Hurricane Arthur

[phil882]

18z gfs a tad farther west this run @48hrs.

 

And it strengthens it -3 hPa in the next 48 hours

 

All kidding aside (the model resolution won't be able to resolve the lowest surface pressure), this was an poor model performance by the GFS. Its there with the rest of the model guidance now, but the ECMWF had this a full 36-48 hours before the GFS got a clue. 

[calamity]

Arthur is currently cushioned between the right entrance regions of a pretty powerful jet streak off to the west in the Gulf of Mexico and a newly developing jet streak to the east of the Bahams. It's no surprise that its been able to maintain such deep convection throughout the day.

 

[Superstorm93]

LLC is going to town under the heavy convection. I wonder who called that out last night 

 

 

[David Reimer]

When is the next recon aircraft due into Arthur? 

[wxmeddler]

LLC is going to town under the heavy convection. I wonder who called that out last night 

 

I'm not so sure the LLC is under the heavy convection yet. Based on the way they are fujiwara'ing around each other attm.

[phil882]

Probably will see the intensity raised in the intermediate advisory at 8pm... non-rain contaminated SFMR obs up around 55 knots.

 

[phil882]

The binary interaction between the old llc dropping south and the new llc moving northward under the convection is pretty awesome to watch.

[phil882]

I'm not so sure the LLC is under the heavy convection yet. Based on the way they are fujiwara'ing around each other attm.

 

Well there are two centers... the old one is now dropping off to the southwest as the new center is becoming better established in the low-levels. The fact that we are witnessing binary interaction is indicative that the new center in the deep convection is a low-level based feature (other otherwise there would be no interaction). 

[Superstorm93]

HRRR actually nailed the intensity during last nights runs for what we are seeing right now

 

I could see this pick up rather quickly (nothing too crazy) once the old center rotating around the new center dies off. 

 

[wxmx]

The dreaded '9' look. Shear is low, so mid and low centers will probably stack vertically soon...after that happens we can see an episode of RI

[Superstorm93]

000

NOUS42 KNHC 301653

REPRPD

WEATHER RECONNAISSANCE FLIGHTS

CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.

0100 PM EDT MON 30 JUNE 2014

SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)

VALID 01/1100Z TO 02/1100Z JULY 2014

TCPOD NUMBER.....14-030

I. ATLANTIC REQUIREMENTS

1. SUSPECT AREA (OFF THE FLORIDA EAST COAST)

FLIGHT ONE -- TEAL 70 FLIGHT TWO -- NOAA 49

A. 01/1800Z A. 02/0000Z

B. AFXXX 02BBA INVEST B. NOAA9 03BBA SURV

C. 01/1600Z C. 01/1730Z

D. 28.0N 78.8W D. NA

E. 01/1745Z TO 01/2200Z E. NA

F. SFC TO 10,000 FT F. 41,000 TO 45,000 FT

FLIGHT THREE -- TEAL 71 FLIGHT FOUR -- NOAA 42

A. 02/0600Z, 1200Z A. 02/0900Z

B. AFXXX 0401A CYCLONE B. NOAA2 0501A CYCLONE

C. 02/0400Z C. 02/0600Z

D. 28.6N 80.1W D. 28.8N 80.0W

E. 02/0530Z TO 02/1200Z E. 02/0700Z TO 02/1100Z

F. SFC TO 15,000 FT. F. 12,000 FT

2. SUCCEEDING DAY OUTLOOK:

A. CONTINUE 6-HRLY FIXES.

B. POSSIBLE G-IV MISSION FOR 03/0000Z.

C. POSSIBLE P-3 MISSION AT 02/1800Z

3. REMARKS: MISSION SCHEDULED FOR 01/0000Z AND 01/0600Z

CANCELED BY NHC AT 30/1400Z.

[Superstorm93]

Likely will be near 55 knots by 11pm, so this could actually be a formidable hurricane

  *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    * GOES AVAILABLE,       OHC AVAILABLE       *
                    *      ARTHUR  AL012014  07/01/14  18 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    40    45    50    55    59    68    76    82    89    89    88    77    68
V (KT) LAND       40    45    50    55    59    68    76    82    89    89    88    77    68
V (KT) LGE mod    40    45    49    53    56    61    66    71    72    68    57    50    47
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  EXTP  EXTP  EXTP

