ATL: DEBBY - Post-Tropical

[plasticup]

Can an invest be more uninteresting than 97L?

It's a funny spot for a storm to spin up! But yeah, I'm looking forward to the Cape Verde-type part of the season

[CyclonicFury]

020
ABNT20 KNHC 051726
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sun Aug 5 2018

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

A non-tropical low pressure system centered about 1100 miles
west-southwest of the Azores continues to produce limited shower
activity. Environmental conditions are expected to be only
marginally conducive for the low to acquire subtropical or
tropical characteristics while it moves little over the next
day or so, and then moves north-northeastward through Tuesday.
Additional information on this system can be found in High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...low...30 percent.

&&
High Seas Forecasts issued by the National Weather Service can be
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
on the Web at https://ocean.weather.gov/shtml/NFDHSFAT1.shtml.

$$
Forecaster Pasch

[lrak]

Can an invest be more uninteresting than 97L?

Exactly very strange start for the season. Seems like the Atlantic can't get up and running yet?

[Weather150]

Can an invest be more uninteresting than 97L?

Exactly very strange start for the season. Seems like the Atlantic can't get up and running yet?

Won't really get going until late August.

[CyclonicFury]

Convection has increased east of the center tonight.

[CyclonicFury]

650
ABNT20 KNHC 061138
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Mon Aug 6 2018

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

A non-tropical low pressure system centered about 1200 miles
west-southwest of the Azores is interacting with an upper-level low.
Although the system is producing disorganized showers and
thunderstorms to the east and northeast of the center, environmental
conditions are expected to be only marginally conducive for the low
to acquire subtropical or tropical characteristics while it moves
north or north-northeastward over the next day or so. The low is
forecast to move over cooler waters by Tuesday night, and
development is not expected after that time. Additional information
on this system can be found in High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

&&
High Seas Forecasts issued by the National Weather Service can be
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
on the Web at https://ocean.weather.gov/shtml/NFDHSFAT1.shtml.

$$
Forecaster Brown

[Sciencerocks]

Looks good to me.

[CyclonicFury]

30/30

470
ABNT20 KNHC 061740
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Aug 6 2018

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

A non-tropical low pressure system centered about 1100 miles
west-southwest of the Azores is interacting with an upper-level low.
Although the associated shower and thunderstorm activity has
increased during the past 24 hours, environmental conditions are
expected to be only marginally conducive for additional development
while the system moves north or north-northeastward over the next
day or so. The low is forecast to move over cooler waters Tuesday
night, and development is not expected after that time. Additional
information on this system can be found in High Seas Forecasts
issued by the National Weather Service.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...low...30 percent.

&&
High Seas Forecasts issued by the National Weather Service can be
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
on the Web at https://ocean.weather.gov/shtml/NFDHSFAT1.shtml.

$$
Forecaster Brown

[CyclonicFury]

Looks good to me.

Looks better than a 30/30, should be at least a 50/50 IMO. Often times NHC keeps chances with these subtropics systems too low.

[cycloneye]

A non-tropical low pressure system centered a little more than 1000
miles west-southwest of the Azores is interacting with an upper-
level low, and most of its associated shower activity remains
disorganized. Environmental conditions could favor some development
during the next day or so, but after that time, the low will
encounter increasing cooler waters and development is not
anticipated. The low is already moving toward the north-northeast,
and this motion should continue for the next several days over the
open North Atlantic. Additional information on this system can be
found in High Seas Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...low...30 percent.

[NDG]

97L is looking good tonight, the pesky ULL is finally giving it some breathing room, time for an upgrade if the convection persists through the night.

[AJC3]

97L is looking good tonight, the pesky ULL is finally giving it some breathing room, time for an upgrade if the convection persists through the night.

