September 2020:

[Scott747]

12z ukie brings a strong disturbance/depression towards New Orleans.

Euro ensembles show something similar as the GFS with initial movement as it enters the gulf towards the ngom and then a w bend towards Texas. Is a little further n so half the members take it across la.

For reference my posts are about the as of now undesignated system currently in the Bahamas.

[DoctorMu]

Looks like the SE flow is fighting the front and causing mischief now.

That's a nice line of storms along the front as the Heat pushes back!

71°F in CLL with NW wind at 15 mph. Actually looking forward to mowing!

[davidiowx]

I'll take the rain but today was just gorgeous outside!! I don't want it to go away LOL

[Texaspirate11]

Feels like 102 in Galveston.
What rain and cold front?

[djmike]

Feels like 102 in Galveston.
What rain and cold front?

Haha no rain or front in Beaumont either. HOT. Muggy and still 94. Blech. Baytown westward, enjoy! Hopefully Beaumont and Galveston get the next one. And soon...

[Texaspirate11]

Feels like 102 in Galveston.
What rain and cold front?

Haha no rain or front in Beaumont either. HOT. Muggy and still 94. Blech. Baytown westward, enjoy! Hopefully Beaumont and Galveston get the next one. And soon...

I would like a cold front before Miss Sally gets close to us.

[sambucol]

12z ukie brings a strong disturbance/depression towards New Orleans.

Euro ensembles show something similar as the GFS with initial movement as it enters the gulf towards the ngom and then a w bend towards Texas. Is a little further n so half the members take it across la.

For reference my posts are about the as of now undesignated system currently in the Bahamas.

There are so many systems out there, I’m confused. Which system is the one that the Euro shows a west bend toward Texas?

[jasons2k]

The Bahamas system is now up to 50%. Folks, I think we need to keep an eye on this one:

A large area of disorganized showers and thunderstorms extending
from near the Central and Northwest Bahamas eastward over the
western Atlantic for a few hundred miles is associated with a
surface trough of low pressure. This system is forecast to
move westward, crossing the Bahamas and Florida on Friday and moving
into the eastern Gulf of Mexico over the weekend. Upper-level
winds are expected to become conducive for development, and a
tropical depression could form while this system moves slowly
west-northwestward over the eastern Gulf of Mexico early next week.
Regardless of development, this system is expected to produce
locally heavy rainfall over portions of South Florida and the Keys
during the next couple of days.

* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...50 percent.

[Cpv17]

The Bahamas system is now up to 50%. Folks, I think we need to keep an eye on this one:

A large area of disorganized showers and thunderstorms extending
from near the Central and Northwest Bahamas eastward over the
western Atlantic for a few hundred miles is associated with a
surface trough of low pressure. This system is forecast to
move westward, crossing the Bahamas and Florida on Friday and moving
into the eastern Gulf of Mexico over the weekend. Upper-level
winds are expected to become conducive for development, and a
tropical depression could form while this system moves slowly
west-northwestward over the eastern Gulf of Mexico early next week.
Regardless of development, this system is expected to produce
locally heavy rainfall over portions of South Florida and the Keys
during the next couple of days.

* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...50 percent.

May I ask why? The NHC has this pointed right at SELA. Are ensembles bending this west or something? I’ll admit, I haven’t really paid much attention to this.

[tireman4]

The Bahamas system is now up to 50%. Folks, I think we need to keep an eye on this one:

A large area of disorganized showers and thunderstorms extending
from near the Central and Northwest Bahamas eastward over the
western Atlantic for a few hundred miles is associated with a
surface trough of low pressure. This system is forecast to
move westward, crossing the Bahamas and Florida on Friday and moving
into the eastern Gulf of Mexico over the weekend. Upper-level
winds are expected to become conducive for development, and a
tropical depression could form while this system moves slowly
west-northwestward over the eastern Gulf of Mexico early next week.
Regardless of development, this system is expected to produce
locally heavy rainfall over portions of South Florida and the Keys
during the next couple of days.

* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...50 percent.

May I ask why? The NHC has this pointed right at SELA. Are ensembles bending this west or something? I’ll admit, I haven’t really paid much attention to this.

It is that time of the year. We just had the 120 year anniversary of the 1900 Storm. Always keep a weather eye toward the Atlantic. Srain has preached this for years.

