ATL: DON - Remnant - Discussion

[ozonepete]

Outflow boundary racing out of the convection, could well see Don exposed soon as has just been noted...

Convection will probably weaken in the next 2-3hrs before another bursting phase sets off some point in the 9-12hrs range IMO.

Those outflow boundaries are also telling us there's still dry air getting into the system at mid-levels. That could remain an issue all the way to the coast, although lower levels have moistened nicely - you guys posted 23-25C dewpoints at flight level from RECON.

[Dave]

[MBryant]

Looking at this:

http://climate.cod.edu/flanis/2km.php?loop=1&type=vis&region=Yucatan&numimages=12

I don't know where they get NW?

If you look at the counter-clockwise clouds at the lower level, there is a northwest component. The upper level (I assume) cloud to the center's south appears to be due west in movement. This is what I think they are describing as "uncovered" due to sheer.

But I'm just an interested observer of over forty years. I really got into hurricanes a little before the 1970 season with it's two eyed storms (like Felice) and neutercanes.

[ozonepete]

That's a 200mb level forecast. Need to see shear from low to mid/upper levels.

I was showing that because it was in agreement with the 850mb winds at the time. I was assuming there wasn't much mid-level shear.

OK.

[Dave]

000
URNT12 KNHC 281615
VORTEX DATA MESSAGE AL042011
A. 28/15:48:40Z
B. 24 deg 15 min N
090 deg 19 min W
C. 850 mb 1458 m
D. 45 kt
E. 048 deg 86 nm
F. 150 deg 52 kt
G. 048 deg 70 nm
H. 1005 mb
I. 18 C / 1524 m
J. 24 C / 1524 m
K. 9 C / NA
L. NA
M. NA
N. 1345 / 8
O. 0.02 / 1 nm
P. AF303 0204A DON OB 11
MAX FL WIND 52 KT NE QUAD 15:26:00Z
;

[Dave]

000
UZNT13 KNHC 281615
XXAA 78168 99244 70902 08240 99007 27408 14037 00066 26605 13037
92753 23005 13538 85491 20058 14031 88999 77999
31313 09608 81544
61616 AF303 0204A DON OB 12
62626 MXWNDBND SPL 2440N09017W 1546 MBL WND 13538 AEV 20802 DLM W
ND 14037 007843 WL150 13537 084 REL 2439N09016W 154454 SPG 2439N0
9018W 154626 =
XXBB 78168 99244 70902 08240 00007 27408 11973 24602 22859 21640
21212 00007 14037 11004 13034 22998 13038 33982 14040 44974 13534
55963 14042 66947 14542 77913 14538 88905 15034 99892 14539 11859
14533 22843 13530
31313 09608 81544
61616 AF303 0204A DON OB 12
62626 MXWNDBND SPL 2440N09017W 1546 MBL WND 13538 AEV 20802 DLM W
ND 14037 007843 WL150 13537 084 REL 2439N09016W 154454 SPG 2439N0
9018W 154626 =

[SouthDadeFish]

Don has been a very fun storm to watch and learn from. Hopefully he ends up bringing much more good than harm.

[Dave]

Decoded VDM
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 28th day of the month at 16:15Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 303)
Storm Number & Year: 04L in 2011
Storm Name: Don (flight in the North Atlantic basin)
Mission Number: 2
Observation Number: 11
A. Time of Center Fix: 28th day of the month at 15:48:40Z
B. Center Fix Coordinates: 24°15'N 90°19'W (24.25N 90.3167W)
B. Center Fix Location: 396 miles (638 km) to the S (182°) from New Orleans, LA, USA.
C. Minimum Height at Standard Level: 1,458m (4,783ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 45kts (~ 51.8mph)
E. Location of the Estimated Maximum Surface Wind: 86 nautical miles (99 statute miles) to the NE (48°) of center fix
F. Maximum Flight Level Wind Inbound: From 150° at 52kts (From the SSE at ~ 59.8mph)
G. Location of Maximum Flight Level Wind Inbound: 70 nautical miles (81 statute miles) to the NE (48°) of center fix
H. Minimum Sea Level Pressure: 1005mb (29.68 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 1,524m (5,000ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 24°C (75°F) at a pressure alt. of 1,524m (5,000ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 9°C (48°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile
Remarks Section:
Maximum Flight Level Wind: 52kts (~ 59.8mph) in the northeast quadrant at 15:26:00Z

[Dave]

