ATL: HARVEY - Post-Tropical - Discussion

[dukeblue219]

Raw number from current pass is 943.8 so probably some slight strengthening to 946ish on the VDM?

[Christiana]

I'm afraid this is going to be another example of not being a major on the SS Scale, but being in the Cat 4-5 territory with surge. This alone sometimes I think is misleading to folks who think they will be fine if a storm is not a "major" possibly believing that reduces not just wind intensity but ALL storm associated dangers. The extended time this storm will produce an onshore flow is liable to provide a surge higher than forecast, especially if this thing travels further north towards the bend, not to mention the south shores of the barriers. This thing if it stays over water moving slowly for another day or more could push a huge wall of water ahead of it. The media is obsessed with the Saffir Simpson, surge is THE major player in loss of life and in most times complete structure collapse. If I am missing something here, please explain, this is yet another huge learning experience. Stay Safe TX! Prayers.

[cycloneye]

[Aric Dunn]

103 fl next set might yield higher numbers.

151930 2652N 09552W 6967 02868 9716 +127 +127 156100 103 090 016 00

[MississippiWx]

Harvey is strengthening again and recon obs seem to show the EWRC is almost complete. Will have to wait for VDM.

[GCANE]

This may start to level off in intensity.
There is a convective cap over a portion of Texas inland from the coast associated with Harvey's cloud cover.
Land interaction starting to take effect.
Also, looks like Harvey is tracking into lower Theta-E.
However, there is a strong 3500 CAPE in feed from the SW quad.
Strengthening could continue if Harvey pulls more north or if overall convection pulls in and tightens in radius.

[bvigal]

It looks like a CAT 3 to me based on SAT presentation. At this point a strong CAT 2 or CAT 3 really doesn't make a difference as far as impact...and who knows Harvey may have more surprises in store as well.

Good point! It's only 1 MPH below a Cat 3, per 10am advisory, right?

[hd44]

https://www.youtube.com/watch?v=uP9CzoB73Gg
Another ewrc example was Mathew you can see it in link. The key to intensification after ewrc is perfect conditions. There is some chance Harvey could intensify as shear is light.

[smithtim]

The 11am from NHC is very well written... it basically says that it looks like he's going through an EWRC and while usually this process causes the storm to lose a little intensity initially it is very true if the storm again becomes stable with new eyewall structure not only will the windfield expand but could continue intensification! This is very well written and it is important for the public to know the truth is a lot is still not understood about EWRC & RI and honestly can not predict - it could stay steady maybe even lower few mph BUT also could easily jump up easily another 20 mph if not more before landfall- the only truth is be prepared for the worst and let us hope & pray for the good people of Texas that doesn't happen!

BTW also have to say NHC did a great job on this forecast... 11am yesterday we had a 65 mph storm, and 24 hours later we have a 110 mph ( their 24 hrs prediction yesterday was 105 ). That's pretty amazing as they gave very good advice to a storm that worked through a pretty extreme case of RI!

[Cunxi Huang]

Harvey could be a real MH now. SFMR near 100 kt plus flight-level wind 112 kt.

152000 2653N 09550W 6967 02899 9760 +118 +118 152109 112 090 016 00

[CryHavoc]

There is no good news with Harvey, I still think he will reach Cat 4 status prior to landfall as the winds are still trying to catch up.

This will very likely be one of the biggest if not the biggest natural disaster in US history.

Please stop with this kind of hyperbole.

We know it will be bad, but it doesn't do any good to speculate about damage right now except in the sense of trying to warn people to be safe and not venture out into this storm.

[Blown Away]

Cloud tops definitely warming...

[Aric Dunn]

Cloud tops definitely warming...

very normal..

[CryHavoc]

Cloud tops definitely warming...

Yep. W eye looking a little worse for wear, however it's cleared out on the satellite so that might indicate that it was just catching it's breath.

[RL3AO]

There is no good news with Harvey, I still think he will reach Cat 4 status prior to landfall as the winds are still trying to catch up.

This will very likely be one of the biggest if not the biggest natural disaster in US history.

Please stop with this kind of hyperbole.

We know it will be bad, but it doesn't do any good to speculate about damage right now except in the sense of trying to warn people to be safe and not venture out into this storm.

I don't think it's that hyperbolic. Likely will be one of the worst natural disasters in the US this century (to date).

[tropicwatch]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 25th day of the month at 15:28Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5305
Storm Number & Year: 09 in 2017
Storm Name: Harvey (flight in the North Atlantic basin)
Mission Number: 17
Observation Number: 31
A. Time of Center Fix: 25th day of the month at 15:15:20Z
B. Center Fix Coordinates: 26°45'N 96°05'W (26.75N 96.0833W)
B. Center Fix Location: 104 statute miles (167 km) to the ENE (57°) from Brownsville, TX, USA.
C. Minimum Height at Standard Level: 2,631m (8,632ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 94kts (~ 108.2mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 7 nautical miles (8 statute miles) to the NW (325°) of center fix
F. Maximum Flight Level Wind Inbound: From 65° at 102kts (From the ENE at ~ 117.4mph)
G. Location of Maximum Flight Level Wind Inbound: 11 nautical miles (13 statute miles) to the NW (320°) of center fix
H. Minimum Sea Level Pressure: 947mb (27.97 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 11°C (52°F) at a pressure alt. of 3,055m (10,023ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 17°C (63°F) at a pressure alt. of 3,049m (10,003ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 13°C (55°F)
K. 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 18 nautical miles (21 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1.25 nautical miles

Remarks Section:
Maximum Outbound and Flight Level Wind: 112kts (~ 128.9mph) which was observed 15 nautical miles (17 statute miles) to the NE (55°) from the flight level center at 15:20:00Z
Dropsonde Surface Wind at Center: From 295° at 6kts (From the WNW at 7mph)

[NDG]

Winds are finally responding to the pressure falls this morning.

152000 2653N 09550W 6967 02899 9760 +118 +118 152109 112 090 016 00

[Aric Dunn]

152000 2653N 09550W 6967 02899 9760 +118 +118 152109 112 090 016 00

112.

looks like a cat 3 now..

[RL3AO]

Cloud tops definitely warming...

100% normal. All that incoming solar radiation is warming the top of the clouds.

[hd44]

12z Gfs takes it into the 930s accounting with poor pressure at 15z point on the model.