ATL: KARL - Post-Tropical - Discussion

[GCANE]

Latest from AMSU, about 1.5 hrs ago, has it opening up.

[Kazmit]

It does look worse on visual satellite... The circulation is less visible.

[JaxGator]

Strangely enough, there's lower shear over Karl per the shear map but there's also more at work such as the mid-level dry air.

[cycloneye]

Is his opinion.

 https://twitter.com/BigJoeBastardi/status/777140341589807104

[gatorcane]

Some good consensus with the models but Karl is already heading south of what these models are showing:

[gatorcane]

JB makes a good point. Models have been pretty bad this year not to mention Karl keeps losing latitude which is going against the 12Z model guidance. It is possible if Karl keeps losing latitude (and stays more shallow than expected) that the models will shift more west in response.

[SFLcane]

Models aren't god BUT they paint a very ugly picture in terms of conditions ahead. I for one don't put much stock in any guidance especially given how horrific they have been thus far this season. Don't need models to see atmosphere is just hostile.

[Gustywind]

JB makes a good point. Models have been pretty bad this year not to mention Karl keeps losing latitude which is going against the 12Z model guidance. It is possible if Karl keeps losing latitude (and stays more shallow than expected) that the models will shift more west in response.

Interresting point Gatorcane. You know better than me that shallow systemt tend to trek on a Westerly course often. We should continue to keep an eye on this one. Us the Leewards do not let your guard down as we never know, any system could be suspicious.

[cycloneye]

BULLETIN
TROPICAL STORM KARL ADVISORY NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016
1100 AM AST SAT SEP 17 2016

...KARL REMAINS A SHEARED TROPICAL STORM...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.3N 39.0W
ABOUT 1500 MI...2415 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...1004 MB...29.65 INCHES



TROPICAL STORM KARL DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016
1100 AM AST SAT SEP 17 2016

Karl has been in a fairly steady state during the past day or more
with convection periodically firing near the center and a larger
area of more continuous thunderstorms far from the center. Ship
BATFR18 reported sustained winds of about 40 kt at 1100 UTC, which
support keeping that wind speed for this advisory. The shear that
has been affecting Karl should gradually diminish over the next
couple of days as it moves away from a nearby upper-level low. A
small amount of weakening is possible in the short term since the
system is still struggling against the shear. Thereafter,
strengthening is anticipated due to Karl likely moving over
very warm waters concurrent with rather light shear. One question
mark is the amount of available moisture in the mid-levels, with
both the ECMWF and the GFS showing a somewhat dry environment. While
a lot of the tropical-cyclone-specific intensity guidance shows a
hurricane at long range, the marginal moisture environment forecast
by those two global models makes me think twice about going too
high. The new forecast is very similar to the previous one and is
similar to a blend of the SHIPS/LGEM models.

Karl has been wobbling a little south of due west during the day,
depending on how much convection is near the center. A strengthening
low- to mid-level ridge over the central Atlantic is expected to
continue pushing Karl south of due west during the next 24 hours.
After that time, Karl should move more to the west-northwest around
the weakening ridge through day 4, well to the northeast of the
Leeward Islands, and possibly turn northwestward by 120 hours while
the cyclone approaches a weakness in the ridge. The spread in the
models have increased since the last advisory, perhaps due to Karl's
interaction with the upper-low. The new model consensus and the
previous official forecast were very close to one another, so no
significant changes are made in the new NHC forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 17/1500Z 18.3N 39.0W 40 KT 45 MPH
12H 18/0000Z 18.1N 40.9W 35 KT 40 MPH
24H 18/1200Z 17.8N 43.6W 35 KT 40 MPH
36H 19/0000Z 17.8N 46.2W 40 KT 45 MPH
48H 19/1200Z 18.3N 48.7W 45 KT 50 MPH
72H 20/1200Z 20.2N 54.0W 50 KT 60 MPH
96H 21/1200Z 22.5N 59.0W 60 KT 70 MPH
120H 22/1200Z 25.0N 63.0W 70 KT 80 MPH

$$
Forecaster Blake

[Gustywind]

Decreasing numbers for Karl...


DATE/TIME LAT LON CLASSIFICATION STORM
17/1145 UTC 18.4N 38.3W T1.0/1.5 KARL
17/0545 UTC 18.4N 37.5W T1.5/1.5 KARL
16/2345 UTC 18.5N 36.4W T1.0/1.5 KARL

[Kazmit]

By the looks of this, it doesn't seem to be losing as much latitude as I thought. But I don't know how accurate this is.

[cycloneye]

Extract from 11 AM EDT discussion.Important factor is the Mid-level dry air and Eric Blake discusses it.

One question
mark is the amount of available moisture in the mid-levels, with
both the ECMWF and the GFS showing a somewhat dry environment. While
a lot of the tropical-cyclone-specific intensity guidance shows a
hurricane at long range, the marginal moisture environment forecast
by those two global models makes me think twice about going too
high. The new forecast is very similar to the previous one and is
similar to a blend of the SHIPS/LGEM models.

[floridasun78]

Some good consensus with the models but Karl is already heading south of what these models are showing:

that telling few here their saying going to Bermuda i think too early call that

[AutoPenalti]

Bam, Joe Bastardi just made a very good point that many have not really wanted to discuss. The weaker this gets, the higher the chance it misses it's connecting flight with the trough. Again, like many other invests this year, it's the one to watch.

[Kazmit]

Some good consensus with the models but Karl is already heading south of what these models are showing:

that telling few here their saying going to Bermuda i think too early call that

Too early to be certain about it hitting Bermuda, but not too early to take an eye off it.

[floridasun78]

Some good consensus with the models but Karl is already heading south of what these models are showing:

that telling few here their saying going to Bermuda i think too early call that

Too early to be certain about it hitting Bermuda, but not too early to take an eye off it.

i think models will start soon track more to south because not get stronger as forecast

[cycloneye]

 https://twitter.com/TropicalTidbits/status/777138427900923908




 https://twitter.com/RaleighWx/status/777157486067326976




 https://twitter.com/webberweather/status/777166145044578304

[floridasun78]

i watch hwrf show more closer to Bahamas not turning and bit stronger system by thur and if notice high building it north here link http://www.tropicaltidbits.com/analysis/models/?model=hwrf-p&region=12L&pkg=mslp_wind&runtime=2016091706&fh=126&xpos=0&ypos=342

[floridasun78]

GFDL-P show more weest track no turn yet last run east of Bahama http://www.tropicaltidbits.com/analysis/models/?model=gfdl-p&region=12L&pkg=mslp_wind&runtime=2016091706&fh=54&xpos=0&ypos=99 two models run showing more west and getting strong by wed like hwrf

[gatorcane]

Pretty decent west shift by the GFS beyond 5 days with more of a 500mb ridge over the eastern seaboard of the US and western Atlantic