ATL: CHANTAL - Post-Tropical

[Blown Away]

The 06Z GFDL brings the system into the Northern Bahamas then bends it W towards the East Coast of Central Florida, deepening it:

http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

Models seeing a better Bahama area upper air environment with each run... Starting my mental checklist to prepare...

[torrea40]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 9th day of the month at 13:08Z
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: 2

Observation Number: 06
A. Time of Center Fix: 9th day of the month at 12:57:20Z
B. Center Fix Coordinates: 13°56'N 60°42'W (13.9333N 60.7W)
B. Center Fix Location: 20 miles (31 km) to the ESE (104°) from Castries, Saint Lucia.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 55kts (~ 63.3mph)
E. Location of the Estimated Maximum Surface Wind: 42 nautical miles (48 statute miles) to the ENE (62°) of center fix
F. Maximum Flight Level Wind Inbound: From 118° at 70kts (From the ESE at ~ 80.6mph)
G. Location of Maximum Flight Level Wind Inbound: 47 nautical miles (54 statute miles) to the ENE (60°) 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 364m (1,194ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 366m (1,201ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 23°C (73°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, Pressure and Temperature
N. Fix Level: 1,500 feet
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 2 nautical miles
Remarks Section:
Maximum Flight Level Wind: 70kts (~ 80.6mph) which was observed 47 nautical miles (54 statute miles) to the ENE (60°) from the flight level center at 12:41:00Z

Sea Level Pressure Extrapolation From: Below 1,500 feet
Saint

[Evil Jeremy]

[Evil Jeremy]

000
URNT15 KNHC 091329
AF302 0203A CHANTAL HDOB 20 20130709
132100 1345N 06040W 8436 01592 0139 +153 //// 166024 025 028 004 01
132130 1347N 06042W 8428 01600 0136 +158 +152 166025 026 024 001 00
132200 1348N 06043W 8430 01597 //// +149 //// 171021 025 024 001 01
132230 1349N 06044W 8429 01596 0133 +153 +152 176023 024 023 002 00
132300 1351N 06045W 8429 01596 0132 +159 +153 172022 023 023 002 00
132330 1352N 06047W 8430 01595 0131 +160 +153 176022 024 024 002 00
132400 1353N 06048W 8429 01592 0128 +160 +158 174021 023 025 002 00
132430 1354N 06049W 8430 01586 0121 +164 +158 182018 020 027 002 03
132500 1355N 06051W 8428 01589 0118 +167 +160 191015 018 027 001 00
132530 1355N 06053W 8426 01591 0116 +170 +159 182011 013 026 001 03
132600 1355N 06054W 8430 01586 0121 +162 +158 193008 009 /// /// 05
132630 1356N 06056W 8429 01589 0122 +160 +160 191010 012 /// /// 05
132700 1358N 06055W 8431 01584 0114 +169 +164 187011 012 /// /// 03
132730 1400N 06055W 8426 01588 0109 +175 +164 178013 014 /// /// 03
132800 1401N 06054W 8432 01579 0106 +173 +162 180015 016 /// /// 03
132830 1403N 06053W 8429 01579 0103 +174 +158 182016 017 /// /// 03
132900 1405N 06053W 8426 01580 0100 +179 +149 183018 019 023 001 00
132930 1406N 06052W 8429 01574 0096 +180 +150 183022 022 019 000 00
133000 1408N 06052W 8436 01563 0092 +176 +154 178024 024 018 001 00
133030 1410N 06051W 8427 01572 0087 +185 +139 168024 026 021 002 00
$$
;

[Bocadude85]

12z...Models beginning to bend back towards South Florida

Yea the NHC is now northeast of the TVCN.

[adam0983]

I wonder if the current upper level low Pressure over the Bahamas is playing into the model and I wonder how it will affect Tropical Storm Chantal. This low is providing showers and over the Bahamas and Florida this morning. Just an opinion not a forecast.

[BUCMAN48]

Thank you senorpepr - That will really be the key of what we will be working with. These storms have been known to have center reformations once they come off the mountains, if they chantel even goes over the mountains.

[DESTRUCTION5]

12z...Models beginning to bend back towards South Florida

ZERO ensembles take her out to sea now...looks likely now IF she survives DR she is going to hook a left somewhere in FLs Latitude...

::Disclaimer here::

[AdamFirst]

I wonder if the current upper level low Pressure over the Bahamas is playing into the model and I wonder how it will affect Tropical Storm Chantal. This low is providing showers and over the Bahamas and Florida this morning. Just an opinion not a forecast.

The ULL is the feature that is carving the initial weakness that will draw Chantal to the NW (if it survives Hispaniola of course)

The high is supposed to build in behind it as the ULL moves away; that's why the models are calling for Chantal to meander and head west around Day 5-6 when it reaches 26-27 N latitude

[Miami Storm Tracker]

I am very surprised that the NHC Track is not showing the turn to Florida on days 4 and 5 on the model runs. The GFS is still showing this and most of the models are agreement that this turn will occur at some point. I am waiting to see what the NHC does with the track at 11am. Not a forecast just an opinion.

They started to show it with the 5am advisory. They say in the discussion:

A SLIGHT LEFT TURN IS PREDICTED BY THE END OF THE
FORECAST PERIOD AS THE MODELS SHOW A RIDGE REBUILDING TO THE
NORTHEAST OF CHANTAL BY THAT TIME.

