ATL: CINDY - Post-Tropical - Discussion

Moderator: S2k Moderators

Message
Author
RL3AO
Moderator-Pro Met
Moderator-Pro Met
Posts: 16308
Joined: Thu Jun 14, 2007 10:03 pm
Location: NC

Re: ATL: INVEST 93L - Discussion (Advisories at 5 PM on Potential Cyclone Three

#601 Postby RL3AO » Mon Jun 19, 2017 3:40 pm

Here's confirmation that the birdie was right.
 https://twitter.com/NHC_Atlantic/status/876901920270667776


1 likes   

User avatar
tarheelprogrammer
S2K Supporter
S2K Supporter
Posts: 1793
Joined: Mon Mar 28, 2016 9:25 pm
Location: Raleigh, NC area (Garner, NC)

Re: ATL: INVEST 93L - Models

#602 Postby tarheelprogrammer » Mon Jun 19, 2017 3:40 pm

Steve wrote:I don't know. TV Weathermen seem to like it more.

NAM almost inland at 54 hours at the TX/LA Border and deepening into the 970's. I'm not seeing that at this point, but I wanted to get it in for reference.

Image


If shear dropped off that is possible. NAM is not as irrelevant as it used to be.
0 likes   
My posts are not official forecasts. They are just my opinion and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

RL3AO
Moderator-Pro Met
Moderator-Pro Met
Posts: 16308
Joined: Thu Jun 14, 2007 10:03 pm
Location: NC

Re: ATL: INVEST 93L - Discussion (Advisories at 5 PM on Potential Cyclone Three)

#603 Postby RL3AO » Mon Jun 19, 2017 3:42 pm

Here's the entire day from GOES-16 with about a 1/3rd of the frames skipped to keep the gif a decent size.
Image
3 likes   

User avatar
Steve
S2K Supporter
S2K Supporter
Posts: 9621
Joined: Sat Apr 05, 2003 11:41 pm
Location: Not a state-caster

Re: ATL: INVEST 93L - Models

#604 Postby Steve » Mon Jun 19, 2017 3:44 pm

Agreed, but I can't trust it yet. Sometimes it has a clue, sometimes it's clueless. Intensity would be a bigger guess for it than track. The Track looks okay except maybe a little faster and more north than I was thinking. It's well within the realm of potential though. Looks ugly for points east of that landfall. Looks like while it's headed for the TX/LA Border, it makes a last jump NW and goes in just north of Galveston Bay at 979mb around 60 hours.
1 likes   

User avatar
Steve
S2K Supporter
S2K Supporter
Posts: 9621
Joined: Sat Apr 05, 2003 11:41 pm
Location: Not a state-caster

Re: ATL: THREE- Potential Tropical Cyclone

#605 Postby Steve » Mon Jun 19, 2017 3:47 pm

TS Warning for parts of the LA Coast. That's as far as I've gotten in the advisory (roughly the entire coast)

Potential Tropical Cyclone Three Discussion Number 1
NWS National Hurricane Center Miami FL AL032017
400 PM CDT Mon Jun 19 2017

A pair of ASCAT passes between 15 and 16Z showed that the
disturbance over the Gulf of Mexico has an area of tropical-storm-
force winds within a large area of deep convection 100 to 150 n mi
northeast of a broad low center. The ASCAT data and visible
satellite imagery show that the center is not well defined, and in
fact multiple low-level swirls are evident in the latest imagery. An
Air Force Reserve Hurricane Hunter aircraft is currently
investigating the system and will provide more data on its wind
structure.

The NWS now has the option to issue advisories, watches, and
warnings for disturbances that are not yet a tropical cyclone, but
which pose the threat of bringing tropical storm or hurricane
conditions to land areas within 48 hours. Under previous policy
this was not possible. These systems are known as Potential
Tropical Cyclones in advisory products and are numbered from the
same list as depressions. Because of the threat to the central
Gulf coast, advisories have been initiated on Potential Tropical
Cyclone Three and the appropriate watches/warnings have been issued.
Users should be aware that forecast uncertainty for disturbances is
generally larger than for tropical cyclones, especially beyond 48-72
hours.

The initial intensity is set to 35 kt based on the ASCAT data. The
initial pressure is set to 1002 mb based on extrapolated data from
the aircraft. Only modest strengthening is expected given the
moderate to strong southwesterly shear of around 30 kt expected to
persist over the system during the next couple of days. The NHC
intensity forecast is close to the latest intensity consensus aid.

