ATL: CHANTAL - Post-Tropical

[floridasun78]

ok what i see wind still at 45mph with plane surface wind report until now

[Dave]

URNT15 KNHC 082256
AF302 0103A CHANTAL HDOB 28 20130708
224800 1223N 05348W 9671 00408 0134 +214 +196 145046 047 037 002 00
224830 1225N 05347W 9664 00413 0134 +216 +195 147048 049 037 000 03
224900 1226N 05346W 9666 00412 0134 +216 +198 147047 049 036 000 00
224930 1227N 05345W 9667 00413 0135 +216 +203 146044 046 035 000 00
225000 1228N 05343W 9665 00416 0135 +217 +201 148045 046 036 002 00
225030 1229N 05342W 9664 00416 0136 +217 +202 149045 047 035 001 00
225100 1230N 05341W 9665 00418 0137 +216 +202 150044 045 035 001 00
225130 1231N 05340W 9667 00415 0137 +216 +202 148044 046 035 001 00
225200 1233N 05339W 9665 00417 0139 +215 +204 148044 046 035 002 00
225230 1234N 05338W 9667 00417 0140 +215 +201 147043 045 033 002 00
225300 1234N 05338W 9667 00417 0142 +215 +203 148041 042 033 001 00
225330 1236N 05335W 9665 00420 0143 +215 +200 145040 041 033 002 00
225400 1237N 05334W 9666 00421 0144 +215 +202 144039 040 033 001 00
225430 1238N 05333W 9663 00423 0143 +215 +203 144039 040 033 001 03
225500 1239N 05332W 9667 00420 0144 +215 +201 143039 041 033 002 00
225530 1240N 05331W 9668 00418 0144 +215 +200 143040 041 034 000 00
225600 1242N 05330W 9663 00424 0145 +215 +201 144038 040 032 003 00
225630 1243N 05328W 9667 00422 0144 +216 +197 145040 041 033 002 00
225700 1244N 05327W 9665 00421 0144 +217 +195 149040 040 034 002 00
225730 1245N 05326W 9664 00423 0144 +217 +194 150041 043 034 002 00
$$
;

[Aric Dunn]

the center appears north of those light wind readings pretty much right inline with sat. those light winds are misleading do to its forward motion.

[SapphireSea]

Theoretically wouldn't the winds still be suspect if it is only occurring in the heaviest convection so far away from the LLC? Or have the NHC historically used the highest FL winds regardless of the organization of the system? I would think they would use the best winds closest to the center to "measure" the storm. The powerful FL winds may isolated and not really describe the system. Anyone have the answer?

[SouthDadeFish]

I think 50 knots (60mph) could easily be justified with flight level winds of 58 knots occurring at just 1,000 feet up. I think the NHC will probably go with 45 knots though. Again, just my opinion and not a forecast.

[Alyono]

Theoretically wouldn't the winds still be suspect if it is only occurring in the heaviest convection so far away from the LLC? Or have the NHC historically used the highest FL winds regardless of the organization of the system? I would think they would use the best winds closest to the center to "measure" the storm. The powerful FL winds may isolated and not really describe the system. Anyone have the answer?

the max winds are the highest 1 minute mean winds anywhere within the TV circulation

[weatherwindow]

[quote="Jevo"]Someone do the Big Googly eyed Emote for Chantel's big brother making landfall in the same place in 2 weeks at +348 (obviously its a long term forecast and subject to large track and intensity error
All kidding aside, it certainly is not out of the question. Hutchinson Island will not soon forget 2004 with Frances and Jeanne. Savannah and the Low Country have even longer memories of the twin killers of 1893. In the latter case, the landfalls were not as coincident as those of 04, but the impact was so much more devastating in both life and property. Of course, the first question and the current topic is: how will the track and intensity of Chantal evolve. If the track evolves as the GFS illustrates and Chantal survives to be ejected west, perhaps 04 will emerge as the ultimate analog.

[CrazyC83]

The 58 knot reading was flight level winds....

58 kt at FL = 52 kt at the surface.

