Atlantic Tropical Action 2014

[icebreaker5221]

I took a snap shot of the recon which i believe was is the area,is this where you are talking about

 

I was actually thinking even further south than that, but the general idea (associated with the convection SE of the original / primary LLC) is the same.

[Superstorm93]

Ship report of 1007 mbs and a TON of lightning occurring. 

 

[calm_days]

 

 

This system is still partially interacting with the flow of/some sort of combination between the flow of the older gulf low and the one slowly drifting south of Texas. 

There seem to be possible signs there will be a small unpredictable change in the southeast weather pattern along with this system's development; it could be another weak low forming somewhere north of all of this.

 

There is still a lot of circulatory interference/interaction; this seems to be a strong environment for embedded circulations/depressions.  There are two large occluded lows/remnants in the atlantic and one more huge one in canada stretching over almost the whole CONUS.

 

It's not fully likely, but possible, that the convective complex moving south through GA and AL will also reach this same area of interaction between 91L , the strong gulf low, and the still-existing low that was originally interacting more heavily with 91L.

[Superstorm93]

HWRF

 

[Juliancolton]

Nighty night...

[icebreaker5221]

The original LLC seems to be becoming less and less defined over the last several hrs.  Meanwhile, persistent deep convection near Grand Bahama has been resulting in some slow but steady PV re-arrangement.  Unless the original center starts to recover over the next several hrs, I wouldn't be surprised to see the center jump to just north of Grand Bahama island. 

 

Now the original LLC is trying to make a comeback!  What a hot mess.

[NJHurricane]

Watching visible this afternoon has been awesome. You can see how the deeper convection in the southern quadrant of the storm is now drawing in the small surface circulation. The wind core is pretty broad, so this inner wind circulation can easily be "pulled" in the direction where the strongest vertical motion is inducing vortex stretching to the outer wind maxima (in this case in the Southern Quadrant).

http://climate.cod.edu/flanis/satellite/1km/index.php?type=S_Florida-vis-48

Its also funny how you can see a tiny convective cloud in the inner core that is sheared off to the north as the llc gets drawn into the much larger convective complex to its south.

wish to heck I could remember which one it is but either the Euro or GEM last night depicted the convection being almost all to the south at this time frame like we are seeing

[Ground Scouring]

Sometimes I just don't get the NHC.  Here we have a system, just off the Florida coast that is obviously getting its act together and will impact Florida/SE coast in some way.  So many times we have a crap system way down in the tropics that gets a TD status when it could be argued its not.  Even though at 5pm this system may be just slightly,slightly below the threshold, why in the hell not error on the side that it is a TD.  For the 6pm newscasts, for all the boating interests, on a holiday week a TD is going to get more attention than a system that is not.  Give the heads up now not later this   evening, instead of waiting a few hours when people are not watching news. People will wake up tomorrow AM and have a 50mph named storm just off the coast.Thunderstorms are wrapping around the center, pressure is falling so use common sense and start getting the word earlier verses later.  

Considering that the NHC regularly accepts feedback from the public on how to improve its products, I doubt that a situation like this hasn't come up previously (it has), so the NHC must have faced critique for short-term TCs-in-waiting just off the U.S. coast (or ex-TCs like "superstorm" Sandy). I would imagine that critique like yours is being taken into account here.

You can see the dry air nicely looking at WV (and a nice PW overlay product provided by the NHC).

 

 

PW to the northwest of the system is below 2.00" and drops below 1.50" as you approach the Carolina coastline... its this dry air that had been feeding into the circulation and keeping most of the NW quadrant clear of significant convection. This probably also favors a small TC developing rather than a large sprawling center (like what we see with TC Douglas in the EPAC which have very high mid-level moisture according to SHIPS). If it can just mix out the dry air in its immediate vicinity, it may have the potential for a significant intensification episode in the days to come.

Is the low PW the reason why the 18Z HWRF and GFDL runs do not take 91L past mid-range TS status?

