September 2019 - Warm End of September

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Ptarmigan
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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by Ptarmigan » Mon Sep 23, 2019 5:56 pm

Scott747 wrote:
Mon Sep 23, 2019 5:52 pm
Models are really in a crazy mood now.

The GFS has been showing some really lowering of pressures across the western Caribbean in the long range.

18z has a system in the longer range (unrelated to Karen) that comes out of the Caribbean and hits around Corpus as a hurricane.

Just crazy seeing runs this late in the season favoring the Western gulf, even if it is in the longer range...
I take long range forecast models with a grain of salt.

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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by srainhoutx » Mon Sep 23, 2019 6:07 pm

As mentioned around mid September, a very conducive Hemispheric Pattern for the Atlantic Basin has arrived. The MJO is in Phase 1 as well as lower pressures and rising air and the strongest Convectively Couple Kelvin Wave of the Hurricane Season is right overhead. I am not surprised to see the Tropics active and I am certainly not surprised the computer models are indicating activity. As that strong CCKW passes, I suspect we will see additional development in the Atlantic Basin. Fingers crossed for that first cold front real soon... ;)
09232019 MJO diagram_40days_forecast_GEFS_member.gif
09232019 MJO ECMF_phase_51m_small.gif
09232019 MJO twc_globe_mjo_vp200.png
09232019 CCKW twc_mjoCCKW_vp200.png
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by jasons2k » Mon Sep 23, 2019 7:00 pm

The current pattern isn’t typical of one we see in late September. Have to look at the pattern, not the calendar.

On another note - it’s nice to see everything looks green and alive again. There are some brown cypress trees with bright green tips. It’s almost like springtime in the fall...

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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by Scott747 » Mon Sep 23, 2019 11:45 pm

Thankfully it's the very end of the long range....

0z GFS has Harvey part II. A little weaker on landfall/overall rain and a little further s.

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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by Cpv17 » Mon Sep 23, 2019 11:53 pm

Scott747 wrote:
Mon Sep 23, 2019 11:45 pm
Thankfully it's the very end of the long range....

0z GFS has Harvey part II. A little weaker on landfall/overall rain and a little further s.
With lowering pressures in the region around the W. Caribbean/Yucatán and a SE ridge there’s no telling what will happen. Fun model watching times ahead.

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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by Scott747 » Tue Sep 24, 2019 12:09 am

Cpv17 wrote:
Mon Sep 23, 2019 11:53 pm
Scott747 wrote:
Mon Sep 23, 2019 11:45 pm
Thankfully it's the very end of the long range....

0z GFS has Harvey part II. A little weaker on landfall/overall rain and a little further s.
With lowering pressures in the region around the W. Caribbean/Yucatán and a SE ridge there’s no telling what will happen. Fun model watching times ahead.
Correct. I'd guess that the euro over the next few days will begin picking up on the CA system. After that I still have a hard time believing the ridging would remain that strong for so long heading into mid October.

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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by Katdaddy » Tue Sep 24, 2019 5:01 am

Hot and mostly sunny skies across much of SE TX the next fews. Some isolated showers and a thunderstorm possibly across SW portions of SE TX. Moisture returns late this week and weekend with scattered showers and thunderstorms.

The tropics remain active but no concern for the TX Coast for the next 5 days. A small area of disturbed weather will move across S GOM and BOC into MX. The current NHC forecast still show a turn W or WSW toward FL this weekend however this 5 days out and the track will be depend on the strength of high pressure ridge to the N and NW of Karen.

The Houston-Galveston NWS mention the long range models hinting at our first cold front in 2 weeks which could easily change:

With the beginning of autumn yesterday, our minds of course have started to wonder about the potential for the first cold frontal passage of the season. Global models are hinting at this possibility for the end of next week or beginning of next weekend...but if 240-hour model forecasts have taught us anything, it`s that now is not the time to get your hopes up just yet.
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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by sau27 » Tue Sep 24, 2019 8:45 am

Scott747 wrote:
Tue Sep 24, 2019 12:09 am
Cpv17 wrote:
Mon Sep 23, 2019 11:53 pm
Scott747 wrote:
Mon Sep 23, 2019 11:45 pm
Thankfully it's the very end of the long range....

0z GFS has Harvey part II. A little weaker on landfall/overall rain and a little further s.
With lowering pressures in the region around the W. Caribbean/Yucatán and a SE ridge there’s no telling what will happen. Fun model watching times ahead.
Correct. I'd guess that the euro over the next few days will begin picking up on the CA system. After that I still have a hard time believing the ridging would remain that strong for so long heading into mid October.
That 00z GFS is wild. I don't think I've seen a modeled storm loop around to the backside of an incoming trough and then continue westward.

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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by tireman4 » Tue Sep 24, 2019 9:38 am

Well, and some folks will have to correct me if I am wrong, but October 2004, did we not have a ridging in effect. I say this because it was hot the whole month. I record heat..even on Halloween..88 degrees...
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Re: September 2019 - Gulf Moisture Returns/Tracking TS Karen

Post by tireman4 » Tue Sep 24, 2019 9:40 am

00
FXUS64 KHGX 241107
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
607 AM CDT Tue Sep 24 2019

.AVIATION [12Z TAF Issuance]...
A mixture of IFR to VFR ceilings this morning across the SE TX
terminals. Anticipate patchy fog to fill in and ceilings to lower
potentially as low as LIFR at isolated sites before sunrise.
Should see improvement shortly after sunrise. Otherwise, winds
should be light out of the southeast today. Most showers should
stay to the west of any terminals this afternoon, with CLL
standing the best chance for impacts if any. At the time the
probability of CLL seeing showers looks low enough given the
recent runs of high-res guidance that have taken out any VCSH
mention. A low SCT-BKN deck looks to potentially build back in
during the early morning hours, with the development of patchy fog
once again possible.

Hathaway

&&

.PREV DISCUSSION /Issued 405 AM CDT Tue Sep 24 2019/...

.SHORT TERM [Today Through Tonight]...
Fairly quiet in the short term, with patchy to areas of fog being
the main focus this morning. Dew point depressions are slowly
closing to between one to two degrees mostly along and north of
I-10. Visibilities could lower to between 1 to 5 miles at times,
with isolated locations potentially impacted by visibilities of
less than one mile at times. Most of the fog should burn off
quickly after sunrise. Surface ridging is continuing to build in
from the east, bringing with it much drier precipitable water
values (PWs) as seen in the GOES-16 total precipitable water
imagery. PWs of less than 1.5 inches should continue to push in
from the east today and into tomorrow. Areas west of I-45 will see
another day of PWs closer to 1.6 to 1.8 inches. Short term
guidance is continuing to trend drier, with only a slight chance
for showers today from Matagorda to Brazos County and westward.
That said, the region should see ample sunshine by the afternoon
hours, allowing high temperatures to rise into the low to mid 90s.
Low temperatures tonight will fall into the upper 60s to 70s,
with drier air in place and radiational cooling in full swing
under the influence of the ridge.

Hathaway

&&

.LONG TERM [Wednesday Through Tuesday]...
Overall, the initial trend for the area continues to be
characterized by the presence of upper-level ridging over the
central US and surface high pressure over SE Texas. The reduced
onshore moisture transport which will hinder the development of
diurnally-driven convection through mid-week slowly begins to
subside by Wednesday, and precipitation coverage becomes more
widespread by the weekend. On Wednesday, global model guidance is
in agreement in showing the a weak disturbance embedded within
upper-level zonal flow as the upper-level ridge shifts eastward.
The positive vorticity advection (PVA) stemming from this feature
along with a brief localized plume of enhanced precipitable water
(PW) values visible on recent NAM guidance should allow for the
development of showers and thunderstorms across the western half
of the CWA. While the vorticity maximum may linger offshore,
reduced PWs otherwise will remain in place through Friday morning
and PoPs remain generally low as a result. By Saturday, enhanced
moisture transport returns as the upper-level ridge shifts
eastward. With onshore flow picking up and PWs potentially in the
2+ inch range, precipitation coverage should increase over the
weekend, with the development of stronger storms possible. The
upper-level ridge looks to build back in from the east late in the
weekend, and typical diurnally driven shower and thunderstorm
activity is to be expected.

With the beginning of autumn yesterday, our minds of course have
started to wonder about the potential for the first cold frontal
passage of the season. Global models are hinting at this possibility
for the end of next week or beginning of next weekend...but if 240-
hour model forecasts have taught us anything, it`s that now is not
the time to get your hopes up just yet.

Cady

&&

.MARINE...
Light to moderate onshore flow remains over the upper Texas Gulf
waters and across both Matagorda and Galveston Bay this morning.
Should be mostly quiet through a majority of the week, with only
a chance for showers across the Gulf waters each morning. The
chance for precipitation increases Friday as better moisture is
advected across the region. Therefore expect more widespread
coverage of showers and thunderstorms late Friday through the
weekend. Onshore flow will also increase in speed during this time
frame as the pressure gradient tightens. Winds out of the S to SE
should reach SCEC criteria by late Friday and into the early part
of next week. Seas will also build to 4 to 6 feet across the Gulf
waters during this time frame.

Hathaway

&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL) 94 71 94 71 93 / 20 0 10 0 10
Houston (IAH) 91 72 90 72 90 / 10 0 10 0 10
Galveston (GLS) 92 79 88 79 88 / 10 10 10 0 20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...None.
GM...None.

&&

$$

AVIATION...08

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