ATL: NATE - Post Tropical - Discussion

[Aric Dunn]

REcon also showing a failt flat pressure field along with the wind field... wont be able to RI unless the stacking issues goes away.. otherwise just slow strengthening

[CrazyC83]

URNT15 KNHC 062332
AF307 0716A NATE HDOB 20 20171006
232230 2052N 08552W 8432 01443 9939 +194 +191 283026 026 031 001 01
232300 2051N 08553W 8428 01447 9943 +194 +181 284028 028 031 001 03
232330 2050N 08554W 8434 01446 9946 +189 +186 283031 032 033 000 00
232400 2049N 08556W 8428 01456 9949 +191 +182 281031 033 033 002 03
232430 2047N 08557W 8429 01456 9956 +187 +170 275036 038 035 001 00
232500 2046N 08558W 8430 01455 9956 +187 +169 274039 040 038 001 00
232530 2045N 08559W 8426 01463 9963 +181 +174 282041 041 038 002 00
232600 2044N 08600W 8431 01461 //// +177 //// 287038 041 037 001 05
232630 2043N 08601W 8428 01466 //// +169 //// 291034 035 036 001 01
232700 2042N 08602W 8433 01464 //// +176 //// 290035 037 036 002 01
232730 2041N 08603W 8423 01476 9986 +174 //// 291036 038 040 004 01
232800 2040N 08604W 8434 01469 //// +169 //// 291041 043 040 004 01
232830 2039N 08606W 8422 01483 //// +176 //// 291044 045 039 002 05
232900 2038N 08607W 8429 01478 //// +179 //// 293041 043 040 002 01
232930 2037N 08608W 8433 01480 //// +176 //// 290041 042 038 002 01
233000 2036N 08609W 8429 01483 9991 +178 +174 294040 041 036 002 00
233030 2035N 08610W 8430 01485 9991 +185 +169 293037 039 037 001 00
233100 2034N 08611W 8430 01487 9993 +185 +164 289036 036 035 001 00
233130 2032N 08612W 8432 01488 9995 +184 +164 288035 035 035 000 00
233200 2031N 08613W 8429 01492 9998 +180 +168 287032 034 035 000 00
$$
;

[tolakram]

000
URNT12 KWBC 062323
VORTEX DATA MESSAGE AL162017
A. 06/22:55:20Z
B. 21 deg 03 min N
085 deg 43 min W
C. 700 mb 3032 m
D. 49 kt
E. 083 deg 20 nm
F. 163 deg 70 kt
G. 086 deg 40 nm
H. 992 mb
I. 12 C / 3046 m
J. 14 C / 3063 m
K. 10 C / NA
L. NA
M. NA
N. 1345 / 7
O. .01 / 4 nm
P. NOAA2 WC16A NATE OB 10
MAX FL WIND 70 KT 086 / 40 NM 22:46:12Z
MAX FL TEMP 14 C 270 / 14 NM FROM FL CNTR
CNTR DROPSONDE SFC WIND 175 / 13 KTS

[tolakram]

VDM 992MB which is lower than most, if not all, of the models had Nate at.

[tolakram]

000
URNT12 KWBC 062323
VORTEX DATA MESSAGE AL162017
A. 06/22:55:20Z
B. 21 deg 03 min N
085 deg 43 min W
C. 700 mb 3032 m
D. 49 kt
E. 083 deg 20 nm
F. 163 deg 70 kt
G. 086 deg 40 nm
H. 992 mb
I. 12 C / 3046 m
J. 14 C / 3063 m
K. 10 C / NA
L. NA
M. NA
N. 1345 / 7
O. .01 / 4 nm
P. NOAA2 WC16A NATE OB 10
MAX FL WIND 70 KT 086 / 40 NM 22:46:12Z
MAX FL TEMP 14 C 270 / 14 NM FROM FL CNTR
CNTR DROPSONDE SFC WIND 175 / 13 KTS

[txwatcher91]

True BUT warm air does not necessarily mean humid air once you get more than 100-200ft off sea level. Most people focus on 100-200 miles at sea level near the path of the eye/center, so much of their expectations and suggestions are based on ground/sea level observations, which is why many here are expecting and suggesting RI.... Versus the models showing it failing to intensify too much are also looking at med and upper level interactions which can keep the core from warming up too much/too fast, or some mid to high level dry air continually interacting as is common in October storms. This is why they are still suggesting a weak Cat 1 at US landfall.

