ATL: DEBBY - Post-Tropical

[robbielyn]

Looks like some temporary weakening is about to ensue over the next couple of hours. That hot tower we saw earlier likely collapsed as well as the other plume of convection and sent out twin outflow boundaries. BTW, very off topic, but does Debby look like a bug or bee now with its head to the north and butt to the south?

Hahaha. It sure is a bee in our bonnet here in Florida thats for sure.

[CYCLONE MIKE]

Jonathan, what is your take on the overall upper air pattern this morning. Does the ull look to be weakening and moving more south with decreasing southerly shear? And do you see the finally see the high building in causing the much anticipated stall and westward movement today? Overall structure looks better to me this morning and now seems to actually be expanding westward some.

[southerngale]

Is JB sticking to his guns?

Joe Bastardi ‏@BigJoeBastardi
Euro Ensembles indicate its operational model is an outlier in track of Debby. Many stay on west track to Texas


And a little humor...
https://twitter.com/BigJoeBastardi/status/216847437774602242/photo/1

[jlauderdal]

FLL getting more action this morning




Uploaded with ImageShack.us

[cycloneye]

URNT15 KNHC 241117
AF302 0204A DEBBY HDOB 10 20120624
111000 2817N 08618W 8429 01468 //// +175 //// 127011 011 010 001 01
111030 2816N 08619W 8428 01468 //// +175 //// 121012 013 009 003 01
111100 2815N 08620W 8431 01465 //// +184 //// 108012 013 004 003 01
111130 2814N 08622W 8429 01467 //// +180 //// 099013 014 003 002 05
111200 2812N 08623W 8430 01463 //// +181 //// 095014 014 003 001 01
111230 2811N 08625W 8432 01462 //// +180 //// 095015 016 001 002 01
111300 2811N 08625W 8432 01462 //// +185 //// 093015 016 004 000 01
111330 2809N 08627W 8430 01461 //// +185 //// 084015 016 008 001 01
111400 2807N 08629W 8430 01460 //// +182 //// 072017 017 007 002 01
111430 2806N 08630W 8432 01457 //// +183 //// 063016 016 006 002 01
111500 2805N 08632W 8428 01458 //// +181 //// 057016 017 008 001 01
111530 2804N 08633W 8432 01454 //// +175 //// 051017 017 008 002 01
111600 2802N 08635W 8429 01452 //// +177 //// 055017 018 009 003 05
111630 2801N 08634W 8431 01452 //// +183 //// 052014 015 007 002 01
111700 2759N 08633W 8432 01449 //// +180 //// 060007 012 011 001 01
111730 2758N 08632W 8429 01450 //// +185 //// 081007 008 011 002 01
111800 2757N 08631W 8429 01446 //// +168 //// 068008 009 017 005 01
111830 2755N 08630W 8425 01450 //// +173 //// 086007 010 013 002 05
111900 2754N 08629W 8425 01450 //// +180 //// 081005 007 008 001 01
111930 2752N 08629W 8430 01443 //// +186 //// 039001 005 006 001 01

[Dave]

I forgot to log out last night..sheesh. I can work for an hour this morning then again later today if needed.

[wjs3]

Looks like some temporary weakening is about to ensue over the next couple of hours. That hot tower we saw earlier likely collapsed as well as the other plume of convection and sent out twin outflow boundaries. BTW, very off topic, but does Debby look like a bug or bee now with its head to the north and butt to the south?

Don't these look a little cold/cirrus-y to be outflows?

I don't disagree with he overall weakening analysis and wouldn't be surprised to see outflow boundaries, but shouldn't they be lower level/warmer, not the same temp (and therefore height) as the thunderstorm tops?

Visibles will tell, of course!

[Dave]

000
UZNT13 KNHC 241111
XXAA 74115 99289 70866 08186 99001 23616 06055 00013 23416 06057
92692 20440 05570 85424 18850 04564 70070 11220 07543 50581 02304
12018 88999 77999
31313 09608 81044
61616 AF302 0204A DEBBY OB 03
62626 SPL 2886N08666W 1051 MBL WND 06067 AEV 20802 DLM WND 06544
001486 WL150 06063 084 REL 2890N08656W 104401 SPG 2886N08666W 105
149 =
XXBB 74118 99289 70866 08186 00001 23616 11951 21026 22850 18850
33758 13413 44656 08626 55500 02304 66486 04900
21212 00001 06055 11997 06064 22984 06064 33966 06070 44927 05571
55886 05063 66850 04564 77800 04553 88731 08047 99689 07037 11608
09526 22528 09522 33503 10519 44486 14016
31313 09608 81044
61616 AF302 0204A DEBBY OB 03
62626 SPL 2886N08666W 1051 MBL WND 06067 AEV 20802 DLM WND 06544
001486 WL150 06063 084 REL 2890N08656W 104401 SPG 2886N08666W 105
149 =
;

[Javlin]

Is JB sticking to his guns?

