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

General Weather Discussions and Analysis
User avatar
tireman4
Global Moderator
Global Moderator
Posts: 4437
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Flood Warning...
Attachments
Flood Warning 05 13 19.JPG
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Monday morning weather briefing from Jeff:

After a brief break…somewhat active weather will return to the region through next weekend.

Fairly dry air mass by mid May standards is in place this morning, but that will change as high pressure moves eastward allowing onshore winds to return. Humid air mass south of the region over the Gulf of Mexico is clearly seen in visible images with dense smoke from out of control wildfires in southern Mexico. Thick smoke and humidity will return to the region on Tuesday and will remain in place through much of the week as southerly flow becomes established.

Upper level flow out of the WSW may bring a few disturbances toward the region…the first will be tonight into Tuesday morning. Some of the models develop a thunderstorm complex over central TX and move this complex toward SE TX, but do show significant weakening as it approaches the area Tuesday morning. Meso model have not been great of late especially with these complex of storms coming out of central TX, so not sure exactly how this will play out tonight. Think the best rain chances will be across our western counties and toward Matagorda Bay, but if the complex holds together longer than expected, rain could reach I-45.

Overall trend for the rest of the week will be scattered showers and thunderstorms on Wednesday and then isolated to scattered showers and thunderstorms Thursday and Friday. Air mass will be fairly unstable each day, but will need some sort of trigger to get storms going. Not seeing a lot to trigger storms, but would not rule out some activity each day.

Next Weekend:
Forecast becomes more interesting by next weekend as the next upper level trough moves into the plains. Severe weather and heavy rainfall will be possible again for some locations over the southern and central plains, but at this time it is uncertain where this may occur. Plenty of time to watch to see how SE TX may fall into this active period starting next weekend.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
stormlover
Posts: 439
Joined: Wed Dec 04, 2013 10:21 am
Location: Lumberton TX
Contact:

Looking like this weekend maybe Sunday could see some rain
User avatar
tireman4
Global Moderator
Global Moderator
Posts: 4437
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

000
FXUS64 KHGX 131748
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1248 PM CDT Mon May 13 2019

.AVIATION...
Southern TAF sites will get a small cu field this afternoon but
for the remainder of TAF sites, just some mid/high level clouds
are expected through 00z. E-SE winds expected today as high
pressure over N TX drifts east. An upper level disturbance
will bring scattered shra/tsra over the the southern half of the
region on Tuesday. Will carry a VCSH for LBX and added a VCSH for
IAH for the afternoon (18-00z). 43

&&

.PREV DISCUSSION... /ISSUED 1058 AM CDT Mon May 13 2019/

UPDATE...
High pressure moving across eastern Texas to blame for the great
start to the work week weather-wise. Mostly clear skies with
the region under a relatively drier air mass will have temperatures
steadily climbing into upper 70s to lower 80s. Weak winds are
veering around to the east and should be more south of east across
the coastal counties as heating initiates a late day sea breeze.
Higher moisture will be creeping up from the southwest through
Tuesday....increasing clouds and convective chances around Matagorda
Bay early tomorrow. The latest higher resolution modeling solution(s)
have active weather developing across our southwestern CWA
tomorrow. Thus, there will be higher probabilities for Tuesday
thunderstorms southwest of the city. 31
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Heat of the day pop up non severe thunderstorms are possible today as a compact upper low moves across Texas. Daily sea breeze showers and storms are appear possible the rest of the work week. We will need to monitor for organized thunderstorms Saturday afternoon into Sunday. It looks like a significant Severe Weather Outbreak is possible across the Plains and the Mid West on Friday extending into at least mid next week.
Attachments
051472019 SPC Day 4 day4prob.gif
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
jasons2k
Posts: 5360
Joined: Thu Feb 04, 2010 12:54 pm
Location: Imperial Oaks
Contact:

Keeping an eye on the convection to the NW - looking for outflow boundaries.

