ATL: KARL - Post-Tropical - Discussion

[cycloneye]

Here is when 12z ECMWF has it at 923 mbs just south of Bermuda.

[cycloneye]

In Weatherbell,is more lower the pressure (912 mbs) but is a paid site so no posting here.

[GCANE]

GFDL is now bumping shear back up in a couple days.
We'll see if the other models follow suit.

[GCANE]

COAMPS is closing it off in about 120 hrs.
Pretty much a wave until then.

[floridasun78]

No TS winds as per latest ASCAT, and it barely looks closed. Won't surprise me to see Karl degenerate to a wave by tomorrow at this rate with regeneration seeming increasingly unlikely.

i notice you post all system will become open wave you want KARL go alway you like wxman say when post in forum i never seen post keep eye on system

[cycloneye]

 https://twitter.com/NHC_TAFB/status/777230011971596289

[floridasun78]

COAMPS is closing it off in about 120 hrs.
Pretty much a wave until then.

this models i was looking at COAMPS site one post look having moving due west right?

[GCANE]

COAMPS 500mb Forecast with 850mb vort:

http://www.nrlmry.navy.mil/coamps-web/w ... om&tau=999

Ridge north of Karl seems to erode a little 90 to 114 hrs
Ridge builds and anchors over the SE CONUS 108 hrs and out.

[SouthFLTropics]

At this range, considering how poorly the models have performed this year, I am not ready to discount an East Coast CONUS threat. Until this thing is Northeast of my position I will continue to watch closely. We've been fooled before at this time of year into thinking something was recurving only to have it get trapped and head west (Jeanne 2004). The slow and meander east of the Bahamas is the telltale sign of the uncertainty in my opinion. If it was a clear cut recurve you would see the trough swing in and the steady curve past Bermuda and out to sea. We aren't seeing that in the model runs as of yet.

[floridasun78]

COAMPS 500mb Forecast with 850mb vort:

http://www.nrlmry.navy.mil/coamps-web/w ... om&tau=999

Ridge north of Karl seems to erode a little 90 to 114 hrs
Ridge builds and anchors over the SE CONUS 108 hrs and out.

so west to wnw movement?

[floridasun78]

At this range, considering how poorly the models have performed this year, I am not ready to discount an East Coast CONUS threat. Until this thing is Northeast of my position I will continue to watch closely. We've been fooled before at this time of year into thinking something was recurving only to have it get trapped and head west (Jeanne 2004). The slow and meander east of the Bahamas is the telltale sign of the uncertainty in my opinion. If it was a clear cut recurve you would see the trough swing in and the steady curve past Bermuda and out to sea. We aren't seeing that in the model runs as of yet.

by staying weaker and expect it look models will change more to west next hours and cone will be move more west a lot were calling Bermuda storm still could be still bit early call that

[GCANE]

COAMPS is closing it off in about 120 hrs.
Pretty much a wave until then.

this models i was looking at COAMPS site one post look having moving due west right?

Yes, keeps Karl as an open wave moving due west until just north of PR.

[GCANE]

COAMPS 500mb Forecast with 850mb vort:

http://www.nrlmry.navy.mil/coamps-web/w ... om&tau=999

Ridge north of Karl seems to erode a little 90 to 114 hrs
Ridge builds and anchors over the SE CONUS 108 hrs and out.

so west to wnw movement?

GFS is showing a bit of a weaker ridge over the SE CONUS at that time with pop-up convection.
With that scenario, could drive Karl closer to the coast.

[cycloneye]

 https://twitter.com/BigJoeBastardi/status/777237103285526528

[GCANE]

Wind speeds recorded at Buoy 41139
20.000 N 38.000 W

[cycloneye]

...KARL FORECAST TO STRENGTHEN NEXT WEEK...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.1N 40.4W
ABOUT 1410 MI...2270 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES

The biggest change since the last
cycle is that model guidance is showing a stronger ridge in the
central Atlantic, which would prolong the west-northwestward
motion. The track models have shifted westward at long range, and
the official forecast is moved in that direction, but not as far
west as the 12Z ECMWF/GFS solutions.

[cycloneye]

TROPICAL STORM KARL DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016
500 PM AST SAT SEP 17 2016

Convection continues to flare up and down near the center of Karl,
with a larger mass well to the northeast of the center. In
addition, the circulation looks more elongated than earlier today,
perhaps due to the convective asymmetry. The initial wind speed is
held at 40 kt since the system does not look all that different,
although the satellite classifications are a bit lower.

Karl could still weaken a little bit in the short term while the
cyclone is in a recovery stage from its interaction with an
upper-level low. Gradual strengthening is then forecast by early
next week as the storm encounters very warm water, low shear, and a
marginal moisture environment. Model guidance is very similar to
the previous cycle, except for the ECMWF which shows a more powerful
cyclone by day 5. Very little change was made to the official
forecast, which continues to be most similar to a blend of the
SHIPS/LGEM models.

The initial motion estimate is unchanged from the previous one,
265/11. Karl should begin to gain some latitude by Monday as it
moves around the southern side of the subtropical ridge. A
west-northwestward motion is forecast to begin on Tuesday due to
the orientation of the ridge, and this motion could continue for
the rest of the 5-day period. The biggest change since the last
cycle is that model guidance is showing a stronger ridge in the
central Atlantic, which would prolong the west-northwestward
motion. The track models have shifted westward at long range, and
the official forecast is moved in that direction, but not as far
west as the 12Z ECMWF/GFS solutions.

FORECAST POSITIONS AND MAX WINDS

INIT 17/2100Z 18.1N 40.4W 40 KT 45 MPH
12H 18/0600Z 17.9N 42.3W 35 KT 40 MPH
24H 18/1800Z 17.8N 45.0W 40 KT 45 MPH
36H 19/0600Z 18.1N 47.6W 40 KT 45 MPH
48H 19/1800Z 18.8N 50.3W 45 KT 50 MPH
72H 20/1800Z 20.6N 55.4W 50 KT 60 MPH
96H 21/1800Z 23.0N 60.5W 60 KT 70 MPH
120H 22/1800Z 25.0N 64.5W 70 KT 80 MPH

$$
Forecaster Blake

[gatorcane]

So the question is will the models keep shifting west in the long-range or is that as far west as they will go?

[Alyono]

So the question is will the models keep shifting west in the long-range or is that as far west as they will go?

first, Karl has to survive

[Kazmit]

So the question is will the models keep shifting west in the long-range or is that as far west as they will go?

Well, most models expect a somewhat sharp recurve near the end of the NHC's current 5 day cone. I don't think it will go much farther west (or at least I hope not).