[tireman4]

000
FXUS64 KHGX 110012
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
712 PM CDT Thu Sep 10 2020

.AVIATION [00Z TAF Issuance]...

This afternoon`s activity will continue to decrease through the
next hour or so with the loss of daytime heating. In its wake...
we should begin to see winds shift to the NNW across SE TX this
evening/overnight. This cooler shallow air mass filtering down/
across the region will also bring with it MVFR/IFR CIGS to most
of the CWA tonight through early tomorrow morning. Did keep the
mention of VCSH in for some sites as near-term models are show-
ing another round of activity during the afternoon. This may be
in response to another short-wave moving in from the W/SW along
with daytime heating. 41

[jasons2k]

So I guess the front lives on for a bit longer...you can see it on radar pushing offshore again. What an interesting day...

[Cpv17]

The Bahamas system is now up to 50%. Folks, I think we need to keep an eye on this one:

May I ask why? The NHC has this pointed right at SELA. Are ensembles bending this west or something? I’ll admit, I haven’t really paid much attention to this.

It is that time of the year. We just had the 120 year anniversary of the 1900 Storm. Always keep a weather eye toward the Atlantic. Srain has preached this for years.

I just don’t see this headed our way as of now but I know it can change.

[Scott747]

0z GFS is similar to the earlier runs today. Tries to develop it off the w coast of Florida before heading towards the ngom and then again the energy is bending back w towards Texas before washing out.

[Scott747]

The disturbed area in the Bahamas is now 96l. Hurricane models should begin running by 12z.

[tireman4]

If you are wondering why they use 90s for invests...


0-49 are TCs, STCs, or potential TCs. Basically these are the numbers we use starting with TDs in the Atlantic (TD01, TD02, TD03, etc.). In fact, the ATCF is hard coded to only go up to 49. If we were to ever get up to 49 systems in one year, we would actually start over at TD01 for number 50.

50-79 are for internal use only. NOAA will often use these before operational invests are designated to communicate among internal departments and NRL.

80-89 are for system tests. Rare, but if the NHC wants to test some new model updates/internal system changes they will use these.

90-99 are operational invests. These are further broken down by basin:

L is for Atlantic.
E is for East Pacific.
C is for Central Pacific.
W is for West Pacific.
B is for Indian Ocean (Bay of Bengal).
A is for Indian Ocean (Arabian Sea).
S is for Southwest Indian Ocean/Australia (west of 135E)
P is for Australia/South Pacific (east of 135E)
Q is for South Atlantic (generally only used by NRL).

[tireman4]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Fri Sep 11 2020

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:



A surface trough of low pressure located over the northwestern
Bahamas is producing a large area of disorganized showers and
thunderstorms that extend from the northwestern and central Bahamas
eastward a few hundred miles over the western Atlantic. This
system is forecast to move westward at about 10 mph, crossing the
Bahamas and Florida today and tonight and moving into the eastern
Gulf of Mexico on Saturday. Upper-level winds are expected to
become conducive for development, and a tropical depression could
form while this system moves slowly west-northwestward over the
eastern Gulf of Mexico this weekend and early next week. Regardless
of development, this system is expected to produce locally heavy
rainfall over portions of the Bahamas, South Florida, and the
Florida Keys during the next couple of days.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...60 percent.

[tireman4]

000
FXUS64 KHGX 111132
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
632 AM CDT Fri Sep 11 2020

.AVIATION [12Z TAF Issuance]...

Lingering showers still showing up on the latest radar imagery,
but should remain west of all terminals as precipitation tapers
off over the next couple of hours. Most terminals are reporting
high-end IFR to low-end MVFR cigs as we approach 12Z, with these
conditions expected to persist through the mid-morning. Expect
north to northeast winds to increase to around 10 knots this
afternoon as cigs lift above VFR thresholds. Daytime heating is
likely to generate some airmass thunderstorms this afternoon, but
have included VCTS wording in TAF package given expected scattered
to isolated nature in coverage. Light and variable winds develop
overnight. NAM fcst soundings hint at the redevelopment of sub-VFR
cigs overnight, but this development should be more limited as
near-surface moisture looks to decrease.

&&

.PREV DISCUSSION... /ISSUED 414 AM CDT Fri Sep 11 2020/

DISCUSSION...

