ATL: IRMA - Post-Tropical - Discussion

[cycloneye]

@TropicalTidbits
Forecast for #Irma is subtle. Stronger TC would usually move more north due to beta drift, but deeper vortex could feel upper southward flow

 https://twitter.com/TropicalTidbits/status/902927021554237441

[chaser1]

Looks like we're gonna have another major soon.

Yep, I'd go with that. I'd guess staring in the 3-4 day range. Even 48 hours wouldn't shock me, though a few days to occur is more likely

[Aric Dunn]

@TropicalTidbits
Forecast for #Irma is subtle. Stronger TC would usually move more north due to beta drift, but deeper vortex could feel upper southward flow

 https://twitter.com/TropicalTidbits/status/902927021554237441

southward flow meaning north to south..

[chaser1]

Actually slightly lost latitude, I was thinking looking at the satelite loops that the convective coverage looked like it had moved slightly south of west recently but you can never tell if your eyes are playing tricks on you!

Models did suggest it would move near due west for a time today, but I'm interested to see the track in the near future because there is a decent WSW surge in the clouds to the north of Irma, and when that happens it suggests there is some decent ridging going on to the north.

Also might mean the models will shift south a little in the mid range

Quite possibly though I think we will need to see if that continues for any length of time, may just be an organisational wobble.

With that being said, the GFS begins the 290-300 motion pretty much right now looking at the high resolution charts, its forecasted by the GFS to be above 17N by 06z, so thats a benchmark to watch for. Easily do-able at this point but if it doesn't make it, maybe just a hint the upper pattern is more ridgy than expected.

.... and an even bigger hint that these initial model runs are quite likely to adjust simply given that they'll have better initialization with consecutive runs and with a better exact handle on the storms COC

[chaser1]

Some dry air lurking to the NW:



Maybe why the Euro keeps it as a TS for the next 4 days

Irma looks organized enough where it shouldn't be too much of a hindrance, but it will probably stop her from intensifying.

"stop her from intensifying"? 8-ball says "highly doubtful"

[chaser1]

@TropicalTidbits
Forecast for #Irma is subtle. Stronger TC would usually move more north due to beta drift, but deeper vortex could feel upper southward flow

 https://twitter.com/TropicalTidbits/status/902927021554237441

southward flow meaning north to south..

I was scratching my head there too? Meaning, remove "flow" and insert "motion".... correct?

[Aric Dunn]

@TropicalTidbits
Forecast for #Irma is subtle. Stronger TC would usually move more north due to beta drift, but deeper vortex could feel upper southward flow

 https://twitter.com/TropicalTidbits/status/902927021554237441

southward flow meaning north to south..

I was scratching my head there too? Meaning, remove "flow" and insert "motion".... correct?

look at the wind barbs they are coming from the nne not the other way..

[Aric Dunn]

nice burst of convection within the "eyewall" occuring now.

[NDG]

Looking good.

[Hurricane Andrew]

Looking good.

That is an immense burst of convection over the CoC.

[RL3AO]

I was gonna give Aric a little crap for his eyewall comment. Then I saw this microwave image from about three hours ago. Center was located at 16.4°N 30.3°W.

[KWT]

nice burst of convection within the "eyewall" occuring now.

Yeah, its internally looking very good, I think the dry air to the NW will stop it developing too much IF it does end up tracking to the WNW in the next 24-36hrs.

IF it carries on westwards then that dry air may never become a problem and Irma will be stronger earlier, and with it probably stay further south in general.

RL3AO, almost certainly a proto eyewall there, maybe center is a touch south of where the current estimates are as well, which would make sense as the system overall seemed to chug slightly south of west a few hours ago. Now appears to be due west.

No signs yet of that 290-300 motion the models have been advertising for the next 24hrs.

[chaser1]

Irma's Lowest Pressure Pole! Pole closes 0Z Sept. 2 (didn't know if it were appropriate to start an entirely new thread for this)

I'm going to go with 919mb

[jlauderdal]

Irma's Lowest Pressure Pole! Pole closes 0Z Sept. 2 (didn't know if it were appropriate to start an entirely new thread for this)

I'm going to go with 919mb

932

[Aric Dunn]

I was gonna give Aric a little crap for his eyewall comment. Then I saw this microwave image from about three hours ago. Center was located at 16.4°N 30.3°W.

lol.. you dont need microwave with this convective pattern

besides i posted microwave a couple hours ago that is now 5 hoursold showing

[stormreader]

Looking good.

Could be an understatement. Storm just clearing Cabo Verde Islands with this kind of organization.

[Hurricane Andrew]

Irma's Lowest Pressure Pole! Pole closes 0Z Sept. 2 (didn't know if it were appropriate to start an entirely new thread for this)

I'm going to go with 919mb

929

[Hurricane Andrew]

I see a 270-280 motion ATM...and the center appears to be tracking somewhat south of the NHC forecast points. My untrained eye, of course.

[Scorpion]

Irma's Lowest Pressure Pole! Pole closes 0Z Sept. 2 (didn't know if it were appropriate to start an entirely new thread for this)

I'm going to go with 919mb

908

[Hurricane Andrew]

Latest ADT reduces winds to 39kt, but turns off the rapid weakening flag.

Code: Select all


                     UW - CIMSS                     
              ADVANCED DVORAK TECHNIQUE       
                  ADT-Version 8.2.1               
         Tropical Cyclone Intensity Algorithm       

             ----- Current Analysis -----
     Date :  30 AUG 2017    Time :   194500 UTC
      Lat :   16:21:16 N     Lon :   30:59:25 W

     
                CI# /Pressure/ Vmax
                2.7 /1002.3mb/ 39.0kt

     
             Final T#  Adj T#  Raw T#
                2.2     2.6     3.2

 Center Temp : -61.0C    Cloud Region Temp : -45.8C

 Scene Type : CURVED BAND with 0.83 ARC in LT GRAY

 Positioning Method : FORECAST INTERPOLATION

 Ocean Basin : ATLANTIC     
 Dvorak CI > MSLP Conversion Used : CKZ Method 

 Tno/CI Rules : Constraint Limits : 0.5T/hour
                   Weakening Flag : ON   
           Rapid Dissipation Flag : OFF   

 C/K/Z MSLP Estimate Inputs :
  - Average 34 knot radii : N/A
  - Environmental MSLP    : 1012mb

 Satellite Name :    MSG3
 Satellite Viewing Angle : 40.2 degrees