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General Weather/Earth Sciences Topics => Tropical Weather => Topic started by: ocala on July 07, 2019, 12:04:01 PM

Title: Possible tropical development NE GOM
Post by: ocala on July 07, 2019, 12:04:01 PM
Currently a low over northern Mississippi is forecasted to move SE to the GOM.
Conditions are favorable for development but not until later in the week.
TPC has it at 40%. Very strange genesis if it does develop. 
Stay tuned.
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 08, 2019, 12:19:11 PM
Currently a low over northern Mississippi is forecasted to move SE to the GOM.

 Very strange genesis if it does develop. 

Indeed.  They don't normally start inland, let alone that far.  It was a bugger too with lots of wind and inland rotation.  At one point our storms were moving from NE to SW, then almost due N to S.

Last I looked the 5 day forecast was up to 70%.

Title: Re: Possible tropical development NE GOM
Post by: Jstx on July 08, 2019, 03:24:54 PM
Currently a low over northern Mississippi is forecasted to move SE to the GOM.
Conditions are favorable for development but not until later in the week.
TPC has it at 40%. Very strange genesis if it does develop. 
Stay tuned.

First heard of this potential cyclone a few days ago when it was over the Kentucky-Tennessee border.
"Very strange genesis" indeed. Can't remember ever hearing of a forecast like this one before, either the HPC models have really improved or this one is really weird.
Although this genesis pattern is like many North Atlantic systems which begin developing over continental West Africa, and then move offshore into the East Atlantic, where they intensify into a tropical system and generally move westward towards the Caribbean and North or Central America.
We're just not used to seeing one start in the Appalachia-MidSouth region and move south into the Gulf of Mexico to intensify.
I guess 'Climate Change' may be bringing us a lot of stranger stuff. Like scenes from our South Central Texas "Flash Flood Alley" taking place in the DC-MidAtlantic states area recently.
https://www.bing.com/search?q=Flash+flood+Alley&form=OPRTSD&pc=OPER

Been a weathernut to one degree or another for many decades, with a particular interest in tropical WX due to living on or near the southern Texas coast [and as a mariner and sailor], don't remember ever seeing anything like this one before.
Haven't even fully recovered from Harvey yet, dangit, and now some of the spaghetti has this possible TD/TS heading here around the weekend. Maybe nickname it the 'KenTenn Terror'?

Plus there are now six tropical waves in the Atlantic-Carib, and a "disturbance" near the Yucatan, which is actually closer than the KenTenn one.
Title: Re: Possible tropical development NE GOM
Post by: Jstx on July 08, 2019, 03:30:25 PM
Currently a low over northern Mississippi is forecasted to move SE to the GOM.

 Very strange genesis if it does develop. 

Indeed.  They don't normally start inland, let alone that far.  It was a bugger too with lots of wind and inland rotation.  At one point our storms were moving from NE to SW, then almost due N to S.

Last I looked the 5 day forecast was up to 70%.

2 day is 30%, 5 day now at 80% chance of formation; as of the HPC map today @1327 EDT.
Title: Re: Possible tropical development NE GOM
Post by: CW2274 on July 08, 2019, 03:37:04 PM
Currently a low over northern Mississippi is forecasted to move SE to the GOM.
Conditions are favorable for development but not until later in the week.
TPC has it at 40%. Very strange genesis if it does develop. 
Stay tuned.
Been a weathernut to one degree or another for many decades, with a particular interest in tropical WX due to living on or near the southern Texas coast [and as a mariner and sailor], don't remember ever seeing anything like this one before.
Same here. Obviously conditions are progged for this low to find a favorable environment in the Gulf to take on tropical characteristics, then it just as well have crossed the Atlantic.
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 08, 2019, 03:52:51 PM
If you pick through the various AFDs posted by PAH around the 5th and 6th, you'll find tidbits like this:

"Issued at 1225 PM CDT Fri Jul 5 2019

MCV over Missouri will continue to move slowly ESE toward the area,
with a another circulation on 6.19 channel wvapor imagery moving
toward west TN
"

https://forecast.weather.gov/product.php?site=PAH&issuedby=PAH&product=AFD&format=CI&version=39&glossary=1

There are a few references to closed circulation also.

Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 08, 2019, 03:57:48 PM
This may be one of the earliest references:

"National Weather Service Paducah KY
615 AM CDT Fri Jul 5 2019

.SHORT TERM...(Today through Sunday night)
Issued at 245 AM CDT Fri Jul 5 2019

Weak mid-level ridging overnight has kept most of the overnight
convection at bay, ahead of closed mid-level circulation that has
been parked over the northwest quarter of Missouri since late
Thursday. There is also an MCV over central Arkansas that is
moving slowly northeast toward southeast Missouri and will likely
phase (as depicted by the Canadian guidance) with the closed
circulation further north in Missouri later today.
"

https://forecast.weather.gov/product.php?site=PAH&issuedby=PAH&product=AFD&format=CI&version=41&glossary=1



Title: Re: Possible tropical development NE GOM
Post by: Jstx on July 08, 2019, 04:02:37 PM
Currently a low over northern Mississippi is forecasted to move SE to the GOM.
Conditions are favorable for development but not until later in the week.
TPC has it at 40%. Very strange genesis if it does develop. 
Stay tuned.
Been a weathernut to one degree or another for many decades, with a particular interest in tropical WX due to living on or near the southern Texas coast [and as a mariner and sailor], don't remember ever seeing anything like this one before.
Same here. Obviously conditions are progged for this low to find a favorable environment in the Gulf to take on tropical characteristics, then it just as well have crossed the Atlantic.

Yep, continents, oceans, TCs, parts is parts.
NHC is on it:

"ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Jul 8 2019

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

1. A trough of low pressure located over central Georgia is forecast
to move southward toward the northeastern Gulf of Mexico, where a
broad area of low pressure is expected to form on Wednesday.
Environmental and ocean conditions are forecast to be conducive for
development and a tropical depression is likely to form by the end
of the week while the low moves slowly westward over northern Gulf
of Mexico. Regardless of development, this system has the potential
to produce heavy rainfall along portions of the northern and eastern
U.S. Gulf Coast later this week.  For more information about the
rainfall threat, please see products issued by your local weather
forecast office and the NOAA Weather Prediction Center.  Interests
along the Gulf Coast from the Upper Texas coast to the western
Florida peninsula should monitor the progress of this system.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...high...80 percent.

Forecaster Stewart
"
"000
AXNT20 KNHC 081736
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
136 PM EDT Mon Jul 8 2019
...
GULF OF MEXICO...

A surface trough extends over the NE Gulf of Mexico from the
Florida Big Bend to 26N84W. Scattered showers and tstorms are seen
from 25N-29N, east of 85W. The remainder of the Gulf is under
weak surface ridging with gentle winds.

A broad area of low pressure is expected to form on Wednesday in
the northeastern Gulf of Mexico. A tropical depression is likely
to form by the end of the week while the low moves slowly westward
over the northern Gulf of Mexico. Winds to near gale force are
expected in the northern Gulf of Mexico later this week along
with squally weather and high seas, regardless of tropical cyclone
formation. If the system were to become a tropical storm, then
higher winds and seas would occur. Heavy rainfall is possible
along portions of the northern and eastern U.S. Gulf Coast later
this week. Interests along the Gulf Coast from the Upper Texas
coast to the western Florida peninsula should monitor the progress
of this system.
"
Title: Re: Possible tropical development NE GOM
Post by: Jstx on July 08, 2019, 04:48:44 PM
If you pick through the various AFDs posted by PAH around the 5th and 6th, you'll find tidbits like this:

"Issued at 1225 PM CDT Fri Jul 5 2019

MCV over Missouri will continue to move slowly ESE toward the area,
with a another circulation on 6.19 channel wvapor imagery moving
toward west TN
"

https://forecast.weather.gov/product.php?site=PAH&issuedby=PAH&product=AFD&format=CI&version=39&glossary=1

There are a few references to closed circulation also.

