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Re: Tracking the Tropics: Hermine & 92L

Posted: Fri Sep 02, 2016 2:56 pm
by srainhoutx
18Z best track analysis suggests a 1009mb low near 12N 46W moving quickly West associated with there rather sharp trough axis. It does appear as the sun begins to set across the Central Atlantic that moisture is being drawn up toward the broad area of low pressure from the ITCZ and scattered convection has held together throughout the day. Not expecting any development before it slows down somewhere in the Caribbean Sea early to mid next week.

Image

Re: Tracking the Tropics: Hermine & 92L

Posted: Sat Sep 03, 2016 8:13 am
by srainhoutx
The 12Z track and intensity guidance advertises 92L should continue heading generally West to WNW arriving across the Lesser Antilles tomorrow into Monday with squally weather and perhaps some gusty winds. 92L is surrounded by very dry and stable Saharan Air and until it slows down and enters the Caribbean Sea where some slightly better moisture is available, not expecting much if any development until the disturbance nears the Western Caribbean later next week.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sat Sep 03, 2016 6:50 pm
by Skyguy
Image

Deep South Texas is in deep trouble if this verifies.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sat Sep 03, 2016 7:44 pm
by srainhoutx
The 2Z ensembles suggest development of 92L will be slow. While the various computer models schemes may be interesting to the enthusiast, let's wait and see what develops over the next 3 to 5 days... ;)

Re: Tracking the Tropics: Hermine & 92L

Posted: Sat Sep 03, 2016 8:16 pm
by Skyguy
srainhoutx wrote:The 2Z ensembles suggest development of 92L will be slow. While the various computer models schemes may be interesting to the enthusiast, let's wait and see what develops over the next 3 to 5 days... ;)
Well, at least it's not aiming anything at SE Texas right now. Or is it?

Re: Tracking the Tropics: Hermine & 92L

Posted: Sat Sep 03, 2016 8:44 pm
by Skyguy
A closer look

Image

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 8:44 am
by jasons2k
I have to agree with some other posters...all the phantom storms produced by the CMC at 200+ hours out really aren't worthy of discussion. It will show this every day, every year from August - September. It's just garbage.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 8:57 am
by cperk
jasons wrote:I have to agree with some other posters...all the phantom storms produced by the CMC at 200+ hours out really aren't worthy of discussion. It will show this every day, every year from August - September. It's just garbage.
Agreed,but a broken clock is right twice a day,for now 92L simply bears watching. :)

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 9:18 am
by srainhoutx
Looking at the morning Updated Day 8+ Super Ensemble schemes as well as the MJO and CCKW atmospheric indicators, if the energy associated with 92L does indeed slow down and survive the trek across the Central Caribbean 'Graveyard' to the NW Caribbean as the 06Z GFS suggests, we may need to monitor the disturbance a bit closer.

Image

The ensemble guidance is suggesting a weakness over Texas/Louisiana next weekend and lower pressures across the Western Gulf. I see there is some potential for a stalling frontal boundary across portions of the Southern Plains and a surge of deep tropical moisture associated with the energy that is 92L moving out of the NW Caribbean Sea into the Yucatan Peninsula and Southern/SW Gulf. Until we actually see if TC Genesis occurs, it is always best to look toward the Ensemble trends versus individual model runs. We clearly learned that with Hermine and that should serve as a very recent reminder that until something actually forms...if it ever does, the models will swing wildly with every run. Remember that once Hermine actually formed, the models actually 'keyed' in on reasonable solutions.

I see RECON may fly tomorrow afternoon S of Hispaniola to investigate this disturbance, if necessary. We will monitor the day to day developments since we are in Peak Season and past experience tells us that any topical mischief in the Western Atlantic Basin during early to mid September has the potential to organize, if conditions are 'just right'. We also have climatology to back the increased interest and for those reasons alone, we watch and wait.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 1:27 pm
by Ptarmigan
Skyguy wrote:A closer look

Image
Interesting to note the central pressure is 965 millibars with 73 mph winds. It is a fairly large storm.

This is from Canadian, so it should be taken with a grain of salt.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 3:14 pm
by srainhoutx
The afternoon 12Z GFS and ECMWF solutions suggest 92L will slow down near the Yucatan Peninsula and begin to organize in the Western/NW Gulf early next week. While it is too soon to know with any certainty exactly what our sensible weather will be beyond 3 to 5 days, the trends are suggesting a potential Tropical troublemaker in our backyard.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 3:38 pm
by cperk
srainhoutx wrote:The afternoon 12Z GFS and ECMWF solutions suggest 92L will slow down near the Yucatan Peninsula and begin to organize in the Western/NW Gulf early next week. While it is too soon to know with any certainty exactly what our sensible weather will be beyond 3 to 5 days, the trends are suggesting a potential Tropical troublemaker in our backyard.
srainhoutx the so called crazy Canadian is getting some support from two of the more reliable models.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 4:22 pm
by srainhoutx
The afternoon updated Weather Prediction Center Day 3 to 7 surface charts suggest a trough of low pressure nearing the Texas Coast on Day 7.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 4:33 pm
by sambucol
What does that trough of low pressure mean for us?

