• Member Statistics

    15,533
    Total Members
    7,904
    Most Online
    Love Snow
    Newest Member
    Love Snow
    Joined
USCAPEWEATHERAF

Tropical Depression 03L

Recommended Posts

Right now we are potentially watching a dangerous situation potentially unfolding.  Given the warmth of the ocean and the shear is expected to drop soon, this system will be in an explosive environment for development.  Oceanic Sea Surface temperatures are around the mid to upper 80s currently in the system's location, with wind shear still around 10-20 knots, enough to slightly disrupt a developing surface low.  Once this drops to around 5-10 knots, this system should take off.  What is strange about this system, is the lack of any model support this morning.  However, we have seen situations in which tropical cyclones do develop without modeled support.  Next NHC update in the next thirty to forty minutes.

Share this post


Link to post
Share on other sites

This disturbance did not need its own thread. It could have been fleshed out under the main seasonal thread like the majority of past invests and areas of interest. If we create a thread for every single invest that pops up, especially when the season becomes active, the board is going to become gluttered fast with systems that never develop.

 

OTOH, if an invest is determined to be of high risk for tropical cyclogenesis, especially if land impacts are certain, or at the very least it has overwhelming modeling support at becoming a named tropical cyclone then, sure, thread away. Otherwise please wait until we have a named storm. Waiting for a named storm used to be more moderated though there were exceptions. This board is nice because it isn't overly moderated. Let's not ruin that.

 

At any rate, per the NHC, there is only a 10% chance of development in the next 48 hrs. Odds only go up 20% for the 5 day outlook. The reason the system lacks any modeling support is due to two factors: 1) Limited surface convergence at the moment: Though the disturbance does have showers and storms and a weak surface low, it still lacks enough diffluence that there isn't alot of lift in the atmosphere. The mid levels also do not scream favorability and there is lingering dry air. 2) Additonally, the disturbance doesn't get genesis support beyond 48 hrs due to modeled strong southwesterly shear in the mid levels associated with an advancing trough off the eastern CONUS. The weak area of low pressure becomes absorbed into a frontal merger. Perhaps something more substantial can stall or evolve between the Carolinas and Bermuda in 5-7 days with a lingering surface trough, but at this point it's a crapshoot.

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sun Jul 21 2019

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

1. A weak area of low pressure just to the east of the
Central Bahamas is producing disorganized showers and a few
thunderstorms.  Some slight development is possible over the
next few days while the disturbance moves westward to
west-northwestward at around 15 mph.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

Forecaster Pasch


 

  • Like 4

Share this post


Link to post
Share on other sites

Actually doesn't look that bad right now, I could see a PTC being issued but still isn't going to develop more then a TD. Any impacts are going to be roughly the same as already advertised. 

Edit: No PTC but odds up to 60% now on the NHC update. 

goes16_vis_94L-3.gif

Share this post


Link to post
Share on other sites
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Jul 22 2019

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

1. Showers and thunderstorms have increased in association with an
area of low pressure located near Andros Island in the Bahamas.
While environmental conditions are only marginally conducive for
development, only a slight increase in the organization of this
system could result in the formation of a tropical depression later
today or tonight.  Additional development is not anticipated after
that time due to strong upper-level winds.  The low is expected to
move northwestward around 15 mph today and north-northwestward to
northward tonight and Tuesday, remaining offshore of the east coast
of the Florida peninsula.  This system will continue to produce
locally heavy rainfall and gusty winds over portions of the
northwest Bahamas through tonight.  Showers and thunderstorms could
also spread over portions of the east coast of the Florida peninsula
tonight and Tuesday.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...medium...60 percent.

