Rita Recon Reports

[cycloneye]

SXXX50 KNHC 230110
AF309 2018A RITA HDOB 21 KNHC
0059. 2445N 08956W 03018 0004 257 072 088 088 072 03057 0000000000
0100 2445N 08954W 03018 0005 256 071 094 094 072 03058 0000000000
0100. 2445N 08951W 03017 0005 253 071 094 094 072 03058 0000000000
0101 2445N 08949W 03017 0005 251 072 098 092 072 03058 0000000000
0101. 2445N 08946W 03018 0006 251 072 096 092 072 03059 0000000000
0102 2445N 08944W 03017 0008 245 071 098 088 071 03060 0000000000
0102. 2444N 08941W 03018 0009 246 070 100 088 072 03063 0000000000
0103 2444N 08939W 03016 0010 246 066 104 092 067 03063 0000000000
0103. 2444N 08936W 03020 0012 247 068 104 086 070 03068 0000000000
0104 2444N 08934W 03016 0012 246 074 098 082 075 03064 0000000000
0104. 2443N 08931W 03017 0014 246 076 094 082 077 03067 0000000000
0105 2443N 08929W 03018 0015 245 076 094 080 077 03068 0000000000
0105. 2444N 08926W 03016 0017 241 073 100 078 075 03069 0000000000
0106 2444N 08924W 03016 0018 239 072 102 074 073 03070 0000000000
0106. 2445N 08921W 03017 0018 237 071 106 066 072 03071 0000000000
0107 2445N 08919W 03018 0020 236 072 102 062 072 03074 0000000000
0107. 2446N 08916W 03016 0021 232 070 112 056 071 03073 0000000000
0108 2446N 08914W 03016 0022 229 067 108 074 068 03074 0000000000
0108. 2446N 08911W 03018 0026 227 062 100 100 064 03080 0000000000
0109 2446N 08909W 03018 0027 224 055 104 104 056 03081 0000000000

[wjs3]

I'll say it has, since it's in the NW quad of the storm is usually one of the weaker ones.

Rita is moving just north of west... this places the strongest theoretical winds about north, so the NW quad isnt going to be 'weak.'

I thought winds were reported as storm relative, meaning that regardless of direction or speed of motion, winds are measured the same in all storms?

Yes, they are. The point in the earlier posts is that the strongest winds in a Tropical Cyclone are typically in the front right quadrant relative to the storm's forward motion. that's what the dscussion above is about--whether Recon has sampled the strongest winds in the storm or not.

[wjs3]

Thanks wjs!

You're welcome

[soonertwister]

I'll say it has, since it's in the NW quad of the storm is usually one of the weaker ones.

Rita is moving just north of west... this places the strongest theoretical winds about north, so the NW quad isnt going to be 'weak.'

I thought winds were reported as storm relative, meaning that regardless of direction or speed of motion, winds are measured the same in all storms?

Yes, they are. The point in the earlier posts is that the strongest winds in a Tropical Cyclone are typically in the front right quadrant relative to the storm's forward motion. that's what the dscussion above is about--whether Recon has sampled the strongest winds in the storm or not.

I had always assumed that in the northern hemisphere the strongest winds were generally found in the northeast quadrant regardless of the direction of motion of the storm - north, south, east, west, or anywhere in between.

[wjs3]

Sooner Twister...

It's relative to the storm motion according to the FAQ at NHC:

http://www.aoml.noaa.gov/hrd/tcfaq/D6.html

[cycloneye]

