September 2021: Hurricane Nicholas

[Cpv17]

Just curious. Why do our storms always seem to want to stall just inland of our coast? Its been years since Ive ever seen a storm come ashore then progress on its same speed into central/northern Texas. They hit our coast, stall, then go NE. Just curious.

Currents break down and the storms have no mechanism to make them move so they just drift around till a trough picks it up and moves it out. It’s really bad if it’s sandwiched between two highs.

[don]

Just curious. Why do our storms always seem to want to stall just inland of our coast? Its been years since Ive ever seen a storm come ashore then progress on its same speed into central/northern Texas. They hit our coast, stall, then go NE. Just curious.

Its due to weak steering currents from storms being trapped under the ridge.I'm not too concerned at this time with a system stalling as it looks like the trough will be able to pull the storm northeast for now.The storm may slow down temporally though as it makes a northeast turn especially if the turn happens over land.

[Stratton20]

I think the mesoscale models are starting to become in range of this event, probably will be better to look at in terms of rainfall accumulations rather than the global models

[djmike]

Ahh ok. Thank you. Just seems no storms ever go to central Tx anymore. Thank you

[Cpv17]

I think the mesoscale models are starting to become in range of this event, probably will be better to look at in terms of rainfall accumulations rather than the global models

Yeah that’s true. Sometimes I forget about those.

[Stormlover2020]

https://twitter.com/bigjoebastardi/stat ... 44320?s=21

[Cromagnum]

https://twitter.com/bigjoebastardi/stat ... 44320?s=21

12 Z euro going toward the http://weatherbell.com concern about the hurricane hit on the upper Texas gulf coast. People should be very concerned as we are still in the enclosed development pattern that has been so prevalent the last two hurricane season

What does that even mean?

[Kingwood36]

https://twitter.com/bigjoebastardi/stat ... 44320?s=21

12 Z euro going toward the http://weatherbell.com concern about the hurricane hit on the upper Texas gulf coast. People should be very concerned as we are still in the enclosed development pattern that has been so prevalent the last two hurricane season

What does that even mean?

He doesn't make alot sense half of the time lol

[Stormlover2020]

He’s saying he think it will be hurricane by upper texas coast and he’s been talking about it since last week

[davidiowx]

He’s essentially saying you can’t rule out a Hurricane coming into the upper TX coast. Which isn’t all that crazy to think. It certainly could happen.

[don]

12Z EURO showing some pretty gusty winds even inland fwiw.Also the 12Z Euro ensembles staying consistent.

[djmike]

How soon do you think we will see a cone and/or watches hoisted?

[Stratton20]

djmike probably as early as tommorow afternoon

[srainhoutx]

How soon do you think we will see a cone and/or watches hoisted?

Possibly as early as tomorrow afternoon depending on what RECON finds. Likely a Potential Tropical Cyclone Watch at least.

[davidiowx]

How soon do you think we will see a cone and/or watches hoisted?

I’m wondering the same. I did see the TCFA was issued. Not sure if that is the beginning of the process to start forecasts/advisories or not.

Edit: was watching the NWS Houston video they put out. They mention watches/warnings could come tomorrow. Here’s the link for anyone interested.

https://m.youtube.com/watch?v=r-5vawno ... e=youtu.be

[srainhoutx]

Saturday afternoon weather briefing from Jeff:

Heavy rainfall likely early next week

Tropical system likely to form over the western Gulf of Mexico on Sunday and move northward.

Area of disturbed weather over the Bay of Campeche is moving slowly toward the WNW and NW and will reach the SW Gulf of Mexico on Sunday where upper level conditions look to become more favorable for the formation of a surface low pressure center. At the same time a trough axis and surge of deep tropical moisture will be spreading NW across the NW Gulf of Mexico and into the TX coast as early as Sunday morning. Rain chances will begin to increase from the coast inland on Sunday as moisture and lift increase. Expecting mostly passing bands of showers and thunderstorms on Sunday, with the more concentrated heavy rains holding off until Monday morning.

Surface low (depression or storm) is likely to form either Sunday or Monday along the east coast of MX or SSE of BRO and then move generally northward right along, slightly inland or just offshore of the lower TX coast on Monday and then NNE into the Matagorda Bay area or upper TX coast early Tuesday. Where exactly the surface low forms remains unclear and continues to yield uncertainty in the exact track forecast and possible impacts. General thinking remains unchanged from earlier that some sort of tropical system will be over the NW Gulf off the TX coast Monday and Tuesday. The majority of the model guidance keep the system as a tropical depression of tropical storm, but the reasonable worst case scenario could be a minimal hurricane or strong tropical storm should the system remain further offshore.

Tropical storm watches/warnings may be required for portions of the TX coast on Sunday.

Impacts:

Rainfall is likely to be the main impact and flooding and flash flooding will be possible.

Rainfall amounts will be strongly tied to the track of the surface low and the position of the NE extending surface trough. Areas to the SE of this trough axis will likely see the greatest rainfall amounts, but where that line sets up is unclear and there will likely be a fairly sharp gradient in rainfall totals across the area. Will continue to favor the coastal areas/counties for the greatest rainfall amounts of widespread 5-8 inches with isolated totals of 12 inches+. Areas inland of the coastal counties up to roughly I-10 can expect 3-5 inches with isolated higher amounts and areas off to the N and NW generally 1-3 inches. This is a fairly rough guestimate at this time and these numbers could go up or down.