Forecaster Pasch

Share this post


Link to post
Share on other sites

bf8e6a0726be31dd6e237b9c4e0af916.jpg

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Jul 22 2019

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

1. Showers and thunderstorms have increased in association with an
area of low pressure located near Andros Island in the Bahamas.
While environmental conditions are only marginally conducive for
development, only a slight increase in the organization of this
system could result in the formation of a tropical depression later
today or tonight. Additional development is not anticipated after
that time due to strong upper-level winds. The low is expected to
move northwestward around 15 mph today and north-northwestward to
northward tonight and Tuesday, remaining offshore of the east coast
of the Florida peninsula. This system will continue to produce
locally heavy rainfall and gusty winds over portions of the
northwest Bahamas through tonight. Showers and thunderstorms could
also spread over portions of the east coast of the Florida peninsula
tonight and Tuesday.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...medium...60 percent.

Forecaster Pasch


.

Share this post


Link to post
Share on other sites
6 hours ago, USCAPEWEATHERAF said:

you will eating your words Matt P.  It is finally developing that outer armor it needs

Maybe it does develop into a TD or maybe even a low grade TS, but this isn't the "dangerous" and "explosive" development you were advertising.

  • Like 2

Share this post


Link to post
Share on other sites
Just now, MattPetrulli said:

Maybe it does develop into a TD or maybe even a low grade TS, but this isn't the "dangerous" and "explosive" development you were advertising.

Pretty much this. We’re seeing gradual development from a system that doesn’t have a lot of time. The ceiling is low. 

  • Like 2

Share this post


Link to post
Share on other sites
Just now, WxWatcher007 said:

Pretty much this. We’re seeing gradual development from a system that doesn’t have a lot of time. The ceiling is low. 

Reminds me of Tropical Storm Julia back in 2016 a little bit.
Also looking at it from Miami radar, it already looks more organized than Barry.

  • Like 1

Share this post


Link to post
Share on other sites

This came  up with no model support. Though it will do little  i think its a sign things will be a bit  more active  than many predicted pre-season

Share this post


Link to post
Share on other sites

No, the disturbance doesn't look half bad. The strong easterly mid level flow that had hampered it has become more southerly due to the disturbance now being positioned on the SW periphery of the Bermuda ridge, which is backing East in response to the strong advancing E CONUS trough. The southwest entrance of the wave at the surface has therefore become more convergent. NHC increase the odds of cyclogenesis and 94L may become a TD, perhaps even weak TS. But we need to see the low level wave axis cutoff in a rather short period of time into a vortex, preferably at the point of that increased surface convergence. Though Invest 94L has a small window of moderate favorability for TC genesis before hostile atmospheric flow and frontal boundary merger, that does not mean it will occur.

a55020a0ca4dab07a6737dcb32918618.gif7e87c94f1a11a8f32e9665d03eb9660b.gif

  • Like 2

Share this post


Link to post
Share on other sites
Tropical Depression Three Discussion Number   1
NWS National Hurricane Center Miami FL       AL032019
500 PM EDT Mon Jul 22 2019

Deep convection has increased in association with the small low
pressure area we have been monitoring near the Bahamas.  Animation
of visible satellite images and scatterometer data indicate that a
closed low-level circulation formed today, and therefore advisories
are being initiated on the system.  Conventional surface
observations along with the scatterometer measurements indicate that
the maximum sustained winds in the cyclone are near 25 kt. The
system is in a marginally favorable environment for strengthening,
as a special 1800 UTC sounding taken by the National Weather Service
Forecast Office here in Miami showed a layer of dry air near the 700
mb level.  The global models do not intensify the system, and only a
slight increase in strength appears likely.  In 36 to 48 hours, the
models indicate that this system will be absorbed by a frontal
trough near the U.S. east coast.

The initial motion estimate is northwestward or 305/11 kt.  Over the
next day or so, the tropical cyclone should move around the western
periphery of a mid-level subtropical ridge, with the center of the
depression expected to remain offshore of the Florida east coast and
the southeastern United States until dissipation.  The official
track forecast follows a small consensus of the only models that
were able to follow the center of the depression in the predicted
fields.

