September 2021: Hurricane Nicholas

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Cpv17
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Re: September 2021: Hurricane Nicholas

Post by Cpv17 » Wed Sep 29, 2021 9:58 am

Kingwood36 wrote:
Wed Sep 29, 2021 9:49 am
Cpv17 wrote:
Wed Sep 29, 2021 9:32 am
Stratton20 wrote:
Wed Sep 29, 2021 8:57 am
Rain chances look to continue through the weekend ! I will gladly take it😄😄
Hell yeah! Bring it on!!
You 2 need to go live in Seattle lol rain every day!
I’ve heard Seattle can be a pretty depressing place to live. They get a lot of light rain there from my understanding. I prefer the heavy stuff. Light rain can sometimes just be a nuisance to me. Plus I would get tired of the clouds all the time. I like my sunshine too. Plus in Seattle they don’t get any severe stuff so I would miss that.

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djmike
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Re: September 2021: Hurricane Nicholas

Post by djmike » Wed Sep 29, 2021 10:21 am

Was this mornings rain all for today? Sunny now. Not bad if we get it out of the way early. Whens the next disturbance? Tonight? Tomorrow?
Mike
Beaumont, TX
(IH-10 & College Street)

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Re: September 2021: Hurricane Nicholas

Post by Cromagnum » Wed Sep 29, 2021 10:28 am

Going to central Texas to work at the ranch and see it's gonna be a toad straggler. Normally I would bless any rainfall out there but why does it have to be on the only weekend I've been out there in months?

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Re: September 2021: Hurricane Nicholas

Post by jasons2k » Wed Sep 29, 2021 10:31 am

Cromagnum wrote:
Wed Sep 29, 2021 10:28 am
Going to central Texas to work at the ranch and see it's gonna be a toad straggler. Normally I would bless any rainfall out there but why does it have to be on the only weekend I've been out there in months?
My friends with ACL tickets are not too happy either.

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tireman4
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Re: September 2021: Hurricane Nicholas

Post by tireman4 » Wed Sep 29, 2021 11:46 am

A Little Late, but no afternoon update to AFD yet..

000
FXUS64 KHGX 291132
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
632 AM CDT Wed Sep 29 2021

.AVIATION [12Z TAF Issuance]...

Squall line exiting the area to the east, but terminals to be
affected by lingering light rain for a few more hours yet to be
replaced by low VFR conditions. Variable and gusty winds from the
storms should become re-established out of the SE/SSE, around 10
knots for the afternoon. There is some chance for redevelopment of
showers and storms this afternoon if enough sun breaks through to
recharge the atmosphere, but confidence too low for any mention
in the TAFs. Expect MVFR or worse ceilings and some patchy fog to
crop up later tonight.

&&

.PREV DISCUSSION /Issued 343 AM CDT Wed Sep 29 2021/...

.DISCUSSION...

A week of active weather continues, exemplified most prominently
early this morning as a line of showers and thunderstorms marches
across Southeast Texas. This will likely be the focus of today`s
action, with briefly heavy rain and gusty winds in and around the
strongest parts of the line. If the line moves through quickly
enough, we could see some redevelopment late this afternoon,
otherwise things will probably be more quiet today once the line
has moved through your neck of the woods.

Don`t get too used to the break, though. With an upper low
spinning nearly in place out west and low level onshore flow
continuing to pump warm, humid Gulf air into the area, we`ll see
periodic bouts of showers and storms into the weekend. A pattern
change will eventually shift things up next week, but until then,
expect to see rain and storms off and on.


.NEAR TERM [Through Today]...

A line of showers and thunderstorms is marching across the area
early this morning, and at 3 am that line was roughly located from
Crockett, through Huntsville, Katy, and Wharton to Victoria (and
points further southwest). While responsible for strong winds and
flash flood warnings in Central Texas, the intensity has waned
somewhat as it moves through our area. Still, terminal doppler
indicates potential for the most intense portions of the line to
carry wind gusts to around 40 mph and some briefly heavy rain.
At one point, KHGX showed what may have been a loose mesocyclone
and a wet microburst in rural Wharton County southeast of Eagle
Lake - so, while this line is maybe not the scariest thing ever,
it isn`t a nothingburger, either.

