ATL: IRMA - Post-Tropical - Discussion

[cycloneye]

CATEGORY 4

AL, 11, 2017090418, , BEST, 0, 167N, 539W, 115, 944, HU

[KWT]

looks like we have a cat 4 now...

Yeah the winds probably do justify it, there was a decent amount of rainfall at the time though and FL winds aren't that impressive, the NHC may go to 110kts instead of the 115kts that the evidence probably backs up. We will see soon enough. my gut is an upgrade may well happen, especially if they get another run with such wind speeds.

EDIT- no sooner do I post that then 115kts confirmed!

Interesting that it is getting stronger despite the eye starting to cloud over again.

[RL3AO]

No more clear double maxima. EWRC wrapping up. Strong cat 4 or even a 5 seems possible by tomorrow.

[Ken711]

How does speed of Irma compare to Matthew coming up the east coast of FL?

[Extratropical94]

URNT15 KNHC 041854
AF309 0311A IRMA HDOB 30 20170904
184500 1622N 05426W 6973 03013 9918 +086 //// 322075 078 062 010 01
184530 1621N 05427W 6965 03031 9939 +080 +080 322071 073 060 006 00
184600 1620N 05428W 6961 03052 9942 +084 //// 317068 070 059 008 01
184630 1618N 05430W 6972 03042 9952 +083 +083 318068 069 057 006 00
184700 1617N 05431W 6964 03058 9966 +077 //// 319066 068 055 006 01
184730 1616N 05432W 6966 03064 9968 +075 +074 314063 065 053 005 00
184800 1615N 05433W 6968 03068 9969 +081 +076 317062 064 052 003 00
184830 1613N 05435W 6973 03069 9990 +076 +074 319061 062 050 007 03
184900 1612N 05436W 6964 03083 9985 +080 +075 312058 061 048 003 00
184930 1611N 05437W 6969 03085 9981 +086 +074 312055 056 045 002 00
185000 1610N 05438W 6967 03087 9978 +091 +071 313054 055 045 002 00
185030 1608N 05440W 6970 03088 9980 +093 +068 313054 055 044 001 00
185100 1607N 05441W 6967 03092 9983 +095 +068 316054 055 042 000 00
185130 1606N 05442W 6970 03096 9991 +092 +064 315054 055 040 000 00
185200 1604N 05443W 6969 03097 9991 +095 +065 318053 054 040 001 03
185230 1603N 05445W 6962 03110 0014 +084 +074 316052 053 040 001 03
185300 1602N 05446W 6955 03119 0016 +092 +092 313048 053 037 011 03
185330 1601N 05447W 6983 03092 0016 +083 +080 319047 050 038 007 00
185400 1559N 05448W 6963 03116 0013 +085 +073 318044 046 038 003 00
185430 1558N 05450W 6967 03115 0011 +087 +080 315044 045 037 001 03

[Sanibel]

Interested to see how GFS compares to the latest Euro east coast of Florida track...

[Hurricane Andrew]

No more clear double maxima. EWRC wrapping up. Strong cat 4 or even a 5 seems possible by tomorrow.

Worryingly, I agree...

[Extratropical94]

center dropsonde, 944 mb with 6 knots

UZNT13 KNHC 041859
XXAA 54197 99167 70540 04264 99944 27410 20006 00/// ///// /////
92179 26211 21008 85925 23014 23508 70604 15815 01003 88999 77999
31313 09608 81836
61616 AF309 0311A IRMA OB 13
62626 CENTER MBL WND 21007 AEV 33304 DLM WND 24005 943689 WL150 2
0508 080 REL 1671N05404W 183618 SPG 1672N05403W 184020 =
XXBB 54198 99167 70540 04264 00944 27410 11850 23014 22702 16216
33689 14011
21212 00944 20006 11896 22006 22885 23010 33850 23508 44689 02505
31313 09608 81836
61616 AF309 0311A IRMA OB 13
62626 CENTER MBL WND 21007 AEV 33304 DLM WND 24005 943689 WL150 2
0508 080 REL 1671N05404W 183618 SPG 1672N05403W 184020 =

[NDG]

Spiral Eye?
First time seeing that description.

URNT12 KNHC 041859
VORTEX DATA MESSAGE AL112017
A. 04/18:36:10Z
B. 16 deg 43 min N
054 deg 01 min W
C. 700 mb 2611 m
D. 113 kt
E. 056 deg 16 nm
F. 141 deg 121 kt
G. 054 deg 21 nm
H. 944 mb
I. 8 C / 3047 m
J. 16 C / 3051 m
K. 13 C / NA
L. SPIRAL
M. C20
N. 12345 / 07
O. 0.02 / 1 nm
P. AF309 0311A IRMA OB 12
MAX FL WIND 121 KT 054 / 21 NM 18:29:00Z
CNTR DROPSONDE SFC WIND 200 / 6 KT

