Arlene (01L) Recon Observations

[chigger11]

It definitely appears to me to be heading n/nw. IF you look at the approx center of circ from the beginning of the visbile loop until the end and track it its pretty obvious to me. Forget all of the surrounding convection, just watch the center.

[drezee]

284
URNT12 KNHC 082103
VORTEX DATA MESSAGE
A. 08/20:52:00Z
B. 17 deg 06 min N
084 deg 01 min W
C. NA mb NA m
D. 15 kt
E. 51 deg 036 nm
F. 097 deg 019 kt
G. 052 deg 036 nm
H. EXTRAP 1004 mb
I. 23 C/ 290 m
J. 24 C/ 288 m
K. 23 C/ NA
L. NA
M. NA
N. 13 /01
O. 0.02 / 10 nm
P. AF305 01AAA INVEST OB 12
MAX FL WIND 19 KT N QUAD 20:40:20 Z
SLP EXTRAP FROM 1500 FT.

[senorpepr]

[VORTEX | ONE (01L) OB #12] Time: 2052Z; Lat: 17.1°N; Long: 84°W; Central Pressure: 1004 mb; Eye Character: N/A; Eye Shape: FALSE; Eye Diameter mi; Max Flt Wnd: 22 mph (N quad); Est Sfc Winds (using 90% reduction): 20 mph; Remarks: Sea level pressure extrap from 1500ft

[Normandy]

Is that the strongest winds measured?

[senorpepr]

Is that the strongest winds measured?

The strongest flight level wind was 22 mph in the northern quad, found at 2040Z.

[Normandy]

Hmm its a very weak TD then.

[Derek Ortt]

90% reduction only applies at 700mb level. At this level, you need a 75-80% reduction of the FL wind

[senorpepr]

90% reduction only applies at 700mb level. At this level, you need a 75-80% reduction of the FL wind

I realize that and the program that I wrote uses 90% because of the typical flight level. I've been rather busy with operational meteorology to bother with that figure. But... since I have a moment....

[VORTEX | ONE (01L) OB #12] Time: 2052Z; Lat: 17.1°N; Long: 84°W; Central Pressure: 1004 mb; Eye Character: N/A; Eye Shape: FALSE; Eye Diameter mi; Max Flt Wnd: 22 mph (N quad); Est Sfc Winds (using 80% reduction): 18 mph; Remarks: Sea level pressure extrap from 1500ft

[senorpepr]

[RECCO | ONE (01L) OB #13] Time: 2115Z; Lat: 16.2°N; Long: 84.9°W; Turbulence: None; Flt Condition: Clear; Flt Level: 951ft; Flt Winds: NW (320°) @ 17 mph; Temp: 75°F; Dewpoint: 75°F; Weather: Broken Skies; Sfc Winds: NW (320°) @ 12 mph; Remarks: Sea level pressure: 1005mb

[senorpepr]

Just a friendly reminder... you can check out http://tropicalupdates.nhcwx.com/recon.htm for updated recon observations as they come onto the NHC website...

[senorpepr]

[RECCO | ONE (01L) OB #15] Time: 2154Z; Lat: 15.9°N; Long: 82.8°W; Turbulence: None; Flt Condition: Clear; Flt Level: 1148ft; Flt Winds: VRB @ 6 mph; Temp: 77°F; Dewpoint: 70°F; Weather: Broken Skies; Sfc Winds: VRB @ 6 mph; Remarks: Sea level pressure: 1005mb


97779 21544 40159 82800 03500 99005 25212 /0005
49905
RMK AF305 01AAA INVEST OB 15

[loon]

Stupid question I'm sure, but when do the model runs usually come out. For instance, the 18Z run for today. Is there a better website out there, I use the Experimental forecast Tropical Cyclone Genesis Potential Fields from psu.edu. I also wonder if they would hold off on the run and wait for the data coming from RECON, or will they just throw that in on the 00Z run (since they didn't get out there until after the 18Z run should have started). I do realize these runs probably take time with all the number crunching they are doing...

just curious

cheers
loon

[senorpepr]

Stupid question I'm sure, but when do the model runs usually come out. For instance, the 18Z run for today. Is there a better website out there, I use the Experimental forecast Tropical Cyclone Genesis Potential Fields from psu.edu. I also wonder if they would hold off on the run and wait for the data coming from RECON, or will they just throw that in on the 00Z run (since they didn't get out there until after the 18Z run should have started). I do realize these runs probably take time with all the number crunching they are doing...

just curious

cheers
loon

Each specific model run is available at different times... it all depends on how many calculations the given model has to perform, what the resolution of the model is, and how far in the future it goes out. Typically, the are a few hours after the initial time. (I'm sure someone here can give you the specifics) With recon, any recon observations will be injested into the model run if they are available. Therefore, any observation after 18Z will not make the 18Z run. They won't delay this run... the newer observations will have to wait to be injested into the 00Z run.

[loon]

Thanks senorpepr. I kind of figured it depended on the amount of data that was fed into the computers. Thanks for answering.

cheers
loon

[senorpepr]

[VORTEX | ONE (01L) OB #16] Time: 2227Z; Lat: 17.2°N; Long: 84°W; Central Pressure: 1003 mb; Eye Character: N/A; Eye Shape: FALSE; Eye Diameter mi; Max Flt Wnd: 22 mph (N quad); Est Sfc Winds (using 80% reduction): 18 mph; Remarks: Sea level pressure extrap from 1500ft


VORTEX DATA MESSAGE
A. 08/22:27:20Z
B. 17 deg 12 min N
084 deg 00 min W
C. NA mb NA m
D. 10 kt
E. 141 deg 062 nm
F. 173 deg 011 kt
G. 139 deg 095 nm
H. EXTRAP 1003 mb
I. 24 C/ 352 m
J. 23 C/ 338 m
K. 23 C/ NA
L. NA
M. NA
N. 13 / 1
O. 0.02 / 10 nm
P. AF305 01AAA INVEST OB 16
MAX FL WIND 19 KT N QUAD 20:40:20 Z
MAX FL TEMP 24 C, 139 / 95NM
SLP EXTRAP FROM 1500 FT.

[Derek Ortt]

that temperature profile seems to indicate that this is subtropical at best. The latest vortex message indicates that the temperature is actually colder in the center than the surrounding environment

[Matt-hurricanewatcher]

19.87 N 85.06 W (19°52'27" N 85°03' 33" W)


Wind Direction (WDIR): ENE ( 70 deg true )
Wind Speed (WSPD): 17.5 kts
Wind Gust (GST): 19.4 kts
Wave Height (WVHT): 3.9 ft
Dominant Wave Period (DPD): 4 sec
Average Period (APD): 3.7 sec
Atmospheric Pressure (PRES): 29.73 in
Pressure Tendency (PTDY): -0.04 in ( Falling )
Air Temperature (ATMP): 82.9 °F
Water Temperature (WTMP): 83.7 °F
Dew Point (DEWP): 77.2 °F
Heat Index (HEAT): 92.1 °F

[Matt-hurricanewatcher]

I would expect a 1006 to 1008 millibars for a tropical depression. But 1003 wow. It appears that the convection is slowly coming together. Banding looks very good on the northeastern quad. Shear seems to be droping. But this could be subtropical? Funny season already.

[JTD]

that temperature profile seems to indicate that this is subtropical at best. The latest vortex message indicates that the temperature is actually colder in the center than the surrounding environment

Derek, should we look for a discontinuation of advisories by NHC by say 5 a.m. Thurs?

[Javlin]

Wouldn't a little more time over the water turn the system from cold core to warm as it develops.