Hurricane Arthur

[Thunder Road]

It's probably also worth noting that the conventional wisdom about the "windy side" and "wet side" of hurricanes affecting NC doesn't totally apply here.  I mean it always does to some extent, but Arthur will likely be a relatively compact, still strengthening system as it passes the OBX.  Many hurricanes affecting NC are close to starting or already undergoing ET, but this shouldn't be one of them.

[dan88]

000

URNT12 KNHC 021853

VORTEX DATA MESSAGE AL012014

A. 02/18:11:00Z

B. 29 deg 25 min N

079 deg 09 min W

C. 850 mb 1386 m

D. 51 kt

E. 327 deg 18 nm

F. 079 deg 50 kt

G. 326 deg 24 nm

H. 996 mb

I. 14 C / 1511 m

J. 18 C / 1513 m

K. 17 C / NA

L. Closed

M. E02/30/20

N. 12345 / 8

O. 0.02 / 1.5 nm

P. AF301 0601A ARTHUR OB 06

MAX OUTBOUND AND MAX FL WIND 63 KT 135 / 19 NM 18:17:00Z

MAX FL TEMP 18 C 321 / 15 NM FROM FL CNTR

CNTR DROPSONDE SFC WIND 145 / 3 KT

[blueheronNC]

Surprised there's not much talk about the significance of all major computer models now converging on a direct hit to the OBX.  That's a significant development.

[Ground Scouring]

Surprised there's not much talk about the significance of all major computer models now converging on a direct hit to the OBX.  That's a significant development.

Not really…all those models show hurricane-force winds remaining offshore. The center would need to pass west of the OBX to give the barrier islands 'cane-force winds. The system will be accelerating, which would put the strongest winds SE of the center even without ET transition. Also, the 18Z intensity models are MUCH less aggressive than the 12Z re: the intensity. The strongest model even levels off the intensity before Arthur reaches the latitude of the OBX. Why? 

 

 

[dan88]

From the NOAA plane

000URNT12 KWBC 021939VORTEX DATA MESSAGE  AL012014A. 02/19:10:27ZB. 29 deg 30 min N  079 deg 07 min WC. NAD. 41 ktE. 250 deg 20 nmF. 322 deg 41 ktG. 248 deg 23 nmH. 995 mbI. 7 C / 3667 mJ. 9 C / 3685 mK. 4 C / NAL. OPEN NEM. C24N. 12345 / NAO. 1 / 1 nmP. NOAA3 0801A ARTHUR OB 04CNTR DROPSONDE WIND 240 / 11 KTMAX OUTBOUND FL WIND AND MAX FL WIND 59 KT 071/37 19:19:10ZMAX FL TEMP 10 C 076 / 6 NM FROM FL CNTR

[dan88]

71kt flight level, high winds on SFMR but rain contaminated.

195530 2953N 07845W 8425 01493 0019 +157 +157 155057 060 053 010 00
195600 2952N 07846W 8449 01465 0015 +152 +152 154064 067 055 007 00
195630 2951N 07847W 8420 01491 0013 +154 +154 149066 068 053 023 00
195700 2950N 07849W 8437 01462 0005 +151 +151 146069 071 059 034 00
195730 2949N 07850W 8422 01468 9992 +156 +156 147070 071 062 040 00
195800 2948N 07851W 8407 01479 9975 +166 +166 160059 070 069 027 00
195830 2947N 07852W 8455 01414 9960 +173 +173 175038 047 067 019 03

[phil882]

NHC will probably keep it at 50 knots or only go up to 55 knots which those kind of blah obs. Basically the system hasn't intensified since last night despite the nice visible satellite presentation. That could change quickly especially given the increasingly impressive structure, but for now we wait. 

 

Edit: Just saw dan88's last set... probably still only 55 knots, but its good to see the FL winds increasing even if the hurricane force SFMR were rain contaminated. 

[dan88]

991.5mb extrap from 850mb

[phil882]

Looks like it might be finally intensifying based on those last set of obs... on the cusp of hurricane intensity. 

[nchighcountrywx]

Excellent 3:00pm Video by Bernie Rayno with Accuweather on NC Impacts from Arthur.

 

http://www.accuweather.com/en/weather-news/tropics-trying-to-come-alive-n/29566708

 

(Video embedded in story)

[Ground Scouring]

NHC will probably keep it at 50 knots or only go up to 55 knots which those kind of blah obs. Basically the system hasn't intensified since last night despite the nice visible satellite presentation. That could change quickly especially given the increasingly impressive structure, but for now we wait. 

