ATL: JOAQUIN - Post-Tropical - Discussion

[Aric Dunn]

Had a nice long nap... I see its pretty much on forecast. looking quite good.

[chaser1]

Had a nice long nap... I see its pretty much on forecast. looking quite good.

Sugar for your coffee?

[LarryWx]

What's the reason for the odd wind-pressure relationship? I think Isaac was the only other Cat 1 that I've seen with such low pressure that wasn't transitioning in the north Atlantic.

Hammy,
I'd say lower than normal surrounding surface pressures is one factor. Look at how far out in all directions is the 1008 mb isobar. There are no nearby sfc highs. All of this is consistent with slow motion.

I suppose it just comes down to the overall gradient (or lack thereof)

Yes, that's what I'm saying...the gradient is relatively weak due to weaker than normal background pressures.

[Aric Dunn]

Had a weird dream last night that Wilmington take a direct hit for some reason..

[Aric Dunn]

Had a nice long nap... I see its pretty much on forecast. looking quite good.

Sugar for your coffee?

rarely do coffee but maybe I will today..

[AutoPenalti]

When you see Joaquin and the 99L swirl it really brings into contrast how being in the right place at the right time is so important and something that can happen in ANY season.

http://i.imgur.com/7tUt6mK.jpg

Winning post of the day! So so true. "General conditions" applies to the broad picture, but has so little to do with those brief moments in time when looking at a span of time that lasts for several months.

That picture is frightening, especially with how close it is.

[Hammy]

Had a weird dream last night that Wilmington take a direct hit for some reason..

Your dream predicted the afternoon GFS run since it seems to go pretty close to that.

Is this strengthening more slowly than expected due to the flatter pressure gradient?

[HurricaneBelle]

WTNT31 KNHC 301744
TCPAT1

BULLETIN
HURRICANE JOAQUIN INTERMEDIATE ADVISORY NUMBER 11A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015
200 PM EDT WED SEP 30 2015

...JOAQUIN CONTINUING TO STRENGTHEN...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...24.4N 72.9W
ABOUT 190 MI...305 KM ENE OF THE CENTRAL BAHAMAS
MAXIMUM SUSTAINED WINDS...85 MPH...135 KM/H
PRESENT MOVEMENT...SW OR 230 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...968 MB...28.58 INCHES

[chaser1]

On satellite, Joaquin is one big # "9".

[summersquall]

When you see Joaquin and the 99L swirl it really brings into contrast how being in the right place at the right time is so important and something that can happen in ANY season.

Absolutely. Was only last week breathing a small but important sigh of relief that the September was coming to an end without a major US mainland event. As a former Cape May local my thoughts are with all along the EC. Found it interesting abeit alarming that the NHC advised in KEY MESSAGES:...should the track trend weatward, an increase in forward speed would likely occur and hurricane watches may be needed as early as Thursday evening.

[Aric Dunn]

Had a weird dream last night that Wilmington take a direct hit for some reason..

Your dream predicted the afternoon GFS run since it seems to go pretty close to that.

Is this strengthening more slowly than expected due to the flatter pressure gradient?

pressure wise its pretty much right along yesterdays 12z models. winds still need to catch up. 971/968 would be more i along the lines of 90+ mph

[Weatherwatcher98]

WTNT31 KNHC 301744
TCPAT1

BULLETIN
HURRICANE JOAQUIN INTERMEDIATE ADVISORY NUMBER 11A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015
200 PM EDT WED SEP 30 2015

...JOAQUIN CONTINUING TO STRENGTHEN...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...24.4N 72.9W
ABOUT 190 MI...305 KM ENE OF THE CENTRAL BAHAMAS
MAXIMUM SUSTAINED WINDS...85 MPH...135 KM/H
PRESENT MOVEMENT...SW OR 230 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...968 MB...28.58 INCHES

Guess not Hammy

[AutoPenalti]

Watching clouds clearing out in a huge widening circle around the storm- extends more west in Gulf than before
Also see that the whole storm system is moving S.W. at a steady clip. (not just the center of storm)
Its hard to imagine the ultra sharp turn (on a dime) to the north - rather a more gradual turn.
I wonder if the math has been done - if the digging Trough is located further west in the gulf?

I am not a Pro - and do not claim to be one.
http://www.ssd.noaa.gov/goes/east/carb/flash-bd.html

I had also noticed as well, how the overall ridging throughout the Caribbean appeared to be building westward all the way to Yucatan. I suppose the entire premise of such a sudden turn to the north, would be a pretty sharp change in the steering flow. You bring up nuances that are reasonable to consider. Even if the evolution of a strong cut-off low were to materialize as forecast, significant implications on ultimate track and intensity could occur if the cut-off low were to develop later then progged. Also, if this low were to develop but with an even greater positive tilt than expected, such might indicate a weaker trough or stronger ridging beneath it. Another obvious factor would simply be whether this cut-off were to develop a bit further east or further west.