[Aric Dunn]

that VDM is wrong look at the wind direction to the north of it ... s to sw winds veering to se as they have been flying away/

[Evil Jeremy]

[SouthDadeFish]

that VDM is wrong look at the wind direction to the north of it ... s to sw winds veering to se as they have been flying away/

I can buy your theory there too, since the extrapolated pressure dropped a bit for a stretch as they flew away from the VDM center.

[SapphireSea]

Theoretically wouldn't the winds still be suspect if it is only occurring in the heaviest convection so far away from the LLC? Or have the NHC historically used the highest FL winds regardless of the organization of the system? I would think they would use the best winds closest to the center to "measure" the storm. The powerful FL winds may isolated and not really describe the system. Anyone have the answer?

the max winds are the highest 1 minute mean winds anywhere within the TV circulation

Ah. I see. I would assume some rounding takes place if the highest winds are isolated. In any event it's quite surprising that it is so strong in at this stage. I thought maybe 45kt and cap out for now, maybe I was/am wrong.

[northjaxpro]

That looks extremely ominous. Thank God that is 386 hours out. Definitely hope that doesn't come to fruition as that will be right on top of me.

We have enough to deal with Chantal in the 5-6 day range, so I don't even want to focus on this for the time being.

[SouthDadeFish]

Will recon be able to do another pass or are they going home now?

[Aric Dunn]

that VDM is wrong look at the wind direction to the north of it ... s to sw winds veering to se as they have been flying away/

I can buy your theory there too, since the extrapolated pressure dropped a bit for a stretch as they flew away from the VDM center.

That whole area down there appears to just be weak winds do to its forward motion... the center should be quite a bit north of that.

[Evil Jeremy]

Will recon be able to do another pass or are they going home now?

Recon is suppoused to be investigating the storm until 8:30pm if I remember right...

[SouthDadeFish]

that VDM is wrong look at the wind direction to the north of it ... s to sw winds veering to se as they have been flying away/

I can buy your theory there too, since the extrapolated pressure dropped a bit for a stretch as they flew away from the VDM center.

That whole area down there appears to just be weak winds do to its forward motion... the center should be quite a bit north of that.

I hope recon can do another pass to verify this.

[Dave]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 8th day of the month at 23:01Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 302)
Storm Number & Year: 03L in 2013
Storm Name: Chantal (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 10
A. Time of Center Fix: 8th day of the month at 22:27:40Z
B. Center Fix Coordinates: 11°38'N 54°34'W (11.6333N 54.5667W)
B. Center Fix Location: 355 miles (572 km) to the ESE (107°) from Bridgetown, Barbados.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 27kts (~ 31.1mph)
E. Location of the Estimated Maximum Surface Wind: 25 nautical miles (29 statute miles) to the ESE (115°) of center fix
F. Maximum Flight Level Wind Inbound: From 179° at 29kts (From the S at ~ 33.4mph)
G. Location of Maximum Flight Level Wind Inbound: 28 nautical miles (32 statute miles) to the ESE (116°) of center fix
H. Minimum Sea Level Pressure: 1010mb (29.83 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 20°C (68°F) at a pressure alt. of 395m (1,296ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 22°C (72°F) at a pressure alt. of 392m (1,286ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 22°C (72°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 and Temperature
N. Fix Level: 1,500 feet
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 9 nautical miles
Remarks Section - Remarks That Were Decoded...
Sea Level Pressure Extrapolation From: Below 1,500 feet
Maximum Flight Level Temp: 22°C (72°F) which was observed 11 nautical miles (13 statute miles) to the ESE (106°) from the flight level center
Remarks Section - Additional Remarks...
PRELIMINARY, DO NOT RETRANSMIT
MAX OUTBOUND AND MAX FL WIND 58 KT 042/37 22:39:30Z
MIN SLP 1010MB 042/21 22:35:00Z

[cycloneye]

Will recon be able to do another pass or are they going home now?

Recon is suppoused to be investigating the storm until 8:30pm if I remember right...

Yes,until 8:30 PM EDT.

08/2030Z TO 09/0030Z

[SouthDadeFish]

Recon found those high flight level winds right where the reds are in this enhanced IR image. This satellite image was taken at about the same time the winds were reported. Keep in mind the satellite images lag behind the real-time recon obs: