, Humble, West University Place,
Katy, Richmond, Galena Park, Tomball, Jacinto City, Jersey Village,
Willis, northern Manvel, Hunters Creek Village and Bunker Hill
Village.