SHEAR (KT)         7     8     9    11    10    12    10    12    20    35    42    42    32
SHEAR ADJ (KT)    -2    -2    -2    -4    -1    -5    -4    -5     2     0     0     2     0
SHEAR DIR         30   346   331   335   334   315   273   275   206   219   211   198   165
SST (C)         28.2  28.1  28.1  28.0  27.9  27.6  27.6  27.2  25.2  22.2  15.4  11.7   9.7
POT. INT. (KT)   135   135   136   135   133   130   132   128   110    92    73    67    66
ADJ. POT. INT.   112   112   114   114   112   111   113   112    97    83    69    65    64
200 MB T (C)   -54.3 -53.9 -53.9 -54.0 -53.7 -53.2 -53.2 -52.8 -52.3 -52.3 -51.9 -50.3 -49.4
TH_E DEV (C)      12    13    12    11    14    12    12     7     7     2     2     0     0
700-500 MB RH     52    48    50    52    52    56    56    54    49    47    44    42    46
GFS VTEX (KT)     13    14    15    16    16    19    20    22    27    31    37    35    35
850 MB ENV VOR   -24   -32   -40   -30   -28   -39    -2     1    21    48   111   163   186
200 MB DIV        31    -2     4    17    35    26    58    26    83    35    54    37    35
700-850 TADV       0     0     0     0    -1     0    10     5   -12   -20   -41   -22   -30
LAND (KM)        101   107   114   114   137   208   143    54   207   253   142    68   117
LAT (DEG N)     27.7  28.0  28.3  28.9  29.4  30.5  32.2  34.3  36.8  39.5  42.3  44.6  46.6
LONG(DEG W)     79.3  79.4  79.4  79.5  79.6  79.2  78.3  76.5  73.5  69.6  64.9  61.0  57.9
STM SPEED (KT)     2     3     5     6     6     7    11    15    19    21    21    16    15
HEAT CONTENT      29    28    27    23    21    26    25     8     0     0     0     0     0

[wxmeddler]

Well there are two centers... the old one is now dropping off to the southwest as the new center is becoming better established in the low-levels. The fact that we are witnessing binary interaction is indicative that the new center in the deep convection is a low-level based feature (other otherwise there would be no interaction). 

 

Makes sense, my thinking was more based on the RECON data in that was that the circulation is tilted (old sfc to convection in mid-lvls). More like a tilted pole with a balance point in the center rather than classic binary interaction.

 

Edit:

HWRF actually captures my thinking nicely (Via: Levi Cowan):

[CUmet]

Makes sense, my thinking was more based on the RECON data in that was that the circulation is tilted (old sfc to convection in mid-lvls). More like a tilted pole with a balance point in the center rather than classic binary interaction.

 

Edit:

HWRF actually captures my thinking nicely (Via: Levi Cowan):

 

It's tricky because a tilted TC vortex can definitely precess (i.e. wobble).  This has been observed in a lot of modeling studies of sheared TCs, although it's difficult to observe in real TCs because you would need continuous data in time and space to confirm that it's occurring.  

In this particular case, we could be seeing precession, or there could also be a mesovortex in the low levels underneath the convection that's causing the old LLC to revolve counterclockwise and eventually become absorbed.  They aren't mutually exclusive either.  In any case, I think we can all agree that Arthur is in the process of vertically-aligning given the low environmental shear, and will likely intensify quite a bit over the next couple days as a result.

[Blizz]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 01 JUL 2014 Time : 224500 UTC
Lat : 27:52:38 N Lon : 79:25:16 W


CI# /Pressure/ Vmax
3.0 / 999.9mb/ 45.0kt


Final T# Adj T# Raw T#
2.5 2.5 2.5

Center Temp : -36.4C Cloud Region Temp : -40.0C

Scene Type : CURVED BAND with 0.54 ARC in LT GRAY

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : FLAG

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 47km
- Environmental MSLP : 1016mb

Satellite Name : GOES13
Satellite Viewing Angle : 32.9 degrees

 

http://tropic.ssec.wisc.edu/real-time/adt/odt01L.html

 

Dry air?

[downeastnc]

the current forecast track is about as bad as one can get for emergancy planners especially here in NC......its a big money weekend along the coast and calling for evacs will make this a expensive storm whether it hits or not. If the track was further west at least it would be clear enough that a landfall was likely and the call to evacuate would be easier. Further east and they might only do mandatory evacs for points north of Cape Lookout......but as it stands now they have to pretty much evac the entire coast just in case I dont envy them the reposonsibilty they have the next few days.

 

http://www.witn.com/home/headlines/Coastal-Counties-Beach-Towns-Preparing-For-Arthur-265391591.html

 

http://www.witn.com/home/headlines/ARTHUR--Cape-Lookout-Evacuating-Visitors-On-Wednesday-265401641.html

[Superstorm93]

http://tropic.ssec.wisc.edu/real-time/adt/odt01L.html

 

Dry air?

 

More like ADT is using the old/dying center.

 

Check radar. This is tightening up real good. The next reconnaissance mission is going to be very interesting. 

 

[jayson]

That is a pretty good looking storm at the moment.

[shaggy]

No doubt that he is getting it together at the moment. The real question is gonna be the track now and if it slides west any and has more of a direct impact on eastern NC. Haven't seen a SE homebrew storm take off like this in a long time.

