Atlantic Tropical Action 2014

[downeastnc]

Remember northward moving storms on the east coast are going to have the strongest winds to the east of the eye.  So if it stays just offshore or is a coast hugger the Carolinas would be on the wet side with lighter winds.  

 

Yeah you need a NNW or at least NNE track and a LF around ILM to get good storm conditions in eastern NC most of the time especially on what we call the "Inner Banks" region.

[U_Thant]

I too am disappointed we don't have recon today, but essentially all this means is we'll have a TD tomorrow instead of today.  Who knows, even if they found a closed CoC today, NHC might still not make the upgrade due to the lack of sufficient deep convection co-located with the CoC (which has always been somewhat subjective / varies by forecaster). 

 

Would re-iterate that the extra dropsonde and flight-level data would have been nice for assimilation, as it's clear that GFS and GGEM are having difficulty with initialization. 

 

 

This

[Ground Scouring]

The low-level center (currently up near ~29°N ~78°W and moving W) will likely reform farther S as deeper convection redevelops N of Grand Bahama Island. Once that happens, steady intensification could occur once a well-define inner core establishes itself. What happens to 91L over the next 24-36 hours won't make much of a difference in its future. On Day 2 and beyond, however, 91L's strength will make a big difference in how rapidly/soon it responds to the developing weakness off the SE coast.

[Eyewall2005]

Here's ur LLC..exposed heading W.

 

[N. OF PIKE]

http://www.ndbc.noaa.gov/station_page.php?station=41009

 

2.0 swell height at 9.1 Secs and ENE direction. First sign of a wave from this thing on East coast. (11pm)

 

swirl looks to be heading SW

[icebreaker5221]

Environment looks more than favorable enough for development.  I'd be very surprised if we don't see at least one decent VHT develop close to the CoC by 12Z. 

[thewxmann]

0Z ECMWF intensifies 91L to 980mb just off of Cape Hatteras in about 4.5 days.

[phil882]

0Z ECMWF intensifies 91L to 980mb just off of Cape Hatteras in about 4.5 days.

 

Probably more importantly, it intensifies 91L much faster early on, with the system threatening the FL/GA/SC in the first 72 hours as an intensifying tropical storm / hurricane.... it eventually makes landfall near Beaufort, NC as a formidable hurricane (probably Cat 2) on 12z Friday.

[phil882]

Down to 1012 hPa now... not too bad considering the ambient pressure is much higher. If we can get just a little more convective organization, we would have a TD.

 

[Solak]

NOAA NWS National Hurricane Center

41 minutes ago

Beginning at 2 p.m. EDT July 1st, NOAA's National Hurricane Center (NHC) will introduce an experimental five-day Graphical Tropical Weather Outlook (GTWO) to accompany its text Tropical Weather Outlook (TWO).

It will be available for both the Atlantic and eastern North Pacific basins and indicate the formation potential of current and future disturbances during the next five days. Shaded areas will represent the potential tropical cyclone formation areas, color-coded by development likelihood.

Also effective at 2 p.m. EDT July 1st, the 48-hour GTWO will no longer indicate the locations of disturbances by encircling them. Instead, for consistency with the new five-day graphic, locations of current disturbances will be marked with an “X”.

Examples of the five-day GTWO and 48-hour GTWO are posted below. For more information, see: http://www.nhc.noaa.gov/news/20140630_pa_FiveDayOutlookGraphic.pdf or watch the video: http://youtu.be/lSTAGhQsZk8

[TropicalAnalystwx13]

Not much change convectively from earlier. Continued northwesterly shear is exposing the low-level center to view. Hoping recon flies this afternoon.

[phil882]

Not much change convectively from earlier. Continued northwesterly shear is exposing the low-level center to view. Hoping recon flies this afternoon.

 

Its not really northerly shear anymore, as the 200-hPa flow has decreased and the llc is moving slowly southward. The problem is that dry air has been ingested directly into the core, and it will take some time (via scattered convection rotating counter-clockwise around the system) to moisten the in-situ environment of 91L. Were the storm embedded in a moist mid-level environment, the 5-10 knots of northerly shear would not be a problem as storm generated outflow from deep robust convection would easily be able to overcome this.

