MAY 2019: Wednesday Storm Complex/Scattered Showers To End May

[srainhoutx]

NWS Houston‏Verified account @NWSHouston · 1m1 minute ago

Rainfall totals from 7AM May 7 to 1AM May 8 for an 18 hr period ranged significantly from under 1" in NW Harris County to as much as 10" near Kingwood and more than 12" SW of Sugar Land. Unfortunately more heavy rainfall will be possible through the end of the week. #houwx #txwx

[Katdaddy]

Areas of SE TX were hit hard with flooding rains yesterday and this will be day 2. Sugarland, TX recorded 10.64”. Flash Flood Watches will be issued for SE TX this morning with some areas receiving 9-12” of additional rain the next several days but as we saw yesterday, this could occur in a day. So far only 2.55” here at the house. In addition, severe weather will be a threat the next 3 days as the active pattern continues. Remain weather aware through the weekend.

[srainhoutx]

Wednesday morning Weather Briefing from Jeff:

Heavy rainfall and flash flood threat will be increasing this afternoon through Saturday.

Tremendous rainfall rates were observed on Tuesday in both NE Harris County and Fort Bend County. A total of 6.48 inches was recorded in 48 minutes in Sugar Land at a home weather station and this nearly equals Harvey’s 1 hour maximum rate of 6.7 inches. 6 hour storm totals averaged 9-10.5 inches over Sugar Land and 7-9 inches over Kingwood.

Today:
Air mass is recovering nicely over the area from the storms of Tuesday and by mid to late morning a very moist and unstable air mass will once again be in place of the region. The next upper level disturbance is already moving into central TX with numerous showers and thunderstorms developing. Expect some sort of line of storms to eventually develop out of central TX and move toward SE TX late this morning or early this afternoon. Meso models (for what they are worth) are showing this line slowing and potentially stalling near I-10 this afternoon. This could yield heavy rainfall this afternoon either side of I-10. WPC keeps the majority of the heavy rainfall to our north today, but the area could certainly see rainfall this afternoon that could result in additional flooding, especially if it falls on areas that were hard hit on Tuesday.

Additionally there is a higher severe weather risk this afternoon especially north of I-10 where large hail, damaging winds, and isolated tornadoes will be possible.

Thursday-Saturday:
A surface frontal boundary will move southward into SE TX and stall near the I-10 corridor. An extremely moist air mass will remain in place along with favorable low level inflow off the Gulf of Mexico and numerous upper level disturbances that will move along the front. Several complexes and clusters of storms can be expected through the period each capable of dropping multiple inches of rainfall. WPC has upgraded the area into a moderate risk of flash flooding for both Thursday and Friday and this seems the logical route at the moment.

Rainfall Amounts:
Widespread rainfall of 5-8 inches with isolated totals of 9-12 inches will be possible today through Saturday. While these totals are spread over a 3 day period, much of what falls will likely fall in bursts with each cluster of storms. Air mass remains very much capable of intense rainfall rates has observed yesterday…a gage in Sugar Land recorded 5.16 inches of rainfall in 1 hour and 15 minutes. Hourly rainfall rates of 2-4 inches per hour will remain possible which will quickly result in urban flash flooding and significant street flooding.

Hydro:
Grounds are saturated and any additional rainfall…especially in areas that saw heavy rains on Tuesday…is going to run directly into creek, bayous, and rivers that area already highly elevated. If the rainfall forecast does indeed verify, flooding of creeks and bayous in Harris County is certainly possible along with house flooding.

While several creeks and bayous are elevated, all are in recession at this time including both the East and West Forks of the San Jacinto River.

WPC Excessive Rainfall and Flash Flood Outlook:

Thursday:

Friday:

[/i]

[srainhoutx]

Severe Weather Watch likely in the not too distant future and closely watching for any development along left over boundaries from last night over our Region...

Mesoscale Discussion 0585
NWS Storm Prediction Center Norman OK
0629 AM CDT Wed May 08 2019

Areas affected...Texas Hill Country into east-central Texas

Concerning...Severe potential...Watch likely

Valid 081129Z - 081230Z

Probability of Watch Issuance...80 percent

SUMMARY...A new convective watch will likely need to be considered
early this morning. A mix of supercells and organized multicell
clusters will be capable of a large hail/severe gust risk. Any
early-day tornado risk will likely remain focused with supercells
along and south of an outflow boundary.

DISCUSSION...Radar mosaic shows an increase in thunderstorm activity
over central TX during the past 2 hours as a lobe of upper forcing
for ascent --associated with a shortwave trough over the southern
High Plains-- continues eastward this morning. KGRK and KEWX VAD
data early this morning show some weakness around 3km AGL (near
700mb). RAP forecast soundings depict this feature but show flow
strengthening from 20-30 kt as the upper wave approaches. This
strengthening in flow will support more favorable hodograph
structure for more organized low-level mesocyclones. It remains
unclear the extent of the tornado risk through mid morning but by
late morning as the aforementioned flow strengthens and greater
buoyancy develops, a risk for a tornado in addition to large
hail/severe gusts may develop along and south of the outflow
boundary.

Farther north approaching the I-20 corridor, rain-cooled air from
early morning thunderstorms will probably limit greater
destabilization from occurring. Nonetheless, an isolated risk for
strong to locally severe gusts and perhaps large hail may affect
this corridor.

..Smith/Thompson.. 05/08/2019

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...HGX...FWD...EWX...SJT...

[unome]

this is a cool tool from NWS San Anjelo's site - enter your address & pinpoint your location on the corresponding local radar loop:

https://www.weather.gov/sjt/NationalRadar

[srainhoutx]

Severe Thunderstorm Watch up for portions of S Central Texas including New Braunfels and Austin. San Antonio not included at this time...

WATCH COUNTY NOTIFICATION FOR WATCH 151
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
654 AM CDT WED MAY 8 2019

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH
151 IN EFFECT UNTIL 1 PM CDT THIS AFTERNOON FOR THE FOLLOWING
AREAS

IN TEXAS THIS WATCH INCLUDES 13 COUNTIES

Code: Select all

IN SOUTH CENTRAL TEXAS

BANDERA               BLANCO                BURNET               
COMAL                 EDWARDS               GILLESPIE            
HAYS                  KENDALL               KERR                 
LLANO                 REAL                  TRAVIS               
WILLIAMSON            

THIS INCLUDES THE CITIES OF AUSTIN, BANDERA, BLANCO, BOERNE,
BURNET, FREDERICKSBURG, GEORGETOWN, KERRVILLE, LEAKEY, LLANO,
NEW BRAUNFELS, ROCKSPRINGS, AND SAN MARCOS.

[/i]

[CrashTestDummy]

this is a cool tool from NWS San Anjelo's site - enter your address & pinpoint your location on the corresponding local radar loop:

https://www.weather.gov/sjt/NationalRadar

That's pretty cool! Thank you for sharing.

We got about 2-1/3" of rain yesterday in northeast Brazoria County. There's standing water back in the yard like we had all winter. Sheesh!

[unome]

Meso 1 over TX/LA - this is RAMMB's Slider with GeoColor(CIRA) overlaid with Band 13(Clean IR Longwave) - slider button at top

https://col.st/0XSei

[unome]

updated Day1 Convective Outlook https://www.spc.noaa.gov/products/outlo ... _1300.html

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Wed May 08 2019

Valid 081300Z - 091200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY THROUGH
EARLY TONIGHT FROM CENTRAL TX TO AR AND NORTHERN LA...

...SUMMARY...
Large hail, damaging winds, and a couple of tornadoes will be
possible today into early tonight from central Texas to Arkansas and
northern Louisiana.

...TX/AR/LA through early tonight...
A larger-scale trough will persist from the northern Plains to the
southern Rockies, as a primary shortwave trough ejects northeastward
from the southern High Plains this morning to KS this afternoon and
IA by early tonight. Preceding the primary shortwave trough, an MCV
over eastern KS will likewise move northeastward toward northern
IL/southern WI by early tonight. Outflow with overnight/ongoing
convection across OK has partially masked the synoptic front which
appears to be farther north in KS. Developing convection from the
Edwards Plateau to northwest TX will likely grow upscale in the zone
of ascent downstream from the ejecting southern High Plains trough.
Gradual mergers of the TX/OK storms should lead to a more extensive
convective band that will subsequently spread eastward toward the
Arklatex, prior to weakening this evening close to the MS River.

The storms will be maintained today by an influx of rich low-level
moisture from the western Gulf of Mexico, near the east edge of an
elevated mixed layer plume. Vertical shear will be sufficient for
organized bowing segments and/or embedded supercells, with an
attendant threat for damaging winds, large hail, and a couple of
tornadoes.

...Western/central OK and vicinity this afternoon/evening...
In the wake of the morning convection, residual low-level moisture
(dewpoints in the 55-62 F range) and surface heating in cloud breaks
this afternoon will contribute to some destabilization across
western OK and vicinity. Most of the numerical model guidance still
appears to be too moist near the surface, given the extensive
convective overturning and cold pool generation overnight and into
this morning across OK. Thus, buoyancy will likely be weaker, which
will tend to limit the severe threat, despite deep-layer vertical
shear favorable for supercells.