Given the broad nature of the low, the initial motion estimate is a
rather uncertain 350/08. During the first 12 to 24 hours the system
will move northward to north-northwestward due to the a weakness in
the subtropical ridge over the northern Gulf and then the system
should slow and turn more northwestward as it interacts with an
upper-level low currently situated off the Texas coast. The details
of this interaction will have significant implications on the track
of the system, and there remains a fair amount of model spread. The
HWRF is on the right side of the guidance envelope, with a track
toward southeastern Louisiana while the UKMET and ECMWF show a
solution toward southwest Louisiana or extreme eastern Texas. For
now, the NHC forecast lies in the middle of the guidance envelope
and a little left of the TCVA consensus aid. Given the disorganized
nature of the circulation and the fact that the wind and rain
hazards extend well north and east of the center, users are
encouraged to not focus on the details of the track forecast.

The primary hazard from this disturbance is expected to be heavy
rainfall over portions of the central and eastern Gulf Coast.

FORECAST POSITIONS AND MAX WINDS

INIT 19/2100Z 24.7N 88.7W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 20/0600Z 26.0N 89.5W 35 KT 40 MPH
24H 20/1800Z 27.2N 90.6W 40 KT 45 MPH...TROPICAL CYCLONE
36H 21/0600Z 27.9N 91.4W 40 KT 45 MPH
48H 21/1800Z 28.7N 92.3W 40 KT 45 MPH
72H 22/1800Z 32.0N 93.5W 30 KT 35 MPH...INLAND
96H 23/1800Z 35.5N 90.5W 25 KT 30 MPH...POST-TROP/INLAND
Last edited by Steve on Mon Jun 19, 2017 3:49 pm, edited 1 time in total.
0 likes   

User avatar
PTrackerLA
Category 5
Category 5
Posts: 5277
Age: 41
Joined: Thu Oct 10, 2002 8:40 pm
Location: Lafayette, LA

Re: ATL: THREE- Potential Tropical Cyclone

#606 Postby PTrackerLA » Mon Jun 19, 2017 3:47 pm

Here we go...so Watches and Warnings will go up shortly I'd imagine...?
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145328
Age: 68
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: ATL: THREE- Potential Tropical Cyclone

#607 Postby cycloneye » Mon Jun 19, 2017 3:48 pm

PTrackerLA wrote:Here we go...so Watches and Warnings will go up shortly I'd imagine...?


That is correct.
0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

RL3AO
Moderator-Pro Met
Moderator-Pro Met
Posts: 16308
Joined: Thu Jun 14, 2007 10:03 pm
Location: NC

Re: ATL: THREE- Potential Tropical Cyclone

#608 Postby RL3AO » Mon Jun 19, 2017 3:49 pm

PTrackerLA wrote:Here we go...so Watches and Warnings will go up shortly I'd imagine...?


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

A Tropical Storm Warning is in effect from Intracoastal City,
Louisiana, to the Mouth of the Pearl River.

A Tropical Storm Watch is in effect from west of Intracoastal City
to High Island, Texas.
0 likes   

CrazyC83
Professional-Met
Professional-Met
Posts: 34002
Joined: Tue Mar 07, 2006 11:57 pm
Location: Deep South, for the first time!

Re: ATL: THREE - Recon

#609 Postby CrazyC83 » Mon Jun 19, 2017 3:49 pm

URNT15 KNHC 192048
AF305 01AAA INVEST HDOB 11 20170619
195400 2426N 08917W 9758 00244 0032 +239 +232 002023 024 026 000 00
195430 2426N 08915W 9771 00224 0024 +240 +233 004022 023 025 000 00
195500 2425N 08913W 9768 00225 0023 +240 +235 001020 021 024 000 00
195530 2425N 08911W 9768 00225 0023 +240 +234 001019 020 021 000 00
195600 2425N 08909W 9770 00224 0023 +239 +233 000017 019 021 000 00
195630 2425N 08907W 9770 00224 0023 +239 +234 359015 016 022 000 00
195700 2425N 08906W 9769 00224 0022 +240 +233 002013 014 021 000 00
195730 2425N 08904W 9771 00223 0021 +240 +233 005011 013 020 000 00
195800 2425N 08902W 9772 00222 0021 +240 +234 010009 010 019 000 00
195830 2425N 08900W 9770 00223 0021 +240 +234 019008 008 018 000 00
195900 2425N 08858W 9772 00220 0021 +239 +232 012006 008 018 001 00
195930 2425N 08856W 9770 00222 0020 +236 +230 005005 006 017 000 00
200000 2425N 08854W 9770 00223 0021 +235 +233 001003 004 016 000 01
200030 2425N 08853W 9788 00203 //// +235 //// 061002 002 017 000 01
200100 2425N 08851W 9770 00222 //// +235 //// 156005 008 018 000 01
200130 2425N 08849W 9834 00161 //// +231 //// 158010 011 020 002 01
200200 2425N 08847W 9826 00164 //// +228 //// 175013 015 020 002 01
200230 2425N 08846W 9830 00158 //// +231 //// 187013 015 021 002 05
200300 2425N 08844W 9832 00157 //// +235 //// 186011 012 017 001 05
200330 2425N 08842W 9829 00158 0008 +241 +238 182011 011 017 000 01
$$
;

