Welcome to American Weather
WxWatcher007

Hurricane Gert

85 posts in this topic

If the NHC forecast holds true, it looks to me like this would be an atrocious showing by the GFS and pretty ugly showing by the Euro WRT intensity. This is ~72 hours from now. We'll see what TD 8 does, but this is a reminder of the challenges we still have in tropical intensity forecasting. 

gfs_mslp_wind_atl_14.png

ecmwf_z500_mslp_eus_4.png

hwrf-p_mslp_wind_99L_27.png

Tropical Depression Eight Discussion Number   1
NWS National Hurricane Center Miami FL       AL082017
1100 PM EDT Sat Aug 12 2017

Late afternoon GOES-16 visible satellite images showed that the
circulation associated with the low pressure located northeast of
the Bahamas had become better defined.  Since that time, the
night-time microphysics RGB product and other infrared satellite
pictures have continued to show an improvement in the circulation,
and recent ASCAT data show that the system has acquired a well-
defined center. Deep convection is organized in a large curved band,
however the center is located near the western edge of the band.
NOAA buoy 41046 located southeast of the center reported 25 to 30 kt
winds earlier this evening, and the scatterometer data support an
initial wind speed of 30 kt.

The depression is moving north-northwestward or 330/11 kt.
The depression should move north-northwestward to northward
around the western side of a deep-layer ridge over the central
Atlantic through Sunday night. It is expected to reach the
mid-latitude westerlies by late Monday and begin to accelerate
northeastward ahead of a short-wave trough that will be approaching
the northeastern United States.  The steering currents are well
established over the western Atlantic and the track guidance is in
good agreement on the forecast scenario. The NHC track forecast lies
near the various consensus aids.

The intensity forecast is more problematic.  The system is expected
to traverse warm water and remain in a low-shear environment during
the next day or so, but intrusions of dry mid-level air are likely
to limit strengthening.  The statistical guidance and the HWRF favor
more significant intensification than the global models, which
generally do not show much deepening.  In deference to the global
models, the NHC forecast is below the consensus, especially later in
the period.  The system is likely to become extratropical in 3 to 4
days, and the extratropical portion of the forecast is based on
guidance provided by the NOAA Ocean Prediction Center.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0300Z 25.3N  70.3W   30 KT  35 MPH
 12H  13/1200Z 27.0N  71.2W   35 KT  40 MPH
 24H  14/0000Z 29.0N  71.9W   40 KT  45 MPH
 36H  14/1200Z 30.7N  72.0W   45 KT  50 MPH
 48H  15/0000Z 32.2N  71.4W   50 KT  60 MPH
 72H  16/0000Z 36.2N  66.9W   55 KT  65 MPH
 96H  17/0000Z 41.5N  54.5W   50 KT  60 MPH...POST-TROP/EXTRATROP
120H  18/0000Z 45.5N  39.0W   45 KT  50 MPH...POST-TROP/EXTRATROP

Share this post


Link to post
Share on other sites

This is going to slip inbetween the interior trough and backing ridge over the Atlantic. We may even be looking at our next hurricane as this system may have favorable upper environment support as it turns N and eventually NNE. If the system can establish a core, the dry region between the Southeast/Mid-Atlantic and Bermuda may not be sufficient enough to stop it from intensifying to at least a strong TS or minimal cane. It has plenty of time to strengthen before getting ejected out into the North Atlantic.




Share this post


Link to post
Share on other sites

Been following 99L's progress for the past 7+ days.  Interestingly, the CMC has been by far the most consistent with regards to both track and intensity during that time.  It has been unwavering in its insistence on development and trajectory along the general forecast track.  GFS has been pretty bad during that time.

Edit:  Ironically, the CMC (with its 00z run) suddenly will be way off on intensity, if the NHC forecast vetifies; as I suspect it Will.  

Share this post


Link to post
Share on other sites

Now that I don't stay up on things like I use to --- I find this URL helpful as a briefing site. Enjoy!

www.ral.ucar.edu/hurricanes/realtime/current

Share this post


Link to post
Share on other sites

Gert may really take off this evening if it can consolidate a core. The MLC still looks slightly tilted south from the broader LLC. However, a strong band is intensifying in the eastern semicircle and that may allow things to ramp up rather quicky over night as northerly shear relaxes. I think Gert is going to end up stronger than a Cat 1 cane. I don't know if it will become a major, but it's going to have 48 hours of good upper support. I certainly won't be surprised if it reaches Cat 3 as it follows along the Gulf Stream OTS.



I'm not sure why but every time I say the name Gert it gives me chuckle. Glad this storm will be relatively unimpactful except for shipping lanes.

Share this post


Link to post
Share on other sites

Struggling even after it escaped the tropics. Looks  like alot  of dry air  is wrapping  in.

Share this post


Link to post
Share on other sites

...GERT BECOMES THE SECOND HURRICANE OF THE 2017 SEASON...