Incidentally, my dew point is still a relatively low 63.
stormlover
Posts: 439
Joined: Wed Dec 04, 2013 10:21 am
Location: Lumberton TX
Contact:

Cap will win
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

We are keeping an eye on the Weekend Weather. A powerful storm system will move from California to the Southern Rockies/Plains Friday setting the stage for a potential large severe weather episode extending from West Texas to Nebraska. On Saturday, thunderstorms may become more organized and a squall line could develop into Central Texas and begin a march East. There are still some timing issues to be ironed out as well as any mesoscale features we cannot know until the thunderstorms actually form. I believe the Saturday afternoon/evening time period will be worth monitoring. The storm system could be a little slower meaning rain and storms could extend into Sunday. Areas along and N of I-10 look to have the best chance of any severe thunderstorms as of this morning. Of course that is subject to change as we get closer to the end of the work week.
Attachments
05152019 SPC Day 3 day3otlk_0730.gif
05152019 SPC Day 4 day4prob.gif
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
Texaspirate11
Posts: 1278
Joined: Tue Dec 31, 2013 12:24 am
Contact:

Lucky me, I'll be working in Austin...NBC sports...outdoor coverage...yay
Just because you're disabled, you don't have to be a victim
Be Weather Aware & Prepared!
Barbara Jordan Winner in Media
Disability Integration Consultant
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

NWSWGRFC‏Verified account @NWSWGRFC · 6m6 minutes ago

The weather break is over and it is time to get flood prepared. Organized thunderstorms and heavy rainfall over the Brazos, Trinity, Neches, and Sabine Rivers will likely generate new river flooding. Be Aware and Be Prepared! #txflood

Attachments
05152019 WGRFC D6nUNSYWkAAeq40.jpg
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Glancing ahead to the long Memorial Day Holiday period, the Climate Prediction Center Experimental Long Range Outlook suggests a deep Western trough will continue and we are on the Western periphery of a strong SE Ridge where locations under that big High Pressure dome could see very hot temperatures and little in the way of rainfall. Texas looks to be in a weakness where rainfall could continue as May nears an end.
Attachments
05152019 temp_probhazards_d8_14_contours.png
05152019 precip_probhazards_d8_14_contours.png
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
jasons2k
Posts: 5360
Joined: Thu Feb 04, 2010 12:54 pm
Location: Imperial Oaks
Contact:

Break isn’t over just yet. Nice day today.
Cpv17
Posts: 5234
Joined: Fri Aug 31, 2018 1:58 pm
Location: El Campo/Wharton
Contact:

srainhoutx wrote: Wed May 15, 2019 3:01 pm Glancing ahead to the long Memorial Day Holiday period, the Climate Prediction Center Experimental Long Range Outlook suggests a deep Western trough will continue and we are on the Western periphery of a strong SE Ridge where locations under that big High Pressure dome could see very hot temperatures and little in the way of rainfall. Texas looks to be in a weakness where rainfall could continue as May nears an end.
I hope so, but I fear not all of our area will see much rain. I’ve heard the southern half of the viewing area could be dry particularly the coastal counties.
stormlover
Posts: 439
Joined: Wed Dec 04, 2013 10:21 am
Location: Lumberton TX
Contact:

Yep looks like nothing to bad maybe a shower light on Saturday and Sunday around 50 percent
Cpv17
Posts: 5234
Joined: Fri Aug 31, 2018 1:58 pm
Location: El Campo/Wharton
Contact:

Now that it’s mid May our best chances for precip might have to come from the tropics via the Pacific or Gulf side. Cold fronts don’t have enough punch to make it this far south anymore.
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

https://www.wpc.ncep.noaa.gov/basicwx/a ... p_ndfd.gif

https://www.spc.noaa.gov/products/outlook/day3otlk.html
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0228 AM CDT Thu May 16 2019

Valid 181200Z - 191200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL
AND NORTHEAST TEXAS...

...SUMMARY...
Severe storms are possible over a large area Saturday, from Texas to
Iowa, with the greatest threat across central/northeast Texas toward
the Arklatex where a few tornadoes, hail and wind are possible.