The satellite evolution of this thing is pretty fascinating. Near 97L (A), which had been completely exposed late this afternoon, there was a small upper level low (B) to its NW moving away from 97L's exposed center. Just NW of the small upper low, there was (and is) a very small low level vortex (C) that's started tooting some convection. It appears as if the small upper low is weakening/dissipating, and 97L is trying to tuck underneath the area of (now) central convection. I suspect that small LL vortex will deform/shear out as it gets entrained into the circulation of 97L.

[Extratropical94]

Up to 50/50:

Satellite data indicate that thunderstorm activity during the past
several hours has increased and become better organized in
association with a well-defined, non-tropical low pressure system
centered about 950 miles west-southwest of the Azores. Environmental
conditions are expected to be somewhat conducive for the system to
acquire subtropical or tropical characteristics later today. By
Wednesday, however, the low will encounter increasingly cooler
waters, which will hinder development while the system moves toward
the north-northeast over the open North Atlantic. Additional
information on this system can be found in High Seas Forecasts
issued by the National Weather Service.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.

[cycloneye]

Up to 60%/60%

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Tue Aug 7 2018

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

1. Early visible satellite images indicate that the shower activity
associated with a non-tropical low pressure system located a little
more than 900 miles west-southwest of the Azores continues to
show some signs of organization. Although the shower activity has
decreased somewhat during the past few hours, this system could
still acquire subtropical or tropical characteristics later today.
By Wednesday, however, the low will encounter increasingly cooler
waters, which will hinder development while the system moves toward
the north-northeast over the open North Atlantic. Additional
information on this system can be found in High Seas Forecasts
issued by the National Weather Service.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...medium...60 percent.

High Seas Forecasts issued by the National Weather Service can be
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
on the Web at https://ocean.weather.gov/shtml/NFDHSFAT1.shtml.

Forecaster Avila

[cycloneye]

@BigJoeBastardi
Seasons 4th named storm I think gets christened today right in middle of our highest ace% average area, out in the middle of nowhere. Could impact UK/Ireland in longer range

[CyclonicFury]

Now SS Debby

[cycloneye]

@EricBlake12
Fun new scatterometer features on @Weathernerds - you can see the pass near #Debby this morning. Check it out! https://www.weathernerds.org/satellite/floaters/ …

 https://twitter.com/EricBlake12/status/1026872252313346048

[weathaguyry]

Has that classic subtropical look with thinner clouds in the middle and heavier convection around it like a donut, pretty cool to look at considering there's nothing else interesting in the basin

[CyclonicFury]

716
WTNT44 KNHC 072032
TCDAT4

Subtropical Storm Debby Discussion Number 2
NWS National Hurricane Center Miami FL AL042018
500 PM AST Tue Aug 07 2018

Debby's cloud pattern consists of a cyclonically curved convective
band wrapping around a large but somewhat vigorous circulation. TAFB
provided a subtropical classification of ST2.5, while an earlier
ship located to the east of the center reported 35 kt. These data is
used to assign the current intensity of the subtropical cyclone.
Although transition to a tropical cyclone is still possible during
the next 24 hours, no significant strengthening is anticipated since
Debby will soon be moving over cool waters and become fully embedded
within a larger mid-latitude trough in a day or so. Debby is
forecast to dissipate in about 48 hours or earlier.

The best estimate of the initial motion is toward the north or 355
degrees at 13 kt. The subtropical storm should continue on this
general track with a decrease in forward speed for the next 24
hours or so and then turn to the northeast ahead of the trough,
which will eventually absorb Debby.

FORECAST POSITIONS AND MAX WINDS

INIT 07/2100Z 39.7N 49.2W 35 KT 40 MPH
12H 08/0600Z 41.0N 49.5W 35 KT 40 MPH
24H 08/1800Z 42.3N 48.5W 35 KT 40 MPH
36H 09/0600Z 44.0N 46.0W 30 KT 35 MPH
48H 09/1800Z...DISSIPATED

$$
Forecaster Avila

[euro6208]

The only basin in the world to recognize such systems regularly and is good at it. I know of a few in the WPAC this year that were likely *Subtropical*.