Hurricane Arthur

[Hvward]

I'm pretty sure that's what he meant, he's a seasoned hurricane chaser.

 

Thanks just clarifying.

[calamity]

One more full day of Arthur.

 

[SN_Lover]

90-100 knots @ 500 feet!

 

gr2analyst 2014-07-03 21-29-50-68.png

some 122 kt's in the last pass. possible overperformer? 

[mob1]

Tha loop is absolutely stunning.

[downeastnc]

One more full day of Arthur.

 

 

That's a unique one with the thunderstorm action on the western fringe.....good stuff

[Superstorm93]

One more full day of Arthur.

 

 

 

Calamity loops are one of the best things about these tropical threads. 

 

[Sunny and Warm]

That's a unique one with the thunderstorm action on the western fringe.....good stuff

Those western fringe t-storms passed over Hilton Head with severe weather and lots of lightning.  A nice event outside the main storm.

[AlaskaETC]

Is that the front you can see pushing Arthur?

[AlaskaETC]

Anyone have a good NEXRAD link that shows the SAILS?

[Superstorm93]

Recon needs to hit the SE side...

 

[David Reimer]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 4th day of the month at 01:55Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Storm Number & Year: 01L in 2014
Storm Name: Arthur (flight in the North Atlantic basin)
Mission Number: 14
Observation Number: 09
A. Time of Center Fix: 4th day of the month at 1:42:10Z
B. Center Fix Coordinates: 34°21'N 76°57'W (34.35N 76.95W)
B. Center Fix Location: 29 miles (46 km) to the SSW (204°) from Morehead City, NC, USA.
C. Minimum Height at Standard Level: 2,886m (9,469ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 81kts (~ 93.2mph)
E. Location of the Estimated Maximum Surface Wind: 24 nautical miles (28 statute miles) to the ENE (60°) of center fix
F. Maximum Flight Level Wind Inbound: From 154° at 76kts (From the SSE at ~ 87.5mph)
G. Location of Maximum Flight Level Wind Inbound: 24 nautical miles (28 statute miles) to the ENE (60°) of center fix
H. Minimum Sea Level Pressure: 977mb (28.85 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 8°C (46°F) at a pressure alt. of 3,051m (10,010ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 13°C (55°F) at a pressure alt. of 3,047m (9,997ft)
K. Dewpoint Temp & Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Closed 
M. Eye Shape & Diameter: Circular with a diameter of 20 nautical miles (23 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile
Remarks Section:
Maximum Flight Level Wind: 76kts (~ 87.5mph) which was observed 24 nautical miles (28 statute miles) to the ENE (60°) from the flight level center at 1:35:00Z
DropsondeSurface Wind at Center: From 265° at 9kts (From the W at 10mph)

[Superstorm93]

125 mph winds over Cape Lookout @ 1000 feet 

 

CMAN station last reported 71 knots. 

 

[downeastnc]

Mitchell Field on Hatteras already gusting to 55 mph and they are roughly 100 miles NE of the center.....

[Superstorm93]

That can't be right...

 

 

[ncforecaster89]

I'm just east of Beaufort, NORTH Carolina; sorry for the typo.

[Eskimo Joe]

Fort Macon, NC: 87 mph wind gust at 10:24 pm ET via emergency mgr

[gulfcane]

lol @ tweet above....no birds in the eye...they self evacuated long ago. 

[tmagan]

That can't be right...

 

ScreenHunter_85 Jul. 03 22.21.png

If you look at GRLevel3 from the same radar and go to HCA, it shows up as 'BI', which is biological. By the way it has been observed before when an eye makes landfall, birds will basically 'dive bomb' to the surface.

[Snow_Miser]

[David Reimer]

Crazy watching the mesovortices rotate around in the eye from the Morehead City NEXRAD. First Cat2+ hurricane since Ike to make landfall in the United States. First time we've observed a hurricane making landfall using dual-pol data as well. The researchers should have quite a bit of data to go through. 

[Dunkman]

Crazy watching the mesovortices rotate around in the eye from the Morehead City NEXRAD. First Cat2+ hurricane since Ike to make landfall in the United States. First time we've observed a hurricane making landfall using dual-pol data as well. The researchers should have quite a bit of data to go through. 

Not to mention having the eye within 20 miles of the radar site.  It has been a fascinating watch for me.

[KChuck]

Station CLKN7 - Cape Lookout, NC reported 62 knots gusting to 73 at 10pm. Wind Direction (WDIR): SE ( 130 deg true ) Wind Speed (WSPD): 62 kts Wind Gust (GST): 73 kts Atmospheric Pressure (PRES): 29.29 in Pressure Tendency (PTDY): -0.44 in ( Falling Rapidly ) Air Temperature (ATMP): 76.1 °F Wind Speed at 10 meters (WSPD10M): 62 kts Wind Speed at 20 meters (WSPD20M): 66 kts   Question. With Arthur riding up the sound...will this help ease the back flooding of the sound once Arthur passes? Usually if a cane passes to the east of the barrier it blows a lot of water back into the sound causing extensive flooding. What effects should be expected from the current projected path?

[Superstorm93]

Crazy watching the mesovortices rotate around in the eye from the Morehead City NEXRAD. First Cat2+ hurricane since Ike to make landfall in the United States. First time we've observed a hurricane making landfall using dual-pol data as well. The researchers should have quite a bit of data to go through. 

 

 

 

[David Reimer]

kmhx_20140704_0230.png

 

gr2analyst 2014-07-03 22-27-08-37.png

 

gr2analyst 2014-07-03 22-26-42-15.png

 

That's literally amazing! I reintroduce the Ike Bear for the occasion.  

 

[phil882]

Not to mention having the eye within 20 miles of the radar site. It has been a fascinating watch for me.