The next week or so can roughly be broken down into a
meteorological play of three acts. If we are to extend the
metaphor, please enjoy this playbill/discussion. A brief synopsis
of the play is below, followed by more technical details about the
show.

Act 1: In The Wake of The Front - Our heroes (the residents of
Southeast Texas, naturally) enjoy a couple days of fair(ish)
weather after yesterday`s frontal passage. The air is relatively
dry - not ideally so, but enough for some small respite from the
week`s oppressive heat and humidity. Rain, while not completely
absent, will be reduced.

Act 2: A Gulf Trough Approaches - Late this weekend, a strange
trough comes towards our Gulf waters from the eastern Gulf. It is
unknown precisely what danger this trough will bear, though the
experts in Miami currently expect only low potential for tropical
development. Despite that, this new arrival will bring more
active weather - both in stronger winds and waves on the water,
and also increased moisture to raise humidity as well as fuel
showers and thunderstorms over the land.

Act 3: Another Trough Arrives - As the new work week opens, this
first trough is expected to pass by our area on its way towards
Mexico. But our heroes are given no chance to rest, as we are
beset by a new trough that is currently over the Bahamas. Again,
we will have to confer with the experts in Miami as to the true
nature of this area of low pressure - be it open trough or
tropical cyclone. Regardless, we can expect the stretch of higher
humidity, increased seas, and greater potential for showers and
storms to pester our heroes deep into the new week.

SHORT TERM [Through Sunday Night]...

A fairly wet weekend looks in store for most of the area with
precipitation chances on the rise as the weekend progresses. Despite
the onshore flow pattern that has developed in the wake of
yesterday`s weak surface boundary, near-surface moisture remains
ample across the region with global models continuing to indicate
surface PW values of 2.0+ inches across the majority of the CWA
through Friday. With cloud cover remaining fairly widespread and
some cool advection via northeasterly surface winds, highs should
be moderated a bit today with the bulk of the Houston metro
topping out around 90 while the northwest zones stay in the mid to
upper 80s. Some isolated showers and storms are likely to develop
once again this afternoon, with the bulk of the activity across
the metro and near the coast where convective temps (88-90 per
latest NAM fcst soundings) will be more easily reachable.

Heading into the middle of the weekend, our interests turn to the
approach of the first of two weak systems that are currently being
monitored for tropical development. On Saturday evening and into
Sunday, an easterly wave currently located in the Central Gulf will
approach the coastal waters. Global models are indicating a fairly
robust surge of moisture associated with this feature, with fairly
good agreement between latest GFS, ECMWF, CMC, & NAM runs in raising
PW values along the coast to the vicinity of 2.5 in. This ample
swath of moisture combined with daytime heating should drive the
development of more widespread showers and storms through Sunday.
Given that there`s still some uncertainty regarding the development
of this expectedly weak system, have kept the weekend`s PoPs
slightly under the latest national blend guidance...however these
may need to be adjusted upward in the coming forecast packages as
confidence increases.

Weekend highs will be on the rise with conditions continuing to
remain summer-like for the time being. Dew points should rise back
up into the mid 70s across the area by tomorrow which will bring
back those oh-so-familiar triple digit heat indicies to those areas
that have seen temporary relief over the past couple of days.

LONG TERM [Monday Through Friday]...

By Monday morning, the lead Gulf trough should be well beyond us,
making its way towards the Northeast Mexican coast. However, the
oncoming trough behind it looks to be keeping midlevel heights
from rebounding all that much, and at the surface, we`ll see
continued easterly flow that should keep precipitable waters
pretty high - still around 2.5 inches on Monday, and able to amp
up our diurnal shower/storm cycle. It feels awkward to have likely
PoPs in place on Day 4, but everything seems to point to an
active weather pattern early next week.

Wednesday might give us a relative lull - and the emphasis here
really is on `relative`. Precipitable water is still progged to be
above 2 inches, so I keep PoPs fairly high, albeit toned down a
bit from the early week. I`d also expect this moat between the
lead trough and the following trough to give us a little more sun,
and so I push high temps up just a touch towards 90 degrees, with
things maxing out in the lower 90s on the Coastal Plain centered
roughly along US-59.