146
URNT15 KNHC 281617
AF303 0204A DON HDOB 38 20110728
160800 2331N 09107W 8425 01575 0104 +173 +056 324013 014 /// /// 03
160830 2330N 09108W 8429 01572 0104 +171 +057 315012 012 /// /// 03
160900 2329N 09109W 8426 01575 0105 +172 +057 323013 013 /// /// 03
160930 2328N 09111W 8428 01574 0104 +173 +057 327012 013 /// /// 03
161000 2326N 09112W 8434 01568 0106 +172 +057 322013 013 /// /// 03
161030 2325N 09113W 8425 01579 0108 +171 +058 325013 013 /// /// 03
161100 2324N 09114W 8430 01573 0106 +170 +058 328013 013 /// /// 03
161130 2323N 09116W 8428 01575 0106 +170 +058 332013 014 /// /// 03
161200 2322N 09117W 8431 01572 0108 +167 +058 327013 014 /// /// 03
161230 2320N 09116W 8430 01573 0109 +166 +058 311011 011 /// /// 03
161300 2320N 09115W 8430 01574 0109 +165 +060 298009 010 /// /// 03
161330 2321N 09113W 8429 01573 0109 +165 +060 294010 011 /// /// 03
161400 2321N 09111W 8431 01569 0106 +169 +059 296011 012 /// /// 03
161430 2321N 09109W 8430 01572 0106 +169 +058 290010 011 /// /// 03
161500 2322N 09108W 8429 01573 0108 +167 +058 285010 010 /// /// 03
161530 2322N 09106W 8430 01572 0107 +168 +058 285010 010 /// /// 03
161600 2322N 09104W 8429 01572 0106 +169 +058 289011 011 /// /// 03
161630 2322N 09102W 8430 01571 0105 +170 +058 283011 011 /// /// 03
161700 2322N 09100W 8432 01571 0105 +170 +058 276012 012 /// /// 03
161730 2323N 09058W 8429 01572 0105 +170 +057 275011 011 /// /// 03
$$
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[TeamPlayersBlue]

I hope this storm at gets a large rain shield before it hits the coast. Almost feel like we can 'steal' at least 3 inches of rain out of this storm here.

[KWT]

Those outflow boundaries are also telling us there's still dry air getting into the system at mid-levels. That could remain an issue all the way to the coast, although lower levels have moistened nicely - you guys posted 23-25C dewpoints at flight level from RECON.

Yep and if I remember what Derek Ortt used to say correctly, thats nearly always related to some form of mid level shear occuring which allows the dry air to drive into the core of the system.

[SouthDadeFish]

Latest VDM says 45 knots at the surface. If he can become vertically stacked again, he could make a run at hurricane status with the tight pressure gradient we have here.

Edit: Although VDM said pressure rose to 1005mb. Not surprising with the lack of convection over the center.

[Dave]

[TropicalAnalystwx13]

Don's mid-level and low-level centers are decoupling...Shear is really doing a number on the system. Additionally, the lowest pressure recon just found was 1005 mb. Not looking good for Don or Texas.

[KWT]

Latest VDM says 45 knots at the surface. If he can become vertically stacked again, he could make a run at hurricane status with the tight pressure gradient we have here.

Yep, of course thats the question, will it be able to ever get conditions to become virtically stacked...my guess at the moment is probably not.

[petit_bois]

what's the opposite of "bombing"
After all the hype yesterday the reality is setting in... Models did a pretty good job with this.

[SouthDadeFish]

Latest VDM says 45 knots at the surface. If he can become vertically stacked again, he could make a run at hurricane status with the tight pressure gradient we have here.

Yep, of course thats the question, will it be able to ever get conditions to become virtically stacked...my guess at the moment is probably not.

KWT, you may very well be right. I still have a little faith in him. Thanks for the shear discussion

[Dave]

[petit_bois]

Looking at this:

http://climate.cod.edu/flanis/2km.php?loop=1&type=vis&region=Yucatan&numimages=12

I don't know where they get NW?

the low lever circulation is moving NW... the upper level cloub mass is moving West

[Dave]

854
URNT15 KNHC 281627
AF303 0204A DON HDOB 39 20110728
161800 2323N 09057W 8428 01573 0104 +170 +056 274011 012 /// /// 03
161830 2323N 09055W 8430 01571 0104 +170 +056 267011 011 /// /// 03
161900 2323N 09053W 8430 01568 0103 +170 +056 267011 012 /// /// 03
161930 2323N 09051W 8430 01569 0103 +170 +056 267012 012 /// /// 03
162000 2324N 09049W 8431 01567 0102 +168 +056 271012 013 /// /// 03
162030 2324N 09047W 8428 01567 0104 +162 +055 260014 015 /// /// 03
162100 2324N 09046W 8429 01568 0105 +163 +053 270014 015 /// /// 03
162130 2324N 09044W 8430 01567 0111 +153 +050 262016 017 /// /// 03
162200 2324N 09042W 8426 01569 0112 +149 +046 265015 016 /// /// 03
162230 2325N 09040W 8428 01574 0115 +150 +043 254014 016 /// /// 03
162300 2325N 09038W 8426 01571 0108 +157 +041 235015 017 /// /// 03
162330 2325N 09036W 8429 01567 0109 +156 +040 238015 017 /// /// 03
162400 2325N 09035W 8429 01567 0104 +162 +040 227017 018 /// /// 03
162430 2325N 09033W 8432 01566 0105 +164 +040 228016 016 /// /// 03
162500 2326N 09031W 8429 01568 0106 +165 +043 228016 016 /// /// 03
162530 2326N 09029W 8432 01566 0102 +166 +047 233015 016 /// /// 03
162600 2326N 09027W 8434 01563 0103 +165 +053 233015 016 /// /// 03
162630 2326N 09025W 8429 01569 0103 +165 +059 232015 015 /// /// 03
162700 2326N 09024W 8432 01566 0101 +167 +064 229015 015 /// /// 03
162730 2327N 09022W 8429 01573 0102 +170 +068 224015 016 /// /// 33
$$
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