[Superstorm93]

 

 

 

XNT23 KNES 020021
TCSNTL

A. 01L (ARTHUR)

B. 01/2345Z

C. 27.8N

D. 79.5W

E. THREE/GOES-E

F. T2.5/2.5/D1.5/24HRS

G. IR/EIR/VIS/SSMIS

H. REMARKS...SYSTEM IS MUCH IMPROVED FROM 24 HOURS AGO WITH RELAXED
SHEAR AND LARGE AREA OF PERSISTENT DEEP CONVECTION. LLCC REMAINS ON
THE PERIPHERY OF COLD DENSE OVERCAST IN THE EASTERN SEMICIRCLE IN THE
TRANSITION FROM A SHEAR PATTERN TO MORE OF A BANDING ONE. 4 TENTHS BANDING
GIVES DT=2.5. MET=2.5 BASED ON 24 HOUR RAPID DEVELOPMENT TREND. PT=2.5. FT
IS BASED ON DT.

I. ADDL POSITIONS

01/2146Z 28.1N 79.2W SSMIS

[Supercane]

No doubt that he is getting it together at the moment. The real question is gonna be the track now and if it slides west any and has more of a direct impact on eastern NC. Haven't seen a SE homebrew storm take off like this in a long time.

 

Yeah, you're right -- not since Ophelia 2005. It's pretty impressive that this is happening in the first week of July.

[Will - Rutgers]

This has been a really fun and interesting storm to watch so far.

[smog strangler]

Water water everywhere and not a drop to drink. In yet another case to drive the point home just a bit further as if it is even needed, being on the west side of a system like Arthur who is stepping it up a notch is no place to be for a extreme wx enthusiast. And that is where I sit!

[nj2va]

Dare County EM met tonight but no decision has been made on evacuations for the Outer banks.

[Jackstraw]

Absolute perfect opportunity from a research stand point.  The potential of a weeks worth of data, within reach of every tool available, with a storm from formation to possibly a high end Cat 1, low end Cat 2.  I'd throw every tool in my arsenal at an opportunity like this if I were the NHC.  Oh yes, budgets

[calm_days]

No doubt that he is getting it together at the moment. The real question is gonna be the track now and if it slides west any and has more of a direct impact on eastern NC. Haven't seen a SE homebrew storm take off like this in a long time.

 

Yes. there is less popularity to tracking of anomalies or unique aspects of large ULL systems, but, the current atlantic and northern continental occluded ULLs are quite large, and there are others around them as well, creating a very different and seemingly quite atypical surroundings for any atlantic tropical system. 

 

satellite imagery on two scales that includes the ULLs

[phil882]

As the system consolidates dry air will actually become it's ally. If the shear remains low, the dry air will act to keep the feeder bands from dominating vs the inner core. Could be an exciting 24-48 hours

[downeastnc]

Dare County EM met tonight but no decision has been made on evacuations for the Outer banks.

 

They will have to make some kind of call tomorrow, if this thing ends up a TS skirting to the east then they will catch hell for running everyone off even though its the right call. On th other hand if they dont do anything and we end up with a Cat 2 that goes west or over the OBX they will have 10's of thousands of people stuck on islands with no way off and no power, water etc. Its the big story around here...kind like Amity with the shark thing in teh movie Jaws, no one wants to pull the trigger on evacuations. If Arthur goes off tonight and we have a decent hurricane by noon tomorrow with forecast for a Cat 2 up this way they will have to go mandatory. I am sure all hotel rooms in my town will be gone by thursday as folks move inland but stay close enough to get back quick if it misses.

[Ground Scouring]

the current forecast track is about as bad as one can get for emergancy planners especially here in NC......its a big money weekend along the coast and calling for evacs will make this a expensive storm whether it hits or not. If the track was further west at least it would be clear enough that a landfall was likely and the call to evacuate would be easier. Further east and they might only do mandatory evacs for points north of Cape Lookout......but as it stands now they have to pretty much evac the entire coast just in case I dont envy them the reposonsibilty they have the next few days.

 

http://www.witn.com/home/headlines/Coastal-Counties-Beach-Towns-Preparing-For-Arthur-265391591.html

 

http://www.witn.com/home/headlines/ARTHUR--Cape-Lookout-Evacuating-Visitors-On-Wednesday-265401641.html

This will probably be a huge bust if it were to just scrape the Outer Banks with the worst effects offshore…the potential for complacency is high, as so many systems in recent seasons have ended up east of the forecast models while sliding past the Carolinas. Even if Arthur were to become 85 kt or stronger, based on the current track and expected acceleration (to the NE) the Outer Banks would likely receive only TS winds--unless things change.

[nj2va]

They will have to make some kind of call tomorrow, if this thing ends up a TS skirting to the east then they will catch hell for running everyone off even though its the right call. On th other hand if they dont do anything and we end up with a Cat 2 that goes west or over the OBX they will have 10's of thousands of people stuck on islands with no way off and no power, water etc. Its the big story around here...kind like Amity with the shark thing in teh movie Jaws, no one wants to pull the trigger on evacuations. If Arthur goes off tonight and we have a decent hurricane by noon tomorrow with forecast for a Cat 2 up this way they will have to go mandatory. I am sure all hotel rooms in my town will be gone by thursday as folks move inland but stay close enough to get back quick if it misses.

Yup, agreed. We are on Hatteras for the week right now. Just booked a hotel room inland just in case.