EPAC: HILDA - Recon

[Kingarabian]

Chris, this is almost unbelievable.

All that shear + dry air and it managed to strengthen enough to have its eyewall closed?

[Kingarabian]

000
URPN15 KNHC 110401
AF303 0310E HILDA HDOB 16 20150811
035200 1736N 14945W 6965 03171 0079 +104 +104 124033 041 039 012 00
035230 1738N 14945W 6963 03177 0084 +098 +098 122031 033 038 008 00
035300 1740N 14945W 6975 03162 0092 +088 //// 111024 031 036 009 05
035330 1742N 14946W 6958 03184 0073 +090 +086 113027 029 /// /// 05
035400 1742N 14947W 6971 03165 0067 +090 +086 121027 029 /// /// 05
035430 1740N 14948W 6974 03168 //// +092 //// 133030 034 033 002 01
035500 1739N 14950W 6969 03171 0061 +098 +087 129032 036 033 002 01
035530 1738N 14951W 6967 03173 0069 +095 +086 130032 034 032 001 00
035600 1736N 14952W 6968 03172 //// +089 //// 137041 042 030 001 01
035630 1735N 14953W 6970 03167 //// +090 //// 138040 042 029 001 01
035700 1734N 14955W 6970 03166 //// +094 //// 139042 043 028 002 01
035730 1733N 14956W 6961 03173 //// +094 //// 138039 042 030 003 01
035800 1731N 14957W 6964 03169 0059 +096 +090 135037 038 030 003 00
035830 1730N 14959W 6966 03167 0057 +097 +086 130036 037 032 003 00
035900 1729N 15000W 6969 03163 0058 +095 +086 129035 035 035 004 00
035930 1728N 15001W 6969 03162 0061 +092 +090 127035 036 037 006 00
040000 1726N 15003W 6966 03165 0062 +093 +092 130038 039 038 006 00
040030 1725N 15004W 6967 03163 0057 +096 +094 129038 039 038 006 00
040100 1724N 15005W 6965 03161 0057 +095 //// 128041 043 041 005 01
040130 1722N 15007W 6967 03155 0050 +099 +098 125042 043 040 008 00
$$
;

[Chris_in_Tampa]

That first vortex did note it as being closed:

Product: Air Force Vortex Message (URPN12 KNHC)
Transmitted: 11th day of the month at 3:33Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5303
Storm Number & Year: 10 in 2015
Storm Name: Hilda (flight in the Northeast Pacific basin)
Mission Number: 3
Observation Number: 06
A. Time of Center Fix: 11th day of the month at 3:17:10Z
B. Center Fix Coordinates: 16°48'N 150°37'W (16.8N 150.6167W)
C. Minimum Height at Standard Level: 2,954m (9,692ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 80kts (~ 92.1mph)
E. Location of the Estimated Maximum Surface Wind: 3 nautical miles (3 statute miles) to the WNW (286°) of center fix
F. Maximum Flight Level Wind Inbound: From 28° at 81kts (From the NNE at ~ 93.2mph)
G. Location of Maximum Flight Level Wind Inbound: 10 nautical miles (12 statute miles) to the WNW (287°) of center fix
H. Minimum Sea Level Pressure: 981mb (28.97 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 12°C (54°F) at a pressure alt. of 3,050m (10,007ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 3,047m (9,997ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 8°C (46°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Closed
M. Eye Shape & Diameter: Circular with a diameter of 28 nautical miles (32 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: 1.5 nautical miles

Remarks Section:
Maximum Outbound and Flight Level Wind: 84kts (~ 96.7mph) which was observed 12 nautical miles (14 statute miles) to the SE (134°) from the flight level center at 3:20:30Z
Dropsonde Surface Wind at Center: From 350° at 5kts (From the N at 6mph)

[Chris_in_Tampa]

It is impressive it remains stacked despite the high analysed shear. The flight level center and surface center are aligned. When the sonde fell from flight level it landed where the surface center is, with just 5 knots of wind from the north.

