CPAC: INVEST 96C

[Kingarabian]

Looks to be Lane?

[Yellow Evan]

This is the system people have been clamouring to be upgraded for a few days now.

* EAST PACIFIC 2018 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* INVEST CP962018 09/02/18 06 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 40 39 35 30 25 19 16 DIS DIS DIS DIS DIS DIS
V (KT) LAND 40 39 35 30 25 19 16 DIS DIS DIS DIS DIS DIS
V (KT) LGEM 40 39 36 32 28 22 17 DIS DIS DIS DIS DIS DIS
Storm Type TROP TROP TROP TROP TROP EXTP EXTP EXTP EXTP EXTP EXTP EXTP EXTP

SHEAR (KT) 24 31 28 19 13 18 31 27 28 39 42 34 32
SHEAR ADJ (KT) 0 1 2 0 0 3 0 0 4 2 5 6 2
SHEAR DIR 325 346 355 350 325 252 255 245 237 259 290 306 314
SST (C) 22.1 21.0 19.8 18.8 17.5 14.0 11.2 9.0 10.7 9.8 14.6 9.1 11.2
POT. INT. (KT) 83 71 60 60 61 63 65 66 66 66 66 64 61
200 MB T (C) -56.7 -57.0 -56.9 -56.9 -56.7 -57.0 -56.9 -57.4 -57.6 -56.6 -54.2 -51.6 -49.9
200 MB VXT (C) 0.4 0.1 0.1 0.0 0.0 0.0 -0.2 -0.8 0.6 0.8 0.4 0.4 0.8
TH_E DEV (C) 1 0 0 0 0 0 0 0 0 0 0 0 0
700-500 MB RH 60 56 54 55 56 59 53 47 49 62 70 74 70
MODEL VTX (KT) 20 20 17 16 14 13 12 13 11 8 6 5 7
850 MB ENV VOR 44 36 41 21 7 9 6 -35 -84 -54 14 56 64
200 MB DIV -8 -17 -18 -1 -6 29 38 42 19 20 63 77 60
700-850 TADV 16 13 11 10 14 17 41 50 40 20 28 0 -15
LAND (KM) 2220 2134 2064 2013 1931 1688 1339 1136 649 138 64 -382 -167
LAT (DEG N) 39.8 40.8 41.6 42.2 43.0 45.3 49.0 53.6 58.8 63.0 64.6 63.7 62.4
LONG(DEG W) 178.0 178.2 178.3 178.4 178.2 177.4 176.4 177.3 178.7 173.5 161.5 151.0 146.4
STM SPEED (KT) 11 9 7 7 9 15 21 26 25 26 27 18 9
HEAT CONTENT 0 0 0 0 0 0 0 0 0 0 0 3 3

FORECAST TRACK FROM TABM INITIAL HEADING/SPEED (DEG/KT):355/ 11 CX,CY: 0/ 11
T-12 MAX WIND: 40 PRESSURE OF STEERING LEVEL (MB): 775 (MEAN=584)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 12.9 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 74.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 55 KT IN 48 HR): 0.0

INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
6 12 18 24 36 48 60 72 84 96 108 120
----------------------------------------------------------
SAMPLE MEAN CHANGE 0. 0. 1. 1. 1. 1. 1. 0. -1. -1. -2. -3.
SST POTENTIAL -1. -3. -5. -8. -11. -11. -8. -8. -7. -7. -8. -8.
VERTICAL SHEAR MAG 1. 2. 4. 6. 6. 0. -11. -25. -41. -54. -55. -54.
VERTICAL SHEAR ADJ 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 1. 1.
VERTICAL SHEAR DIR 0. 0. -1. -1. 1. 4. 7. 9. 11. 12. 12. 11.
PERSISTENCE 0. 0. 0. -1. -1. -1. 0. 0. 0. 0. 0. 0.
200/250 MB TEMP. 0. 0. 0. 1. 2. 4. 7. 11. 17. 21. 24. 21.
THETA_E EXCESS -1. -2. -3. -5. -7. -10. -12. -14. -15. -16. -17. -18.
700-500 MB RH 0. 0. 0. 0. -1. -1. -1. -2. -2. -1. -1. -1.
MODEL VTX TENDENCY 0. -2. -3. -6. -7. -7. -9. -12. -17. -20. -21. -18.
850 MB ENV VORTICITY 0. 0. 0. 0. 0. 0. 0. 1. 2. 2. 2. 2.
200 MB DIVERGENCE 0. -1. -1. -2. -2. -2. -2. -2. -2. -2. -2. -1.
850-700 T ADVEC 0. 0. 0. 0. 0. 1. 3. 5. 6. 7. 9. 11.
ZONAL STORM MOTION 0. -1. -1. -1. -2. -3. -3. -3. -2. -2. -2. -2.
STEERING LEVEL PRES 0. 0. 1. 1. 1. 2. 2. 2. 3. 4. 4. 5.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 1. 1. 2. 2. 2. 2.
GOES PREDICTORS 1. 1. 1. 1. 1. 1. 0. 0. 0. -1. -1. -1.
OCEAN HEAT CONTENT 0. 0. -1. -1. -1. -1. -1. 0. 0. 0. 0. 0.
RI POTENTIAL 0. 0. -1. -1. -2. -3. -3. -2. 0. 1. 2. 3.
----------------------------------------------------------
TOTAL CHANGE -1. -5. -10. -15. -21. -24. -30. -38. -48. -55. -53. -50.

CURRENT MAX WIND (KT): 40. LAT, LON: 39.8 178.0

** 2018 E. Pacific RI INDEX CP962018 INVEST 09/02/18 06 UTC **
(SHIPS-RII PREDICTOR TABLE for 30 KT OR MORE MAXIMUM WIND INCREASE IN NEXT 24-h)

Predictor Value RI Predictor Range Scaled Value(0-1) % Contribution
POT = MPI-VMAX (KT) : 26.8 40.5 to 149.3 0.00 0.0
12 HR PERSISTENCE (KT) : 0.0 -22.0 to 44.0 0.33 999.0
850-200 MB SHEAR (KT) : 23.1 19.6 to 1.4 0.00 0.0
HEAT CONTENT (KJ/CM2) : 0.0 1.8 to 106.7 0.00 0.0
D200 (10**7s-1) : -10.0 -33.0 to 156.2 0.12 999.0
STD DEV OF IR BR TEMP : 12.9 37.8 to 2.1 0.70 999.0
MAXIMUM WIND (KT) : 40.0 22.5 to 132.0 0.51 999.0
BL DRY-AIR FLUX (W/M2) : 224.6 721.6 to -82.5 0.62 999.0
%area of TPW <45 mm upshear : 71.7 62.3 to 0.0 0.00 0.0
2nd PC OF IR BR TEMP : -0.3 2.2 to -1.9 0.60 999.0

SHIPS Prob RI for 20kt/ 12hr RI threshold= 0% is 0.0 times climatological mean ( 6.1%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 0% is 0.0 times climatological mean (12.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 0% is 0.0 times climatological mean ( 8.4%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 0% is 0.0 times climatological mean ( 6.0%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times climatological mean ( 4.0%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 0% is 0.0 times climatological mean ( 6.5%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 0% is 0.0 times climatological mean ( 5.9%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 0% is 0.0 times climatological mean ( 4.8%)

Matrix of RI probabilities
------------------------------------------------------------------------------
RI (kt / h) | 20/12 | 25/24 | 30/24 | 35/24 | 40/24 | 45/36 | 55/48 |65/72
------------------------------------------------------------------------------
SHIPS-RII: 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
Logistic: 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
Bayesian: 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
Consensus: 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
DTOPS: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%

## ANNULAR HURRICANE INDEX (AHI) CP962018 INVEST 09/02/18 06 UTC ##
## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=3 NFAIL=4 ##
## AHI= 0 (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##

CONTRIBUTIONS TO ANNULAR INDEX

[Yellow Evan]

02/0530 UTC 39.7N 178.0W T3.0/3.0 96C -- Central Pacific

[doomhaMwx]

[AJC3]

TBH, I'm not sure there should even be a separate thread on this.

Retitling the Lane thread "Lane_96C" would be more appropriate, in spite of what has (and more importantly has NOT) been 'officially' acknowledged...