Whether El Nino is causing an unusual impact on larger scale atmospheric conditions, ultimately affecting the dynamic evolution of regional weather features or perhaps someone just spilled Pepsi over all of the Global and Regional model computers..., there's just little doubt that mid to long range forecasting seems to have become somewhat less reliable (at least as such applies to tropical development).

If my theory holds true and If this is the case then this MAY be the costliest error in a recent decade.

[LarryWx]

WTNT31 KNHC 301744
TCPAT1

SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...24.4N 72.9W
PRESENT MOVEMENT...SW OR 230 DEGREES AT 6 MPH...9 KM/H

Compare this 2PM position to the prog from 11 AM advisory for six hours from now: 12H 01/0000Z 24.3N 73.2W 80 KT 90 MPH

So, it is still moving SW vs the NHC's progged WSW motion between 11 AM and 8 PM EDT. It has moved from 24.7 N at 11 AM down to 24.4 N at 2 PM. It is now only 0.1 north of the projected 8 PM position. This is suggesting a good chance for another southward adjustment at the 5 PM advisory.

[Aric Dunn]

WTNT31 KNHC 301744
TCPAT1

SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...24.4N 72.9W
PRESENT MOVEMENT...SW OR 230 DEGREES AT 6 MPH...9 KM/H

Compare this 2PM position to the prog from 11 AM advisory for six hours from now: 12H 01/0000Z 24.3N 73.2W 80 KT 90 MPH

So, it is still moving SW vs the NHC's progged WSW motion between 11 AM and 8 PM EDT. It has moved from 24.7 N at 11 AM down to 24.4 N at 2 PM. It is now only 0.1 north of the projected 8 PM position. This is suggesting a good chance for another southward adjustment at the 5 PM advisory.

as of right now its following the NHC track quite well.

[chaser1]

Southwest motion so far today, right on track as forecasted by NHC however the 12 hour forecast from 12Z this a.m. sure does indicate that Joaquin is moving distinctly faster than anticipated. Stronger or westward building ridge?

Oh waiter....., please check with the kitchen and make sure that our large cut-off low is prepared and presented as anticipated, lol.

[alienstorm]

The one thing that I am concerned with is that the shortwave high pressure system that is inducing the SW motion my be being pump by Joaquin. This in turn will endure a longer SW motion and the sharp northward turn will be more circular thus the end result will be closer to the coast then previous anticipated.

[Aric Dunn]

well one thing for pretty much certain the little island of san salvador is going to have a very prolonged hurricane pretty much on top of it for 24 hrs or so..

[Cyclenall]

Had a weird dream last night that Wilmington take a direct hit for some reason..

What did it look like? I haven't had a hurricane dream in a long time but I've had a few in the last couple years.

Joaquin looks exactly what I thought it would at this time.

[Steve]

Glad to see the NHC on the ball as usual with the especially mentioned "Key Messages" at the bottom of the 11am discussion. Those are all critical to note for anyone who in the near term wants to whine about why the NHC did or didn't do something. Those 3 points can't be overestimated:

1) Low confidence in track (something we were saying yesterday and Monday with those options on the table);

2) Any increasing threat to the US could easily mean a quicker landfall if further west adjustments are made;

and 3) Heavy frontal rainfall along the east coast could hamper preparations.

An addendum from me for Point 3: It shouldn't need to be said here, but as a reminder, wet/saturated soils have a tendency to allow trees to blow over in heavier winds. I've seen several hundred year old live oak trees on their sides with root systems sticking up 15-20" into the air. Be aware of initial wind directions relative to the position of your house. If you are in a high impact area and have large trees next to your home, know which directions the winds will be coming in from and what they will reverse to once the center passes. Generally here in New Orleans with a storm approaching from the South or Southeast, we get winds out of the NE. After the center passes, they generally switch to out of the Southwest. Once your threat area is recognized, your local forecast offices of the NWS will tell you what the conditions will be in your area. If it's winds up to 80 out of the East, and you have large trees to the east of your home, you probably don't want to be on that side. Obviously it's the reverse once the winds shift. From personal experience, my home during Katrina had a 50 year old pecan tree about 10 feet from my house that fell onto it from the NE. Luckily it was close enough to the house that it rested there and just messed up the roof on that side. Had it been 5-10 feet further away, it would have come crashing down.