100 or 200 feet off sea level? I find that statement baffling. the atmosphere is incredibly juiced over the Florida peninsula with Ruskin mentioning 2.2-2.4" PWATS in their earlier discussion. that would be impressive at any point in midsummer let alone early Oct and that air is advecting westward over the Gulf. I have no idea whether Nate will strengthen a good bit before landfall but based on the high octane airmass to the north and the rapidly improving satellite signature this afternoon a good round of intensification may be underway right now. Folks in the hurricane warning area should be expecting a hurricane and hoping for weakening. But as of now it looks like things are steadily escalating.

There are multiple things at play here, I am just explaining multiple dimensions that I've heard and read forecasters talking about that could possibly affect this storm, thus which prevent this from intensifying much beyond a weak Cat 1. You could see a very similar phenomenon with Hurricane Nate of 2011, where these same issues in early Sept. (cooler water temps, dry air) only allowed it to be classified as a Cat 1 hurricane for only 1 day, despite it sitting out over the gulf (Bay of Campeche) for 4+ days. Yes they are different storms and events but similar factors from that one will also affect this one based on circumstances and location. Remember that cooler water could very well be drawn from that same bay into this storm.

Due to the unknown factors, NHC and other forecasters have said it may intensify a bit more than expected primarily to cover their back side in case it does stay outside of the dry air from the dropping jet stream. That is the joy of the unknown, people see something and make suggestions, but ultimately mother nature will do what she wants regardless of our opinions.

https://www.atmos-chem-phys.net/17/10349/2017/
https://en.wikipedia.org/wiki/Hurricane_Nate_(2011)

PWAT values are a good indicator of the amount of moisture throughout the atmosphere. Values of 2.2-2.4 as referenced by pscyclone are VERY high and indicate a moisture column not just at the surface but throughout the atmosphere. The system you mentioned actually had quite a bit of dry air and lower PWAT values near it hence the issues it had. This system does not. The only issue this system will battle is the fast forward speed. If it manages to organize despite that then there isn’t anything to hold this back. Also of note, dry air is usually only a hindrance to systems just developing or when strong shear is present. Once a storm organizes into a hurricane it’s usually effected much less by any dry air unless shear is involved.

[tolakram]

SLIDER IR

http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=conus&x=6035&y=6430&z=3&im=18&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=13&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

[tolakram]

000
URNT12 KNHC 062345
VORTEX DATA MESSAGE AL162017
A. 06/23:16:00Z
B. 21 deg 09 min N
085 deg 49 min W
C. 850 mb 1359 m
D. 38 kt
E. 354 deg 25 nm
F. 110 deg 55 kt
G. 360 deg 31 nm
H. 991 mb
I. 18 C / 1523 m
J. 21 C / 1525 m
K. 19 C / NA
L. NA
M. NA
N. 12345 / 08
O. 0.02 / 1.5 nm
P. AF307 0716A NATE OB 06
MAX FL WIND 55 KT 000 / 31 NM 23:05:00Z
CNTR DROPSONDE SFC WIND 150 / 10 KT
;

This is lower than all the models so it's already outperforming.

[tolakram]

000
URNT12 KNHC 062345
VORTEX DATA MESSAGE AL162017
A. 06/23:16:00Z
B. 21 deg 09 min N
085 deg 49 min W
C. 850 mb 1359 m
D. 38 kt
E. 354 deg 25 nm
F. 110 deg 55 kt
G. 360 deg 31 nm
H. 991 mb
I. 18 C / 1523 m
J. 21 C / 1525 m
K. 19 C / NA
L. NA
M. NA
N. 12345 / 08
O. 0.02 / 1.5 nm
P. AF307 0716A NATE OB 06
MAX FL WIND 55 KT 000 / 31 NM 23:05:00Z
CNTR DROPSONDE SFC WIND 150 / 10 KT
;

[tropicwatch]

Think they will move some hurricane warnings eastward or wait to see if it continues on east side of track for the 11pm update?

[tolakram]

Think they will move some hurricane warnings eastward or wait to see if it continues on east side of track for the 11pm update?

Even if it's tot he east of the NHC track landfall may be in the same place. GFS takes aim at NO and then goes east just before landfall, Euro goes straight in. Both are east of NHC early.

So in other words, I have no idea.