SXXX50 KNHC 230120
AF309 2018A RITA HDOB 22 KNHC
0109. 2446N 08907W 03019 0029 220 056 100 098 058 03084 0000000000
0110 2446N 08905W 03019 0033 223 060 102 086 060 03088 0000000000
0110. 2446N 08902W 03015 0036 223 060 102 068 060 03087 0000000000
0111 2446N 08900W 03017 0038 222 060 104 062 060 03091 0000000000
0111. 2446N 08858W 03019 0041 217 060 104 064 060 03096 0000000000
0112 2446N 08855W 03016 0044 218 060 100 066 061 03095 0000000000
0112. 2446N 08853W 03016 0046 218 060 092 070 060 03098 0000000000
0113 2446N 08851W 03017 0047 215 059 088 080 059 03100 0000000000
0113. 2447N 08849W 03017 0049 214 059 092 082 059 03101 0000000000
0114 2447N 08847W 03022 0055 208 058 094 080 058 03114 0000000000
0114. 2449N 08846W 03015 0055 205 057 096 080 057 03106 0000000000
0115 2450N 08847W 03015 0046 210 056 092 082 056 03097 0000000000
0115. 2451N 08849W 03018 0043 210 057 092 078 058 03097 0000000000
0116 2453N 08850W 03019 0041 210 058 094 070 059 03096 0000000000
0116. 2454N 08852W 03018 0038 207 059 102 064 060 03091 0000000000
0117 2455N 08853W 03013 0035 212 061 100 066 062 03084 0000000000
0117. 2457N 08855W 03021 0031 210 062 096 078 063 03088 0000000000
0118 2458N 08856W 03019 0028 210 061 090 090 062 03083 0000000000
0118. 2459N 08858W 03014 0023 209 060 090 090 060 03073 0000000000
0119 2501N 08859W 03015 0020 212 061 102 102 061 03071 0000000000

[Wthrman13]

I'll say it has, since it's in the NW quad of the storm is usually one of the weaker ones.

Rita is moving just north of west... this places the strongest theoretical winds about north, so the NW quad isnt going to be 'weak.'

I thought winds were reported as storm relative, meaning that regardless of direction or speed of motion, winds are measured the same in all storms?

Yes, they are. The point in the earlier posts is that the strongest winds in a Tropical Cyclone are typically in the front right quadrant relative to the storm's forward motion. that's what the dscussion above is about--whether Recon has sampled the strongest winds in the storm or not.

I had always assumed that in the northern hemisphere the strongest winds were generally found in the northeast quadrant regardless of the direction of motion of the storm - north, south, east, west, or anywhere in between.

Nope, this has been explained many times before. For a exactly circular vortex (with intensity the same in all sectors), the strongest winds will be found to the right of the direction of motion in the northern hemisphere, and to the left in the southern. Obviously a real tropical cyclone isn't exactly symmetric, but it approximately is, so the same principle applies. For example consider a Category 3 hurricane with 115 mph maximum winds that is initially stationary. For simplicity assume that the winds are the same at flight level and at ground level (merely for the sake of argument) A recon aircraft sampling the winds will find 115 mph max winds in all quadrants. Now, suppose this idealized hurricane begins to move to the west at 15 mph, without changing its intensity. The wind speeds will now reflect the effect of vector addition of the forward motion. So, on the north side of the storm, the winds will add to the forward motion, yielding 130 mph winds relative to the surface, while on the south side, the winds will subtract from the forward motion, yielding winds of 100 mph there.

Does this make sense? I think I've had to explain this something like 5 times on this board in the past year

[cycloneye]