Joe Bastardi ‏@BigJoeBastardi
Euro Ensembles indicate its operational model is an outlier in track of Debby. Many stay on west track to Texas


And a little humor...
https://twitter.com/BigJoeBastardi/status/216847437774602242/photo/1

Thats funny

[SoupBone]

What a crazy morning to wake up to. She looks somewhat ragged on radar. I wonder how much more east they will shift the track. Her track will surely make a difference in Louisiana's wide range of potential conditions.

[Dave]

DECODED DROPSONDE 03

Code: Select all

Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)
Transmitted: 24th day of the month at 11:11Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 302)
Storm Number: 04
Storm Name: Debby (flight in the North Atlantic basin)
Mission Number: 2
Observation Number: 03

Part A...


Date: Near the closest hour of 11Z on the 24th day of the month
Highest Mandatory Level For Which Wind Was Reported: 500mb
Coordinates: 28.9N 86.6W
Location: 105 miles (168 km) to the SSW (213°) from Panama City, FL, USA.
Marsden Square: 081 (About)

Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed
1001mb (29.56 inHg) Sea Level (Surface) 23.6°C (74.5°F) 22.0°C (71.6°F) 60° (from the ENE) 55 knots (63 mph)
1000mb 13m (43 ft) 23.4°C (74.1°F) 21.8°C (71.2°F) 60° (from the ENE) 57 knots (66 mph)
925mb 692m (2,270 ft) 20.4°C (68.7°F) 16.4°C (61.5°F) 55° (from the NE) 70 knots (81 mph)
850mb 1,424m (4,672 ft) 18.8°C (65.8°F) Approximately 14°C (57°F) 45° (from the NE) 64 knots (74 mph)
700mb 3,070m (10,072 ft) 11.2°C (52.2°F) 9.2°C (48.6°F) 75° (from the ENE) 43 knots (49 mph)
500mb 5,810m (19,062 ft) -2.3°C (27.9°F) -2.7°C (27.1°F) 120° (from the ESE) 18 knots (21 mph)

Information About Radiosonde:
- Launch Time: 10:44Z
- About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction.

Remarks Section...


Splash Location: 28.86N 86.66W
Splash Time: 10:51Z

Release Location: 28.9N 86.56W View map)
Release Time: 10:44:01Z

Splash Location: 28.86N 86.66W (
Splash Time: 10:51:49Z

Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding):
- Wind Direction: 60° (from the ENE)
- Wind Speed: 67 knots (77 mph)

Deep Layer Mean Wind (average wind over the depth of the sounding):
- Wind Direction: 65° (from the ENE)
- Wind Speed: 44 knots (51 mph)
- Depth of Sounding: From 486mb to 1001mb

Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding:
- Lowest 150m: 159 gpm - 9 gpm (522 geo. feet - 30 geo. feet)
- Wind Direction: 60° (from the ENE)
- Wind Speed: 63 knots (72 mph)

Sounding Software Version: AEV 20802


Part B: Data For Significant Levels...


Significant Temperature And Relative Humidity Levels...
Level Air Temperature Dew Point
1001mb (Surface) 23.6°C (74.5°F) 22.0°C (71.6°F)
951mb 21.0°C (69.8°F) 18.4°C (65.1°F)
850mb 18.8°C (65.8°F) Approximately 14°C (57°F)
758mb 13.4°C (56.1°F) 12.1°C (53.8°F)
656mb 8.6°C (47.5°F) 6.0°C (42.8°F)
500mb -2.3°C (27.9°F) -2.7°C (27.1°F)
486mb -4.9°C (23.2°F) -4.9°C (23.2°F)

Significant Wind Levels...
Level Wind Direction Wind Speed
1001mb (Surface) 60° (from the ENE) 55 knots (63 mph)
997mb 60° (from the ENE) 64 knots (74 mph)
984mb 60° (from the ENE) 64 knots (74 mph)
966mb 60° (from the ENE) 70 knots (81 mph)
927mb 55° (from the NE) 71 knots (82 mph)
886mb 50° (from the NE) 63 knots (72 mph)
850mb 45° (from the NE) 64 knots (74 mph)
800mb 45° (from the NE) 53 knots (61 mph)
731mb 80° (from the E) 47 knots (54 mph)
689mb 70° (from the ENE) 37 knots (43 mph)
608mb 95° (from the E) 26 knots (30 mph)
528mb 95° (from the E) 22 knots (25 mph)
503mb 105° (from the ESE) 19 knots (22 mph)
486mb 140° (from the SE) 16 knots (18 mph)




[cycloneye]

Good morning Dave, You can continue.