 

Edit: Just saw dan88's last set... probably still only 55 knots, but its good to see the FL winds increasing even if the hurricane force SFMR were rain contaminated. 

Quick question: Why are the 18Z intensity models more conservative than the 12Z re: the peak intensity? I still can't figure out why…dry air has mixed out and there is really nothing to stop Arthur from reaching high-end Category 1, especially considering the expansion of outflow on the west side.

[dan88]

000

URNT12 KNHC 022021

VORTEX DATA MESSAGE AL012014

A. 02/20:03:50Z

B. 29 deg 42 min N

079 deg 10 min W

C. 850 mb 1354 m

D. 67 kt

E. 070 deg 18 nm

F. 146 deg 71 kt

G. 068 deg 20 nm

H. 992 mb

I. 14 C / 1526 m

J. 20 C / 1525 m

K. 16 C / NA

L. Open NW

M. E30/34/25

N. 12345 / 08

O. 0.02 / 1.5 nm

P. AF301 0601A ARTHUR OB 10

MAX FL WIND 71 KT 068 / 20 NM 19:57:00Z

MAX FL TEMP 19 C 075 / 6 NM FROM FL CNTR

CTR DROPSONDE SFC WIND 150 / 5 KT

[phil882]

Quick question: Why are the 18Z intensity models more conservative than the 12Z re: the peak intensity? I still can't figure out why…dry air has mixed out and there is really nothing to stop Arthur from reaching high-end Category 1, especially considering the expansion of outflow on the west side.

 

I'm not exactly sure why the guidance was less bullish. One thing those graphs don't show is the ECMWF, which was suggesting a pretty intense TC near the Outer Banks (< 970 hPa)

[wxmx]

Quick question: Why are the 18Z intensity models more conservative than the 12Z re: the peak intensity? I still can't figure out why…dry air has mixed out and there is really nothing to stop Arthur from reaching high-end Category 1, especially considering the expansion of outflow on the west side.

Don't really know why, but expect changes. MW and satellite trends are showing that Arthur might be ready for an RIC soon.

 

[SnowGoose69]

I'm not exactly sure why the guidance was less bullish. One thing those graphs don't show is the ECMWF, which was suggesting a pretty intense TC near the Outer Banks (< 970 hPa)

 

I'm still trying to figure out why the globals are so stubbornly west of the NHC models, in some cases 100-150 miles up the coast, I've noticed they tend to have a west bias with recurving systems up the coast but this is getting late in the game for them to be so far west.

[David Reimer]

From the NOAA aircraft

 

202130 3005N 07934W 6423 03811 0012 +066 +029 037033 034 038 000 00
202200 3004N 07933W 6425 03805 9991 +078 +024 037034 035 037 001 00
202230 3002N 07931W 6423 03804 9980 +083 +027 029033 034 037 001 00
202300 3000N 07930W 6423 03802 9986 +077 +030 031033 034 037 000 00
202330 2958N 07929W 6421 03799 9977 +080 +026 030035 037 038 000 00
202400 2956N 07927W 6422 03792 9982 +073 +030 025033 035 040 001 00
202430 2954N 07926W 6419 03791 9967 +077 +044 028034 036 042 001 00
202500 2952N 07925W 6420 03782 9945 +088 +037 027036 037 042 002 00
202530 2950N 07923W 6525 03645 9930 +102 +035 022037 039 043 002 00
202600 2948N 07922W 6612 03528 9931 +105 +041 026042 043 045 002 03
202630 2947N 07919W 6655 03467 9919 +111 +048 021044 045 045 002 00
202700 2946N 07917W 6673 03437 9915 +108 +060 008041 042 042 003 00
202730 2945N 07915W 6665 03434 9891 +116 +068 356037 041 037 000 03
202800 2944N 07913W 6669 03421 9887 +110 +081 353028 031 024 001 00
202830 2944N 07910W 6667 03416 9878 +112 +081 354016 020 020 002 00
202900 2944N 07907W 6670 03413 9879 +110 +070 260003 007 021 000 00
202930 2944N 07905W 6665 03418 9877 +113 +074 180011 015 018 001 00
203000 2943N 07903W 6671 03415 9887 +110 +056 170018 020 017 001 03
203030 2942N 07901W 6669 03421 9884 +113 +055 169022 022 022 000 00
203100 2941N 07859W 6673 03419 9887 +114 +052 182024 025 027 001 00

[Ground Scouring]

I'm still trying to figure out why the globals are so stubbornly west of the NHC models, in some cases 100-150 miles up the coast, I've noticed they tend to have a west bias with recurving systems up the coast but this is getting late in the game for them to be so far west.

