September 2019 - Warm End of September

[Katdaddy]

Lots of tropical moisture headed toward the Middle and Upper TX Coast.

[srainhoutx]

The 06Z GFS is now suggesting some areas in NW Harris, Western Montgomery and Waller Counties could see 5 to 7 inches of rainfall during the work week.

[stormlover]

Gfs finally slowly on board,, it’s getting there

[unome]

SpaceCityWX has posted an update on their blog this morning

https://spacecityweather.com/heavy-rain ... this-week/

https://twitter.com/SpaceCityWX

https://twitter.com/mattlanza

[snowman65]

I don't want too much rain. Salinity level in Sabine Lake is finally getting better and fishing has finally been getting better. We don't need anything messing it up now!!!

[sau27]

Was reminded of a valuable lesson last night: When up at 3am with the baby never check the Euro.

[djmike]

Was reminded of a valuable lesson last night: When up at 3am with the baby never check the Euro.

Whats the euro show for the beaumont area?

[srainhoutx]

After inspection the overnight guidance, the general idea is that a weak surface low stalls along the Middle Texas Coast and somewhat align with vorticities at 500/850/700mb into Wednesday. The weak surface low eventually meanders inland and drifts N from somewhere in Matagorda County passing Fort Bend and Harris Counties just off to the West. Bands of training thunderstorms do develop near and to the East of the weak surface low as it tracks into the Bryan/College Station area. Remember these are just what the models are suggesting and that this sort of forecasting solution is extremely volatile and cannot be know with any certainty beyond 6 to 8 hours, if not less. As always, this sort of pattern where steering currents are weak and heavy rainfall of 2 to 4 inches per hour+ in the model signals can wreak havoc with our potential sensible weather.

[srainhoutx]

NWS Houston‏Verified account @NWSHouston · 11m11 minutes ago

Wet Week Ahead: A slow moving disturbance moving in from the Gulf will bring periods of heavy rainfall from Tuesday night through Thursday. These storms will bring an increased threat of localized flash flooding.

#TXwx #HOUwx #GLSwx #BCSwx

[Cromagnum]

Glad I didn't put down preemergent or fertilizer this weekend. Looks like it will all wash out to sea.

[srainhoutx]

Monday morning Weather Briefing from Jeff:

Potential for heavy rainfall and flash flooding will be increasing this week

Weak low pressure system will meander near the TX coast for several days resulting in multiple impacts

Upper level low that has been talked about since Friday is now reaching the western Gulf of Mexico with both radars from Lake Charles and Houston showing numerous clusters and bands of rainfall across the NW Gulf waters associated with the deeper tropical moisture located just offshore. These bands will begin to rotate inland starting later this morning with very heavy rainfall and gusty winds of 40-45mph. As the upper level low moves slowly westward toward the mid TX coast a weak surface low or surface trough will be developing along the middle and upper TX coast. Models have come into a bit better agreement that a surface low pressure system may form just offshore on Tuesday and drift inland over SE TX Tuesday night into Wednesday. NHC currently gives the system a 10% chance of tropical formation…BUT regardless if something develops tropically or not…the main impact will be heavy rainfall.

Ingredients appear to be coming together in the late Tuesday through Thursday time period for a heavy rainfall event over the region. Surface trough or surface low will drift into the region from the south, PWS values soar to 2.2-2.5 inches, increasing low level SSE/SE flow will help pump an endless supply of moisture into the region. Formation of slow moving clusters and training rainbands appear likely over portions of the area.

While grounds are very dry over much of the region, this weather system will be very capable of producing excessive amounts of rainfall in a short period of time. Rains today and Tuesday especially south of I-10 will go into starting to saturate the very dry ground conditions and expect conditions by Wednesday to support much more run-off. Current HCFCD soil moisture sensors at a depth of 2 inches show moisture values ranging from a low of 4% in Tomball to a high 48% at NRG stadium. I have attached the current soil moisture values for the 2 inch and 4 inch depths across the area.

Rainfall Amounts:
Widespread rainfall amounts of 3-6 inches will be likely over much of the area with isolated totals of 10-15 inches possible. Hourly rainfall rates of 3-4 inches will be possible under any training bands and any slow moving clusters resulting in rapid onset urban flash flooding. The threat for creek, bayou, and river flooding will be increasing by mid week as grounds becoming increasingly saturated and run-off increases.

A flash flood watch will likely be required for portions of the area.

WPC has placed portions of the area under a slight risk for flash flooding for both Tuesday and Wednesday.