 

BULLETIN
Hurricane Gert Advisory Number   9
NWS National Hurricane Center Miami FL       AL082017
1100 PM EDT Mon Aug 14 2017

...GERT BECOMES THE SECOND HURRICANE OF THE 2017 SEASON...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...31.2N 72.3W
ABOUT 445 MI...720 KM W OF BERMUDA
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...986 MB...29.12 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 1100 PM EDT (0300 UTC), the center of Hurricane Gert was located
near latitude 31.2 North, longitude 72.3 West. Gert is moving toward
the north near 8 mph (13 km/h). A turn toward the northeast with an
increase in forward speed is expected late Tuesday or Tuesday night

Maximum sustained winds have increased to near 75 mph (120 km/h)
with higher gusts.  Some strengthening is forecast during the next
48 hours.

Hurricane-force winds extend outward up to 25 miles (35 km) from the
center and tropical-storm-force winds extend outward up to 105 miles
(165 km).

The estimated minimum central pressure is 986 mb (29.12 inches).


HAZARDS AFFECTING LAND
----------------------
SURF:  Swells generated by Gert will spread northward along the
east coast of the United States from North Carolina northward to
Long Island during the next couple of days.  Swells are also
expected to affect Bermuda during the next couple of days.  These
swells are likely to cause life-threatening surf and rip current
conditions.  Please consult products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 500 AM EDT.

$$
Forecaster Blake

Share this post


Link to post
Share on other sites
21 minutes ago, ldub23 said:

Struggling even after it escaped the tropics. Looks  like alot  of dry air  is wrapping  in.

You need to give it a rest

1 person likes this

Share this post


Link to post
Share on other sites
29 minutes ago, ldub23 said:

Struggling even after it escaped the tropics. Looks  like alot  of dry air  is wrapping  in.

As someone who has a hard time understanding tropics and really values those here who know what they're talking about, I beg you to stop posting n these tropical threads please.

1 person likes this

Share this post


Link to post
Share on other sites
9 hours ago, canderson said:

As someone who has a hard time understanding tropics and really values those here who know what they're talking about, I beg you to stop posting n these tropical threads please.

Its the same song and dance from this person in the SE thread as well, on topic Gert should be a good looking cane later this afternoon. Gert is one of  the smaller hurricanes I can remember  off the NC coast as well. TS wind field barely more than 100 miles across....

Share this post


Link to post
Share on other sites
10 hours ago, canderson said:

As someone who has a hard time understanding tropics and really values those here who know what they're talking about, I beg you to stop posting n these tropical threads please.

 

11 hours ago, NJwx85 said:

You need to give it a rest

 

guys that never make predictions themselves, but are the first ones to be there... when someone screws up.  =   funny.  

Share this post


Link to post
Share on other sites
6 minutes ago, Sophisticated Skeptic said:

 

 

guys that never make predictions themselves, but are the first ones to be there... when someone screws up.  =   funny.  

Steering currents turned out to be weak. You were largely accurate in your predictions. Make no mistake, this is a very slow moving system however there are no features at H5 to really take this into the conus or Canada. The East coast lucked out with this -NAO. Which in October or late September would be sufficient to generate a negative tilted cold front.

Share this post


Link to post
Share on other sites
6 minutes ago, Sophisticated Skeptic said:

 

 

guys that never make predictions themselves, but are the first ones to be there... when someone screws up.  =   funny.  

Was this aimed at me? I was pretty confident that 99L was eventually going to develop. I didn't think it was going to take a run at becoming a major but I'm not surprised. 

Share this post


Link to post
Share on other sites
1 hour ago, Sophisticated Skeptic said:

 

 

guys that never make predictions themselves, but are the first ones to be there... when someone screws up.  =   funny.  

I don't know enough about tropics to make any predictions. But I do know better than read junk repeated that is debunked by those who do. 

Share this post


Link to post
Share on other sites

Now that Gert is accelerating Northeast with favorable outflow the system has finally produced a well defined eye on IR loop. The latest advisory puts Gert up to 90MPH and I wouldn't be shocked if the system reaches Cat 2 strength later today.

avn_lalo-animated.gif

Share this post


Link to post
Share on other sites

Not too shabby. This is easily a Cat 2. Gert will most likely succumb to shear over night but it is looking really good right now.

 

20170816-152937.png

Share this post


Link to post
Share on other sites
27 minutes ago, WxWatcher007 said:

To think that this was left for dead just a few days ago. 

And everyone was bashing the Euro for being the only model to show development while the GFS had nothing. 

Share this post


Link to post
Share on other sites

As expected, Gert is now a Category 2. Max winds now of 100MPH. Expected to become extra-tropical by Friday morning.

Share this post


Link to post
Share on other sites

Maxed out at 105mph last night. Since then things have been rapidly deteriorating and this system should be declared extra tropical later today.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.