[Big Easy Breeze]

VDM 992MB which is lower than most, if not all, of the models had Nate at.

Already down to 993; no? Models underestimating the strength?

[NDG]

3 mb drop in 2 hours, down to 991mb.

URNT12 KNHC 062345
VORTEX DATA MESSAGE AL162017
A. 06/23:16:00Z
B. 21 deg 09 min N
085 deg 49 min W
C. 850 mb 1359 m
D. 38 kt
E. 354 deg 25 nm
F. 110 deg 55 kt
G. 360 deg 31 nm
H. 991 mb
I. 18 C / 1523 m
J. 21 C / 1525 m
K. 19 C / NA
L. NA
M. NA
N. 12345 / 08
O. 0.02 / 1.5 nm
P. AF307 0716A NATE OB 06
MAX FL WIND 55 KT 000 / 31 NM 23:05:00Z
CNTR DROPSONDE SFC WIND 150 / 10 KT

[tolakram]

VDM 992MB which is lower than most, if not all, of the models had Nate at.

Already down to 993; no? Models underestimating the strength?

991 mb per very latest.

[NDG]

Think they will move some hurricane warnings eastward or wait to see if it continues on east side of track for the 11pm update?

I doubt it, unless the Euro and GFS make a drastic shift to the right tonight.

[Big Easy Breeze]

VDM 992MB which is lower than most, if not all, of the models had Nate at.

Already down to 993; no? Models underestimating the strength?

991 mb per very latest.

That is pretty low for a disorganized mess.

[CrazyC83]

URNT15 KNHC 062352
AF307 0716A NATE HDOB 22 20171006
234230 2008N 08637W 8432 01509 0029 +170 +161 288021 021 026 001 03
234300 2007N 08638W 8431 01511 0028 +170 +154 288022 022 024 001 00
234330 2006N 08640W 8429 01514 0030 +170 +163 289022 022 022 000 00
234400 2005N 08641W 8429 01512 0032 +170 +168 288022 022 022 000 03
234430 2004N 08642W 8430 01513 0031 +170 +166 283023 023 021 001 00
234500 2002N 08643W 8429 01514 0031 +174 +159 284024 024 021 001 03
234530 2001N 08644W 8429 01515 0031 +172 +158 284024 024 021 000 00
234600 2000N 08645W 8431 01514 0033 +172 +154 286024 024 020 000 03
234630 1959N 08647W 8430 01515 0033 +170 +154 287023 024 018 000 03
234700 1958N 08648W 8429 01517 0033 +173 +155 284022 023 019 000 00
234730 1957N 08649W 8429 01517 0031 +177 +154 281021 021 019 000 03
234800 1956N 08650W 8429 01518 0030 +177 +153 282020 021 019 001 03
234830 1955N 08651W 8431 01516 0032 +175 +150 280021 022 018 000 00
234900 1953N 08652W 8429 01518 0032 +177 +145 283021 021 016 000 00
234930 1952N 08653W 8429 01517 0033 +180 +143 284021 021 016 001 00
235000 1951N 08655W 8428 01519 0033 +177 +139 286021 021 014 001 03
235030 1950N 08656W 8429 01518 0035 +179 +131 290021 021 016 000 00
235100 1949N 08657W 8432 01518 0036 +176 +116 285020 021 016 001 00
235130 1948N 08658W 8430 01519 0038 +177 +109 281020 020 017 001 03
235200 1947N 08659W 8429 01521 0039 +175 +124 281019 020 017 001 00
$$
;

[Big Easy Breeze]

Think they will move some hurricane warnings eastward or wait to see if it continues on east side of track for the 11pm update?

I doubt it, unless the Euro and GFS make a drastic shift to the right tonight.

A small wobble left, or right, at the last minute can always happen. Just be on watch.

[ColdMiser123]

...HURRICANE HUNTER PLANES FIND NATE A LITTLE STRONGER... ...CENTER NOW MOVING THROUGH THE YUCATAN CHANNEL...

7:00 PM CDT Fri Oct 6
Location: 21.4°N 85.9°W
Moving: NNW at 22 mph
Min pressure: 990 mb
Max sustained: 65 mph

[tolakram]

So as Aric was trying to point out last night, which I think I understand, the inhibiting factors are speed of the storm and limited inflow on the west side due to the unnamed storm. It appears unnamed might not be an issue as convection is building NW of the Yuk.