Radar suggests that the turn to the NNE may be starting as we speak. That would mean some extra time over the Gulf Stream for Arthur to go RI. The convective band wrapping around the N side of the formative eye suggests that it may be pulling Arthur toward the NNE. If the turn is starting now, then the OBX definitely won't see anything stronger than TS intensity.

[downeastnc]

I'm still trying to figure out why the globals are so stubbornly west of the NHC models, in some cases 100-150 miles up the coast, I've noticed they tend to have a west bias with recurving systems up the coast but this is getting late in the game for them to be so far west.

 

Due to the angle of these tracks small changes can have big implications down the road, and the impact difference from a Cat 2 into Cape Fear or Swansboo headed NE versus a OBX skimmer headed NE are huge lol......I still cant see how they don't shift it west a bit at 5pm and at least have the center passing over Cape Hatteras.

[Blizz]

Radar suggests that the turn to the NNE may be starting as we speak. That would mean some extra time over the Gulf Stream for Arthur to go RI. The convective band wrapping around the N side of the formative eye suggests that it may be pulling Arthur toward the NNE.

 

 

[Srain]

I suspect another 12 hours or so we will see a quickly intensifying cyclone E of Jacksonville heading generally N to NNE.

[Floydbuster]

The 987 mb looks legit. It's almost there.

[Ground Scouring]

TROPICAL STORM ARTHUR FORECAST/ADVISORY NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012014
2100 UTC WED JUL 02 2014

 

ESTIMATED MINIMUM CENTRAL PRESSURE 992 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 30NE 30SE 0SW 30NW.
34 KT....... 70NE 70SE 60SW 50NW.
12 FT SEAS.. 60NE 75SE 30SW 45NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

 

A HURRICANE WARNING HAS BEEN ISSUED FOR THE NORTH CAROLINA
COAST FROM SURF CITY NORTHWARD TO DUCK...INCLUDING THE PAMLICO AND
EASTERN ALBEMARLE SOUNDS.

A TROPICAL STORM WARNING HAS BEEN ISSUED FROM SOUTH SANTEE RIVER
SOUTH CAROLINA TO SOUTH OF SURF CITY...FROM NORTH OF DUCK TO
CAPE CHARLES LIGHT VIRGINIA...NOT INCLUDING CHEASEPEAKE BAY...AND
FOR WESTERN ALBEMARLE SOUND.

A HURRICANE WATCH HAS BEEN ISSUED FROM LITTLE RIVER INLET
TO SOUTH OF SURF CITY.

[Dunkman]

The 987 mb looks legit. It's almost there.

On the first pass by the NOAA plane the extrapolated pressure from 700mb was about 4mb lower than the dropsonde showed so I would expect 991-992mb on the drop this pass.

[PSUBlizzicane2007]

Arthur could very well be entering a rapid intensification cycle as we speak with those kind of dropping pressures over the past couple of hours. It should be interesting to see what happens later tonight.

[Ground Scouring]

From the 5:00 p.m. discussion:

 

Global models, primarily the ECMWF and the GFS intensify the cyclone
significantly, and also expand the wind field as the center moves
near the North Carolina coast.

This mentioning is interesting, considering that the forecast peak intensity has been lowered to 75 kt.

[bdgwx]

12Z 15km FIM says Arthur will make landfall as a high-end TS or low-end cat. 1 at Beaufort, NC at hour 42 on the morning of July 4th.

 

[downeastnc]

From the 5:00 p.m. discussion:

 

This mentioning is interesting, considering that the forecast peak intensity has been lowered to 75 kt.

Intensity forecasting sucks and this storm could  be a Cat 2 by morning......not sure why they went so conservative on intensity based on recent trends.

[Amped]

Charlestown long range radar is finally picking up a lot more precipitation in the north of the center in the dry air patch.

[jaxjagman]

[Ground Scouring]

Does anyone have a link showing lightning activity in the vicinity of Arthur? That's a key indicator as to whether we have RI on our hands.