[Chris_in_Tampa]

Through 4:11:30Z:

[Kingarabian]

000
URPN15 KNHC 110411
AF303 0310E HILDA HDOB 17 20150811
040200 1721N 15008W 6969 03152 0049 +103 +103 130046 048 040 007 00
040230 1720N 15009W 6969 03148 0051 +101 +101 128048 049 041 007 00
040300 1719N 15011W 6963 03152 0058 +102 +102 127049 049 041 011 00
040330 1717N 15012W 6965 03147 0065 +100 +100 128054 057 043 015 00
040400 1716N 15013W 6962 03147 0055 +096 +096 131058 059 047 009 00
040430 1715N 15014W 6967 03139 0031 +099 +099 131060 060 046 009 00
040500 1714N 15016W 6974 03128 0042 +095 +095 127060 063 046 006 00
040530 1712N 15017W 6970 03129 0053 +092 +092 127062 063 048 008 00
040600 1711N 15018W 6966 03124 0044 +091 +091 127063 063 051 011 00
040630 1710N 15020W 6968 03115 0039 +092 +092 128068 072 052 015 00
040700 1709N 15021W 6951 03123 0033 +096 +096 127072 074 052 034 00
040730 1707N 15022W 6957 03117 0026 +099 +099 126072 074 059 028 00
040800 1706N 15024W 6965 03093 0000 +107 +107 134075 077 060 025 00
040830 1705N 15025W 6960 03098 9985 +115 +115 133076 077 064 017 00
040900 1704N 15026W 6979 03072 9983 +114 +114 138074 076 066 014 00
040930 1703N 15027W 6941 03102 9961 +115 +115 143079 080 071 011 00
041000 1702N 15028W 6975 03050 9950 +115 +115 141078 079 071 011 00
041030 1700N 15030W 6968 03050 9900 +130 +130 138056 075 068 007 00
041100 1659N 15031W 6972 03032 9871 +133 //// 133043 050 071 006 01
041130 1658N 15032W 6967 03026 9860 +130 +128 121036 042 074 004 00
$$
;

[Yellow Evan]

It is impressive it remains stacked despite the high analysed shear. The flight level center and surface center are aligned. When the sonde fell from flight level it landed where the surface center is, with just 5 knots of wind from the north.

I'm not sure if the shear analyzed is real. This is why they should have sent a mission to sample the upper atmosphere.

[Chris_in_Tampa]

I'm not sure if the shear analyzed is real. This is why they should have sent a mission to sample the upper atmosphere.

That's why I say analysed. That's beyond what I can tell. You can tell there is some shear by looking at a satellite loop shearing some of the convection, but how many knots I don't know.

[Kingarabian]

It is impressive it remains stacked despite the high analysed shear. The flight level center and surface center are aligned. When the sonde fell from flight level it landed where the surface center is, with just 5 knots of wind from the north.

I'm not sure if the shear analyzed is real. This is why they should have sent a mission to sample the upper atmosphere.

Precisely what I was asking for.

[Alyono]

:uarrow:

Chris, this is almost unbelievable.

All that shear + dry air and it managed to strengthen enough to have its eyewall closed?

my suspicion is that the shear plots are dead wrong. 40 kts of shear would decapitate a small TC. This seems like 20 kts of shear

[Chris_in_Tampa]

[Kingarabian]

000
URPN15 KNHC 110421
AF303 0310E HILDA HDOB 18 20150811
041200 1657N 15034W 6970 03005 9827 +143 +115 110030 034 073 005 00
041230 1655N 15035W 6969 03002 9810 +151 +110 103024 028 060 004 03
041300 1654N 15036W 6963 03003 9791 +164 +102 096017 021 039 002 00
041330 1652N 15036W 6969 02989 9768 +182 +088 071008 014 027 001 03
041400 1650N 15036W 6966 02993 9761 +189 +081 303003 005 028 002 00
041430 1649N 15034W 6969 02994 9769 +186 +083 242012 017 031 002 03
041500 1647N 15035W 6966 02997 9774 +183 +085 245028 030 026 000 03
041530 1646N 15036W 6953 03015 9775 +180 +084 256036 040 023 002 00
041600 1645N 15037W 6966 03004 9779 +182 +083 263042 044 020 002 00
041630 1644N 15038W 6966 03006 9781 +183 +083 273048 050 021 000 03
041700 1643N 15039W 6983 02995 9808 +167 +093 283053 054 031 001 00
041730 1642N 15041W 6967 03021 9829 +154 +105 286058 065 041 001 00
041800 1641N 15042W 6969 03033 9853 +148 +105 289061 066 055 001 03
041830 1640N 15043W 7004 02988 9846 +160 +092 293075 078 063 001 00
041900 1639N 15044W 7036 02967 9863 +164 +067 296078 080 068 000 03
041930 1639N 15045W 6986 03043 9884 +150 +077 299073 076 068 000 00
042000 1638N 15047W 6966 03081 9916 +134 +084 302067 071 065 003 00
042030 1637N 15048W 6963 03099 9948 +118 +092 305060 064 061 002 00
042100 1636N 15049W 6966 03104 9962 +117 +091 311058 059 049 001 03
042130 1635N 15051W 6974 03106 9985 +108 +096 317055 057 046 000 03
$$
;