 

When you have too much dry air though, those convective towers entrain a lot of dry air, weakening their vertical velocity and preventing them from reaching their maximum height via traditional parcel theory. We will probably be in a busting pattern for a while (~24 hours) as the system attempts to bring the environment back to moist adiabatic.

[Derecho!]

As much as I hate the usual rush to historical analogues in tropical Wx threads I'm surprised that (I think) Diana 1984 hasn't been thrown out there. That was September, though.

[phil882]

As much as I hate the usual rush to historical analogues in tropical Wx threads I'm surprised that (I think) Diana 1984 hasn't been thrown out there. That was September, though.

 

Not a horrible analog... especially given the non-traditional type of genesis with this system. It does look like when 91L gets picked up by the upper-level trough later this week though, it will high tail it out of here and we shouldn't see it hang around the Gulf Stream for too much longer.

[downeastnc]

As much as I hate the usual rush to historical analogues in tropical Wx threads I'm surprised that (I think) Diana 1984 hasn't been thrown out there. That was September, though.

 

LOL I was just looking at that info, that was the first real hurricane to hit NC in my life that I can remember. We had the day off from school because of it but winds never got over 50 mph here.....If she hadn't made that loop though things would have been different for sure.....

 

I can pretty much guarantee a eastern NC hit this weekend since I am moving into a new house.....the house is exactly 100 miles west of Cape Hatteras

[phil882]

FWIW, GFS finally came on board at 06z... and about 36 hours behind the ECMWF.

[TropicalAnalystwx13]

Not sure if Alex 2004 has been thrown out as an analog yet.

[Ground Scouring]

The longer 91L remains weak, the more likely that it will first make a landfall somewhere on the Space Coast before recurving. The 06Z HWRF does suggest such a possibility.

[Kory]

Obviously too early to read much into it, but it looks like the llc is trying to fire a little convection. Dry air is definitely an issue at the moment. Hope we don't get another recon cancellation. 

A recon cancellation would seem nonsensical to me.  We have a system that models show development with very near the coast of the U.S. with potential impacts.  I think they need recon information at this point.  

[downeastnc]

Seems to be getting a little more in the way of storms around the center now and the overall look is better we could be about to see some real sustained convection around the center soon, if it can get some decent storms associated with it they will IMO go straight to Arthur and I doubt they cancel the plane today. They will want to get a idea of what they are dealing with since it will be possibly approaching the coast in the next few days and they may need to go with TS watches etc.....

[hurricaneman]

Recon heading to 91L as we speak and if convection continues to wrap around we may have Arthur sometime tonight

[phil882]

For those new here, you can follow along at the link below (google earth plugin required)

 

http://tropicalatlantic.com/recon/live/

[phil882]

We might be in for a surprise upgrade to TS... there was already a uncontaminated 34 knot SFMR wind with plenty of 30+ knot winds in the cloud free region to the NW of the center. This suggests that 91L might have been a little stronger than the NHC was suggesting the last 24 hours.

000URNT15 KNHC 301733AF304 01BBA INVEST             HDOB 13 20140630172330 2834N 08036W 6996 03199 0174 +078 -027 025018 019 /// /// 03172400 2834N 08034W 7001 03195 0170 +082 -041 027019 019 /// /// 03172430 2834N 08032W 6990 03206 0163 +085 -031 026020 020 /// /// 03172500 2834N 08030W 6999 03193 0158 +088 -020 027019 020 030 000 00172530 2834N 08028W 6996 03198 0162 +086 -026 024019 019 028 001 00172600 2834N 08025W 7000 03193 0162 +085 -022 026020 020 029 001 00172630 2834N 08023W 6994 03199 0159 +086 -025 028020 021 030 000 00172700 2834N 08021W 7002 03189 0161 +085 -026 029020 020 029 000 00172730 2834N 08019W 6992 03200 0161 +085 -038 030021 021 028 000 00172800 2834N 08017W 6996 03194 0161 +084 -028 029020 021 029 000 00172830 2834N 08015W 6995 03195 0155 +088 -023 029020 021 029 000 00172900 2834N 08013W 6995 03192 0157 +086 -044 032022 022 029 000 00172930 2834N 08011W 6996 03192 0156 +086 -018 034023 023 028 000 00173000 2835N 08008W 6997 03190 0154 +088 -017 032022 023 029 001 00173030 2835N 08006W 6998 03190 0151 +090 -042 031022 022 030 000 00173100 2835N 08004W 6998 03188 0150 +090 -023 031022 023 031 000 00173130 2835N 08002W 7002 03182 0150 +087 -038 031023 024 031 000 00173200 2835N 08000W 6999 03186 0153 +085 -046 031023 024 032 001 00173230 2835N 07958W 7063 03136 0180 +090 -027 028023 023 034 000 03173300 2835N 07956W 7585 02536 0190 +118 -037 018023 024 /// /// 03$$