[Yellow Evan]

TBH, I'm not sure there should even be a separate thread on this.

Retitling the Lane thread "Lane_96C" would be more appropriate, in spite of what has (and more importantly has NOT) been 'officially' acknowledged...

 https://twitter.com/NWSHonolulu/status/1035682652416823296

[Kingarabian]

Looks tropical to me?

[Kingarabian]

TBH, I'm not sure there should even be a separate thread on this.

Retitling the Lane thread "Lane_96C" would be more appropriate, in spite of what has (and more importantly has NOT) been 'officially' acknowledged...

Makes sense to me. We can have the posts on this thread sent to the Lane thread.

[AJC3]

TBH, I'm not sure there should even be a separate thread on this.

Retitling the Lane thread "Lane_96C" would be more appropriate, in spite of what has (and more importantly has NOT) been 'officially' acknowledged...

https://twitter.com/NWSHonolulu/status/ ... 2416823296

Yup,I saw that tweet. However, I respectfully disagree with their assessment. The system never dissipated or became absorbed by a different low. It became an elongated post-tropical low that underwent baroclinic enhancement and, in my assessment, (rather than making a brief transition to a extratropical cyclone) regenerated as a subtropical and now a tropical cyclone.

If Ivan 2.0 was, in fact, Ivan, this is surely Lane 2.0. However, following our normal protocol, the PTC Lane thread is locked to prevent cross-posting.

[Hammy]

I'm not entirely sure what's subtropical about this, the ULL is clearly visible well to the south and helping produce light outflow.

[Kingarabian]

Not bashing the CPHC or the NWSHonolulu, I believe they do a good job especially with the little resources that they have available to them.

But it seems that they have different criteria or methodology when it comes to assessing tropical cyclones than the NHC -- especially ones with little land threat or little model support.

There were cases before where the CPHC would ignore obvious but short lived tropical cyclones, most recently 95C.

[tolakram]

We can always combine this thread with Lane later if they reassess. It should be possible using SLIDER and the Himawatchamacallit sat to determine if Lane's circulation dissipated or not.

[CrazyC83]

This will probably get a lot of internal debate, not unlike Ivan. IMO this is Lane (and can be continuously tracked), but some may argue differently. That said, it did weaken overnight it appears. Probably peaked around 0000Z.

[Ptarmigan]

If Lane was absorbed by another low pressure system, is it sill Lane?

I know in 2005 there was Tropical Depression 10 and it got absorbed another tropical wave, which later became Tropical Depression 12 and Katrina.

[1900hurricane]

It's a similar situation with Hurricane Lee last year too.

[Kingarabian]

From the CPHC:

 https://twitter.com/bodyboarder22/status/1036260608465809408

[Sciencerocks]

Looks tropical to me. Had a well defined eye yesterday....

[mrbagyo]

Nice, an "invest" with 40 knots sustained wind. LMAO.

96C INVEST 180902 1800 41.4N 178.1W CPAC 40 1001

[AJC3]

Looks like I took myself up on the challenge and changed my own mind...



After careful examination of the CIMSS 850MB vorticity analyses, I'll have to retract my original assessment. It appears that the remnant vortex did indeed become absorbed into a new low just to its north. It's not Lane after all, but still a STC that IMO briefly became fully tropical.

[CrazyC83]

After careful examination of the CIMSS 850MB vorticity analyses, I'll have to retract my original assessment. It appears that the remnant vortex did indeed become absorbed into a new low just to its north. It's not Lane after all, but still a STC that IMO briefly became fully tropical.

It's definitely not easy to assess. It appears that the remnant LLC became elongated, with two separate MLC's. I did look at the surface analyses and I was able to track the LLC all the way through (as a remnant low) but I'd need to see satellite images of that critical period. From what I could judge, the LLC simply retreated to the new MLC aloft (at 850) and pivoted to it, but remaining its own identity all the way through. I'm not sure what a similar analog in the Atlantic might be - Lee last year?

Still, I would argue it was tropical at least for a while (and may still be). The question is whether to extend Lane's ultimate track and cover it, or treat it as a separate unnamed storm.