...MO/IL area today...
The eastern KS MCV will eject northeastward, with an attendant
modest enhancement to the low-midlevel flow on its eastern flank.
However, low-level moisture and buoyancy will remain somewhat
marginal, and residual cloud cover may also slow surface heating
some. These factors suggest that only low wind/hail probabilities
are warranted.

..Thompson/Smith.. 05/08/2019

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z

[JDsGN]

NWS Houston‏Verified account @NWSHouston · 1m1 minute ago

Rainfall totals from 7AM May 7 to 1AM May 8 for an 18 hr period ranged significantly from under 1" in NW Harris County to as much as 10" near Kingwood and more than 12" SW of Sugar Land. Unfortunately more heavy rainfall will be possible through the end of the week. #houwx #txwx

My house in Fairfield is smack in the Middle of the light green. We might have gotten 0.25" all yesterday according to the rain gauge. Meanwhile we had to drive through 6-8" of water to go get my wife's Grandfather out of his flooded house in Porter off Sorters Road and 1314.

[unome]

a slug of moisture headed into LA

http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

https://radar.weather.gov/Conus/southmissvly_loop.php

[srainhoutx]

Folks in our NW and Northern areas need to pay attention as the day progresses...

Mesoscale Precipitation Discussion 0208
NWS Weather Prediction Center College Park MD
1117 AM EDT Wed May 08 2019

Areas affected...South-Central and Central Texas

Concerning...Heavy rainfall...Flash flooding likely

Valid 081515Z - 082000Z

Summary...Thunderstorms will slowly push across the Texas Triangle
region, between Dallas, San Antonio, and Houston late this morning
and into the afternoon. These thunderstorms may produce hourly
rain rates to around 2 inches, and localized rainfall maxima up to
5 inches in just a few hours. This will likely lead to some flash
flooding.

Discussion...Several squall lines continue to make gradual
eastward progress across central Texas this morning. In general,
they have maintained intensity and organization, despite being at
a time of day typically associated with a convective lull. Models
are in good agreement in showing continued eastward progress over
the next several hours, but mesoscale details may allow for
opportunities for training convection, longer duration of heavy
rain, and localized corridors of 3-5 inches of rainfall. The
northern-most line segment, from the southeast side of DFW metro
to near Hamilton TX, has gained a more west-east orientation with
time. Steady southeast progress may put it in the path of upstream
convection currently over Texas Hill Country; the current
structure and distribution of thunderstorms may thus favor a band
of enhanced rainfall in the Waco-Tyler corridor in east-central
Texas. Although surface-based instability is relatively limited
(with relatively strong SBCINH), elevated CAPE is around 1000-1500
j/kg in this area. Combined with PW around 1.6 inches (GPS-PW
observations) and deep layer bulk shear around 50 knots, the
environment is favorable for maintenance of ongoing organized
convection and hourly rainfall rates approaching 2 inches.

Further south, another corridor of enhanced rainfall is possible
in the vicinity of the Balcones Escarpment or the I-35 corridor
around Austin TX. Surface observations implied a region of
enhanced low-level convergence and a psuedo-warm front from Llano
County east to Burleson County. North of this boundary, surface
winds were backed with temperatures in the mid-upper 60s and dense
low-level cloud cover. To the south, more mixing was occurring
with southerly winds and temperatures rising into the mid-70s. In
the same area, RAP analysis showed a maximum of boundary layer
warm air advection and surface thetae advection. This may
increasingly focus convection in a concentrated area as it moves
from Texas Hill Country into the I-35 corridor. The inflow region
near and south of San Antonio was characterized by fairly strong
instability (CAPE in excess of 2000 j/kg) and a pocket of higher
PWs from 1.7-1.9 inches (GPS-PW observations). This should sustain
vigorous convection into the early afternoon, with the potential
for hourly rain rates exceeding 2 inches at times. Hi-res models
appear to be underestimating the organization and vigor of ongoing
convection. The squall line appears to have a cold pool, with KBBD
(just behind the line) reporting a 61 degree temperature at 15Z,
and that should enable continued maintenance of strong updrafts on
the downshear flank of the line. This area may also be more
vulnerable to flash flooding given recent heavy rainfall. Many
areas from Kerrville and Killeen east to Austin and College
Station have seen 6-10 inches of rain in the past couple weeks,
and FFG is lower in these areas (2-3 inches in 3h). Multiple
hi-res models show 3 inches of rain in 3 hours in this area,
despite generally underestimating the intensity and coverage of
ongoing convection.