Tides:
ENE/E winds over the northern Gulf have resulted in increased tides along the upper TX coast with water levels running 1-2 feet above normal levels. Total water levels at times of high tide of 3.0-3.5 feet will be possible along the upper TX coast today which may result in minor coastal flooding at some of the more vulnerable locations.

Forecasted Rainfall Totals (5 days):

[DoctorMu]

Glad I didn't put down preemergent or fertilizer this weekend. Looks like it will all wash out to sea.

Fertilizer now only makes brown patch season worse (in a month) around here.

[DoctorMu]

Monday morning Weather Briefing from Jeff:

Potential for heavy rainfall and flash flooding will be increasing this week

Weak low pressure system will meander near the TX coast for several days resulting in multiple impacts

Upper level low that has been talked about since Friday is now reaching the western Gulf of Mexico with both radars from Lake Charles and Houston showing numerous clusters and bands of rainfall across the NW Gulf waters associated with the deeper tropical moisture located just offshore. These bands will begin to rotate inland starting later this morning with very heavy rainfall and gusty winds of 40-45mph. As the upper level low moves slowly westward toward the mid TX coast a weak surface low or surface trough will be developing along the middle and upper TX coast. Models have come into a bit better agreement that a surface low pressure system may form just offshore on Tuesday and drift inland over SE TX Tuesday night into Wednesday. NHC currently gives the system a 10% chance of tropical formation…BUT regardless if something develops tropically or not…the main impact will be heavy rainfall.

Ingredients appear to be coming together in the late Tuesday through Thursday time period for a heavy rainfall event over the region. Surface trough or surface low will drift into the region from the south, PWS values soar to 2.2-2.5 inches, increasing low level SSE/SE flow will help pump an endless supply of moisture into the region. Formation of slow moving clusters and training rainbands appear likely over portions of the area.

While grounds are very dry over much of the region, this weather system will be very capable of producing excessive amounts of rainfall in a short period of time. Rains today and Tuesday especially south of I-10 will go into starting to saturate the very dry ground conditions and expect conditions by Wednesday to support much more run-off. Current HCFCD soil moisture sensors at a depth of 2 inches show moisture values ranging from a low of 4% in Tomball to a high 48% at NRG stadium. I have attached the current soil moisture values for the 2 inch and 4 inch depths across the area.

Rainfall Amounts:
Widespread rainfall amounts of 3-6 inches will be likely over much of the area with isolated totals of 10-15 inches possible. Hourly rainfall rates of 3-4 inches will be possible under any training bands and any slow moving clusters resulting in rapid onset urban flash flooding. The threat for creek, bayou, and river flooding will be increasing by mid week as grounds becoming increasingly saturated and run-off increases.

A flash flood watch will likely be required for portions of the area.

WPC has placed portions of the area under a slight risk for flash flooding for both Tuesday and Wednesday.

Tides:
ENE/E winds over the northern Gulf have resulted in increased tides along the upper TX coast with water levels running 1-2 feet above normal levels. Total water levels at times of high tide of 3.0-3.5 feet will be possible along the upper TX coast today which may result in minor coastal flooding at some of the more vulnerable locations.

Forecasted Rainfall Totals (5 days):

It appears the models have moved towards the robust Canadian solution.

[jerryh421]

The NW gulf region certainly looks very active. I wonder if it will have enough time over water to make TD status. I am definitely looking forward to some beneficial rain! I just hope it is nothing serious.

[DoctorMu]

I watered last night. But for only half the time as usual.

You're welcome.

[tireman4]

00
FXUS64 KHGX 152326
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
626 PM CDT Sun Sep 15 2019

.AVIATION...
Late afternoon activity will weaken and dissipate over the next couple
of hours with the loss of heating. We have inland TAF sites VFR overnight
with light winds. Coastal TAFs (GLS and LBX) could see some SHRA/TSRA
move westward across the area overnight and on into the day tomorrow
as the Gulf system as its higher moisture and instability slowly edge
closer to the Texas coast. Not real confident as to how far inland we
will see activity make it during the day. For now, will carry VCSH
as far north as IAH and keep sites N of there dry. NE to E winds during
the day tomorrow with higher speeds near the coast. 42
&&