[Extratropical94]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 4th day of the month at 18:59Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF99-5309
Storm Number & Year: 11 in 2017
Storm Name: Irma (flight in the North Atlantic basin)
Mission Number: 3
Observation Number: 12
A. Time of Center Fix: 4th day of the month at 18:36:10Z
B. Center Fix Coordinates: 16°43'N 54°01'W (16.7167N 54.0167W)
B. Center Fix Location: 449 statute miles (722 km) to the NE (56°) from Bridgetown, Barbados.
C. Minimum Height at Standard Level: 2,611m (8,566ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 113kts (~ 130.0mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 16 nautical miles (18 statute miles) to the NE/ENE (56°) of center fix
F. Maximum Flight Level Wind Inbound: From 141° at 121kts (From the SE at ~ 139.2mph)
G. Location of Maximum Flight Level Wind Inbound: 21 nautical miles (24 statute miles) to the NE (54°) of center fix
H. Minimum Sea Level Pressure: 944mb (27.88 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 8°C (46°F) at a pressure alt. of 3,047m (9,997ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 16°C (61°F) at a pressure alt. of 3,051m (10,010ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 13°C (55°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character (Undecoded): SPIRAL
M. Eye Shape & Diameter: Circular with a diameter of 20 nautical miles (23 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile

Remarks Section:
Maximum Flight Level Wind: 121kts (~ 139.2mph) which was observed 21 nautical miles (24 statute miles) to the NE (54°) from the flight level center at 18:29:00Z
Dropsonde Surface Wind at Center: From 200° at 6kts (From the SSW at 7mph)

[NDG]

How does speed of Irma compare to Matthew coming up the east coast of FL?

If memory serves me correct Matthew was moving a little faster east of FL than what the Euro is forecasting.

[stormreader]

Interested to see how GFS compares to the latest Euro east coast of Florida track...

Becoming more "interesting" for SW Fl now. Any further west shifts at all put it into the keys. Also, looking at later track, I see that push back west into Savannah. Telling me that overall west tendencies are increasing in connection with the forecast north turn.

[GCANE]

[Extratropical94]

URNT15 KNHC 041904
AF309 0311A IRMA HDOB 31 20170904
185500 1557N 05451W 6968 03115 0011 +091 +079 314045 046 036 000 00
185530 1555N 05452W 6967 03118 0014 +090 +075 315046 047 034 001 00
185600 1554N 05453W 6963 03124 0028 +087 +077 316046 047 038 008 00
185630 1553N 05455W 6975 03112 0026 +082 //// 316043 046 033 006 01
185700 1552N 05456W 6966 03130 0019 +091 +077 317041 043 033 001 00
185730 1550N 05457W 6967 03124 0022 +092 +067 315041 042 034 000 00
185800 1549N 05459W 6969 03126 0019 +097 +055 316041 042 032 000 00
185830 1548N 05500W 6967 03131 0022 +097 +054 317040 041 032 000 00
185900 1546N 05501W 6966 03134 0023 +099 +050 317039 039 031 000 00
185930 1545N 05502W 6967 03134 0022 +102 +048 316039 040 030 001 00
190000 1544N 05504W 6969 03132 0022 +100 +053 314038 039 031 001 00
190030 1543N 05505W 6970 03130 0022 +099 +063 317039 040 029 006 00
190100 1541N 05506W 6965 03141 0032 +095 +060 316038 038 030 000 00
190130 1540N 05507W 6969 03134 0036 +091 +063 317038 039 029 002 00
190200 1539N 05509W 6966 03144 0034 +096 +041 312037 038 030 001 00
190230 1537N 05510W 6965 03145 0034 +098 +034 312038 038 030 000 03
190300 1536N 05511W 6970 03138 0030 +102 +030 312037 038 030 000 00
190330 1535N 05512W 6967 03142 0034 +101 +030 309035 036 030 001 00
190400 1534N 05514W 6965 03145 0027 +109 +022 316035 036 030 000 00
190430 1532N 05515W 6969 03143 0033 +105 +034 315034 036 028 000 00

[GCANE]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 4th day of the month at 18:59Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF99-5309
Storm Number & Year: 11 in 2017
Storm Name: Irma (flight in the North Atlantic basin)
Mission Number: 3
Observation Number: 12 ( See all messages of this type for this mission. )
A. Time of Center Fix: 4th day of the month at 18:36:10Z
B. Center Fix Coordinates: 16°43'N 54°01'W (16.7167N 54.0167W)
B. Center Fix Location: 449 statute miles (722 km) to the NE (56°) from Bridgetown, Barbados.
C. Minimum Height at Standard Level: 2,611m (8,566ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 113kts (~ 130.0mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 16 nautical miles (18 statute miles) to the NE/ENE (56°) of center fix
F. Maximum Flight Level Wind Inbound: From 141° at 121kts (From the SE at ~ 139.2mph)
G. Location of Maximum Flight Level Wind Inbound: 21 nautical miles (24 statute miles) to the NE (54°) of center fix
H. Minimum Sea Level Pressure: 944mb (27.88 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 8°C (46°F) at a pressure alt. of 3,047m (9,997ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 16°C (61°F) at a pressure alt. of 3,051m (10,010ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 13°C (55°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character (Undecoded): SPIRAL
M. Eye Shape & Diameter: Circular with a diameter of 20 nautical miles (23 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile

Remarks Section:
Maximum Flight Level Wind: 121kts (~ 139.2mph) which was observed 21 nautical miles (24 statute miles) to the NE (54°) from the flight level center at 18:29:00Z
Dropsonde Surface Wind at Center: From 200° at 6kts (From the SSW at 7mph)

[hohnywx]

 https://twitter.com/MJVentrice/status/904781019492093952

[Ken711]

How does speed of Irma compare to Matthew coming up the east coast of FL?

If memory serves me correct Matthew was moving a little faster east of FL than what the Euro is forecasting.

Thanks.

[Extratropical94]

[tropicwatch]

Cat 4 based on recon?

[GCANE]

May not make the next forecast point