Delayed data coming in.
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145328
Age: 68
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: ATL: THREE- Potential Tropical Cyclone

#610 Postby cycloneye » Mon Jun 19, 2017 3:50 pm


Potential Tropical Cyclone Three Discussion Number 1
NWS National Hurricane Center Miami FL AL032017
400 PM CDT Mon Jun 19 2017

A pair of ASCAT passes between 15 and 16Z showed that the
disturbance over the Gulf of Mexico has an area of tropical-storm-
force winds within a large area of deep convection 100 to 150 n mi
northeast of a broad low center. The ASCAT data and visible
satellite imagery show that the center is not well defined, and in
fact multiple low-level swirls are evident in the latest imagery. An
Air Force Reserve Hurricane Hunter aircraft is currently
investigating the system and will provide more data on its wind
structure.

The NWS now has the option to issue advisories, watches, and
warnings for disturbances that are not yet a tropical cyclone, but
which pose the threat of bringing tropical storm or hurricane
conditions to land areas within 48 hours. Under previous policy
this was not possible. These systems are known as Potential
Tropical Cyclones in advisory products and are numbered from the
same list as depressions. Because of the threat to the central
Gulf coast, advisories have been initiated on Potential Tropical
Cyclone Three and the appropriate watches/warnings have been issued.
Users should be aware that forecast uncertainty for disturbances is
generally larger than for tropical cyclones, especially beyond 48-72
hours.

The initial intensity is set to 35 kt based on the ASCAT data. The
initial pressure is set to 1002 mb based on extrapolated data from
the aircraft. Only modest strengthening is expected given the
moderate to strong southwesterly shear of around 30 kt expected to
persist over the system during the next couple of days. The NHC
intensity forecast is close to the latest intensity consensus aid.

Given the broad nature of the low, the initial motion estimate is a
rather uncertain 350/08. During the first 12 to 24 hours the system
will move northward to north-northwestward due to the a weakness in
the subtropical ridge over the northern Gulf and then the system
should slow and turn more northwestward as it interacts with an
upper-level low currently situated off the Texas coast. The details
of this interaction will have significant implications on the track
of the system, and there remains a fair amount of model spread. The
HWRF is on the right side of the guidance envelope, with a track
toward southeastern Louisiana while the UKMET and ECMWF show a
solution toward southwest Louisiana or extreme eastern Texas. For
now, the NHC forecast lies in the middle of the guidance envelope
and a little left of the TCVA consensus aid. Given the disorganized
nature of the circulation and the fact that the wind and rain
hazards extend well north and east of the center, users are
encouraged to not focus on the details of the track forecast.

The primary hazard from this disturbance is expected to be heavy
rainfall over portions of the central and eastern Gulf Coast.

FORECAST POSITIONS AND MAX WINDS

INIT 19/2100Z 24.7N 88.7W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 20/0600Z 26.0N 89.5W 35 KT 40 MPH
24H 20/1800Z 27.2N 90.6W 40 KT 45 MPH...TROPICAL CYCLONE
36H 21/0600Z 27.9N 91.4W 40 KT 45 MPH
48H 21/1800Z 28.7N 92.3W 40 KT 45 MPH
72H 22/1800Z 32.0N 93.5W 30 KT 35 MPH...INLAND
96H 23/1800Z 35.5N 90.5W 25 KT 30 MPH...POST-TROP/INLAND
120H 24/1800Z...DISSIPATED

$$
Forecaster Brennan
0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
Sambucol
Tropical Storm
Tropical Storm
Posts: 223
Joined: Wed Jul 25, 2007 5:09 pm

Re: ATL: INVEST 93L - Models

#611 Postby Sambucol » Mon Jun 19, 2017 3:50 pm

Steve wrote:Agreed, but I can't trust it yet. Sometimes it has a clue, sometimes it's clueless. Intensity would be a bigger guess for it than track. The Track looks okay except maybe a little faster and more north than I was thinking. It's well within the realm of potential though. Looks ugly for points east of that landfall. Looks like while it's headed for the TX/LA Border, it makes a last jump NW and goes in just north of Galveston Bay at 979mb around 60 hours.

