Hurricane Katrina

[Skyline]

All I can say is wow.

http://www.ssd.noaa.gov/PS/TROP/DATA/RT ... M85/20.jpg

[/img]

[StormsAhead]

What is kind of amazing to me is the fact that the winds never seemed to respond to the 940mb pressure. I really don't have an answer for that one, but it does make me curious.

Actually, could it be the winds did respond but the "X" pattern of the plane just never found them?

The plane found winds that could have been 110 knots at the surface, so it is possible that somewhere else they could have been minimal cat. 4 strength. That is one of the reasons why pressure is often given weight in the intensity, not just the winds found by Recon.

[StormsAhead]

Observation #: 10
Time: 16:28Z
Location: 23.5N 84.0W
Altitude: 3000 meters
Flight-level wind: SW (220°) at 56 knots
Temperature: 11C
Dew Point: 11C
Weather: Rain
700mb Height: 3053 meters
Surface Wind: SSW (200°) at 45 knots

[StormsAhead]

URNT40 KWBC 271640
NOAA3 1312A KATRINA
163030 2337 08403 9928 +0114 208066 +107 +102 208068 999 999
163100 2338 08405 9880 +0099 213065 +107 +104 209067 054 009
163130 2338 08407 9847 +0088 214063 +109 +104 214063 999 999
163200 2338 08409 9891 +0088 211059 +105 +103 207060 999 999
163230 2339 08411 9845 +0073 205061 +109 +103 207061 999 999
163300 2339 08413 9879 +0065 224062 +107 +107 225063 999 999
163330 2339 08414 9915 +0054 223067 +113 +113 224069 999 999
163400 2340 08416 9955 +0057 219067 +107 +107 219068 051 008
163430 2340 08418 9946 +0054 220068 +108 +105 220068 043 007
163500 2341 08420 9925 +0042 221068 +108 +102 221069 047 005
163530 2343 08421 9918 +0030 220069 +113 +095 221070 047 004
163600 2344 08423 9915 +0018 218069 +118 +093 217070 049 007
163630 2346 08425 9926 +0005 218071 +117 +096 218072 999 999
163700 2347 08426 9922 -0005 216073 +113 +099 217073 999 999
163730 2349 08428 9916 -0021 214072 +111 +101 212072 999 999
163800 2350 08430 9920 -0040 215068 +114 +098 213071 999 999
163830 2352 08431 9927 -0064 215069 +113 +102 214070 999 999
163900 2353 08433 9944 -0085 215073 +120 +103 217073 057 009
163930 2354 08434 10014 -0104 215074 +122 +090 215074 055 008
164000 2356 08436 10060 -0127 211077 +112 +097 209078 056 008

78 knots

[StormsAhead]

SXXX50 KNHC 271647
AF306 WX12A KATRINA01 HDOB 08 KNHC
1637 2622N 08658W 07225 0408 051 035 141 207 035 07724 0000000000
1637. 2619N 08657W 07223 0407 050 034 141 207 035 07722 0000000000
1638 2617N 08656W 07223 0405 047 035 141 209 036 07719 0000000000
1638. 2615N 08655W 07187 0403 044 036 139 211 036 07682 0000000000
1639 2612N 08654W 06862 0387 042 039 123 209 040 07340 0000000000
1639. 2609N 08653W 06362 0354 040 042 089 201 043 06803 0000000000
1640 2607N 08652W 05893 0325 038 043 051 191 044 06299 0000000000
1640. 2604N 08651W 05464 0293 047 045 021 177 047 05837 0000000000
1641 2601N 08650W 05042 0253 045 046 006 153 046 05375 0000000000
1641. 2558N 08649W 04624 0217 049 049 030 109 051 04919 0000000000
1642 2556N 08648W 04211 0179 042 047 040 037 047 04452 0000000000
1642. 2553N 08647W 03859 0162 034 047 062 000 047 04067 0000000000
1643 2551N 08646W 03665 0143 045 043 074 028 043 03855 0000000000
1643. 2549N 08645W 03641 0136 046 043 072 036 045 03823 0000000000
1644 2547N 08644W 03662 0130 046 041 072 042 043 03838 0000000000
1644. 2546N 08642W 03658 0129 046 043 070 044 043 03834 0000000000
1645 2545N 08641W 03659 0128 046 042 072 034 043 03832 0000000000
1645. 2543N 08639W 03658 0125 045 041 070 024 042 03829 0000000000
1646 2542N 08638W 03657 0123 044 041 070 022 041 03826 0000000000
1646. 2541N 08636W 03657 0121 044 043 072 020 044 03825 0000000000

