ATL: GERT - Post-Tropical - Discussion

[gatorcane]

Looking better and better:

http://rammb.cira.colostate.edu/ramsdis ... display=12

[StormTracker]

http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=conus&x=8509&y=6171&z=3&im=24&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=1&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

Very nice structure. Hot tower alert! Glad it's not heading this way!

[SouthDadeFish]

Really starting to come together over the last six hours. I would expect an upgrade to TS Gert at 5 pm at this rate.

[tolakram]

Really starting to look like something.

36 frame loop
http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=conus&x=8681&y=5385&z=3&im=36&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=1&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

[cycloneye]

18z Best Track up to Tropical Storm.

AL, 08, 2017081318, , BEST, 0, 277N, 716W, 35, 1011, TS

[Kingarabian]

18z Best Track up to Tropical Storm.

AL, 08, 2017081318, , BEST, 0, 277N, 716W, 35, 1011, TS

Pressure @ 1011mb seems quite high.

[Steve]

18z Best Track up to Tropical Storm.

AL, 08, 2017081318, , BEST, 0, 277N, 716W, 35, 1011, TS

Pressure @ 1011mb seems quite high.

It's relative to the background pressures up to 1027mb and even higher up to 1030 (east of the system contours). That's the Atlantic a lot of the summer which is usually higher than even the coldest highs in the winter along the Gulf.

http://www.opc.ncep.noaa.gov/A_sfc_full_ocean_color.png

[MississippiWx]

18z Best Track up to Tropical Storm.

AL, 08, 2017081318, , BEST, 0, 277N, 716W, 35, 1011, TS

No doubt a tropical storm. Spiral banding is impressive and continuing to improve. If it can wrap a strong band into the core, it may make a run at hurricane strength.

[SouthDadeFish]

Beautiful spiral banding:



The surface center seems a little displaced to the west of the mid-level center though.

[GeneratorPower]

Beautiful spiral banding:



The surface center seems a little displaced to the west of the mid-level center though.

Most beautifulest tropical depression ever.

[Hammy]

Too bad we don't have recon--given the size and background pressure this looks like more than 35kt.

[northjaxpro]

Nice spiral banding now!

[caneman]

I am a biased, enthusiastic and aggressive tropical cyclone forecaster, and normally would have bit on forecasting TD8 to become a hurricane. It is because of the GFS that I have laid up on making this potential mistake. The GFS has seemingly forecasted the inhibiting factors well, while the EURO has seemingly forecasted the conducive factors well. A blend of the two is usually the best bet. With a blend of the other major models breaking ties.

Amen brother. You said it well. I'm neither a defender or supporter of any model. I'm a big proponent of the blend of all models is usually best with a lean towards the hot hand. Having the CMC and others increase their accuracy is a good thing for forecasting. Back on subject.

[floridasun78]

so td8 move out high building for next system?

[MGC]

08L has excellent form for a TD. Looks close to TS intensity. Keep out to sea please.....MGC

[cycloneye]

BULLETIN
Tropical Storm Gert Advisory Number 4
NWS National Hurricane Center Miami FL AL082017
500 PM EDT Sun Aug 13 2017

...DEPRESSION STRENGTHENS TO TROPICAL STORM GERT...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...28.1N 71.7W
ABOUT 505 MI...810 KM WSW OF BERMUDA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1011 MB...29.86 INCHES

Tropical Storm Gert Discussion Number 4
NWS National Hurricane Center Miami FL AL082017
500 PM EDT Sun Aug 13 2017

Satellite images indicate that the tropical cyclone is gradually
strengthening. The banding features have become better established
during the last several hours, and the system has become less
vertically tilted. The Dvorak classification from TAFB and ADT
values from CIMSS at the University of Wisconsin support increasing
the initial wind speed to 35 kt, making the system Tropical Storm
Gert.

Gert is moving north-northwestward at 9 kt on the southwestern
periphery of a subtropical ridge. A northward motion is expected
tonight and Monday while the system rounds the western side of the
ridge, and Gert is expected to be about midway between Bermuda and
North Carolina on Monday and Tuesday. After that time, a
progressively faster motion to the northeast and east-northeast is
forecast as the system moves on the north side of the ridge and
becomes embedded in the mid-latitude westerlies until it dissipates
in about 5 days. The track guidance remains in very good agreement,
and only small changes were made to the previous NHC prediction.
This forecast lies near the middle of the tightly clustered guidance
envelope.

The system is over warm 29 deg C SSTs, and it will remain over
these warm waters during the next few days. In addition, the global
models indicate that the upper-level pattern should become conducive
for strengthening during the next 36 hours or so. The combination
of these conditions should allow Gert to strengthen during the next
couple of days. Thereafter, a sharp increase in west-southwesterly
shear, drier air, and decreasing sea surface temperatures should end
the strengthening trend and lead to extratropical transition in
a little more than 3 days. The NHC intensity forecast is slightly
above the previous one, but remains on the lower side of the
guidance.

The center of Gert recently passed very near NOAA buoy 41047, and
that data has been helpful in estimating the minimum pressure of the
system.

FORECAST POSITIONS AND MAX WINDS

INIT 13/2100Z 28.1N 71.7W 35 KT 40 MPH
12H 14/0600Z 29.3N 72.1W 40 KT 45 MPH
24H 14/1800Z 31.1N 72.1W 50 KT 60 MPH
36H 15/0600Z 32.9N 71.3W 55 KT 65 MPH
48H 15/1800Z 35.1N 68.8W 55 KT 65 MPH
72H 16/1800Z 39.8N 59.1W 50 KT 60 MPH
96H 17/1800Z 45.0N 44.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 18/1800Z...DISSIPATED

$$
Forecaster Cangialosi

[RL3AO]

It's on the board.

Code: Select all

Atlantic Accumulated Cyclone Energy
Name                  System ACE    Max Intensity
------------------  ------------  ---------------
Arlene (01L) [TCR]        0.81                 45
Bret (02L)                0.6875               40
Cindy (03L)               1.55                 50
Four (04L)                0                    25
Don (05L)                 0.6875               40
Emily (06L)               0.6075               45
Franklin (07L)            3.685                75
Gert (08L)                0.1225               35

Season Total              8.15


[northjaxpro]

Gert will split the goalposts so to speak, moving between North Carolina and Bermuda in the short term. Some good swells will be generated along the Mid Atlantic coast next few days. I think there is a decent chance for Gert to attain hurricane status in the next 36 hours or so, although NHC currently is not forecasting that to happen.

[NDG]

Beautiful storm.

[Emmett_Brown]

Gert really is a nice symmetrical illustration of how an anti cyclone forms above a developing TC... you can clearly see the cyclonic and anticyclonic flow like two perfect discs stacked together. Bravo Gert, you are much prettier than your name.