SXXX50 KNHC 230130
AF309 2018A RITA HDOB 23 KNHC
0119. 2502N 08900W 03020 0018 213 065 102 094 068 03074 0000000000
0120 2503N 08902W 03016 0014 215 070 106 062 071 03065 0000000000
0120. 2504N 08903W 03016 0011 217 073 106 060 075 03063 0000000000
0121 2506N 08904W 03019 0006 218 075 094 072 075 03061 0000000000
0121. 2507N 08906W 03018 0003 216 073 090 086 074 03057 0000000000
0122 2508N 08907W 03017 5001 214 069 102 092 070 03051 0000000000
0122. 2510N 08909W 03017 5006 215 071 104 098 074 03046 0000000000
0123 2511N 08910W 03018 5011 216 077 090 090 078 03043 0000000000
0123. 2512N 08911W 03016 5015 217 079 086 086 081 03037 0000000000
0124 2513N 08913W 03016 5022 217 073 080 080 076 03030 0000000000
0124. 2515N 08914W 03024 5025 221 059 084 084 064 03035 0000000000
0125 2516N 08915W 03010 5026 223 057 094 094 058 03020 0000000000
0125. 2517N 08917W 03020 5030 220 057 108 108 058 03026 0000000000
0126 2518N 08918W 03016 5033 221 060 112 112 062 03019 0000000000
0126. 2520N 08919W 03018 5036 221 065 116 114 067 03018 0000000000
0127 2521N 08921W 03017 5040 220 067 120 104 068 03013 0000000000
0127. 2522N 08922W 03016 5046 221 067 118 106 068 03006 0000000000
0128 2523N 08924W 03018 5050 221 065 120 110 066 03003 0000000000
0128. 2525N 08925W 03017 5055 224 067 122 102 067 02997 0000000000
0129 2526N 08926W 03018 5060 225 069 118 104 069 02993 0000000000

[gotoman38]

what are the important numbers to look for, and does anyone have a guide on how to decode this kinda stuff?

This is an airforce recon flight minobs reading....

I'll attempt

left to right:

time lat long alt dval wdir wspd airtemp dewpt maxwnd radaralt status

0119 2501N 08859W 03015 0020 212 061 102 102 061 03071 0000000000

is:
1:19 zulu (9:19 pm edt)
25 deg 01 min north
88 deg 59 min west
3015 meters pressure altitude
20 D value ?
212 deg wind direction
61 knots wind
10.2 C temperature
10.2 C dew point
61 max wind (kts)
3071 meters radar altitude
all status OK

pls correct if need be

[LTHLBLU]

what are the important numbers to look for, and does anyone have a guide on how to decode this kinda stuff?

This is an airforce recon flight minobs reading....

I'll attempt

left to right:

time lat long alt dval wdir wspd airtemp dewpt maxwnd radaralt status

0119 2501N 08859W 03015 0020 212 061 102 102 061 03071 0000000000

is:
1:19 zulu (9:19 pm edt)
25 deg 01 min north
88 deg 59 min west
3015 meters pressure altitude
20 D value ?
212 deg wind direction
61 knots wind
10.2 C temperature
10.2 C dew point
61 max wind (kts)
3071 meters radar altitude
all status OK

pls correct if need be

thanks, that helps

[cycloneye]

URNT14 KNHC 230048
SUPPLEMENTARY VORTEX DATA MESSAGE
INBOUND
LAT LON jHHH TTDD ddfff
01273 10886 13052 10808 14072
02271 20888 23031 20909 13072
03269 30890 33002 30808 13080
04268 40891 43969 41111 12074
05266 50893 53919 51010 13078
06264 60895 63826 61010 13105
07262 70897 73603 71513 14104
MF262 M0896 MF123
OBS 01 AT 23:38:30Z
OBS 07 AT 00:06:10Z
OBS 01 SFC WND /////
OUTBOUND
LAT LON jHHH TTDD ddfff
01258 10901 13581 11413 32095
02257 20903 23813 21010 32095
03255 30905 33907 30909 32078
04253 40907 43955 41010 32061
05251 50909 53988 51010 33073
06250 60911 63021 61008 31065
MF258 M0902 MF123
OBS 01 AT 00:15:20Z
OBS 06 AT 00:37:00Z
OBS 06 SFC WND /////
AF309 2018A RITA OB 09

[soonertwister]

Sooner Twister...

It's relative to the storm motion according to the FAQ at NHC:

http://www.aoml.noaa.gov/hrd/tcfaq/D6.html

I am aware of that FAQ. What I'm trying to say here is that if the strongest winds are at 45 degrees (NE) and the storm motion is at 315 degrees (NW), then 90 degrees to the right of the storm motion people will experience the highest apparent winds, because the storm relative wind speed + forward motion = effective wind.