[Superstorm93]

TXNT23 KNES 010016

TCSNTL

A. TROPICAL DISTURBANCE (91L)

B. 30/2345Z

C. 27.9N

D. 78.5W

E. THREE/GOES-E

F. T1.0/1.5/S0.0/24HRS

G. IR/EIR/VIS

H. REMARKS...CONVECTION IS SLIGHTLY MORE NUMEROUS/VIGOROUS THAN 24

HOURS AGO BUT HAS DECREASED PAST 6 HOURS. STILL UNDERGOING SHEAR AND

USED SHEAR MATRIX FOR DT. CIRCULAR DEFINED CLOUD LINES WITH CENTER LESS

THAN 75NM FROM CONVECTION WITH LIMITED CONVECTION GIVES DT=1.0. MET=1.5

BASED ON SLOW DEVELOPMENT FROM 24 HOURS AGO. PT=1.0. FT IS BASED ON PT.

 

AL, 91, 2014070100, , BEST, 0, 276N, 790W, 30, 1008, LO

 

 

 

 

Nice drop in pressure today under marginally favorable conditions 

[Akeem the African Dream]

Still looks like crap.  I stick with my call last night about overall strength.

 

Low end TS with anything beyond that an added bonus.

[Ground Scouring]

There has been a sudden and significant intensification of banding features on the south side of the broad LLC over the past hour and a half…that could be significant if the band continues to wrap around as it appears to be attempting to do so. Still, I'm skeptical that, with a stable air mass to its NW, 91L will be able to organize significantly over the next two days (before QG forcing takes over during recurvature).

 

Note the big blow-up of a hot tower NNE of Freeport, Grand Bahama:

 

[NJHurricane]

There has been a sudden and significant intensification of banding features on the south side of the broad LLC over the past hour and a half…that could be significant if the band continues to wrap around as it appears to be attempting to do so. Still, I'm skeptical that, with a stable air mass to its NW, 91L will be able to organize significantly over the next two days (before QG forcing takes over during recurvature).

 

Note the big blow-up of a hot tower NNE of Freeport, Grand Bahama:

 

If the Euro is correct fierce looking southern quadrants that struggle to wrap around may be a persistent feature for a while

[Hurr_Tracker13]

This thing is started to blow up with convection. Could be interesting to see tonight, over warm waters, storms have a mind of their own sometimes. At least it is something to track for the time being.

[Superstorm93]

Low now slipping into the convection

 

 

HRRR Analysis 

 

[smog strangler]

I am in Port Saint Lucie and a beautiful and calm partly cloudy evening. So close yet so far! 

Todays extremely quick showers from furthest most circulation produced .08 in the gauge. 

Interesting to see what tomorrow brings.

 

 

Low now slipping into the convection:

 

[Juliancolton]

Here we go. TD 1 initiated. http://www.nhc.noaa.gov/text/refresh/MIATCMAT1+shtml/010253.shtml

[Superstorm93]

91L has become TD1

 

[Hurr_Tracker13]

It is looking better at the moment, there might be a low forming right now under this convection.

[smog strangler]

So NHC has what could be Arthur as a TS almost immediately going forward but I suspect the the Treasure and Space coasts of FL will see minimal effects due to near term issues with convection wrapping around. Some quick fast moving showers (and locally heavy) on hand for Florida tomorrow but organized truly TC bands look very hard to come by.

 

Definitely subject to change. Good to see the NHC's first thoughts. 

 

[Superstorm93]

Here we go...

 

http://www.americanwx.com/bb/index.php/topic/44000-tropical-depression-one/

[icebreaker5221]

With anomalously high shear and low instability in both the MDR and the Caribbean, plus the tendency of El Ninos to produce early-season homebrews, TD1 is pretty much exactly what you'd expect. 