...Synopsis...
Strong southwest flow aloft will exist over the Plains as a intense
embedded shortwave trough develops over OK and north TX during the
day and ejects northeast toward MO overnight. At the surface, low
pressure will generally exist over KS and OK and will develop
northeast into IA late. A moist air mass will reside ahead of the
low track and east of a cold front/dryline advancing across TX
during the day. The northern extent of any severe threat will be
delimited by an east-west stationary front which will remain roughly
from IA into PA. The greatest threat for severe weather will be
over central into northeast TX where instability will be greatest.

...Much of central and northeast TX...
Models continue to indicate an early batch of storms across
northwest TX Saturday morning, with substantial drying behind. This
may reduce severe weather chances across parts of OK and KS should
this occur. Otherwise, this MCS will continue to gain strength as it
pushes east across northern and central TX where 70s F dewpoints
will contribute to 2000-3000 J/kg MUCAPE. Ahead of this line of
storms, southerly 850 mb winds on the order of 40 kt will contribute
to low-level shear, with supercell wind profiles expected.
Therefore, both isolated cells or cells within a line are possible,
with damaging winds, large hail, and a few tornadoes. This threat
may extend as far northeast as AR overnight, depending on how
unstable it remains.

Farther north into IA, a pocket of relatively undisturbed air will
exist near the boundary, with scattered cells producing large hail.

..Jewell.. 05/16/2019

NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z
User avatar
tireman4
Global Moderator
Global Moderator
Posts: 4437
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Weekend Outlook
Attachments
Weekend Outlook 05 16 19.JPG
User avatar
tireman4
Global Moderator
Global Moderator
Posts: 4437
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

SPC Risk Catagories
Attachments
SPC Risk Catagories 05 16 19.JPG
User avatar
tireman4
Global Moderator
Global Moderator
Posts: 4437
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Severe Storms This Weekend?
Attachments
Severe Thunderstorm Forecast 05 16 19.JPG
User avatar
tireman4
Global Moderator
Global Moderator
Posts: 4437
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

000
FXUS64 KHGX 161137
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
637 AM CDT Thu May 16 2019

.AVIATION...
SCT to occasionally BKN clouds around 2000 feet are moving northward
across the area early this morning. Expect clouds to thin this morning
with VFR at all sites later this morning and on through this afternoon.
Still looks like best chance for SHRA/TSRA development today will be
in/around the LBX and SGR areas. Any activity that develops should
be gone by shortly after sunset. Might see MVFR ceilings develop overnight
and on into tomorrow morning. Mainly SE winds 5 to 10 knots today. 42
&&

.PREV DISCUSSION... /ISSUED 411 AM CDT Thu May 16 2019/

DISCUSSION...

Still expect a seasonable end to the work week, and while we may
not manage to stay totally dry, any afternoon showers and storms
are going to be pretty limited.

Saturday night into Sunday morning continues to be the time to
watch for more significant storms, and there is some potential for
severe weather and perhaps some locally heavy rainfall. Lots of
details to suss out on potential impact for our area. There are
still failure modes possible, but the top end threat could be
significant in the northwestern third of our area.

Guidance now shows one more upper disturbance working through
Tuesday night before ridging builds and looks to give us a bit of
a break from spring and an early taste of summer.

NEAR TERM [Through Friday]...

Not much to say about today and tomorrow, really. It will
basically be exactly what you`d expect out of mid-May in Southeast
Texas. Look for lows in the 60s north to around 70 degrees near
the coast, and afternoon highs around the middle 80s. The
seabreeze will be around to provide a focus for a handful of
showers and storms (more today than tomorrow), but I would expect
most to stay dry over the next couple days.

SHORT TERM [Saturday and Sunday]...

This weekend is a potential severe weather event that has been in
the making for much of the week. Earlier on in the week it looked
like a slam dunk big chase day in the Central and Southern Plains.
Now it appears the most significant storms may occur closer to
home.