Using that formula, if the winds in the northeast quadrant are 20 mph faster than those in the southwest quadrant, and the hurricane is moving in the rather unusual direction of southeast, then the strongest apparent winds will only be 90 degrees to the right of storm motion if the forward speed exceeds half the difference between the speed in the NW and SW quadrants, or 10 mph.

So if the highest winds were 145 knots in the NE quadrant and you are in the right eyewall, the maximum sustained wind you would receive would be windspeed + forward motion, and in the left eyewall it would be windspeed - forward motion, if the storm direction was NW.

That's why I brought up storm relative wind speed. I've always thought measured windspeed excluded forward motion, in order to ensure consistency of measurement from one storm to the next.

[cycloneye]

SXXX50 KNHC 230140
AF309 2018A RITA HDOB 24 KNHC
0129. 2527N 08928W 03017 5065 224 069 110 110 069 02988 0000000000
0130 2528N 08929W 03017 5071 221 068 110 108 068 02981 0000000000
0130. 2529N 08930W 03016 5078 220 070 110 108 070 02974 0000000000
0131 2531N 08932W 03017 5084 220 072 110 108 073 02969 0000000000
0131. 2532N 08933W 03018 5090 222 073 110 108 073 02963 0000000000
0132 2533N 08934W 03016 5099 222 076 112 102 077 02953 0000000000
0132. 2534N 08936W 03017 5108 222 077 114 106 078 02945 0000000000
0133 2536N 08937W 03018 5118 222 080 114 106 081 02935 0000000000
0133. 2537N 08938W 03018 5128 223 083 118 100 085 02925 0000000000
0134 2538N 08940W 03015 5140 225 086 122 092 086 02910 0000000000
0134. 2539N 08941W 03018 5151 225 087 124 094 089 02901 0000000000
0135 2540N 08942W 03018 5164 226 090 128 100 091 02890 0000000000
0135. 2541N 08943W 03020 5179 222 090 120 110 092 02876 0000000000
0136 2543N 08945W 03013 5196 222 095 118 114 097 02852 0000000000
0136. 2544N 08946W 03016 5213 224 100 100 100 102 02838 0000000000
0137 2545N 08947W 03023 5234 224 092 096 096 094 02824 0000000000
0137. 2546N 08948W 03014 5255 225 096 116 116 101 02794 0000000000
0138 2547N 08950W 03017 5276 227 100 126 126 102 02775 0000000000
0138. 2548N 08951W 03020 5303 229 103 118 118 105 02753 0000000000
0139 2549N 08952W 03016 5332 226 104 122 122 106 02719 0000000000

[cycloneye]

SXXX50 KNHC 230150
AF309 2018A RITA HDOB 25 KNHC
0139. 2550N 08953W 03017 5364 226 107 134 134 109 02688 0000000000
0140 2552N 08954W 03020 5388 230 101 160 138 104 02666 0000000000
0140. 2553N 08956W 03017 5414 227 095 162 126 097 02638 0000000000
0141 2554N 08957W 03015 5442 226 098 162 106 099 02608 0000000000
0141. 2555N 08958W 03019 5479 228 102 156 124 103 02574 0000000000
0142 2556N 08959W 03043 5514 230 087 152 152 096 02564 0000000000
0142. 2557N 09001W 03048 5543 230 067 160 160 074 02540 0000000000
0143 2558N 09002W 03049 5569 226 053 158 158 058 02514 0000000000
0143. 2600N 09003W 03044 5590 227 042 162 162 046 02489 0000000000
0144 2601N 09005W 03049 5607 224 033 166 160 036 02476 0000000000
0144. 2602N 09006W 03045 5621 234 019 166 156 023 02458 0000000000
0145 2604N 09007W 03048 5628 242 003 162 158 012 02455 0000000000
0145. 2605N 09009W 03048 5628 056 015 162 160 022 02455 0000000000
0146 2606N 09010W 03047 5618 055 036 156 156 045 02464 0000000000
0146. 2608N 09011W 03046 5597 053 053 154 154 056 02483 0000000000
0147 2609N 09013W 03051 5571 050 062 154 154 065 02515 0000000000
0147. 2610N 09014W 03048 5542 047 082 140 140 095 02540 0000000000
0148 2611N 09015W 03042 5507 046 102 136 136 104 02569 0000000000
0148. 2612N 09017W 03051 5471 047 105 148 134 106 02615 0000000000
0149 2613N 09018W 03047 5437 047 101 138 138 103 02645 0000000000

