Hurricane Arthur

[Superstorm93]

976.7 with 35 knot winds

[phil882]

There were also SFMR hurricane force winds in the SW quadrant, one of the weaker quads given the current motion. 

[Jackstraw]

I found this interesting.....

 

INTERESTS ALONG THE UNITED STATES EAST COAST NORTH OF THE WARNING

AREA...PRIMARILY IN SOUTHEASTERN NEW ENGLAND...SHOULD MONITOR THE
PROGRESS OF ARTHUR.

[NaoPos]

976.7 with 35 knot winds

What's that equate to roughly?

[Superstorm93]

What's that equate to roughly?

 

The rule is that you subtract 1mb for every 10mph, so that's roughly 972/973

 

VDM will probably be higher. 

[PSUBlizzicane2007]

The HD obs this pass are a bit underwhelming... 79 kt is the highest flight level wind so far

[phil882]

The HD obs this pass are a bit underwhelming... 79 kt is the highest flight level wind so far

 

Keep in mind the strongest winds earlier were observed in the E quadrant, where the strongest winds would traditionally be located for a northward moving storm. 

[Superstorm93]

Vortex Data Message

000
URNT12 KNHC 031518
VORTEX DATA MESSAGE   AL012014
A. 03/15:02:50Z
B. 32 deg 25 min N
  078 deg 39 min W
C. 700 mb 2906 m
D. 66 kt
E. 360 deg 0 nm
F. 297 deg 62 kt
G. 199 deg 18 nm
H. 980 mb
I. 13 C / 3046 m
J. 14 C / 3046 m
K. NA / NA
L. OPEN SW
M. C30
N. 12345 / 07
O. 0.02 / 3 nm
P. AF301 1101A ARTHUR             OB 04
MAX FL WIND 62 KT 199 / 18 NM 14:57:00Z
MAX OUTBOUND FL WIND 79 KT 048 / 23 NM 15:10:00Z
MAX FL TEMP 16 C 179 / 13 NM FROM FL CNTR
;

[calamity]

Morning visible loop.

 

[phil882]

 

Love to hear the explanation behind the MSLP staying @ 980 

 

The pressure is from a dropsonde rather than the extrapolated pressure from the plane at 700 hPa. 

[Superstorm93]

Account for the fact that the NHC position is already 8 miles too far east...

 

[IsentropicLift]

12z GFS tracks right into Wilmington. Worst case for OBX.

[Superstorm93]

The pressure is from a dropsonde rather than the extrapolated pressure from the plane at 700 hPa. 

 

Didn't see a sonde released into the eye, but one splashed at 988mb/77mph, so that makes sense. 

[DiehardFF]

Just thinking aloud here, if the front stalls at the right spot, could it be possible for Arthur to actually ride up the coast, lets say 50-100 miles off instead of 200-250 miles?

 

Unless the storm starts going more NE instead of NNE, I am thinking the NHC will have to adjust a little bit.

[bobbutts]

Look at how much of the convection has moved West during the loop.

http://mp1.met.psu.edu/~fxg1/SATRAPID/anim16ir.html

If were just basing on satellite xtrap we'd be coming onshore mid SC

 

Comparatively estimating the center by radar it appears to be moving slightly East in the last hour.

A bit confusing to observe, and probably a bit maddening for those in the SC/NC coasts.

[Superstorm93]

[featherwx]

Look at how much of the convection has moved West during the loop.

http://mp1.met.psu.edu/~fxg1/SATRAPID/anim16ir.html

If were just basing on satellite xtrap we'd be coming onshore mid SC

 

Comparatively estimating the center by radar it appears to be moving slightly East in the last hour.

A bit confusing to observe, and probably a bit maddening for those in the SC/NC coasts.

Yeah, I noticed a little wobble to the east as well. We'll have to wait and see if this becomes a trend rather than a blip.

[DopplerWx]

Look at how much of the convection has moved West during the loop.

http://mp1.met.psu.edu/~fxg1/SATRAPID/anim16ir.html

If were just basing on satellite xtrap we'd be coming onshore mid SC

 

Comparatively estimating the center by radar it appears to be moving slightly East in the last hour.

A bit confusing to observe, and probably a bit maddening for those in the SC/NC coasts.

intensifying storms will wobble, and throughout the morning the storm has made the turn more NE instead of north.  we deal with this every year where people go crazy watching the radar for small wobbles east and west.  it is important to focus on the overall heading rather than comparing radar updates in 15 minute intervals.

[Amped]

Account for the fact that the NHC position is already 8 miles too far east...

at201401_model_zoom.gif

The points don't always connect with a straight line. It really depends on how sharp of a turn it makes later. It will probably be west of the NHC track but they are usually within 10 miles at this time range.

[bobbutts]

intensifying storms will wobble, and throughout the morning the storm has made the turn more NE instead of north.  we deal with this every year where people go crazy watching the radar for small wobbles east and west.  it is important to focus on the overall heading rather than comparing radar updates in 15 minute intervals.

Yeah, I am aware of this and not going crazy.  It's why I used a longer time scale and compared two products rather than a single one and used terms like "appears" rather than declaring.

I only comment on this storm because the movement on the satellite is so pronounced.

[Ground Scouring]

Maybe this is temporary, but radar indicates that the dry air in the S quadrant may be mixing out, with a band of convection developing south of the eye. How much time is needed for the dry air to be converted into moist adiabatic state?

[Superstorm93]

First center pass actually raises some questions...

 

Check out the temp differential. 

I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 13°C (55°F) at a pressure alt. of 3,046m (9,993ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 14°C (57°F) at a pressure alt. of 3,046m (9,993ft)
[attachment=130594:grearth 2014-07-03 11-50-27-08.png]

[Superstorm93]

Maybe this is temporary, but radar indicates that the dry air in the S quadrant may be mixing out, with a band of convection developing south of the eye. How much time is needed for the dry air to be converted into moist adiabatic state?

 

Eye is closing up big time on radar and the visible presentation has improved markedly since daybreak. I'd say that we've already reached that point. 

 

[DiehardFF]

 

First center pass actually raises some questions...

 

Check out the temp differential. 

I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 13°C (55°F) at a pressure alt. of 3,046m (9,993ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 14°C (57°F) at a pressure alt. of 3,046m (9,993ft)

 

What does this mean? Sorry, not very informed in the TC department.

[Sophisticated Skeptic]

NNW wobble just now.

 

best satellite -

 

http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=29&lon=-80&info=vis&zoom=1&width=1000&height=800&quality=95&type=Animation&palette=ir1.pal&numframes=10&map=latlon

[Superstorm93]

What does this mean? Sorry, not very informed in the TC department.

 

Typically you'd like to see a bigger temp spread between the outside environment and the eye, but this first pass seems a little strange in my opinion. The second pass should hopefully clear things up. 

[Dunkman]

Typically you'd like to see a bigger temp spread between the outside environment and the eye, but this first pass seems a little strange in my opinion. The second pass should hopefully clear things up. 

Arthur took a gulp of dry air and it seems to have disrupted the core for a time.  However, right now the storm seems to be mixing it out rather rapidly and I also wouldn't be surprised to see it look much stronger in the next couple passes.

[wxmx]

Structural inner core changes may be dictating some of the more left than expected translation movement. I'm fairly confident this will be a landfall farther to the left of the forecast, and maybe straddle the NC coast for a good stretch.

[Hvward]

People surfing at Wrightsville Beach.  Waves getting bigger.

 

http://www.surfchex.com/index.php

 

Carolina Beach which is closer to the action:

 

http://www.surfchex.com/carolina-beach-web-cam.php

[Superstorm93]