At 979mb, what would the winds be?
1 likes   

User avatar
fci
S2K Supporter
S2K Supporter
Posts: 3324
Joined: Tue Sep 14, 2004 10:29 am
Location: Lake Worth, FL

Re: ATL: INVEST 93L - Discussion

#612 Postby fci » Mon Jun 19, 2017 3:52 pm

Airboy wrote:Sorry if it's a bit off topic, but is this " PTC" (Potential Tropical Cyclone) something new for this season? Never heard NHC useing that label before?


From the NHC:
The NWS now has the option to issue advisories, watches, and warnings for disturbances that are not yet a tropical cyclone, but which pose the threat of bringing tropical storm or hurricane conditions to land areas within 48 hours. Under previous policy this was not possible. These systems are known as Potential Tropical Cyclones in advisory products and are numbered from the same list as depressions. Because of the threat to the central Gulf coast, advisories have been initiated on Potential Tropical Cyclone Three and the appropriate watches/warnings have been issued.
Users should be aware that forecast uncertainty for disturbances is generally larger than for tropical cyclones, especially beyond 48-72 hours.
0 likes   
Personal Forecast Disclaimer:
My posts are just my opinion and are most likely not backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
Bottom line is that I am just expressing my opinion!!!

RL3AO
Moderator-Pro Met
Moderator-Pro Met
Posts: 16308
Joined: Thu Jun 14, 2007 10:03 pm
Location: NC

Re: ATL: THREE- Potential Tropical Cyclone

#613 Postby RL3AO » Mon Jun 19, 2017 3:53 pm

We also get to see these new products in action.
Image
Image
1 likes   

User avatar
HurricaneBrain
S2K Supporter
S2K Supporter
Posts: 520
Joined: Thu Jun 30, 2011 2:07 pm

Re: ATL: INVEST 93L - Models

#614 Postby HurricaneBrain » Mon Jun 19, 2017 3:54 pm

96 mph Category 2
Sambucol wrote:
Steve wrote:Agreed, but I can't trust it yet. Sometimes it has a clue, sometimes it's clueless. Intensity would be a bigger guess for it than track. The Track looks okay except maybe a little faster and more north than I was thinking. It's well within the realm of potential though. Looks ugly for points east of that landfall. Looks like while it's headed for the TX/LA Border, it makes a last jump NW and goes in just north of Galveston Bay at 979mb around 60 hours.

At 979mb, what would the winds be?
1 likes   

User avatar
Sambucol
Tropical Storm
Tropical Storm
Posts: 223
Joined: Wed Jul 25, 2007 5:09 pm

Re: ATL: INVEST 93L - Models

#615 Postby Sambucol » Mon Jun 19, 2017 3:55 pm

HurricaneBrain wrote:96 mph Category 2
Sambucol wrote:
Steve wrote:Agreed, but I can't trust it yet. Sometimes it has a clue, sometimes it's clueless. Intensity would be a bigger guess for it than track. The Track looks okay except maybe a little faster and more north than I was thinking. It's well within the realm of potential though. Looks ugly for points east of that landfall. Looks like while it's headed for the TX/LA Border, it makes a last jump NW and goes in just north of Galveston Bay at 979mb around 60 hours.


Thank you. Those are some high winds to deal with.
At 979mb, what would the winds be?
0 likes   

User avatar
Tireman4
S2K Supporter
S2K Supporter
Posts: 5853
Age: 59
Joined: Fri Jun 30, 2006 1:08 pm
Location: Humble, Texas
Contact:

Re: ATL: THREE- Potential Tropical Cyclone

#616 Postby Tireman4 » Mon Jun 19, 2017 3:56 pm

From HGX AFD

Afternoon AFD from HGX:

Area Forecast Discussion
National Weather Service Houston/Galveston TX
349 PM CDT Mon Jun 19 2017

.DISCUSSION...
Major question of the forecast is obviously Potential Tropical
Cyclone 3, located north of the Yucatan Peninsula, currently given
an 80 percent chance of development in the next couple of days by
NHC. At this time, think any developing storm will be heavily
sheared with most impacts to our east. However, any western
deviation in track would begin to slide impacts into our area - it's
a close call, so continue to monitor the forecast.


.SHORT TERM [Through Tonight]...

