September 2019 - Warm End of September

[srainhoutx]

Update from Jeff:

Area of surface low pressure has formed just off the upper TX coast between Palacios and Freeport. Offshore observations show a defined surface low has formed and radar data from Houston indicates that winds 1500-2000 ft off the surface east of this low are ranging from 40-50mph. NHC is closely monitoring the situation and indicates that a tropical depression could form in the next few hours.

The low is drifting to the NNE at less than 5mph and this motion is expected to continue with bands of rainfall moving inland across the coast. Heaviest rains will focus along the coast and inland mainly along and SE of US 59 today

[jasons2k]

The surface observations nicely highlight the closed circulation that is also observed on radar. This is pretty conclusive proof the circulation of Invest 98L is well defined & closed. pic.twitter.com/BPjL1KW7F8
-- Philippe Papin (@pppapin) September 17, 2019

https://twitter.com/pppapin/status/1173990750301782016

[mcheer23]

It's a TD.Jjust waiting to see if NHC declares one.

[jasons2k]

The low is drifting to the NNE

That's the key folks. It's not moving due north. It's probably gonna track just east of downtown closer Galveston Bay and the majority of the heaviest rain will be there and points east.

[stormlover]

yeah no doubt jason, its east then what the models have been showing

[Cpv17]

https://www.tropicaltidbits.com/analysi ... 1712&fh=13

this would not be good for houston and beaumont

Feast or famine. Would be complete bust here.

Saturday and Sunday it looked like a for sure thing for us out on the west side, but models started trending east late Sunday and into Monday. Sucks, but I’m not surprised at all by it. Often times the Houston area and points east of there get in on the action from these tropical systems. The Houston area is just a magnet for these types of events.

[srainhoutx]

Mesoscale Precipitation Discussion 0859
NWS Weather Prediction Center College Park MD
1214 PM EDT Tue Sep 17 2019

Areas affected...Upper Texas Coast

Concerning...Heavy rainfall...Flash flooding possible

Valid 171613Z - 172040Z

Summary...A tropical disturbance near the Upper Texas Coast will
continue to produce rain across the region. A concentrated area of
heavy bands may develop near and just south and west of the
Houston metro this afternoon, which may lead to flash flooding.

Discussion...Regional radars generally showed a broader area of
stratiform rain across the Upper Texas Coast, with RAP analysis
indicating a minimum of instability (MLCAPE approx. 500 j/kg) in
the same area. Recent observational trends at KBQX -- an offshore
platform -- suggest the surface low associated with the tropical
disturbance is situated within 25mi of the coast (but still
offshore) as of 16Z. Heavy, convective rain bands are most likely
to be concentrated just to the east of this surface low.
Instability is notably stronger offshore, and low-level (surface
to 850mb) winds are strongest in the same area. The overlap of
strong onshore moisture flux and greater instability should allow
for more organized rain bands. As the low drifts closer to the
coast, and perhaps onshore, this afternoon, the concern would be
that the aforementioned favorable environment would also push
onshore. Model forecasts maintain relatively strong, southerly
925-850mb winds into the afternoon just east of the low, which
would focus the onshore low-level moisture flux into the Upper
Texas Coast very near the Houston metro area.

The 12Z HREF has the highest blended mean QPF in a small section
of the Texas coast in Brazoria, Galveston, and southern Harris
Counties. This makes sense based on observational data trends and
the position of the surface low at the moment. KHGX radar and
GOES-16 IR satellite show stronger convection and cooling cloud
tops to the east of the low, and a NW-NNW drift of the low would
eventually place that convection over the Brazoria and Galveston
County area. Although the area has been relatively dry, the
co-location of the expected heaviest rainfall with a more
urbanized section of the coastline should make flash flooding
possible this afternoon. Given the tropical environment, with PW
values in excess of 2.5 inches, rain rates exceeding 2 in/hr are
likely in the strongest convective rain bands. Rain rates could be
much higher than that if stronger instability can be tapped and
low-level convergence remains focused in the same area for several
hours or more. This area will be monitored into the evening and
overnight hours, as the diurnal cycle of tropical convection would
tend to concentrate convection closer to the low overnight, and
that could compound flooding concerns beyond the timeframe of this
discussion. For more information, see the Day 1 Excessive Rainfall
Outlook.

Lamers

ATTN...WFO...HGX...

[stormlover]

UKMET puts a hurting on houston and beaumont

http://tropic.ssec.wisc.edu/real-time/s ... plit&time=

[jasons2k]

a NW-NNW drift of the low would eventually place that convection over the Brazoria and Galveston County area.

So which is it? This is important -- extremely important right now.

[srainhoutx]

IF I lived in Matagorda County or N and E of there, I would not be letting my guard down...

[davidiowx]

IF I lived in Matagorda County or N and E of there, I would not be letting my guard down...

So Fort Bend County area

[Kingwood36]

IF I lived in Matagorda County or N and E of there, I would not be letting my guard down...

What about brazoria county near freeport and angleton

[Cpv17]

a NW-NNW drift of the low would eventually place that convection over the Brazoria and Galveston County area.

So which is it? This is important -- extremely important right now.

I’m right there with you Jasons. I wanted this to come inland around Corpus or Port A so many more of us in drought stricken Texas could’ve seen a lot more beneficial rains. Very frustrating times for a lot of us.

[Cpv17]

IF I lived in Matagorda County or N and E of there, I would not be letting my guard down...

What about brazoria county near freeport and angleton

That area will get plenty of rain. Easily 7-8” in that area probably more.

[Cpv17]

IF I lived in Matagorda County or N and E of there, I would not be letting my guard down...

So Fort Bend County area

Fort Bend County should get plenty as well. Especially the eastern half of the county.

[txbear]

Basically due south of Freeport/Lake Jackson, correct? I'm just trying to get a bead on any directional movement with the center. At times, it appears like it's meandering its way slight W of NW but I believe radar returns have an illusion effect to make it seem so.

Perhaps mine eyes weren't deceiving me?

[sau27]

NHC just upgraded to TD 11

[tireman4]

98 L Feeder Band

[jerryh421]

We now have Tropical Depression Eleven off the Texas coast!

[tireman4]

5000 Cape To The East of TD 11