FORECAST POSITIONS AND MAX WINDS

INIT  22/2100Z 25.6N  78.6W   25 KT  30 MPH
 12H  23/0600Z 27.2N  79.7W   30 KT  35 MPH
 24H  23/1800Z 30.1N  79.6W   30 KT  35 MPH
 36H  24/0600Z 33.7N  77.8W   25 KT  30 MPH
 48H  24/1800Z...DISSIPATED

$$
Forecaster Pasch

203330_5day_cone_no_line_and_wind.png

  • Like 1

Share this post


Link to post
Share on other sites

In all fairness, if it was one month later with a building ridge to the north, we'd be in a heap of trouble.

Share this post


Link to post
Share on other sites
24 minutes ago, USCAPEWEATHERAF said:

Ok. I thought it would be a more serious situation then it turned out to become, but it has developed into an official depression.

LOL

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, USCAPEWEATHERAF said:

Ok. I thought it would be a more serious situation then it turned out to become, but it has developed into an official depression.

I thought it was a useful call. Storms can and do pop up almost out of nowhere and we dismiss potential seeds at our peril.

Meanwhile, am glad the NHC has now taken note.

  • Like 2

Share this post


Link to post
Share on other sites

At least there was a short-lived attempt earlier by the system to organize. That process has hit a brick wall. Papin mentioned mid level dry air may have been pulled down by cool downdrafts, flooding the boundary layer with low Theta-E, as evidenced by soundings. This has retarded additonal convection until the low level column can remoisten, as some convergence may be resumed once low level easterly flow into convection over the penninsula subsides.

The weak low level vortex assisted by the temporary banded convection earlier this afternoon is already showing signs of elongation and stretching lattitudinally without support of sustained additional convection to keep it tight / well-defined. Our TD may open back up into the wave axis as this process amplifies / shear increases tomorrow. Simply put, this system is on life support; without sustained convection, TD3 will dissipate faster than anticipated.

 

  • Like 2

Share this post


Link to post
Share on other sites

466 
WTNT43 KNHC 230232
TCDAT3

Tropical Depression Three Discussion Number   2
NWS National Hurricane Center Miami FL       AL032019
1100 PM EDT Mon Jul 22 2019

The depression has become less organized this evening.  Much of the
deep convection seen earlier in the day has dissipated, and the
cyclone currently consists of a swirl of low-level clouds with some
shower activity.  The initial intensity is held at 25 kt based on
the earlier ASCAT data.

The system is moving northwestward at 9 kt, steered by the
southwestern periphery of the Atlantic subtropical ridge.  A turn to
the north and north-northeast with a notable increase in forward
speed is expected on Tuesday as the depression moves in the
flow between the subtropical ridge and an approaching deep-layer
trough moving across the eastern United States.  The NHC track
forecast is similar to the previous one and keeps the center of the
cyclone offshore of the east coast of Florida.  This prediction is
near the multi-model consensus TVCN.

Significant strengthening of the depression is not expected given
its poor initial state and because it is forecast to move into a
region of strong southwesterly flow aloft by late Tuesday.  In
fact, the global and regional models all show the depression opening
into a trough within the next 24 hours, with the remnants of the
system becoming absorbed within a frontal zone off the southeast
U.S. on Wednesday.  The NHC intensity forecast is a little lower
than the previous one and now shows dissipation occurring sooner, by
36 hours.

Direct impacts from the depression are expected to be limited to 1
to 3 inches of rainfall in the Bahamas and along the east coast of
Florida.


FORECAST POSITIONS AND MAX WINDS

INIT  23/0300Z 26.1N  79.3W   25 KT  30 MPH
 12H  23/1200Z 28.4N  79.8W   25 KT  30 MPH
 24H  24/0000Z 31.7N  78.5W   30 KT  35 MPH
 36H  24/1200Z...DISSIPATED

$$
Forecaster Cangialosi

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.