I think he means more of a sharper west bend. The GFDL/HWRF/GFS are showing a pretty sharp west bend into the Florida peninsula with the HWRF towards South Florida and GFDL towards Central Florida on the two extreme ends. So you have to wonder when they start to bend the forecast track more to the left...the NHC likes to make gradual changes generally, so it may take a couple more advisories for them to show Chantal hitting Florida.

This would be an if, but if the high is a bit stronger when it builds back in, a possible wsw turn sort of like Katrina. Which brought the center over Dade county, and the stronger part of the storm. Again just a thought, not backed by any data.

[SouthFloridawx]

What's the reduction?

[cycloneye]

[Evil Jeremy]

000
URNT15 KNHC 091339
AF302 0203A CHANTAL HDOB 21 20130709
133100 1412N 06051W 8429 01569 0088 +178 +151 167027 029 027 001 00
133130 1414N 06051W 8429 01569 0090 +174 +162 157033 034 031 003 00
133200 1415N 06050W 8428 01562 0080 +179 +160 153036 038 036 002 00
133230 1417N 06050W 8432 01560 0083 +176 +161 144041 044 040 001 00
133300 1419N 06050W 8432 01565 0093 +170 +164 136045 047 041 000 00
133330 1421N 06050W 8425 01575 0096 +170 +163 132049 049 042 003 00
133400 1423N 06049W 8433 01571 0102 +168 +156 127052 054 051 005 00
133430 1425N 06049W 8428 01579 0117 +161 //// 127053 054 053 005 01
133500 1427N 06049W 8428 01583 0130 +154 //// 123061 063 064 008 01
133530 1428N 06049W 8429 01584 0132 +150 //// 119060 063 084 009 05
133600 1430N 06048W 8429 01589 0136 +146 //// 120062 063 066 010 05
133630 1432N 06048W 8427 01593 0135 +153 //// 119059 061 068 008 01
133700 1434N 06048W 8435 01588 0130 +160 +158 118061 061 065 009 03
133730 1435N 06048W 8430 01596 0130 +163 +155 116062 063 046 001 00
133800 1437N 06047W 8426 01600 0131 +161 +157 117062 063 047 002 00
133830 1439N 06047W 8426 01600 0138 +159 //// 120065 067 048 005 01
133900 1441N 06047W 8433 01594 0141 +156 //// 121066 067 049 004 01
133930 1442N 06047W 8434 01595 0148 +152 //// 120068 069 050 005 01
134000 1444N 06046W 8423 01610 0152 +155 //// 117064 068 050 008 01
134030 1446N 06046W 8427 01606 0158 +156 +156 119062 065 052 011 00
$$
;

[Evil Jeremy]

68kts SFMR unflagged, that has to be invalid though, right?

133630 1432N 06048W 8427 01593 0135 +153 //// 119059 061 068 008 01


EDIT: Lets chalk that very high number up to the fact that recon was flying very close to the island of Martinique at the time, and that observation is surrounded by numerous other flagged obs. I doubt it's an accurate reading.

[RL3AO]

The plane was over or right off the coast of Martinique when those high SFMR values occurred. I'd probably throw them out for now.

[Alyono]

not valid.... land contamination

[Evil Jeremy]

75kts FL unflagged. Multiple unflagged FL readings from 70kts-75kts.

[Evil Jeremy]

000
URNT15 KNHC 091349
AF302 0203A CHANTAL HDOB 22 20130709
134100 1448N 06046W 8438 01597 0163 +152 +152 117064 064 051 007 00
134130 1449N 06046W 8425 01611 0151 +150 //// 118065 068 050 006 01
134200 1451N 06046W 8433 01605 0156 +147 //// 117070 070 049 004 01
134230 1453N 06045W 8429 01612 0156 +150 +139 116069 071 047 002 05
134300 1455N 06045W 8427 01614 0159 +149 +134 115070 072 044 002 03
134330 1456N 06047W 8433 01605 0155 +152 +130 112071 075 044 003 03
134400 1455N 06049W 8428 01612 0158 +150 +141 109072 073 046 002 00
134430 1455N 06052W 8429 01611 0157 +150 +144 110071 074 050 003 00
134500 1455N 06054W 8424 01618 0159 +148 +148 109072 073 050 003 01
134530 1455N 06056W 8431 01613 0161 +150 //// 108072 074 046 003 01
134600 1455N 06058W 8430 01610 0154 +150 //// 109068 069 048 003 01
134630 1455N 06101W 8426 01614 0155 +150 //// 109065 067 048 002 01
134700 1455N 06103W 8427 01611 0155 +151 //// 105064 064 048 004 01
134730 1455N 06105W 8427 01610 0164 +144 //// 104066 067 051 005 01
134800 1455N 06107W 8427 01610 0164 +147 //// 101065 066 050 006 01
134830 1455N 06110W 8422 01611 0162 +142 //// 096066 068 050 005 01
134900 1455N 06112W 8436 01595 0151 +144 //// 094070 070 049 003 01
134930 1455N 06114W 8438 01595 0154 +144 //// 094069 071 046 003 01
135000 1455N 06116W 8629 01411 0160 +152 //// 094069 070 045 001 01
135030 1455N 06119W 8854 01193 //// +160 //// 091062 068 045 001 01
$$
;

[Alyono]

even though the hurricane force surface winds likely are not valid... somehow this is nearing hurricane intensity, despite a pathetic appearance on satellite

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