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 6:57 pm
by srainhoutx
two_atl_5d0 (11).png
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT SUN SEP 4 2016

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

The National Hurricane Center is issuing advisories on Post-Tropical
Cyclone Hermine, located off of the mid-Atlantic coast of the United
States.

1. A broad area of low pressure associated with a tropical wave is
moving across the Lesser Antilles and continues to produce a large
area of disorganized showers and thunderstorms. Significant
development of this system appears unlikely while it moves westward
at 15 to 20 mph across the Caribbean Sea during the next several
days. This disturbance will continue to produce locally heavy
rainfall and gusty winds over portions of the Lesser Antilles
through Monday morning, and should spread over Puerto Rico and
Hispaniola during the next couple of days.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...low...30 percent

Forecaster Brown

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 7:17 pm
by worrybug
sambucol wrote:What does that trough of low pressure mean for us?
maybe something like this:

Image


I'm getting nervous, guys. If 92L does the same thing to Texas that Hermine did to Florida.........

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 7:21 pm
by Skyguy
srainhoutx wrote:The afternoon 12Z GFS and ECMWF solutions suggest 92L will slow down near the Yucatan Peninsula and begin to organize in the Western/NW Gulf early next week. While it is too soon to know with any certainty exactly what our sensible weather will be beyond 3 to 5 days, the trends are suggesting a potential Tropical troublemaker in our backyard.

Maybe this might be our saving grace, Srainhoutex. HGX says:
In the far extended the ECMWF does bring a cold front into the
area for Saturday while the GFS stalls this front north of the
area. Both models bring a stronger front into the area the
following Tuesday at 228hrs. Upper level pattern seems supportive
of a front with a trough pushing across the Great Lakes.

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 7:27 pm
by Skyguy
Image


IMHO:

92L continues somewhat quickly to the west, and based on forecast steering, I would expect this motion to continue during the next 96 hours, with maybe a slight dip just south of west briefly. Based on this, if the forecast steering pattern remains unchanged, INVEST 92L (or whatever becomes of it) may cross the Yucatan Peninsula around Belize, or north of Belize, but still over the Yucatan Peninsula. Steering beyond that time is up in the air, but models may suggest after day 5 (120 hours), the slim probability of this entering the extreme S. GOMEX. Now I'm not going to put much credence in this right now, not until the system becomes better organized, so the models have a better defined LLC to initialize. Based on the 18Z dynamic guidance, I think I'll sick to the TVCN/TVCC consensus track. (It's in blue, BTW)

Re: Tracking the Tropics: Hermine & 92L

Posted: Sun Sep 04, 2016 7:59 pm
by worrybug
srainhoutx wrote:The afternoon 12Z GFS and ECMWF solutions suggest 92L will slow down near the Yucatan Peninsula and begin to organize in the Western/NW Gulf early next week. While it is too soon to know with any certainty exactly what our sensible weather will be beyond 3 to 5 days, the trends are suggesting a potential Tropical troublemaker in our backyard.

When it rains it pours, srainhoutex:

Area Forecast Discussion
National Weather Service Lake Charles LA
738 PM CDT SUN SEP 4 2016

.DISCUSSION...
Afternoon showers and thunderstorms continues into this evening later
than previously expected. With abundance of Gulf moisture and the
weak boundary moving north, can expect scattered coverage for the
next couple of hours, slowly diminishing inland. However, keeping
chance of showers and thunderstorms for coastal waters and coastal
parishes/counties this evening and overnight, as additional
convection is expected across the northern Gulf.

DML

&&

.PREV DISCUSSION... /issued 625 PM CDT SUN SEP 4 2016/

DISCUSSION...
For the 09/05/16 0000 UTC TAF package.

AVIATION...
Thunderstorm activity is continuing to diminish this afternoon
and will have VCTS near LFT and ARA until 02Z. Conditions should
be VFR through early Monday morning. Expect showers and
thunderstorms to increase throughout the day with most of the
activity during the mid afternoon. Will carry TEMPO TSRA over most
TAF sites by early afternoon. At AEX...will begin TEMPO TSRA
around mid afternoon.

PREV DISCUSSION... /issued 306 PM CDT SUN SEP 4 2016/

DISCUSSION...
A more active weather pattern is set up for the next few days,
thanks to an active mid to upper level shortwave pattern rotating
around the ridge of high pressure to our east. Most thunderstorm
activity will start in the early morning hours in the coastal
waters, transitioning to over land after sunrise, and moving north
of the I-10 corridor by midday.

A drier period is expected by Thursday, but then there is a trend next
weekend for above normal rain chances, thanks to a tropical wave
that is currently approaching the eastern Caribbean, expected to
be in the southern Gulf of Mexico next weekend. While we are not
expecting significant development from this system, per NHC, it
could cause a wetter period again next weekend.


It's certainly got Louisiana's attention, all right. :cry:

Re: Tracking the Tropics: Hermine & 92L

Posted: Mon Sep 05, 2016 12:13 am
by Skyguy
Image

00Z has this feature by the 12th, but loses it by the 13th.