 

Fits well with climo for the period too

 

[calm_days]

 

This seems more like something archival for after the fact; just how much space really existed around this system due to the atlantic and also gulf blocking.  It isn't too common and certainly makes this a distinct/maybe historically relevant aspect of the 2014 season.

[calm_days]

 

Here is an up to date, wider view.

Shown here is [what as an amateur I can only describe as saturated, slow moving air over the gulf region, where a few small ULLs that were interacting with the cyclogenesis of 91L before melting into what is seen in the above and previous image] the amorphous GOM feature that slowed down the trough still remaining in place. 

 

When will this, as well as the atlantic ocean ULL that has been nearly stationary, change? 

Although they are not as interesting as tropical cyclones at first, they were present throughout the development of this one, and so in many senses are as crucial to the history of why this storm formed as well as how they themselves are like noteworthy storms or regions.  I am sure at least a few professionals are already interested and it may be something to watch/discuss during this next bit of time.

[Supercane]

Realizing that Arthur is somewhat of an unusual storm, I decided to look up all the years that had a solid (50KT+) TS or hurricane hit the US east coast (defined as north of FL) before August.

 

Counting 2014, there have been 11 such years since 1851. Interestingly, almost all had at least one additional impact of note along the US east coast. They are listed below:

 

1867 - Hurricane passes very close to Outer Banks and Cape Cod

1901 - (only year with nothing of note to follow)

1908 - Hurricane hits NC

1916 - Hurricane hits SC, another moderate TS hits GA

1945 - Upper-end TS hits SC (formerly a FL major hurricane)

1959 - Hurricane Gracie hits SC
1960 - Hurricane Donna hits NC and New England

1972 - Upper-end TS Carrie passes very close to Cape Cod

1985 - Hurricane Gloria hits Outer Banks and New England

1996 - Hurricane Fran hits NC

2014 - ??

 

Also, if I arbitrarily extend the end date to August 5, that would include 2004 -- which later saw Hurricanes Charley and Gaston hit SC.

 

Given that an El Nino is forming and that the AMO has been running on the cooler side, the odds of any long-tracking storm making it to the US east coast are low. However, using the above statistics as a guide, I wouldn't bet on Arthur being the last tropical cyclone to impact the US east coast this year.

[SnowGoose69]

I wonder if the total ACE from Arthur alone was at least half of the entire 2013 season.

[wxtrackercody]

I wonder if the total ACE from Arthur alone was at least half of the entire 2013 season.

No. Arthur accumulated 6.8075 units of ACE compared to the 2013 seasonal total of 36.12 units, or 18.8% percent of the 2013 seasonal total.

[calm_days]

Realizing that Arthur is somewhat of an unusual storm, I decided to look up all the years that had a solid (50KT+) TS or hurricane hit the US east coast (defined as north of FL) before August.

 

Counting 2014, there have been 11 such years since 1851. Interestingly, almost all had at least one additional impact of note along the US east coast.

 

This is a very wise observation.   Although it can't be certain what type of formation will occur, the GOM system that had been indirectly associated with Arthur from the beginning is starting to change, now that the region of dry air connected to the subtropical system is increasing around its western side.  Due to what would seem to be a very slow movement of this region, if it begins to develop it could very much become tropical in nature.

 

animation showing this interaction:

[hurricaneman]

Once again the SE coast is has an interesting area in the same area Arthur formed, a lemon has been given for that area so it may need to be monitored

[icebreaker5221]

Once again the SE coast is has an interesting area in the same area Arthur formed, a lemon has been given for that area so it may need to be monitored

 

Unlike Arthur, this one isn't going to have the chance to slow-brew near the coast - steering flow is too strong and will push it northeast.  Best case scenario we get a subtropical storm form around 40 N north of Bermuda. 

[bigtenfan]

I do not know if this is related but I flew from FLL to PHL today. Flights going both ways had air traffic control delays as disturbed weather off of the SE coast caused flights that normally fly over water to NC north to fly over the inland route over Orlando and Savanna.