ATL: RICHARD - Remnant Low - Discussion

[SouthDadeFish]

Big improvement:
Atmospheric Pressure (PRES): 29.85 in
Pressure Tendency (PTDY): -0.07 in ( Falling )

Nice sign of organization going on down there.

http://www.ndbc.noaa.gov/station_page.php?station=42057

[SouthDadeFish]

With all those west winds, albeit weak, this should at least be code red.

[wxman57]

Vortex message in - 17.4N/83.5W. Doesn't match the wind reports of the LLC location, though. Obs suggest the LLC is closer to 17.5N/83.6W. Could be too weak to classify as a TD presently.

URNT12 KNHC 191914
VORTEX DATA MESSAGE AL992010
A. 19/19:09:00Z
B. 17 deg 23 min N
083 deg 29 min W
C. NA
D. 27 kt
E. 347 deg 20 nm
F. 112 deg 20 kt
G. 347 deg 21 nm
H. EXTRAP 1009 mb
I. 22 C / 303 m
J. 23 C / 302 m
K. 22 C / NA
L. NA
M. NA
N. 134 / 1
O. 0.02 / 5 nm
P. AF303 01IIA INVEST OB 13
MAX FL WIND 20 KT N QUAD 18:59:30Z
SLP EXTRAP FROM BELOW 1500 FT

[jconsor]

The recon hasn't looked at the east side of 99L at all, which is clearly the stronger side, so it's too preliminary to make a determination yet whether this qualifies as a TD.

Buoy 42057 at 16.8N 81.5W (about 100 miles ESE of the center) has been reporting sustained winds over 20 kt the past 3 hours, with 1-minute sustained winds of 27 kt and a peak gust of 35 kt in the past hour.

[cycloneye]

The recon hasn't looked at the east side of the storm at all, which is clearly the stronger side, so it's too preliminary to make a determination yet whether this qualifies as a TD.

Buoy 42057 at 16.8N 81.5W (about 100 miles ESE of the center) has been reporting sustained winds over 20 kt the past 3 hours, with 1-minute sustained winds of 27 kt and a peak gust of 35 kt in the past hour.

Now that they closed the circulation,they may do that.

[SouthDadeFish]

New pressure drop:

5-day plot - Atmospheric Pressure Atmospheric Pressure (PRES): 29.82 in
5-day plot - Pressure Tendency Pressure Tendency (PTDY): -0.09 in ( Falling Rapidly )

[wxman57]

The recon hasn't looked at the east side of 99L at all, which is clearly the stronger side, so it's too preliminary to make a determination yet whether this qualifies as a TD.

Buoy 42057 at 16.8N 81.5W (about 100 miles ESE of the center) has been reporting sustained winds over 20 kt the past 3 hours, with 1-minute sustained winds of 27 kt and a peak gust of 35 kt in the past hour.

http://www.ndbc.noaa.gov/plot_wind_pres ... _label=EDT

I'm thinking of the requirement for significant convection near the center to upgrade. Not much convection there yet. It's clearly weaker than Paula was 60 hours before the NHC upgraded it. But maybe they'll pull the trigger earlier with this one?

[jconsor]

I definitely agree that 99L's convection is rather paltry and tops have warmed in the past 12 hours. However, the fact that buoy 42057 has seen winds around 25 kt with gusts of 30-35 kt the past 3 hours with convective bands overhead suggests the convection is relatively efficient at transporting higher winds to the surface. Winds were only around 10 kt at buoy 42057 before the convective bands began moving in.

I'm thinking of the requirement for significant convection near the center to upgrade. Not much convection there yet. It's clearly weaker than Paula was 60 hours before the NHC upgraded it. But maybe they'll pull the trigger earlier with this one?

[SouthDadeFish]

They didn't pull the trigger with Paula IMO because they LOVE to have recon data support classification and will often wait until recon flies out there even if it already looks very much like a tropical depression. Since recon already flew out there, I wouldn't be surprised to see a TD, especially since they sent out the vortex message.

[wxman57]

Surface plot with satellite:

[HURAKAN]

If the NHC believes that the system is likely to intensify from now on, I wouldn't be surprised to see a TD at 5 pm.

[HURAKAN]

Latest

[Blown Away]

Interesting the 18z TVCN consensus loops 99L and then turns it NW, clipping the NE Yucatan, the heads towards the GOMER with very little land interaction!!