AF plane...51 knots

[milankovitch]

Heres a good loop showing the concentric eyewalls.
http://weather.msfc.nasa.gov/cgi-bin/post-goes

Katrina is soon to pass over a bubble of very high HHC. Possibly another to the northwest if the track doesn't deviate.



It's a deeper 26 degree isotherm and higher HHC from here on out.

[WindRunner]

And still aways away from the center too.

[StormsAhead]

DROPSONDE
Flight: AF306 WX12A
Observation #: 2
Location: 26.6N 87.1W
Surface: Pressure 1004mb; Wind NE (55°) at 27 knots
1000mb: Height 37 meters; Wind NE (55°) at 31 knots
925mb: Height 726 meters; Wind NE (50°) at 36 knots
850mb: Height 1459 meters; Wind ENE (60°) at 35 knots
700mb: Height 3105 meters; Wind ENE (60°) at 37 knots
500mb: Height 5850 meters; Wind NE (50°) at 40 knots
400mb: Height 7580 meters; Wind NE (50°) at 30 knots

[StormsAhead]

RECCO OBSERVATION
Flight: AF306 WX12A
Observation #: 3
Time: 16:49Z
Location: 25.6N 86.5W
Altitude: 3660 meters
Flight-level wind: NE (40°) at 45 knots
Temperature: 8C
Dew Point: 2C
Weather: Broken Clouds
D-Value: 110 meters

[rockyman]

12z GFS now back to New Orleans (6z was further east):

https://www.fnmoc.navy.mil/mywxmap/chart.do?username=guest&lat=40.223186&width=800&chartTypeId=chart11&height=600&watch=1125144000000&requestId=1124992704992.1278.8&lon=-109.943695&projection=Mercator&name=NCEP_GFS_6_180%3AGlobal_One_Degree&span=9465245.0&tau=3240

12z NOGAPS is now over east central LA (west of NOLA):
https://www.fnmoc.navy.mil/mywxmap/chart.do?username=guest&lat=40.223186&width=800&chartTypeId=chart11&height=600&watch=1125144000000&requestId=1124992704992.1278.13&lon=-109.943695&projection=Mercator&name=NOGAPS%3AGlobal_1_Degree&span=9465245.0&tau=3960

[StormsAhead]

DROPSONDE
Flight: AF306 WX12A
Observation #: 4
Location: 26.3N 86.9W
Surface: Pressure 1003mb; Wind NE (40°) at 29 knots
1000mb: Height 28 meters; Wind NE (45°) at 31 knots
925mb: Height 717 meters; Wind NE (50°) at 40 knots
850mb: Height 1451 meters; Wind NE (55°) at 40 knots
700mb: Height 3101 meters; Wind NE (45°) at 36 knots
500mb: Height 5840 meters; Wind ENE (55°) at 42 knots
400mb: Height 7570 meters; Wind NE (50°) at 36 knots

[StormsAhead]