Here in S Cntl Texas/Coastal Bend, we've always gotten frequent year-round MCS's/MCC's * that tend to originate from N to W Texas, the Big Bend, and the Mexican mountains [esp. Sierra del Burro] N & NW of us. If these MCx's hold together I've seen them continue out into the GOM, and they will then sometimes intensify.
But never remember any transforming into a TC, although their SE trajectory usually then bends NE'ward and going ashore near Houston/E TX/LA, with them getting some rain and wind.

Now that I think of it, going to look up TS Allison[s, there were several], et al., which did major flood damage in the Houston area. Allison formed quickly, close to shore, wondering if such an MCS preceded it?
This one is 'different' for sure.

*  Some MCS/MCC/MCV's can be very severe locally, doing major damage here. And rarely, combining with other WX factors, causing major Central TX flash floods from the Hill Country to the coast [in 'Flash Flood Alley'].

 [Edit to show MCS/MCC's affecting locally with MCV's. Watch the dang teevee WX people and forget half you learned; most of them rarely call WX phenomena by their proper terms, particularly stuff like MCS/MCV's. You have to observe the sat&radar yourself.
https://en.wikipedia.org/wiki/Mesoscale_convective_complex
https://en.wikipedia.org/wiki/Mesoscale_convective_system
https://en.wikipedia.org/wiki/Mesovortices#Mesoscale_convective_vortex
https://en.wikipedia.org/wiki/Brown_ocean_effect

"An MCV that moves into tropical waters, such as the Gulf of Mexico, can serve as the nucleus for a tropical storm or hurricane. MCVs, like mesovortices, often cause an intensification of convective downburst winds and can lead to tornadogenesis.[7] One form of MCV is the "comma head" of a line echo wave pattern (LEWP)."  ]
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 08, 2019, 04:53:13 PM
Been picking up a few comments from Blake at NHC saying how odd this is, but it would be even more odd if it turns out there were able to forecast it based on where it formed.
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 08, 2019, 05:00:40 PM
Code: [Select]

06 20:53 SW 3 10.00 Light Rain FEW050 BKN100 74 70 88% NA NA 29.98 1015.0
06 19:53 W 3 10.00 Mostly Cloudy FEW085 BKN110 75 70 84% NA NA 29.96 1014.1 [b]1.20 [/b]
06 18:53 N 26 G 40 1.00 Thunderstorm Heavy Rain Fog/Mist and Windy FEW016 BKN033 OVC070 74 70 90 74 88% NA NA 29.98 1014.8 0.15 0.15

I watched radar as PAH got over an inch of rain out of this as a heavy band trained right over them the other day.

Title: Re: Possible tropical development NE GOM
Post by: galfert on July 08, 2019, 05:10:56 PM
Just so others can see what we are talking about.

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Looks interesting. And that gulf water is very warm!

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Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 08, 2019, 05:38:29 PM
And it might come back, completing the loop?

"Area Forecast Discussion
National Weather Service Paducah KY
216 PM CDT Mon Jul 8 2019

The models are in disagreement as to an
area of low pressure that develops in the Gulf of Mexico. The GFS
washes it out over southern TX with area returning to a typical
summertime pattern of hot and humid conditions with afternoon
chances of storms. The ECMWF really intensifies this area of low
pressure bringing it ashore further north on the TX coast and moving
it north into the Plains. The 12Z run of the ECMWF is slightly
further west of the 00z run.
"

Title: Re: Possible tropical development NE GOM
Post by: CW2274 on July 08, 2019, 05:52:13 PM
If you pick through the various AFDs posted by PAH around the 5th and 6th, you'll find tidbits like this:

"Issued at 1225 PM CDT Fri Jul 5 2019

MCV over Missouri will continue to move slowly ESE toward the area,
with a another circulation on 6.19 channel wvapor imagery moving
toward west TN
"

https://forecast.weather.gov/product.php?site=PAH&issuedby=PAH&product=AFD&format=CI&version=39&glossary=1

There are a few references to closed circulation also.
Watch the dang teevee WX people and forget half you learned; most of them rarely call WX phenomena by their proper terms, particularly stuff like MCS/MCV's. You have to observe the sat&radar yourself.
For those unaware, an MCV is almost always only visible on the visible satellite (daytime only) or via a radar signature.
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 08, 2019, 05:56:13 PM
For those unaware, an MCV is almost always only visible on the visible satellite (daytime only) or via a radar signature.