Given the incoming tropical air mass, hourly rainfall rates of 2-4 inches will be possible and even with dry grounds this can quickly lead to run-off and flooding especially in urban areas. Overall flood threat will grow with time as grounds saturate. The tropical system is NOT expected to slow down or stall over the area.

Tides and seas will also be on the increase as winds build from the ESE and SE into the 15-25kt range by late Sunday into Monday and seas into the 6-10ft range. Increasing seas will result in wave run-up along the coast and coastal flooding will be possible at times of high tide, especially in the normal low lying and flood prone areas. Total water level of 3.0-4.0 ft above MLLW (barnacle level) is possible at high tides on Monday and Tuesday.

Given the uncertainty in the forecast track, these impacts may change…some significantly…over the next 24 -48 hours and it is important to monitor local trusted sources of weather information.

[DoctorMu]

Enjoying one last day of dry weather...the dewpoint is 48°F and the heat index is 3°F under the ambient temperature!!

The bad news is that the Frontier Internet dudes dug yesterday and hit my sprinkler box, rendering it useless to my chagrin this afternoon.

The good news is the high potential rain this week. Still expect a flood to famine SE to NW gradient across the area. We'll see.


Area Forecast Discussion
National Weather Service Houston/Galveston TX
348 PM CDT Sat Sep 11 2021

.SHORT TERM [Tonight Through Sunday Night]...

The recent reprieve from summer-like humidity is coming to an end as
a plume of Gulf moisture works its way into SE TX. Observations over
the past 24 hours indicate increases in near-surface dewpoint
temperature on the order of 10 degF, with this trend expected to
continue overnight as winds continue to veer to the southeast
offshore. By tomorrow afternoon, global models indicate an increase
in total PW values to over 2.0 in, a sharp increase from the sub-1.0
in values observed today. As such, the threat for diurnally driven
showers and storms will be on the increase with scattered
precipitation in the forecast by tomorrow afternoon. Look for highs
on Sunday to once again reach the mid-90s, though the increase in
surface dew points will produce maximum heat index values in the
upper 90s. Overnight lows will increase with the concurrent increase
in cloud cover, with most locations seeing the mid to upper 70s.

We remain heavily focused on Invest 94L, a tropical disturbance
currently under investigation in the Southwestern Gulf of Mexico.
This system is likely to develop into a tropical depression or storm
in the coming days and is expected to bring periods of heavy rain
to SE TX beginning on Monday. See the Long Term section below for
additional information regarding this system.

Cady

&&

.LONG TERM [Monday Through Saturday]...

All eyes continue to be focused on 94L (by now a tropical depression
or tropical storm?) as it moves northward toward the Texas coast.
Parts of Southeast Texas (where exactly is still to be determined
but most likely around/south of the I-10 corridor on Monday morning)
will be experiencing rounds of showers and thunderstorms with the
potential for locally heavy rainfall, and this activity should spread
inland during the day. A Flash Flood Watch might be needed for parts
of our forecast area. Rounds of storms (locally heavy rainfall of
2 to 4 inches per hour the main weather threat with precipitable
water values in a 2.00 to 2.50 inch range along with decent low
level convergence and upper level divergence) should persist into
Monday night and Tuesday. If the system has strengthened, and
depending on how strong it gets, we might be dealing with an
increasing wind threat too. At this time, anticipating rainfall
totals of 5 to 10 inches with locally higher amounts possible,
mainly in/around the coastal counties and possibly one or more
tier of counties inland where WPC has a Slight Risk of excessive
rainfall in their latest Day 2 and Day 3 Outlooks. Also, look for
an increasing risk of elevated tides and possible coastal flooding.
There could be significant chances in the locations and amounts
forecast as a lot will depend on the track and strength of this
system, so stay tuned! Even after this system eventually moves off
to our east (late Wednesday or Thursday?), rain chances will remain
in the forecast through Saturday as precipitable water values
remain around/above 1.50 inches for a large part of the area. 42

&&

.MARINE...

Winds and seas will continue to gradually increase into the first half
of the week as an easterly wave moves into the Texas coastal waters.
Unsettled weather, with several rounds of showers and thunderstorms
and the potential for locally heavy rain, can be expected beginning
on Sunday and likely continuing into next week. Mariners should closely
monitor the latest forecasts as there is increasing potential for some
tropical development in the Bay of Campeche and western Gulf that could
work its way toward the middle to upper Texas coastal areas. If this
happens, higher winds and seas can be expected. 42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 65 93 73 87 73 / 0 10 20 70 30
Houston (IAH) 70 91 75 85 73 / 10 60 60 80 60
Galveston (GLS) 79 88 79 84 78 / 30 70 80 80 70

[weatherguy425]

HAFS-B (NHC experimental model) came in a bit more organized with 94-L; upper-end tropical storm riding up the coast with an eventual landfall between Sargent and Galveston or so.

Despite warm waters, it’s important to note that wind shear and dry air will be negating factors for any rapid strengthening. We’ll see.

[srainhoutx]

Enjoying one last day of dry weather...the dewpoint is 48°F and the heat index is 3°F under the ambient temperature!!

That upper trough certainly brought a taste of Fall here in the Smoky Mountains. My low yesterday was 49 and 51 this morning. I'm already seeing signs of the leaf change at the upper Valley level. Red's are making an appearance for the early trees as well as some yellow.

[weatherguy425]

18Z GFS continues its idea of a more offshore track, in fact, even further offshore within the firs 48 hours, or so, followed by a similar landfall point as the 12Z - around the state line.