URNT40 KWBC 271650
NOAA3 1312A KATRINA
164030 2357 08438 10130 -0147 214080 +105 +104 214081 060 008
164100 2358 08440 10183 -0173 215082 +105 +103 215083 062 008
164130 2359 08441 10175 -0195 214081 +120 +090 215083 066 007
164200 2401 08443 10162 -0217 210081 +129 +098 211084 066 007
164230 2402 08445 10233 -0242 212086 +117 +106 213087 999 999
164300 2403 08447 10193 -0281 213088 +102 +102 215089 999 999
164330 2404 08449 10112 -0329 215091 +112 +112 217093 999 999
164400 2405 08450 10255 -0363 224091 +116 +116 222095 999 999
164430 2406 08452 10282 -0415 226091 +116 +116 228093 999 999
164500 2407 08453 10481 -0444 237085 +123 +123 236095 999 999
164530 2409 08455 10521 -0466 232072 +129 +129 229073 088 008
164600 2410 08457 10478 -0503 227072 +130 +128 227072 084 008
164630 2411 08458 10480 -0548 226069 +142 +112 226070 081 006
164700 2413 08500 10484 -0594 225068 +148 +106 225068 076 005
164730 2414 08501 10491 -0647 224071 +150 +103 226073 071 003
164800 2416 08503 10601 -0700 223076 +151 +097 220077 066 002
164830 2417 08504 10617 -0766 218078 +148 +124 218078 066 006
164900 2418 08506 10717 -0852 214078 +149 +120 216083 067 007
164930 2419 08508 10762 -0938 213056 +156 +150 209061 999 999
165000 2421 08510 10859 -0994 214038 +171 +135 213045 059 004

NOAA flight...95 knots FL

[WindRunner]

Do they usually drop the dropsondes this far from the center?

[jasons2k]

Hail indicates extremely strong updrafts.

[StormsAhead]

SXXX50 KNHC 271657
AF306 WX12A KATRINA01 HDOB 09 KNHC
1647 2539N 08635W 03658 0120 042 044 074 018 044 03825 0000000000
1647. 2538N 08634W 03658 0119 041 044 076 020 044 03824 0000000000
1648 2537N 08632W 03657 0117 044 043 074 022 044 03820 0000000000
1648. 2536N 08631W 03658 0116 045 044 078 020 044 03820 0000000000
1649 2534N 08629W 03658 0114 046 044 076 022 045 03818 0000000000
1649. 2533N 08628W 03658 0112 042 045 076 020 045 03816 0000000000
1650 2532N 08626W 03656 0110 046 046 076 028 048 03812 0000000000
1650. 2531N 08625W 03660 0107 048 049 078 020 050 03813 0000000000
1651 2529N 08624W 03658 0106 045 050 084 018 051 03810 0000000000
1651. 2528N 08622W 03656 0103 046 053 086 020 053 03806 0000000000
1652 2527N 08621W 03657 0100 046 054 078 024 056 03804 0000000000
1652. 2525N 08619W 03656 0098 047 057 074 026 057 03800 0000000000
1653 2524N 08618W 03660 0096 048 058 074 024 058 03802 0000000000
1653. 2523N 08617W 03659 0094 047 058 074 026 058 03798 0000000000
1654 2522N 08615W 03657 0091 046 060 072 028 061 03795 0000000000
1654. 2520N 08614W 03656 0088 046 061 072 026 062 03790 0000000000
1655 2519N 08612W 03658 0085 049 062 068 038 063 03789 0000000000
1655. 2518N 08611W 03658 0082 047 062 066 044 062 03786 0000000000
1656 2517N 08610W 03655 0078 045 061 070 044 062 03779 0000000000
1656. 2515N 08608W 03658 0074 045 062 070 044 062 03778 0000000000

AF flight...63 knots

[StormsAhead]

Do they usually drop the dropsondes this far from the center?

They sometimes send one before going into the core, may want to sample a rainband or something.

[Sanibel]

Its an ERC Sanibel.

I disagree.

It is an Eyewall Replacement Cycle combined with structure shock caused by impacting the CONUS border.

Katrina enjoyed her tropical envelope while moving WSW, but has now hit the CONUS weather border. The impact has caused the outer edges to square off and the inner core to expand into an ERC shock reaction.