[Chris_in_Tampa]

NE to SW pass:

Lowest Extrapolated Sfc. Pressure: 976.1 mb
Flight Level Wind (30 sec. Avg.): 79 knots (90.9 mph)
Peak (10 sec. Avg.) Flight Level Wind: 80 knots (~ 92.1 mph)
SFMR Peak (10s Avg.) Sfc. Wind: 74 knots (~ 85.2 mph)

[Chris_in_Tampa]

983mb with 18 knots of surface wind

UZPN13 KNHC 110427
XXAA 61047 99168 71506 05260 99983 26414 13518 00650 ///// /////
92540 24427 14522 85279 20809 14015 70959 19461 31502 88999 77999
31313 09608 80413
61616 AF303 0310E HILDA OB 12
62626 CENTER MBL WND 14022 AEV 07775 DLM WND 16015 983696 WL150 1
3522 084 REL 1684N15060W 041351 SPG 1685N15059W 041836 =
XXBB 61048 99168 71506 05260 00983 26414 11944 25634 22850 20809
33812 18611 44780 19245 55755 21661 66712 21063 77696 19061
21212 00983 13518 11980 13522 22953 13025 33927 15022 44919 14020
55872 14515 66850 14015 77799 15019 88779 17518 99768 21523 11758
21024 22722 20511 33696 33504
31313 09608 80413
61616 AF303 0310E HILDA OB 12
62626 CENTER MBL WND 14022 AEV 07775 DLM WND 16015 983696 WL150 1
3522 084 REL 1684N15060W 041351 SPG 1685N15059W 041836 =

[Yellow Evan]

:uarrow:

Chris, this is almost unbelievable.

All that shear + dry air and it managed to strengthen enough to have its eyewall closed?

my suspicion is that the shear plots are dead wrong. 40 kts of shear would decapitate a small TC. This seems like 20 kts of shear

Agreed. There's clearly not zero shear as the storm isn't too organized, but it's not rapidly falling apart, though part of it might have to do with strong outflow and ITCZ support.

[Chris_in_Tampa]

UZPN13 KNHC 110425
XXAA 61047 99171 71504 05270 99996 25203 05066 00539 ///// /////
92646 21803 08592 85379 18803 11080 70034 11601 14072 88999 77999
31313 09608 80408
61616 AF303 0310E HILDA OB 11
62626 EYEWALL 045 MBL WND 07079 AEV 07775 DLM WND 10572 995697 WL
150 05580 084 REL 1707N15043W 040855 SPG 1709N15054W 041335 =
XXBB 61048 99171 71504 05270 00996 25203 11850 18803 22697 11400
21212 00996 05066 11992 05074 22988 06080 33980 06085 44973 06581
55967 07092 66957 07576 77948 08074 88927 08592 99910 08580 11903
09083 22895 09579 33882 10085 44873 10574 55869 11076 66861 11088
77854 11085 88850 11080 99697 14071
31313 09608 80408
61616 AF303 0310E HILDA OB 11
62626 EYEWALL 045 MBL WND 07079 AEV 07775 DLM WND 10572 995697 WL
150 05580 084 REL 1707N15043W 040855 SPG 1709N15054W 041335 =





A lot of those higher elevations on Hawaii, the Big Island, will be getting higher winds than at the surface. A look at a comparison from a sonde of the winds (momentary winds) at various levels.