Through tomorrow, the typical summertime pattern should reign for
most of the area, though by Tuesday afternoon falling heights aloft
should help allow for increased convection over the Gulf waters and
potentially the immediate coast. In the meantime, very isolated
activity along the seabreeze is possible into the evening hours
before the loss of sun wanes activity.


.MEDIUM TERM [Tuesday Through Wednesday Night]...

The most impactful portion of the forecast is also the most
uncertain. Fortunately, the guidance envelope has shrunk today.
Still, the west outliers come ashore around Galveston Bay, so we are
not totally out of the woods yet. If we were to assume a west
outlier landfall, the storm should still be heavily sheared to the
east, keeping much of the impacts east of the Houston metro.

The forecast is based off of a very reasonable track presented
through collaboration with NHC and WPC, which occurs even more to
the east of our area. Some borderline likely PoPs crop up late
Wednesday along our eastern border, but the vast majority of the
area will see a chance of rain or drier. Similarly, it may be a bit
breezy our of the northeast on the west side of the cyclone, but
nothing excessive - it may be not even be quite at a level that
would necessitate a wind advisory.

Now, with all that said, we still lack a true center, which makes
model guidance considerable more unreliable that usual, as specific
models may or may not accurately determine where the eventual center
will take hold. If you've been watching the satellite (especially G-
16) today, you've seen multiple little whorls near or ejected from
the convective mass over the Gulf. None so far have taken as a more
dominant center of circulation. Once a more dominant center emerges,
guidance should become more reliable. Until - and even after - then,
continue to monitor the forecasts, and still stand ready to take
necessary precautions in case of a move to the west, as rainfall of
6 to 8 inches or more will be possible in such an instance.


.LONG TERM [Thursday Through Monday]...

Now, regardless of guidance, this potential TC looks to accelerate
northeast of the area Friday, leaving us with a return to a more
typical June atmosphere. The big change from the past several days,
however, is that the southwestern US ridge will be weaker, and
though the Atlantic subtropical ridge will be working to build
westward, it will largely set up deep onshore flow, which should
boost precipitation potential. So, rather than the very dry weather
we've seen lately, scattered showers and storms should again return
to be more the rule. The retreat of the southwestern US ridge should
also result in slightly cooler temperatures, with highs closer to 90
degrees than the middle 90s.
0 likes   

User avatar
galaxy401
Category 5
Category 5
Posts: 2419
Age: 30
Joined: Sat Aug 25, 2012 9:04 pm
Location: Casa Grande, Arizona

Re: ATL: THREE- Potential Tropical Cyclone

#617 Postby galaxy401 » Mon Jun 19, 2017 4:01 pm

With that large system and multiple small centers, this is reminding me of Arlene from 2005.
0 likes   
Got my eyes on moving right into Hurricane Alley: Florida.

Aric Dunn
Category 5
Category 5
Posts: 21238
Age: 42
Joined: Sun Sep 19, 2004 9:58 pm
Location: Ready for the Chase.
Contact:

Re: ATL: THREE- Potential Tropical Cyclone

#618 Postby Aric Dunn » Mon Jun 19, 2017 4:06 pm

lol there is a natural "L" on the middle of the circ with some clouds


Image
1 likes   
Note: If I make a post that is brief. Please refer back to previous posts for the analysis or reasoning. I do not re-write/qoute what my initial post said each time.
If there is nothing before... then just ask :)

Space & Atmospheric Physicist, Embry-Riddle Aeronautical University,
I believe the sky is falling...

User avatar
HurricaneBrain
S2K Supporter
S2K Supporter
Posts: 520
Joined: Thu Jun 30, 2011 2:07 pm

Re: ATL: INVEST 93L - Models

#619 Postby HurricaneBrain » Mon Jun 19, 2017 4:08 pm

Will probably top out at only 50 mph.
Sambucol wrote:
HurricaneBrain wrote:96 mph Category 2
Sambucol wrote:
Thank you. Those are some high winds to deal with.
At 979mb, what would the winds be?
1 likes   

RL3AO
Moderator-Pro Met
Moderator-Pro Met
Posts: 16308
Joined: Thu Jun 14, 2007 10:03 pm
Location: NC

Re: ATL: THREE- Potential Tropical Cyclone

#620 Postby RL3AO » Mon Jun 19, 2017 4:11 pm

Image

I marked the center of circulation on the first frame. I found it interesting that the cirrus is starting to expand westward. Now, can some new convection develop near/over the center soon?
2 likes   


Return to “2017”

Who is online

Users browsing this forum: No registered users and 7 guests