I did have some concern at the beginning of the shift that the
line was beginning to take on more of an MCV look on radar, and
mesoanalysis hinted at a broader mesolow starting to form. I am
not a fan of MCVs near the coast tapping into an onshore moisture
feed from a nocturnal low level jet. Fortunately, it appears that
we are now getting a more classical squall line structure as the
line has stopped curling up and stood back up more, and obs
suggest a more typical squall line circulation setting up with a
pre-line trough, and a mesohigh setting up behind the line (the
SPC mesoanalysis scheme doesn`t really have the resolution to do
it justice, but it is trying really, really hard to do it, so
props to it on that effort).

This makes me feel better about the line continuing to be driven
by its cold pool and keep rain from piling up too much as it moves
across the area (and the Houston metro) over the next several
hours. Though, I am wondering about the potential for gusty wake
low winds, so I`ll be watching obs back in Central Texas near the
enhanced trailing stratiform band for any signs of that
developing.

This line is likely to be the main action today. Between it and
trailing stratiform rain, I`d expect things to get pretty well
worked over. As failed attempts at new convective development over
the Hill Country indicate, we`ll probably need to watch for storms
trying to fire again in the afternoon as the atmosphere tries to
reload, and the quicker this overnight/early morning action clears
out, the better a chance we`ll have at a brief round two before
sunset likely puts an end to things. Because of this, I drag out
chance PoPs through the whole afternoon, but this is a bit of a
hedge, and I would not be surprised to see some of those PoPs
shaved down by the day shift. Similarly, I`ve nudged today`s high
temperature forecast down some, but it is also hedged a bit based
on whether some sun manages to break through for the afternoon, or
if clouds stick with us through the day. I`ve still got some upper
80s back in the northwest on the assumption that they`ll see a
little more sun today, but if the clouds and even some light
trailing showers linger, we`re not likely to even reach those
highs.


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

As the current upper vort max moves out, and perhaps we even see
some really subtle shortwave ridging in its wake, tonight looks
relatively calm with only some lingering slight chances of rain in
the area. Overnight lows are pretty close to persistence as the
low level onshore flow isn`t going anywhere, and should provide a
pretty solid temperature floor. Given the environment, and recent
rains provide some more moisture to work with, some patchy fog
and/or low stratus is a plausible scenario. Look for your typical
foggy spots and the places that have gotten the most rain recently
as your more likely spots to see fog crop up overnight.

While it doesn`t look nearly as impressive as this current
shortwave trough in the guidance, look for the next upper
disturbance/trough/ripple/thing to boost shower and storm
potential to move in again on Thursday. Showers and storms look a
little more likely near the coast than inland with this one, but
given how subtle this feature is, I`m not terribly confident in my
ability to precisely place it even 36 hours out. Given the
setup, and assuming the vort max tracks where it does in the
guidance, a focus on the coast looks probable, but it`s also not
a slam dunk.


.LONG TERM [Friday Night Through Wednesday]...

Scattered to numerous showers and storms will continue on Friday
with SE TX remaining within a favorable synoptic pattern for
widespread precipitation development. By this time, the now
negatively tilted upper trough will have positioned itself over the
TX Panhandle region. SE TX will be situated within a coupled upper
jet pattern, providing ample upper divergence to sustain widespread
precipitation during the day on Friday. Moisture will continue to be
abundant given the persistent onshore flow, with values expected to
remain in excess of 2.0 in per the latest global model guidance.
Finally, global models continue to show sufficient instability as
SBCAPE values remain on the order of 2000 J/kg. Have opted to go on
the higher end of available guidance for PoPs on Friday given this
favorable pattern. Like we`ve seen today, this setup should be able
to produce some efficient rain producing storms with total rainfall
of several inches possible.