And with this, the rotation was pretty obvious.  If you can pull the radar data for that day, you'll see it.  I've seen better defined, but that wasn't the worst either.

 
Title: Re: Possible tropical development NE GOM
Post by: Vette-kid on July 09, 2019, 09:13:29 AM
Now Invest 92L.  We are watching this pretty close.  About all we know so far is that we are going to get wet.  Sadly, even after Michael there is a lot of apathy around here.
Title: Re: Possible tropical development NE GOM
Post by: towards2112 on July 09, 2019, 11:30:15 AM
Houston reporting in !!
Title: Re: Possible tropical development NE GOM
Post by: galfert on July 09, 2019, 09:53:16 PM
Looks like a lot of water for New Orleans.

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Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 10, 2019, 11:28:13 AM
TROPICAL CYCLONE EXPECTED TO FORM BY THURSDAY OVER THE NORTHERN GULF OF MEXICO... ...STORM SURGE AND TROPICAL STORM WATCHES ISSUED AND HEAVY RAINFALL EXPECTED...
10:00 AM CDT Wed Jul 10
Location: 28.5°N 86.4°W
Moving: WSW at 8 mph
Min pressure: 1011 mb
Max sustained: 30 mph


Title: Re: Possible tropical development NE GOM
Post by: galfert on July 10, 2019, 02:09:48 PM
This....

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...and many streets are already underwater.
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 10, 2019, 05:51:06 PM
Now they're pegging it to come in as a Hurricane just about where Humberto did a few years back.

Title: Re: Possible tropical development NE GOM
Post by: Jasiu on July 10, 2019, 06:43:27 PM
So odd to see tropical watches and warnings issued for something that isn't even named yet. (not questioning that it is the right thing to do...)
Title: Re: Possible tropical development NE GOM
Post by: galfert on July 10, 2019, 06:54:04 PM
Yep....looks like its going to turn into Barry.
Title: Re: Possible tropical development NE GOM
Post by: Vette-kid on July 10, 2019, 09:38:21 PM
Someone educate me, why are they calling this cyclone?  I thought cyclone was in the South Pacific??
Title: Re: Possible tropical development NE GOM
Post by: CW2274 on July 10, 2019, 10:05:49 PM
Someone educate me, why are they calling this cyclone?  I thought cyclone was in the South Pacific??
In the broad sense, it is a cyclone, just as any low pressure area is. I'm assuming in this particular usage, instead pinning it down to something more descriptive by saying 'depression, storm, or outright hurricane', cyclone was used as it's all encompassing, regardless of intensity. 
Title: Re: Possible tropical development NE GOM
Post by: Jasiu on July 10, 2019, 10:07:38 PM
https://en.wikipedia.org/wiki/Cyclone (https://en.wikipedia.org/wiki/Cyclone)
Title: Re: Possible tropical development NE GOM
Post by: galfert on July 10, 2019, 10:13:53 PM
The key here is to realize that cyclone and tropical cyclone are two different things.

Tropical cyclone or cyclone. What’s the difference?
A tropical cyclone is a generic term used by meteorologists to describe a rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has closed, low-level circulation. Once a tropical cyclone reaches maximum sustained winds of 74 miles per hour or higher, it is then classified as a hurricane, typhoon, or cyclone depending upon where the storm originates in the world.

Tropical cyclones rotate counterclockwise in the Northern Hemisphere.