The storm has no other reason to jump up in pressure so badly in prime conditions...

[StormsAhead]

URNT40 KWBC 271700
NOAA3 1312A KATRINA
165030 2422 08512 10960 -1031 197022 +172 +128 204027 032 002
165100 2422 08514 10948 -1059 131009 +165 +128 169011 024 002
165130 2421 08516 10968 -1073 350008 +161 +125 329015 026 002
165200 2421 08518 10956 -1045 326032 +150 +132 328038 999 999
165230 2421 08520 10928 -1007 340040 +144 +136 341041 051 006
165300 2422 08521 10536 -0999 355046 +154 +134 000048 057 004
165330 2423 08523 10265 -0977 004061 +159 +144 007065 066 006
165400 2425 08524 10049 -0942 010068 +158 +152 009068 067 006
165430 2426 08525 10017 -0889 016071 +162 +131 017072 065 006
165500 2427 08527 10030 -0824 020072 +172 +100 020073 062 006
165530 2428 08528 10036 -0771 020069 +174 +102 021071 059 005
165600 2430 08530 10028 -0722 023066 +158 +111 021067 056 004
165630 2431 08531 10031 -0673 023065 +153 +109 025067 057 004
165700 2432 08532 10025 -0641 026064 +161 +107 023065 056 004
165730 2433 08534 10034 -0618 029061 +165 +099 030062 059 003
165800 2435 08535 10027 -0588 030059 +161 +100 030059 065 003
165830 2436 08537 10030 -0560 034058 +149 +112 033059 071 005
165900 2438 08539 10031 -0526 033065 +158 +127 036067 074 005
165930 2439 08540 10033 -0485 036072 +159 +132 035074 075 005
170000 2440 08542 10031 -0436 032081 +155 +130 030084 075 005

Outer wall still much stronger...at least 84 knots.

[StormsAhead]

URNT40 KWBC 271710
NOAA3 1312A KATRINA
170030 2442 08543 10028 -0386 033089 +155 +123 035093 073 003
170100 2443 08545 10019 -0347 030083 +147 +113 030084 069 003
170130 2444 08546 10022 -0318 032081 +138 +107 031082 070 003
170200 2445 08548 10034 -0286 032078 +135 +112 033079 068 002
170230 2447 08549 10036 -0257 033078 +135 +100 032079 067 004
170300 2448 08550 10028 -0226 035079 +137 +088 035080 066 003
170330 2450 08552 10025 -0199 037079 +137 +082 037079 064 004
170400 2451 08554 10027 -0171 039076 +132 +089 038076 061 004
170430 2452 08555 10030 -0145 039073 +127 +102 038074 058 003
170500 2454 08557 10026 -0126 043072 +125 +110 042073 057 003
170530 2455 08558 10026 -0108 044069 +121 +104 043070 056 004
170600 2457 08600 10026 -0090 046068 +120 +109 046069 055 003
170630 2458 08602 10032 -0070 047069 +120 +107 047070 055 004
170700 2500 08603 10022 -0052 047070 +117 +104 047070 053 004
170730 2501 08605 10030 -0036 047067 +116 +100 047067 051 003
170800 2502 08606 10031 -0018 043067 +115 +092 045067 050 002
170830 2504 08608 10027 -0004 044067 +118 +093 044068 050 002
170900 2505 08610 10032 +0010 044065 +115 +093 045066 049 002
170930 2507 08611 10031 +0021 043062 +109 +099 042063 050 002
171000 2508 08613 10027 +0033 044062 +108 +100 044062 048 002

93 knots.

[StormsAhead]

URNT12 KNHC 271725
VORTEX DATA MESSAGE
A. 27/1651Z
B. 24 DEG 22 MIN N
85 DEG 15 MIN W
C. 700 MB 2653 M
D. N/A
E. N/A
F. 220 DEG 96 KT
G. 125 DEG 29 NM
H. 949 MB
NOAA3 1312A KATRINA OB 11

Pressure may have become steady...