[Chris_in_Tampa]

URPN12 KNHC 110427
VORTEX DATA MESSAGE EP102015
A. 11/04:14:00Z
B. 16 deg 50 min N
150 deg 36 min W
C. 700 mb 2953 m
D. 74 kt
E. 033 deg 7 nm
F. 143 deg 80 kt
G. 039 deg 13 nm
H. 983 mb
I. 12 C / 3045 m
J. 19 C / 3050 m
K. 8 C / NA
L. OPEN SE
M. C32
N. 12345 / 7
O. 0.02 / 1 nm
P. AF303 0310E HILDA OB 10
MAX FL WIND 84 KT 146 / 15 NM 03:20:30Z
CNTR DROPSONDE SFC WIND 135 / 18 KT
;

[Chris_in_Tampa]

Product: Air Force Vortex Message (URPN12 KNHC)
Transmitted: 11th day of the month at 4:27Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5303
Storm Number & Year: 10 in 2015
Storm Name: Hilda (flight in the Northeast Pacific basin)
Mission Number: 3
Observation Number: 10
A. Time of Center Fix: 11th day of the month at 4:14:00Z
B. Center Fix Coordinates: 16°50'N 150°36'W (16.8333N 150.6W)
C. Minimum Height at Standard Level: 2,953m (9,688ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 74kts (~ 85.2mph)
E. Location of the Estimated Maximum Surface Wind: 7 nautical miles (8 statute miles) to the NNE (33°) of center fix
F. Maximum Flight Level Wind Inbound: From 143° at 80kts (From the SE at ~ 92.1mph)
G. Location of Maximum Flight Level Wind Inbound: 13 nautical miles (15 statute miles) to the NE (39°) of center fix
H. Minimum Sea Level Pressure: 983mb (29.03 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 12°C (54°F) at a pressure alt. of 3,045m (9,990ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 3,050m (10,007ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 8°C (46°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Open in the southeast
M. Eye Shape & Diameter: Circular with a diameter of 32 nautical miles (37 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile

Remarks Section:
Maximum Flight Level Wind: 84kts (~ 96.7mph) which was observed 15 nautical miles (17 statute miles) to the SE/SSE (146°) from the flight level center at 3:20:30Z
Dropsonde Surface Wind at Center: From 135° at 18kts (From the SE at 21mph)

[Chris_in_Tampa]

Through 4:41:30Z:



The 983mb should be a little lower because the surface center was missed. The wind was from the SE at 18 knots at the surface. The sonde icon is where the vortex coordinates are, usually from the flight level center it seems. The surface center should be somewhat to the SW from that icon. It did move in the direction it appears it did based on vortex messages from the first and second pass.

[Kingarabian]

000
URPN15 KNHC 110441
AF303 0310E HILDA HDOB 20 20150811
043200 1609N 15118W 6967 03170 0059 +100 +066 309014 015 013 000 00
043230 1608N 15119W 6960 03178 0065 +096 +068 312015 015 010 001 03
043300 1606N 15118W 6965 03172 0068 +094 +070 311015 015 013 000 00
043330 1606N 15116W 6965 03172 0068 +095 +071 312015 016 014 000 00
043400 1605N 15114W 6967 03170 0071 +092 +073 316015 015 016 000 00
043430 1604N 15112W 6965 03174 0074 +090 +074 314017 018 015 000 00
043500 1603N 15110W 6963 03173 0073 +090 +077 312019 019 016 000 00
043530 1602N 15109W 6966 03170 0072 +091 +075 311019 019 016 000 00
043600 1602N 15107W 6970 03164 0069 +090 +074 308019 020 017 000 00
043630 1601N 15105W 6967 03170 0069 +091 +075 303019 020 017 000 00
043700 1600N 15103W 6965 03170 0068 +091 +076 302020 021 016 000 00
043730 1559N 15101W 6970 03162 0065 +092 +076 300020 020 017 000 00
043800 1558N 15059W 6967 03164 0067 +089 +079 295020 021 019 000 00
043830 1558N 15058W 6963 03169 0067 +090 +079 297020 021 017 000 00
043900 1557N 15056W 6962 03169 0061 +094 +077 292022 022 014 001 00
043930 1556N 15054W 6967 03166 0064 +092 +078 288020 022 014 000 00
044000 1555N 15052W 6966 03167 0069 +089 +081 284019 021 012 000 00
044030 1554N 15050W 6961 03174 0068 +090 +080 285020 021 015 000 00
044100 1553N 15048W 6967 03167 //// +084 //// 273021 022 017 000 01
044130 1553N 15047W 6970 03164 //// +080 //// 265021 022 013 001 01
$$
;