Where we earlier anticipated one strong, deep, upper trough
digging to the Panhandles, there`s now pretty strong model
agreement in a bit of a split trough. One vort max will be up
north around Nebraska, while another digs south into the Red River
Valley. Along with this, an upper jet streak that had looked to
curl around the base of this trough now looks like it might be
oriented more to the southeast, pointed in the direction of
Southeast Texas. It`s a bit farther off than I`d "like" to see,
and we`re not exactly in a left exit region of this streak, but a
qualitative look seems to imply diffluence aloft. Without a real
strong front, the LLJ doesn`t veer to southwesterly until late
Saturday night, which means onshore flow (and likely an influx of
higher theta-e air) until storms firing off the dryline to our
west/northwest earlier in the day arrive. Thus, we should have
plenty of instability waiting for us despite storm arrival after
peak heating.

Now, despite several things pointing to strong storms, this is no
slam dunk, either. The NAM goes so far as to kill off the day`s
storms before arriving in our area, with a new line starting up
perhaps right on top of Houston and Galveston Bay, but not really
getting serious until it`s exited our area stage right. Our area
wouldn`t get more than some showers, maybe a rumble of thunder.
That`s a bit of a weird flex, but okay. If that`s what the
atmosphere wants to do, I`d gladly take it. I`m only able to
speculate as to what the failure mode is here, but given the
change in forecast scenario we`ve seen since the beginning of the
week, I`m not going to rule it out. But, for what it`s worth, the
CIPS analogs are not impressed with potential for rain in our area
Saturday night. It is...virtually dry.

Anyway, I was mildly surprised by SPC`s guidance tonight of
covering our northwestern third in an Enhanced threat area (level 3
of 5) along with a hatched area for significant severe. But on
the other hand, given the trends in the severe environment, it
appears to be a reasonable upper-end scenario for us at this time.
Progged precipitable water ranges from 1.7 to 2.0 inches, and
with enough shear for well-organized updrafts, the strongest
storms could drop an inch or two of rain real quick before moving
on. Expectation is for any line to be pretty progressive, so I
don`t know about widespread heavy rain/flooding concerns, but
localized problems would crop up if the rainiest storms fall on
the unluckiest places.

LONG TERM [Monday Through Thursday]...

Because of the progressive pattern, things should clear out pretty
quickly, giving us a relatively benign Monday. However, where the
guidance used to build a monster upper ridge over us, it spins in
a new upper low from the northwest to hold that ridging at bay.
This one aims to dig into Texas as well, which will give us
another shot at showers and storms Tuesday night into Wednesday.
Am still awaiting the new extended outlook from SPC, but given the
current guidance, I would expect them to slide down or expand
their 15 percent risk area over Northeast Texas to the south
towards our area some. Like this weekend, with the new guidance my
confidence is not as high as it once was, and the lesson stares us
right in the face of asserting too much at long range. But, at
this time, it looks like we at least have a chance for some
stronger thunderstorms Tuesday night into Wednesday.

After that, the guidance is back to building big upper ridges over
the Southeastern US. I continue to skeptically keep forecast highs
below 90 degrees until I see evidence of this actually happening,
rather than simply being predicted in the 200+ hour range and
sliding further into the future with each model run. Should it
happen, here come a round of 90 degree highs later next week.
Either way, we`re pushing towards late May. Summer is
coming...it`s practically here!

MARINE...

Light to moderate onshore winds persist into Friday. Winds and
seas begin increasing during the day on Friday and on into
Saturday night as the pressure gradient tightens. Caution and/
or Advisory flags are a good possibility during that timeframe.
Tides will continue to run above normal. Will need to keep an
eye on forecast levels around times of high tide beginning Friday
night as some guidance still has them peaking near Coastal Flood
Advisory thresholds. Winds and seas look to build even more on
Monday and Monday night as the pressure gradient tightens up once
again. Flags will be needed. 42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 85 67 86 71 85 / 10 0 10 20 70
Houston (IAH) 85 69 86 73 86 / 10 0 20 20 50
Galveston (GLS) 80 75 81 75 82 / 10 0 10 10 30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$
Post Reply
  • Information