Models continue to diverge regarding the potential approach of a
weak cold front this weekend. By late Saturday, a front extending
across the Central CONUS from a weak low over the Great Lakes will
push into SE TX, bringing with it showers and thunderstorms. The
remainder of the forecast hinges on exactly how far the boundary
will be able to push offshore before stalling. The latest EC has
come in a bit more progressive, stalling the front just offshore.
Nonetheless, the GFS remains the most progressive with the boundary
pushing well into the coastal waters. While drier air should move
into the area as weak to moderate northerly winds develop behind the
boundary, it remains uncertain as to the extend to which
precipitation will linger around the coast for the remainder of the
weekend. Given this, have opted to maintain 20-30% values for Sunday
and Monday across the Houston Metro and along the coast.

The beginning of next week looks to be a bit drier as PWs drop below
1.0 in in the wake of the fropa. With broad surface high pressure
remaining in place over the Central Plains, PoPs will diminish while
surface dew points should feel a bit more comfortable in the 60s.
Showers and storms may still linger along the coast depending on the
course of the frontal boundary.

Regarding temperatures, values should remain near seasonable norms
with afternoon highs generally remaining in the mid/upper 80s while
lows hover around 70. The fropa should lead to some cooler and drier
conditions by early next week with afternoon highs potentially
dipping into the lower 80s in some locations.


.MARINE...

Small Craft Advisory remains in effect over the next several hours
as moderate to strong southerly winds ahead of an approaching line
of storms continue over the coastal waters. A brief northerly wind
shift is expected in the wake of the departure of the storm complex
this morning, though flow should quickly return to an onshore regime
by late this afternoon. With the onshore flow pattern remaining in
place through the weekend and moisture abundant, scattered to
numerous showers and storms will continue to develop. By Sunday,
however, the approach of a surface cold frontal boundary will bring
about a pattern change. Models disagree regarding to the extent the
front will push offshore. Should the boundary stall out closer to
the coast, additional rounds of showers and storms will be more
likely through the early part of next week.

&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL) 88 73 89 72 82 / 40 20 40 50 80
Houston (IAH) 84 73 86 73 82 / 70 30 50 50 80
Galveston (GLS) 83 78 85 78 83 / 70 40 50 60 80

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...None.
GM...Small Craft Advisory until 8 AM CDT this morning 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...Galveston Bay...Matagorda
Bay...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.


&&

$$

DISCUSSION...Luchs
NEAR TERM...Luchs
SHORT TERM...Luchs
LONG TERM...Cady
AVIATION...Luchs
MARINE...Cady

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Re: September 2021: Hurricane Nicholas

Post by tireman4 » Wed Sep 29, 2021 2:08 pm

XUS64 KHGX 291747
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1247 PM CDT Wed Sep 29 2021

.AVIATION [18Z TAF Issuance]...

Quite the complicated forecast initially with a couple of sites
(CXO and UTS) still holding on tight to IFR/MVFR ceilings.
Thinking that these will lift over the next couple of hours. For
the remainder of the sites, VFR conditions and southerly to
southeasterly winds will prevail through the afternoon/evening
hours. In the overnight hours for IAH and sites northward, models
are still insistent on a round of IFR ceilings and fog which looks
increasingly likely as skies become increasingly clearer from the
west. For HOU and sites southward, overnight ceilings may become
MVFR or flirt with the category, but most impacts should remain to
the north. The biggest window for IFR/MVFR ceilings is between
09z-15z. After 15z, southerly winds begin to increase and with
some mixing we`ll see ceilings rise to at least MVFR. Light
showers will parallel along the coastline overnight/early Thursday
morning as well, only impacting LBX and GLS. The 12z run of the
CAMs are a bit variable on when showers/thunderstorms develop
further inland, but 19z-21z looks to be a good ballpark number for
now.