[JonathanBelles]

Jonathan, what is your take on the overall upper air pattern this morning. Does the ull look to be weakening and moving more south with decreasing southerly shear? And do you see the finally building in causing the much anticipated stall and westward movement today? Overall structure looks better to me this morning and now seems to actually be expanding westward some.

The ULL seems to be getting squished to the south by the large warm core ridge centered over the central plains, and it seems to be slowly weakening. Shear is dropping over the system, but at this point its not necessarily all shear that is causing unfavorable conditions. Debby is very ill-stacked, and she will have to blow up storms over her center instead of to the east as she has the last two days. Motion is going to be erratic today and probably tomorrow too. Debby is very close to an area of little steering and will enter that today. I think the NHC is spot on with a gentle movement to the north or northwest by only 2-5 mph today.

[KWT]

Is JB sticking to his guns?

Joe Bastardi ‏@BigJoeBastardi
Euro Ensembles indicate its operational model is an outlier in track of Debby. Many stay on west track to Texas


And a little humor...
https://twitter.com/BigJoeBastardi/status/216847437774602242/photo/1

Yeah from what I've heard the ensembls are mainly further west. Still when you've got many of the operationals shifting east it does make you think.

Alo yep those sure do look like outflow boundaries. Looking forward to Vis.imagery very soon!

[Dave]

[Dave]

Ok will need a relief around 9 am this morning.

[Dave]

000
URNT15 KNHC 241127
AF302 0204A DEBBY HDOB 11 20120624
112000 2751N 08629W 8431 01440 //// +186 //// 246003 004 008 004 05
112030 2749N 08630W 8423 01449 //// +194 //// 270004 005 014 003 01
112100 2748N 08631W 8437 01437 //// +185 //// 280005 005 014 003 01
112130 2747N 08633W 8426 01447 //// +191 //// 308009 011 009 001 01
112200 2746N 08634W 8429 01444 //// +189 //// 310015 016 013 002 01
112230 2744N 08635W 8426 01449 //// +184 //// 307016 017 014 001 01
112300 2743N 08637W 8431 01445 //// +181 //// 310018 020 017 002 01
112330 2742N 08638W 8429 01447 //// +184 //// 315020 021 017 002 01
112400 2741N 08639W 8434 01445 //// +184 //// 315021 021 016 002 01
112430 2740N 08640W 8426 01454 //// +186 //// 313024 025 018 002 01
112500 2738N 08642W 8429 01455 //// +186 //// 315025 025 020 000 01
112530 2737N 08643W 8429 01457 //// +183 //// 317026 026 020 001 01
112600 2736N 08644W 8429 01458 //// +180 //// 321027 028 023 000 01
112630 2735N 08646W 8429 01460 //// +175 //// 318029 030 025 003 01
112700 2734N 08647W 8430 01460 //// +178 //// 321028 030 024 002 01
112730 2732N 08648W 8432 01462 //// +160 //// 325025 028 022 003 01
112800 2731N 08650W 8428 01466 //// +172 //// 317021 023 021 003 01
112830 2730N 08651W 8429 01466 //// +177 //// 314022 023 021 002 01
112900 2729N 08652W 8432 01464 //// +173 //// 315025 025 020 002 01
112930 2728N 08653W 8430 01467 //// +166 //// 316024 025 020 001 01
$$
;

[caneman]

What a blown forecast by NHC. Really bothers me that they went all in with one model. IT further bothers me that they didn't just make a full change instead of trying to stair step. Most of the people I know who don't track just looked at the map and said 'oh, it's going to Texas'. Hope the NHC learns from this. Fortunately for us in Florida it wasn't a Hurricane. We are however getting pounded with rain.

[CYCLONE MIKE]

Jonathan, what is your take on the overall upper air pattern this morning. Does the ull look to be weakening and moving more south with decreasing southerly shear? And do you see the finally building in causing the much anticipated stall and westward movement today? Overall structure looks better to me this morning and now seems to actually be expanding westward some.

The ULL seems to be getting squished to the south by the large warm core ridge centered over the central plains, and it seems to be slowly weakening. Shear is dropping over the system, but at this point its not necessarily all shear that is causing unfavorable conditions. Debby is very ill-stacked, and she will have to blow up storms over her center instead of to the east as she has the last two days. Motion is going to be erratic today and probably tomorrow too. Debby is very close to an area of little steering and will enter that today. I think the NHC is spot on with a gentle movement to the north or northwest by only 2-5 mph today.

Good analysis, thank you.

[KWT]

Well as I said its hard to make a middle ground really and instead they chose a track that would keep it over the Gulf for as long as possible. Once they feel more confident in the models the track speed will increase and a landfall will be shown.