[CrazyC83]

I personally wouldn't upgrade it now to TD19 - too weak. Winds only support about 20 kt and the organization isn't that great.

[wxman57]

Interesting the 18z TVCN consensus loops 99L and then turns it NW, clipping the NE Yucatan, the heads towards the GOMER with very little land interaction!!

That's because it's incorporating the GFDL track, the right outlier in the models. Most other models take it south then west, passing over or near Honduras. GFDL takes it northeast then west (just south of Cuba). HWRF into northern Belize. Consensus is right in between the various scenarios toward the northern Yucatan. Simple as that.

[cycloneye]

ATCF updated a new position.

AL, 99, 2010101918, , BEST, 0, 174N, 834W, 30, 1008, LO

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

[wxman57]

Models just initialized as "Disturbance Invest (AL992010) at 18Z. 17.4N/83.4W with 30 kts at 00hrs. No hint of an upgrade there.

[Blown Away]

Interesting the 18z TVCN consensus loops 99L and then turns it NW, clipping the NE Yucatan, the heads towards the GOMER with very little land interaction!!

That's because it's incorporating the GFDL track, the right outlier in the models. Most other models take it south then west, passing over or near Honduras. GFDL takes it northeast then west (just south of Cuba). HWRF into northern Belize. Consensus is right in between the various scenarios toward the northern Yucatan. Simple as that.

NHC generally splits the middle also, correct? So if 99L were classified we might see a track close to the TVCN consensus. Earlier TVCN runs buried 99L into CA, so maybe there is a change in the pattern for now?

[LarryWx]

A couple of days ago I posted the climo stats for mid to late Oct. W. Caribbean TC's that formed at 15N or further south/77.5W or further west, which is where Richard had earlier been progged to form by the gfs on a number of runs. Those stats suggested about a 40% chance for a U.S. hit as well as ~40% chance of an ending in C.A./MX. They also suggested only ~20% chance for a miss of the US to the east.

However, it nows appears likely that Richard will form much further north: within the 15-20N, 80-85W box. What does that say about the various scenario probablities? For those who would like some U.S. action, this is good news (as one might expect due to the much closer start point to the U.S.) because the % of these that hit the U.S. was higher while the % of those that ended their tracks in/near C.A./MX was smaller.

Breakdown for the 1851-2009 mid to late OCT W. Caribbean TC's:

- 9 (64%) hit the U.S. with 6 of these (43% of the total) hitting S or C FL (all as 'canes)
- 3 (21%) missed the U.S. to the east
- 2 (14%) hit Belize (both at no stronger than TS strength)

If I lived in C or S FL, I'd pay extra attention for a potential threat.

For the nine that hit the U.S., the average # of days from birth as a TD+ til the hit was ~4.5. The # of days were as follows:

7, 7, 5, 5, 5, 3, 3, 3, 2

[cycloneye]

Decoded VDM:

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 19th day of the month at 19:37Z
Corrected: This observation corrected a previous observation.
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 303)
Mission Purpose: Investigate eight suspect area (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 13
A. Time of Center Fix: 19th day of the month at 19:09:00Z
B. Center Fix Coordinates: 17°23'N 83°29'W (17.3833N 83.4833W) (View map)
B. Center Fix Location: 191 miles (308 km) to the SW (226°) from George Town, Cayman Islands (GBR).
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: 20 nautical miles (23 statute miles) to the NNW (347°) of center fix
F. Maximum Flight Level Wind Inbound: From 112° at 20kts (From the ESE at ~ 23.0mph)
G. Location of Maximum Flight Level Wind Inbound: 21 nautical miles (24 statute miles) to the NNW (347°) of center fix
H. Minimum Sea Level Pressure: 1009mb (29.80 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 22°C (72°F) at a pressure alt. of 303m (994ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 302m (991ft)
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 Pressure
N. Fix Level: 1,500 feet
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 5 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 20kts (~ 23.0mph) in the north quadrant at 18:59:30Z
Maximum Flight Level Wind Outbound: 21kts (~ 24.2mph) in the southeast quadrant at 19:15:30Z
Sea Level Pressure Extrapolation From: Below 1,500 feet
Remarks Section - Additional Remarks...
BEST WINDSHIFT CENTER WAS AT 19:05:50Z AT 17 31N 83 35W