&&

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DoctorMu
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Re: September 2021: Hurricane Nicholas

Post by DoctorMu » Thu Sep 30, 2021 9:28 am

Area Forecast Discussion
National Weather Service Houston/Galveston TX
637 AM CDT Thu Sep 30 2021

.AVIATION [12Z TAF Issuance]...

In broad strokes, pretty high confidence in the expected evolution
of today`s weather. Patchy fog and low stratus north of Houston
terminals will improve later this morning to VFR. Scattered to
numerous showers and storms emerge this afternoon, with best
chance for rain at the coastal terminals. A brief respite this
evening as clouds scatter out, then chances begin to return at the
end of the period as next upper disturbance approaches.

The specifics will be a bit harder to pin down, so windows are
still a little on the large side to err on the side of caution.

&&

.PREV DISCUSSION /Issued 334 AM CDT Thu Sep 30 2021/...

.DISCUSSION...

The bulk of the "action" in the forecast period is in the first
half, as a stretch of active weather continues thanks to an upper
low spinning slowly in from the Southwest US. Off and on periods
of showers and storms can be expected to continue into the
weekend, until a shift to more fair weather looks to establish
itself early next week.
With rain potential diminishing, daytime
highs also look to drift up next week to near and above seasonal
averages, but not unreasonably so thanks to a modest cold front
bringing in the pattern change. All in all, this should make the
first full week of October a relatively seasonable one.




.SHORT TERM [Through Friday Night]...

Thanks to our ample moisture in the environment from our active
stretch of weather of late, patchy fog is cropping up in the usual
foggy spots north of the Houston metro (think the Two Cs - Conroe
and Cleveland, and the like places) and this patchy fog is
expected to continue into the morning hours.

Aloft, a southwest-northeast channel between an upper high over
the Gulf and an upper low over the Four Corners has been in place
for a minute and doesn`t look to be going anywhere anytime soon.
As lobes of vorticity are shed off the larger upper low, they
shoot through this channel and support periods of showers and
thunderstorms in the area.
For today, guidance continues to
suggest the vort max crossing the area will be more towards the
coast and the nearshore Gulf,
and so I continue to focus the
highest PoPs in that area.

That`s not to say the inland part of the forecast area will stay
totally dry today - I`d just expect the coverage of rain to be
less the more inland you look today. That said, with this setup, I
go noticeably warmer for highs in the northwest, pushing 90
degrees up around Caldwell and B/CS. The coolest temps look to be
in the southeast, on the east side of Galveston Bay.

This evening should give us a relative lull in showers and storms
as the day`s vort max exits the area, but there`s another
shortwave trough/vort max that will roll around that will boost
potential for showers and storms again tomorrow. An interesting
factor here will be an upper jet streak that looks to set up
favorably for upward motion tomorrow afternoon. However, this
streak looks to be weakening as it moves into the most favorable
position over Southeast Texas, so even if the timing is good, we
may not get an overlap when diurnal instability is at its highest
in the afternoon.

This slight mis-phasing of ingredients may be the reason why the
CAMs take what looks like a budding MCS in the Hill Country and
don`t really do anything with it as the focus would shift into our
area. I`m entirely okay with this - we could certainly use some
rain, but with precipitable water remaining up around or above
two inches tomorrow, a storm fueled entirely by the available
instability can drop localized flooding rains if it comes down on
the wrong spot, even without the support for a more organized rain
event. It`s the difference between the slight risk for excessive
rain from WPC`s Day 2 outlook to our west and the marginal over
our area. On top of some moderate instability, HREF shear is in
the 20 knot range - this isn`t going to be making any supercells,
but may tilt a stronger storm enough so that its rainfall doesn`t
immediately collapse its updraft, helping it persist a little
longer. Also, HREF storm motions are 10 knots at most, so we can`t
necessarily count on storm motion to keep rain from piling up much
either.