[downeastnc]

Up to 80% now. 

 

http://www.nhc.noaa.gov/gtwo_atl.shtml

 

It most likely has been a depression for a day or so really, the data from the plane already supports that I think the real question is do they go TD or TS.....

[phil882]

It most likely has been a depression for a day or so really, the data from the plane already supports that I think the real question is do they go TD or TS.....

Probably TS... widespread 35+ knot reports now. Consdiering this is in the dry sector of the storm as well, the winds could be more in the 40-45 knot range in the eastern quadrant.

000URNT15 KNHC 301744AF304 01BBA INVEST             HDOB 14 20140630173330 2835N 07954W 7919 02168 0187 +136 -032 019024 024 /// /// 03173400 2835N 07951W 8257 01816 0195 +148 -033 017024 024 /// /// 03173430 2835N 07949W 8613 01453 0193 +167 -029 018025 026 /// /// 03173500 2835N 07947W 8928 01139 0187 +181 -035 015025 026 036 000 03173530 2835N 07945W 9211 00873 0185 +193 -035 012024 025 /// /// 03173600 2835N 07943W 9562 00543 0176 +214 -039 010023 024 034 002 00173630 2835N 07941W 9598 00491 0154 +219 -036 008025 026 036 000 00173700 2835N 07939W 9589 00496 0153 +214 -045 016024 027 035 004 00173730 2835N 07937W 9597 00488 0154 +214 -053 017027 028 037 002 00173800 2835N 07936W 9593 00490 0151 +220 -044 019027 028 033 000 00173830 2835N 07936W 9593 00490 0150 +218 -047 018026 027 035 000 00173900 2835N 07932W 9598 00486 0151 +215 -057 020024 025 034 002 00173930 2835N 07931W 9597 00486 0150 +215 -058 024023 024 034 001 00174000 2835N 07929W 9596 00488 0151 +215 -051 022024 025 034 001 00174030 2835N 07927W 9588 00493 0150 +215 -046 023023 025 034 000 00174100 2835N 07926W 9597 00485 0149 +215 -058 022024 025 033 001 00174130 2835N 07924W 9593 00491 0150 +213 -052 027024 026 033 001 00174200 2835N 07922W 9587 00492 0148 +213 -059 028024 026 032 000 00174230 2835N 07921W 9597 00482 0147 +215 -078 029024 025 032 001 00174300 2835N 07919W 9592 00487 0147 +216 -058 030023 025 033 000 00$$;

[wxmeddler]

Yeah, SFMR really lighting up now. Also one thing to note is that when the plane was descending through 700mb, the air was pretty dry. 8/-5°C

[phil882]

Yeah, SFMR really lighting up now. Also one thing to note is that when the plane was descending through 700mb, the air was pretty dry. 8/-5°C

 

Yep... and that's something that the system will have to work on the next 24 hours... will take some time to moisten up the column.

[downeastnc]

Looks like we have Arthur think they go with a special advisory at 2pm or is that not enough time.....

[U_Thant]

It most likely has been a depression for a day or so really, the data from the plane already supports that I think the real question is do they go TD or TS.....

 

While the distinction between "tropical low" and "tropical depression" is really a semantic issue for most folks outside TC operations, it really didn't have the extent of persistent "central" convection to be classified as a TD up until the curved band formed in the S-SE quadrant earlier this morning.

[wxmeddler]

Looks like we have Arthur think they go with a special advisory at 2pm or is that not enough time.....

 

They'll wait for recon of the SE quad to set the max wind.. More likely at 5p.