ATL: ARTHUR - Post-Tropical

[drezee]

Recon posted 1003mb pressure. Definitely tropical, double wind maximum due to convection being away from the center. Structure is in a place that could take advantage of the gulf stream tonight. Solid TS unflagged ob of 46 knots...

112900 2949N 07655W 9262 00732 0086 +158 +151 208038 039 046 033 00

[NDG]

IMO, as it has tracked over the cooler waters during the night Arthur is taking on a more subtropical characteristic, strongest winds are away from the COC and not much temp difference outside the coc.

[NDG]

Recon posted 1003mb pressure. Definitely tropical, double wind maximum due to convection being away from the center. Structure is in a place that could take advantage of the gulf stream tonight. Solid TS unflagged ob of 46 knots...

112900 2949N 07655W 9262 00732 0086 +158 +151 208038 039 046 033 00

Unflagged but that is in a very high rain rate, it is definitely contaminated, IMO.

[NDG]

Pressure down to 1002 mb but they keep winds at 40 mph.

8:00 AM EDT Sun May 17
Location: 30.3°N 77.4°W
Moving: NNE at 9 mph
Min pressure: 1002 mb
Max sustained: 40 mph

[Dylan]

 https://twitter.com/dylanfedericowx/status/1261990805386002437

[ScottNAtlanta]

Found it rather odd that recon noted circular eye 20 miles across. You dont usually see that with systems this weak

[NDG]

Found it rather odd that recon noted circular eye 20 miles across. You dont usually see that with systems this weak

Yes, it has a well defined circular LLC, but is not an eye.

[NDG]

Strongest flight level winds found so are are well away from its coc.

[ScottNAtlanta]

Found it rather odd that recon noted circular eye 20 miles across. You dont usually see that with systems this weak

Yes, it has a well defined circular LLC, but is not an eye.

Which is why I found it odd that the VM specifically said "circular 20 mile eye"

[NDG]

Found it rather odd that recon noted circular eye 20 miles across. You dont usually see that with systems this weak

Yes, it has a well defined circular LLC, but is not an eye.

Which is why I found it odd that the VM specifically said "circular 20 mile eye"

I was just remembering that it is fairly common in weak subtropical systems to have a very well defined COC.

[drezee]

Strongest winds should be in the convection of a weak system...

[drezee]

Recon posted 1003mb pressure. Definitely tropical, double wind maximum due to convection being away from the center. Structure is in a place that could take advantage of the gulf stream tonight. Solid TS unflagged ob of 46 knots...

112900 2949N 07655W 9262 00732 0086 +158 +151 208038 039 046 033 00

Unflagged but that is in a very high rain rate, it is definitely contaminated, IMO.

If it was definitely contaminated then it would be flagged. You can only assume it was contaminated due to possible factors. Big distinction...

[NDG]

Recon posted 1003mb pressure. Definitely tropical, double wind maximum due to convection being away from the center. Structure is in a place that could take advantage of the gulf stream tonight. Solid TS unflagged ob of 46 knots...

112900 2949N 07655W 9262 00732 0086 +158 +151 208038 039 046 033 00

Unflagged but that is in a very high rain rate, it is definitely contaminated, IMO.

If it was definitely contaminated then it would be flagged. You can only assume it was contaminated due to possible factors. Big distinction...

First of all flight level winds were only 39 knots, second of all I have never seen the NHC go with SFMR estimated winds with weak systems when the rain rate is so high and the flight level winds are lower at the same time.

[wxman57]

Recon posted 1003mb pressure. Definitely tropical, double wind maximum due to convection being away from the center. Structure is in a place that could take advantage of the gulf stream tonight. Solid TS unflagged ob of 46 knots...

112900 2949N 07655W 9262 00732 0086 +158 +151 208038 039 046 033 00

Unflagged but that is in a very high rain rate, it is definitely contaminated, IMO.

If it was definitely contaminated then it would be flagged. You can only assume it was contaminated due to possible factors. Big distinction...

That 46kt wind is a 10-second average. However, it looks completely unrealistic and stands out like a sore thumb in the wind plot. Obs around it were contaminated. Low 20s, mid 40s, low 20s very close together screams contamination. Recon may find some 40 kt winds in there in the NE quadrant.

https://www.tropicaltidbits.com/recon/recon_AF305-0301A-ARTHUR_timeseries.png

[drezee]

Unflagged but that is in a very high rain rate, it is definitely contaminated, IMO.

If it was definitely contaminated then it would be flagged. You can only assume it was contaminated due to possible factors. Big distinction...

First of all flight level winds were only 39 knots, second of all I have never seen the NHC go with SFMR estimated winds with weak systems when the rain rate is so high and the flight level winds are lower at the same time.

You missed the point. My assertion was that one cannot definitely say it was contaminated. 57 said it "screams contamination." Which I agree with, my point was it cannot be definitive. I would agree that it is likely not representative of the strength of the system due to the surrounding obs. I would also not set the wind speed at 50 mph(10 sec wind). Someone can guess the instrument was flawed or many other factors. One cannot say it was "definitely " contaminated and be correct.

[NDG]

Arthur is starting to track over warmer waters in the upper 70s, way before getting back up to the gulf stream.

[Aric Dunn]

I know I just woke up.. but is it just me or has Arthur come to crawl the last 6 hours.. pretty much a dead stop at this point.

[drezee]

Arthur is in full naked swirl wobble mode. Convection burst will be important over the next 12 to 18 hours. Any decent tower could pull the circulation 10+ miles. Curious to see if there will be one closer to the gulfstream...left is not the friend of the Outer Banks

[NDG]

Definitely lost some tropical characteristics during the night. Recon finds 48 knots flight level winds in the NE quadrant well away from the COC with SFMR max winds of 38 knots. I would go with 40 knot surface winds, IMO.

[tolakram]

SLIDER

https://rammb-slider.cira.colostate.edu/?sat=goes-16&z=2&im=12&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=mesoscale_01&p%5B0%5D=band_02&x=1028.9573822021484&y=934.9857788085938