To make a long story short (too late!) - we do check some of those
heavy rain boxes, but some of them don`t appear to come together
at the same time, and some other important ingredients aren`t
really there at all. This all goes to support that marginal threat
of flooding rains,
mainly if isolated storms produce a lot of rain
in the wrong spot. But otherwise, there`s less concern for a more
widespread heavy rain event.

Of course, since we`re not really dealing with a big synoptic
bulldozer here, small shifts in the forecast could be important
for overall potential. I`m not real concerned about that here
since some of the mitigating factors are more synoptic in scale
and handled more reliably by the models, but I have also seen how
things can escalate quickly around here more than once, so I know
better than to sleep on things with an upper low to our west.


.LONG TERM [Saturday Through Thursday]...

Our prolonged period of warm, wet, and humid weather will continue
into the weekend, though some relief is in sight with the approach
of a surface cold frontal boundary which should allow some drier air
to move into the area. By Saturday, the prevailing upper trough axis
will begin to push northeastward. Precipitation chances will remain
elevated during the day as deep Gulf moisture remains in place
(total PWs of 2.0 + in) and the area remains within the right rear
quadrant of an associated jet streak aloft. While rain chances
should be higher across the northern half of the region based on
this synoptic pattern, model guidance remains fairly diverse in QPF
distribution and have thus remained broad with PoPs for the time
being.
Both daytime highs (mid 80s) and overnight lows (low/mid 70s)
will follow the trend of the past few days, though these values will
again be complicated by the exact timing of precipitation
development.

A pattern shift arrives on Sunday as a weak low over the Ohio Valley
drags a surface cold front into the South Central CONUS. Latest
GFS/EC solutions are in fairly good agreement regarding this
feature`s arrival, placing it in the Brazos Valley during the
afternoon and taking it offshore during the overnight hours.
Showers
and storms will accompany the advancing front, with northerly winds
developing in its wake. EC appears to have backed off in its recent
trend of stalling the boundary near the coast, coming into line with
the more progressive GFS. That being said, showers could linger over
the coastal waters in the few days following the front depending on
exactly how this scenario evolves.

The upcoming week should be a bit more pleasant across SE TX as
northerly winds behind the departing front allow for some slightly
cooler and drier air to filter in. While this won`t be quite as
dramatic as the previous fropa, seasonable daytime highs in the low
to mid 80s and overnight lows in the upper 50s/60s will prevail
through the end of the forecast period.
Slight precip chances remain
confined to the coast and coastal waters given the uncertainty of
the positioning of the frontal boundary, though PoPs drop to near
zero by late Tuesday.


.MARINE...

Light to moderate onshore winds remain the story through the end of
the weekend with scattered showers and storms possible each day,
with seas remaining around 2 to 4 feet. A pattern shift arrives on
late Sunday/early Monday as a surface cold front pushes into the
coastal waters, with additional showers and storms developing along
the boundary. Guidance remains uncertain regarding the eventual
position and additional rainfall is possible should it stall closer
to the coast. North to northeast winds will develop behind the
departing front though wind speeds should generally remain light to
moderate. Precipitation chances should fully diminish by late
Tuesday or early Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL) 89 73 86 71 84 / 40 40 70 30 70
Houston (IAH) 86 73 85 72 84 / 50 40 70 40 70
Galveston (GLS) 85 77 85 78 84 / 70 60 70 40 70

&&

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Re: September 2021: Hurricane Nicholas

Post by jasons2k » Thu Sep 30, 2021 2:02 pm

Got .86” here from a decent storm.

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Re: September 2021: Hurricane Nicholas

Post by Cpv17 » Thu Sep 30, 2021 2:59 pm

Overall for the state, this event has underperformed so far.

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Re: September 2021: Hurricane Nicholas

Post by djmike » Thu Sep 30, 2021 4:16 pm

With 70% for today, Im part of the 30% that didn’t get a drop.
Mike
Beaumont, TX
(IH-10 & College Street)

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