After that brief intermission, or at least, whatever we get that
passes for one, the next trough looks to move into the picture.
There is probably a little more potential for tropical development
here, given that the lead trough is pretty devoid of convective
activity right now, and is closer to us. Additionally, shear over
the northern half of the Gulf looks to trend downwards a little
bit next week as this thing moves in. Despite all that, the model
guidance is pretty bearish on development, so there`s still quite
a bit of uncertainty here - the models may be sniffing something
out. Or...they may be just be behaving typically badly in handling
TC-genesis. All I have to work with now is the data I have at
hand, so for now my forecast assumes that we will see the approach
of a broad, unorganized area of low pressure carrying a lot of
moisture with it.

This should again, at the least, amp up our diurnal pattern of
showers and storms. If I was uncomfortable about having Likely
PoPs in place in Days 4 and 5, you should see how nervous I am
about putting them in Days 7 and 8! But again - all I have to work
with is the data at hand. And I`m looking at a convectively active
trough over the Bahamas, GOES TPW of up to 2.5 inches (and that`s
ignoring what it might be in the convectively active spots!), and
it should be headed across the Gulf over the next week. The most
likely solution must be a rainy/stormy period! This forecast may
end up busting badly if things change, but despite how aggressive
this forecast is, I`m still being a little more conservative than
the consensus of my guidance.

MARINE...

Behind the advancing weak surface boundary, a light to moderate
onshore flow has developed across the bays and coastal waters. Wind
speeds should remain near or above 15 knots over the next several
hours, which has prompted the issuance of caution flags through 10
AM this morning. Periods of showers and thunderstorms, though
isolated in coverage, will develop offshore through the day today as
near-surface moisture remains widely available. Winds should taper
off to around 10 knots this evening and caution criteria is unlikely
to be met again heading into the weekend.

We continue to monitor two weak systems for potential tropical
development in the Gulf. While the current risk for significant
impacts to SE Texas waters remains low and uncertainty is high,
mariners should continue to monitor the latest tropical weather
information at www.hurricanes.gov.

TROPICAL...

There are two features we are watching in or about to enter the
Gulf of Mexico for impact on our weather in the next week or so
along with the NHC. First off is a trough of low pressure over the
North-Central Gulf, referred to above in the short term section of
this discussion. It is given a relatively small chance for
development, given its current state. The primary expected impact
for our area - as mentioned above - is an increase to waves in the
Gulf and moisture to fuel our typical daily showers and storms as
it cruises by. Tropical development is not off the table, though,
so we will be watching closely in the coming days.

The next feature of interest is another trough over the Bahamas,
which has been more successful in producing showers and
thunderstorms than the lead feature. The environment over the Gulf
is expected to be more conducive for development when it arrives
early next week. So, while the current model consensus is
generally against tropical development, this is another feature to
keep a close eye on early next week. Regardless of that outcome,
this is likely to bring another surge of moisture into our area,
fueling showers and thunderstorms across the region.

Finally, we will also continue to monitor African Easterly Waves
as they emerge from the continent over the Atlantic Ocean. At
least one looks very likely to become a tropical depression in the
next 5 days. These waves are still extremely far away, and there
is no way to tell what impact - if any at all - there may be to
Southeast Texas. Further, it will be quite some time until there
is reliable enough data for anything more than speculation. As it
is the climatological peak of hurricane season, these waves do
bear watching, but require very little attention for now.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 84 69 90 72 91 / 10 0 10 0 30
Houston (IAH) 91 74 94 77 93 / 20 10 20 20 60
Galveston (GLS) 89 81 91 82 91 / 20 20 30 40 60

&&

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

$$

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

[jasons2k]

It’s overcast and 73 with a “dry” northwest wind.

I don’t quite understand all that discussion yesterday (and prior days) about the front, will it make it or not, watching it “wash out” yesterday only to come back with a vengeance and push offshore. Obviously the whole play-by-play was quite a bit different than expected. It all happened but it all got swept under the rug. Today we have “the wake of the front” that 24 hours ago was supposed to never happen.

Oh well, off to watching the tropics.

[jasons2k]

WxMan57 says 96L will make landfall from SE LA to the FL Panhandle as a wave, TD or weak TS this weekend.

The NWS seems confident the system will bring moisture this way later next week.

I see the lines have been drawn now. Will be interesting to watch this one play out.