They are classified as follows:

Tropical Depression: A tropical cyclone with maximum sustained winds of 38 mph (33 knots) or less.
Tropical Storm: A tropical cyclone with maximum sustained winds of 39 to 73 mph (34 to 63 knots).
Hurricane: A tropical cyclone with maximum sustained winds of 74 mph (64 knots) or higher. In the western North Pacific, hurricanes are called typhoons; similar storms in the Indian Ocean and South Pacific Ocean are called cyclones.
Major Hurricane: A tropical cyclone with maximum sustained winds of 111 mph (96 knots) or higher, corresponding to a Category 3, 4 or 5 on the Saffir-Simpson Hurricane Wind Scale.

Source:
https://africanreporter.co.za/84247/hurricane-cyclone-typhoon-tornado-whats-difference/
Title: Re: Possible tropical development NE GOM
Post by: Vette-kid on July 11, 2019, 02:31:57 AM
Thank you kindly [tup]
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 11, 2019, 02:13:58 PM
Tropical Storm Barry Advisory Number   5
NWS National Hurricane Center Miami FL       AL022019
1000 AM CDT Thu Jul 11 2019

...DISTURBANCE BECOMES TROPICAL STORM BARRY...
...DANGEROUS STORM SURGE, HEAVY RAINS, AND WIND CONDITIONS EXPECTED
ACROSS THE NORTH-CENTRAL GULF COAST...
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 11, 2019, 05:58:32 PM
Pardon the pun, but this is extremely depressing.  As noted above, I already had this storm last week, I don't need it again Tuesday.

(https://www.nhc.noaa.gov/storm_graphics/AT02/refresh/AL022019_5day_cone_no_line_and_wind+png/210142.png)

Speaking of which, does anybody have a link to the full track from when they first mentioned it in the TWO posted on the first page of this thread?
Title: Re: Possible tropical development NE GOM
Post by: capeweather on July 11, 2019, 10:00:57 PM
Yes. See pic.

Pardon the pun, but this is extremely depressing.  As noted above, I already had this storm last week, I don't need it again Tuesday.

(https://www.nhc.noaa.gov/storm_graphics/AT02/refresh/AL022019_5day_cone_no_line_and_wind+png/210142.png)

Speaking of which, does anybody have a link to the full track from when they first mentioned it in the TWO posted on the first page of this thread?
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 12, 2019, 03:34:02 AM
That doesn't go back far enough.  See the TWO and AFD I posted earlier.  It started in AR/MO even before NHC picked it up and passed between the two white circled Ds in your map..

Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 12, 2019, 11:58:41 AM
Pink dots sketched in shows how I recall it from previous AFDs, TWOs ... and passing overhead dropping rain and winds.



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Title: Re: Possible tropical development NE GOM
Post by: SlowModem on July 13, 2019, 08:30:07 AM
This storm is going to be a pay me now and pay me later storm.  The high winds and storm surge and rain is going to batter NO today and tonight.  Then, as the storm moves north, all the rainfall is going to be funneled into the Mississippi River and hit NO from the back side.  And as slow as the storm is moving, there's going to be lots and lots of rain.  The CoCoRaHS reports are going to be interesting for the next few days.
Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 13, 2019, 01:06:37 PM
NWS National Hurricane Center Miami FL       AL022019
1000 AM CDT Sat Jul 13 2019

...BARRY BECOMES A HURRICANE AS IT IS MOVING ONTO THE LOUISIANA
COAST...
...DANGEROUS STORM SURGE, HEAVY RAINS, AND WIND CONDITIONS
OCCURRING ACROSS THE NORTH-CENTRAL GULF COAST...


Title: Re: Possible tropical development NE GOM
Post by: WeatherHost on July 13, 2019, 03:32:28 PM
Well, that was quick ...  three hours as a Hurricane?


Tropical Storm Barry Intermediate Advisory Number 13A
NWS National Hurricane Center Miami FL       AL022019
100 PM CDT Sat Jul 13 2019

...BARRY MAKES LANDFALL NEAR INTRACOASTAL CITY LOUISIANA AND WEAKENS
TO A TROPICAL STORM...
...DANGEROUS STORM SURGE, HEAVY RAINS, AND WIND CONDITIONS
CONTINUING ACROSS THE NORTH-CENTRAL GULF COAST...