Lamers

ATTN...WFO...EWX...FWD...HGX...SHV...SJT...

[tireman4]

Tweet from Fort Bend OEM

[Rip76]

https://radar.weather.gov/Conus/southplains_loop.php

Interesting, line of storms seems to be thinning out as it moves East.

But the sun is crankin' here in Stafford right now.

[sau27]

https://radar.weather.gov/Conus/southplains_loop.php

Interesting, line of storms seems to be thinning out as it moves East.

But the sun is crankin' here in Stafford right now.

The sun is shining through here in the Galleria area as well. Aircraft soundings out of the airports show a pretty stout cap in place right now.

[srainhoutx]

Severe Weather Watch possible further East of current Severe Thunderstorm Watch for S Central/Central Texas...

Mesoscale Discussion 0587
NWS Storm Prediction Center Norman OK
1221 PM CDT Wed May 08 2019

Areas affected...East Texas

Concerning...Severe Thunderstorm Watch 151...

Valid 081721Z - 081845Z

The severe weather threat for Severe Thunderstorm Watch 151
continues.

SUMMARY...A severe threat is likely to continue this afternoon
across parts of east Texas. Wind damage, hail and possibly a tornado
may occur with the stronger parts of a squall-line. Weather watch
issuance will be needed to the east of WW 151.

DISCUSSION...The latest radar imagery shows a linear MCS across the
eastern Texas Hill Country. A moist airmass is located ahead of the
MCS with surface dewpoints in the lower 70s F. The RAP is estimating
MLCAPE values across east Texas in the 1500 to 2500 J/kg range. The
MCS will continue to track eastward along a gradient of instability
at about 35 kts. The eastward motion combined with steepening
low-level lapse rates and moderate deep-layer shear will continue a
severe threat. Wind damage will be the greatest threat although, a
tornado can not be ruled out with rotating elements within the line.
Hail will also be possible with the stronger updrafts.

..Broyles/Guyer.. 05/08/2019

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LCH...SHV...HGX...FWD...EWX...

[srainhoutx]

Severe Thunderstorm Watch until 8 PM coming for Bryan/College Station and point East shortly

[srainhoutx]

Wednesday 1:00 PM CDT Weather Update from Jeff:

Line of thunderstorms continues to approach SE TX from the west.

While forecast models continues to insist that this line will weaken, thus far the line remains well intact and approaching the area. The line has remained progressive thus far as it is moving through the I-35 corridor with some slight slowly on the southern end of the feature. Air mass over SE TX is becoming unstable and showers are attempting to develop in the onshore flow ahead of this main line.

Will need to continue to monitor radar trends over the next few hours to see how this line is maintaining itself or if it is in fact going to start to weaken as the forecast models suggest.

[Ounce]

For Calvert and Cameron

Tornado Warning
TXC331-395-081845-
/O.NEW.KFWD.TO.W.0022.190508T1812Z-190508T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Fort Worth TX
112 PM CDT Wed May 8 2019

The National Weather Service in Fort Worth has issued a

* Tornado Warning for...
Robertson County in central Texas...
Northeastern Milam County in central Texas...

* Until 145 PM CDT.

* At 111 PM CDT, a severe thunderstorm capable of producing a tornado
was located 8 miles west of Calvert, or 11 miles northeast of
Cameron, moving east at 40 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...
Hearne, Franklin and Calvert.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to 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 3086 9690 3103 9691 3123 9632 3117 9630
3114 9630 3112 9628 3109 9628 3106 9624
3101 9626 3099 9624 3097 9625 3091 9635
3085 9639
TIME...MOT...LOC 1811Z 269DEG 34KT 3096 9682

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

$$

Hernandez

[Ounce]

Updated Calvert and Hearne:

Severe Weather Statement
National Weather Service Fort Worth TX
129 PM CDT Wed May 8 2019

TXC395-081845-
/O.CON.KFWD.TO.W.0022.000000T0000Z-190508T1845Z/
Robertson TX-
129 PM CDT Wed May 8 2019

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 145 PM CDT FOR CENTRAL
ROBERTSON COUNTY...

At 129 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Hearne, 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.

Locations impacted include...
Hearne, Franklin and Calvert.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter now! Get to an
interior room on the lowest floor of a sturdy building and avoid
windows.

&&

LAT...LON 3086 9662 3097 9670 3123 9632 3116 9630
3114 9630 3113 9629 3109 9628 3106 9624
3101 9626 3099 9624 3097 9625 3092 9634
3091 9635 3085 9639
TIME...MOT...LOC 1829Z 249DEG 42KT 3094 9658

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

$$

Hernandez