[Wthrman13]

That's why I brought up storm relative wind speed. I've always thought measured windspeed excluded forward motion, in order to ensure consistency of measurement from one storm to the next.

Ok, I see where your hangup is. The answer is no, the measured windspeed is just that, the measured wind speed relative to the ground. There is no compensation made for forward motion at all. The raw measured wind speeds can be interpreted as being a combination of a rotational wind component + motion component + "insert any other asymmetry in the wind field here" component.

So, in this regard, the wind speeds and thus the Category rating, to a certain extent, are indeed dependent on the motion of the storm. A fast moving storm that would otherwise be a TS, for example, may actually verify as a hurricane if the forward motion is fast enough to add to the rotational component of the winds on one side enough to result in hurricane force winds.

This seems an endless source of confusion for many, and I agree, it can be confusing, but if you think carefully about it, or better yet, draw pictures (I'm serious, I do this all the time to understand such concepts) it makes much more sense.

[soonertwister]

Thank you Wthrman13. I'd always assumed that windspeed was storm relative, and you've set me straight. I've asked the question before and not gotten a satisfactory answer.

According to what you are saying, if a tropical storm is stationary with 50 mph maximum winds, if the same storm was traveling at 28 mph at 90 degrees motion to the left of the maximum winds, then the measured windspeed would be 78, and thus it would be a hurricane.

[Wthrman13]

Thank you Wthrman13. I'd always assumed that windspeed was storm relative, and you've set me straight. I've asked the question before and not gotten a satisfactory answer.

According to what you are saying, if a tropical storm is stationary with 50 mph maximum winds, if the same storm was traveling at 28 mph at 90 degrees motion to the left of the maximum winds, then the measured windspeed would be 78, and thus it would be a hurricane.

Exactly.

[cycloneye]

391
URNT12 KNHC 230159
VORTEX DATA MESSAGE
A. 23/01:44:40Z
B. 26 deg 03 min N
090 deg 07 min W
C. 700 mb 2381 m
D. NA kt
E. NA deg nm
F. 227 deg 109 kt
G. 136 deg 017 nm
H. 917 mb
I. 12 C/ 3015 m
J. 17 C/ 3044 m
K. 16 C/ NA
L. CLOSED
M. CO18-32
N. 12345/ 7
O. 0.02 / 1 nm
P. AF309 2018A RITA OB 11
MAX FL WIND 123 KT NE QUAD 00:04:20 Z
INNER EYEWALL RAGGED AND OPEN S-E

[wjs3]

SoonerTwister:

Apologize if I offended with the FAQ link. Just trying to help. I see what you were saying now.

[Windy]

468
UZNT13 KNHC 230159
XXAA 73027 99261 70901 08260 99917 26800 20003 00/// ///// /////
92/// ///// ///// 85671 24011 02503 70363 17007 02003 88999 77999
31313 09608 80144
61616 AF309 2018A RITA OB 12
62626 EYE SPL 2606N09013W 0147 MBL WND 22002 AEV 20507 DLM WND 35
501 916725 WL150 21002 081 =
XXBB 73028 99261 70901 08260 00917 26800 11850 24011 22707 18409
33697 16406
21212 00917 20003 11850 02503 22697 02503
31313 09608 80144
61616 AF309 2018A RITA OB 12
62626 EYE SPL 2606N09013W 0147 MBL WND 22002 AEV 20507 DLM WND 35
501 916725 WL150 21002 081 =