If I have time later I'm going to put together a radar animation of Arthur from start to finish. Definitely a fun storm to watch evolve on radar.

[NaoPos]

Landfall?

Tapatalk

[Superstorm93]

So much radar p0rn going on right now. Not very often you have a landfalling Cat 2...

 

Took six years to get this!

 

[CandymanColumbusGA]

Landfall?

Tapatalk

Not quite, but super close... The center of the eye has to move over land to be considered landfall. We still have another 45 minutesish until landfall.

[griteater]

Looks like Ocracoke to Cape Hatteras Lighthouse area will bear the brunt...such a fragile piece of land area even in normal weather

 

[RU848789]

Buoy 41036 just reported a wind gust to 81 mph.

 

 

Didn't know that...thanks for the info.

 

Dropsonde in the eastern eyewall:

 

Level Wind Direction Wind Speed

989mb (Surface) 160° (from the SSE) 80 knots (92 mph)

981mb 160° (from the SSE) 84 knots (97 mph)

974mb 165° (from the SSE) 83 knots (96 mph)

967mb 165° (from the SSE) 93 knots (107 mph)

959mb 180° (from the S) 100 knots (115 mph)

955mb 180° (from the S) 98 knots (113 mph)

950mb 175° (from the S) 105 knots (121 mph)

942mb 175° (from the S) 105 knots (121 mph)

934mb 185° (from the S) 115 knots (132 mph)

927mb 180° (from the S) 105 knots (121 mph)

918mb 185° (from the S) 106 knots (122 mph)

908mb 190° (from the S) 95 knots (109 mph)

891mb 200° (from the SSW) 101 knots (116 mph)

850mb 205° (from the SSW) 97 knots (112 mph)

697mb 215° (from the SW) 89 knots (102 mph)

 

 

Product: Air Force Vortex Message (URNT12 KNHC)

Transmitted: 4th day of the month at 01:55Z

Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)

Storm Number & Year: 01L in 2014

Storm Name: Arthur (flight in the North Atlantic basin)

Mission Number: 14

Observation Number: 09

A. Time of Center Fix: 4th day of the month at 1:42:10Z

B. Center Fix Coordinates: 34°21'N 76°57'W (34.35N 76.95W)

B. Center Fix Location: 29 miles (46 km) to the SSW (204°) from Morehead City, NC, USA.

C. Minimum Height at Standard Level: 2,886m (9,469ft) at 700mb

D. Estimated (by SFMR or visually) Maximum Surface Wind: 81kts (~ 93.2mph)

E. Location of the Estimated Maximum Surface Wind: 24 nautical miles (28 statute miles) to the ENE (60°) of center fix

F. Maximum Flight Level Wind Inbound: From 154° at 76kts (From the SSE at ~ 87.5mph)

G. Location of Maximum Flight Level Wind Inbound: 24 nautical miles (28 statute miles) to the ENE (60°) of center fix

H. Minimum Sea Level Pressure: 977mb (28.85 inHg)

I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 8°C (46°F) at a pressure alt. of 3,051m (10,010ft)

J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 13°C (55°F) at a pressure alt. of 3,047m (9,997ft)

K. Dewpoint Temp & Sea Surface Temp (collected at same location as temp inside eye): Not Available

L. Eye Character: Closed 

M. Eye Shape & Diameter: Circular with a diameter of 20 nautical miles (23 statute miles)

N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature

N. Fix Level: 700mb

O. Navigational Fix Accuracy: 0.02 nautical miles

O. Meteorological Accuracy: 1 nautical mile

Remarks Section:

Maximum Flight Level Wind: 76kts (~ 87.5mph) which was observed 24 nautical miles (28 statute miles) to the ENE (60°) from the flight level center at 1:35:00Z

DropsondeSurface Wind at Center: From 265° at 9kts (From the W at 10mph)

 

I get that there are many different sources of wind speed data, but most people, I think, are interested in knowing what the worst sustained winds are at the land's surface, where people live, vs. the sea surface.  Currently, the NHC is reporting maximum sustained "surface" winds of near 100 mph.  As far as I recall, these are winds at 10 m above the surface.  These reports, I assume, are based on the stepped frequency microwave radaiometer (SMFR) detection system from the hurricane hunter, when available (93 mph, as per above), as these are supposed to be the most accurate or from the plane's dropsonde (92 mph as above) or from satellite Dvorak intensity estimates if neither of these is available - or perhaps from buoys and/or land-based wind speed measurements, if the eyewall is on-shore.  

 

I also completely understand the boundary layer effect (chemical engineers learn a lot about that in fluid mechanics), wherein the wind velocity decreases significantly from a few thousand feet aloft to near the surface and then even moreso from the 10 m "surface" measurement to the speed of zero at the actual surface at 0 m, i.e.,. the ground is not moving, so the "windspeed" at the actual ground level is zero.  What I'd love to know is what the shape of that windspeed vs. height curve looks like from 0 m to 10 m.  It seems like so many times the NHC reports max sustained surface winds at 10 m of "X" and the max reported winds ever measured anywhere that humans are is 10-30% less than that. 

 

I also get that the frictional forces of the land are much greater than the water, so I wonder if a large part of the discrepancy between max reported sustained winds in the storm and max reported sustained winds over land, with most tropical systems, is due to the fact that the strongest winds are usually in the eastern part of the storm, which for east coast storms means that this is over water, so it's only natural that the winds over land, in the western quadrant will be somewhat lower and never reach what is reported for the storm.  For Arthur, do we know what the max sustained winds actually observed over land or at a buoy are and how far below the reported storm max these are?  Would be nice to know what the actual max winds humans experience are vs. what the storm is producing over the ocean.  Comments?