.PREV DISCUSSION... /ISSUED 356 PM CDT Sun Sep 15 2019/

SHORT TERM [Monday Through Tuesday]...
Broad mid/upper level low off the La/Tx coasts will continue its
very slow trek toward the coastal Bend on Tue. Look for shra/tstms
to redevelop and expand in coverage offshore tonight...with some
bands gradually making their way to around, or slightly north, of
the I-10 corridor later Monday afternoon with daytime heating.
Precip should taper off Monday evening, then follow the same
pattern described above late Mon night & Tue. Difference will be
higher areal coverage further inland during the day Tue as
available moisture increases. This should be much needed and
welcome rainfall. Few, if any problems are anticipated, though one
can never rule out the typical very localized street flooding
associated with higher rain rates. 47

LONG TERM [Tuesday Night Through Sunday]...
Though there is high confidence that there will be good chances of
precip Tuesday night thru Thursday across the region, but overall
confidence in the specific details is low. Guidance shows the
mid/upper low drifting to the north and into western parts of se
Tx during this time period. Closer to the surface, models also
show either a surface trof or weak surface low developing - also
moving into the area from the south. How organized, or unorganized,
this feature becomes will go a long way in determining the
potential for either continued steady welcome rainfall, or the
risk of a more prolonged heavy rainfall event associated with
training convective banding (in the case of a more organized
system). There is generally a split between models in regards to
its evolution. PW`s do increase to 2.2-2.5" which are close to
the upper end that`ve been recorded this time of year, so moisture
won`t be a problem. That being said, we will be closely watching
things, but for now there is somewhat concerning signal for a
potentially heavy rain and flash flood threat developing late Tue
night and Wed for areas generally along and south of I-10 and
west of I-45. We`ll see what future models have to say, but will
go ahead an start the mention of locally heavy rainfall wording
there for now.

Chances of precip will continue into Wednesday night & Thurs with
the trof/low and PW`s aoa 2" continuing a slow move north thru the
area. Rain chances taper down Friday and into the weekend. 47

MARINE...
The large, broad cyclonic circulation brought on by a western-moving
north central Gulf upper low will maintain a tight enough pressure
gradient on its northern periphery to produce moderate easterly
winds. These Caution level east to southeasterly Gulf winds will
generally be the dominant wind through late tomorrow. Periods of
showers and thunderstorm rotating in from the east will temporarily
create strong gusty winds and agitate seas. The low should move
onshore sometime late Tuesday into early Wednesday. More persistent
precipitation, possibly heavy, may occur across the local bay and
Gulf waters from Tuesday on through mid week as lift along with the
northeasterly sector of this low taps into high moisture. 31

HYDROLOGY...
Rivers and bayous are well within banks and should remain that way
through at least through the day Tuesday. The ground is dry and
should be able to handle a good bit of rainfall. This of course
will continue to be monitored as we head into the midweek time
period as there is considerable forecast uncertainty in regards to
the potential for some localized higher rainfall rates and
accumulations across portions of the region. 47

CLIMATE...
Another day...another record in Galveston. Tied a 119 year old record
high of 94 previously set in 1900. 47

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 75 98 75 94 73 / 10 10 10 50 30
Houston (IAH) 75 94 75 90 76 / 20 30 30 50 50
Galveston (GLS) 81 90 79 86 80 / 50 60 70 70 80

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk until 8 PM CDT this evening for the
following zones: Galveston Island and Bolivar Peninsula.

GM...SMALL CRAFT SHOULD EXERCISE CAUTION through late Monday night
for the following zones: Coastal waters from Freeport to
Matagorda Ship Channel TX out 20 NM...Coastal waters from
High Island to Freeport TX out 20 NM...Waters from Freeport
to Matagorda Ship Channel TX from 20 to 60 NM...Waters from
High Island to Freeport TX from 20 to 60 NM.

&&

$$

[jasons2k]

Typical SE Texas. We’ll go from flash drought to flash flooding.

Just watching the radar today - fascinating (right word??) to see that band approach Galveston and as soon as it touched land, it just fell apart.

[srainhoutx]

Visible Meso Imagery focused over the NW Gulf is beginning to suggest a bit of spin and possibly a weak surface low developing offshore of The Upper Texas/SW Louisiana Coast.

https://www.tropicaltidbits.com/sat/sat ... roduct=vis

[jerryh421]

Visible Meso Imagery focused over the NW Gulf is beginning to suggest a bit of spin and possibly a weak surface low developing offshore of The Upper Texas/SW Louisiana Coast.

https://www.tropicaltidbits.com/sat/sat ... roduct=vis

Do you think NHC will investigate this area before hitting land?

[stormlover]

No they will name it if it needs to be named they don’t need to go out there