EPAC: GENEVIEVE - Post-Tropical

[aspen]

Talk about an aggressive first advisory. I didn’t think they would forecast a major until this had already become Genevieve.

[gatorcane]

Kudos to the globals especially the GFS who had this way out in the long-range as a major. Should become a powerful hurricane.

[zeehag]

as long as it remains off shore far enough, yaaayyy...basin needs a biggie..just keep em away from land please.

[aspen]

12E/Genevieve will pass through an area of higher OHC starting in 12-18 hours. If it has a decent core by then, that could trigger a phase of RI.

[Yellow Evan]

16/1730 UTC 11.5N 98.1W T2.5/2.5 12E

[Extratropical94]

Hello Genevieve!

12E TWELVE 200816 1800 11.9N 98.4W EPAC 35 1004

[Astromanía]

Another possible strong Genevieve

[cycloneye]

12E GENEVIEVE 200816 1800 11.9N 98.4W EPAC 35 1004

[cycloneye]

* GFS version *
* EAST PACIFIC 2020 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* GENEVIEVE EP122020 08/16/20 18 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
V (KT) NO LAND 35 41 48 56 65 80 97 102 105 100 94 85 74 66 58 50 41
V (KT) LAND 35 41 48 56 65 80 97 102 105 100 94 85 74 66 58 50 41
V (KT) LGEM 35 39 43 48 54 69 88 105 108 98 86 71 56 44 34 27 22
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 3 7 4 3 4 5 7 3 3 5 6 9 15 13 11 16 21
SHEAR ADJ (KT) 0 0 1 3 0 0 -5 -4 -3 -3 0 0 3 4 7 5 9
SHEAR DIR 90 100 103 64 108 119 127 155 149 103 135 146 195 199 204 181 183
SST (C) 29.6 30.0 30.1 30.2 30.2 29.8 29.5 29.3 27.6 26.1 25.4 24.3 23.1 22.4 22.0 21.5 20.9
POT. INT. (KT) 163 167 168 169 169 164 161 158 140 124 117 106 94 85 81 77 71
200 MB T (C) -52.9 -52.6 -52.9 -53.1 -52.8 -52.6 -52.3 -52.3 -51.7 -51.2 -50.8 -50.4 -50.2 -50.1 -50.3 -50.2 -50.0
200 MB VXT (C) 0.1 0.0 0.1 0.2 0.2 0.3 0.4 0.5 0.5 0.6 0.6 0.8 0.9 0.9 1.1 0.9 0.6
TH_E DEV (C) 5 5 4 4 6 7 8 7 6 5 5 3 0 0 0 0 0
700-500 MB RH 81 82 81 81 82 79 78 75 69 62 58 52 53 53 52 48 49
MODEL VTX (KT) 15 17 17 18 20 20 28 28 31 31 31 29 27 26 22 20 17
850 MB ENV VOR 35 37 31 23 25 41 61 79 90 71 69 71 58 57 41 17 21
200 MB DIV 106 127 100 86 101 137 124 89 55 27 30 -5 -12 -7 -2 0 15
700-850 TADV 0 -2 -6 -11 -8 -11 -3 0 -3 -7 -5 -2 9 6 5 10 11
LAND (KM) 456 452 473 474 469 467 476 460 359 373 375 487 536 640 734 811 806
LAT (DEG N) 11.9 12.4 12.8 13.4 14.0 15.5 17.1 18.8 20.4 21.6 22.5 23.5 24.9 xx.x xx.x xx.x xx.x
LONG(DEG W) 98.4 99.9 101.4 102.8 104.2 106.8 108.8 110.6 112.2 113.5 115.0 116.9 119.3 xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT) 17 15 15 15 15 13 12 11 10 9 9 11 11 8 8 11 11
HEAT CONTENT 20 32 51 44 38 29 23 19 5 0 0 0 0 0 0 0 0

FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):290/ 18 CX,CY: -16/ 6
T-12 MAX WIND: 30 PRESSURE OF STEERING LEVEL (MB): 414 (MEAN=587)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 11.8 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 97.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 65.9

INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
------------------------------------------------------------------------------
SAMPLE MEAN CHANGE 0. 0. 1. 1. 1. 2. 1. 1. 0. -0. -1. -2. -3. -4. -4. -5.
SST POTENTIAL -0. -0. -0. 1. 5. 11. 16. 21. 24. 25. 26. 25. 23. 21. 18. 15.
VERTICAL SHEAR MAG 1. 1. 2. 3. 5. 6. 7. 8. 9. 9. 9. 8. 7. 6. 4. 2.
VERTICAL SHEAR ADJ 0. 0. -0. -0. 0. 1. 1. 1. 1. 0. -0. -0. -0. -0. 0. 0.
VERTICAL SHEAR DIR 0. 1. 2. 3. 3. 4. 4. 3. 2. 2. 1. 1. 1. 1. 1. 1.
PERSISTENCE 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
200/250 MB TEMP. -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -0. 1. 1. 2. 4. 4.
THETA_E EXCESS -0. -0. -1. -1. -1. -0. -0. -0. -0. -1. -1. -3. -4. -5. -7. -8.
700-500 MB RH 0. 0. 1. 1. 1. 2. 1. 2. 2. 1. 1. 1. 1. 1. 1. 1.
MODEL VTX TENDENCY 0. 1. 2. 4. 4. 12. 16. 21. 22. 22. 18. 14. 11. 7. 4. 1.
850 MB ENV VORTICITY 0. 0. 0. 0. 0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -1. -0.
200 MB DIVERGENCE 0. 1. 1. 1. 2. 3. 5. 6. 6. 5. 4. 3. 2. 1. 0. 0.
850-700 T ADVEC 0. 0. 0. 0. 0. 0. -0. 0. -0. -0. -0. -0. -0. -0. -0. -0.
ZONAL STORM MOTION 0. 1. 1. 1. 2. 3. 4. 3. 3. 3. 3. 3. 2. 2. 1. -0.
STEERING LEVEL PRES -0. -0. -1. -1. -2. -3. -3. -3. -3. -3. -3. -4. -3. -2. -2. -0.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 1. 1. 2. 2. 3. 3. 3. 3. 4. 4.
GOES PREDICTORS 1. 2. 3. 3. 3. 2. 2. 2. 2. 2. 2. 3. 2. 2. 2. 1.
OCEAN HEAT CONTENT -0. 0. 0. 0. 0. 1. 1. 1. 0. 0. 0. 0. 0. 0. 1. 2.
RI POTENTIAL 2. 5. 8. 13. 19. 18. 11. 3. -2. -6. -10. -12. -12. -12. -12. -12.
------------------------------------------------------------------------------
TOTAL CHANGE 6. 13. 21. 30. 45. 62. 67. 70. 65. 59. 50. 39. 31. 23. 15. 6.

CURRENT MAX WIND (KT): 35. LAT, LON: 11.9 98.4

** 2020 E. Pacific RI INDEX EP122020 GENEVIEVE 08/16/20 18 UTC **
(SHIPS-RII PREDICTOR TABLE for 30 KT OR MOREMAXIMUM WIND INCREASE IN NEXT 24-h)

Predictor Value RI Predictor Range Scaled Value(0-1) % Contribution
POT = MPI-VMAX (KT) : 132.3 40.5 to 149.3 0.84 13.6
12 HR PERSISTENCE (KT) : 5.0 -22.0 to 44.0 0.41 7.8
850-200 MB SHEAR (KT) : 4.2 19.6 to 1.4 0.85 12.5
D200 (10**7s-1) : 104.0 -33.0 to 160.6 0.71 10.8
MAXIMUM WIND (KT) : 35.0 22.5 to 132.0 0.35 4.0
STD DEV OF IR BR TEMP : 11.8 37.8 to 2.1 0.73 6.9
HEAT CONTENT (KJ/CM2) : 37.0 2.7 to 106.7 0.33 2.9
BL DRY-AIR FLUX (W/M2) : 8.8 800.8 to -82.5 0.90 -10.7
%area of TPW <45 mm upshear : 0.0 56.6 to 0.0 1.00 4.0
2nd PC OF IR BR TEMP : -0.4 2.2 to -1.9 0.63 0.7

SHIPS Prob RI for 20kt/ 12hr RI threshold= 21% is 3.3 times climatological mean ( 6.3%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 69% is 5.5 times climatological mean (12.6%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 53% is 6.1 times climatological mean ( 8.6%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 43% is 7.0 times climatological mean ( 6.2%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 33% is 7.9 times climatological mean ( 4.2%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 64% is 9.5 times climatological mean ( 6.7%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 79% is 13.3 times climatological mean ( 5.9%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 63% is 13.3 times climatological mean ( 4.7%)

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: 20.7% 68.7% 52.5% 43.2% 33.3% 63.8% 78.7% 62.7%
Logistic: 37.0% 85.3% 76.6% 67.9% 29.4% 86.5% 79.9% 58.8%
Bayesian: 9.3% 51.4% 53.7% 32.2% 2.1% 59.3% 37.4% 51.6%
Consensus: 22.3% 68.5% 60.9% 47.7% 21.6% 69.9% 65.3% 57.7%
DTOPS: 13.0% 44.0% 27.0% 12.0% 6.0% 40.0% 45.0% 90.0%

## ANNULAR HURRICANE INDEX (AHI) EP122020 GENEVIEVE 08/16/20 18 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) ##

[storminabox]

^Some of the most aggressive RI probabilities I've seen in a long time. This SHOULD be a beastly storm. The key word is should, however the Epac has had other plans this season.

[cycloneye]

Tropical Storm Genevieve Discussion Number 2
NWS National Hurricane Center Miami FL EP122020
400 PM CDT Sun Aug 16 2020

Visible satellite imagery shows that the tropical cyclone is quickly
becoming better organized. Several bands of deep convection are
located around the center, and there is a concentration of
convection near the estimated center, suggesting that a CDO may
already be starting to form. The various satellite intensity
estimates were around 35 kt at 18z, and an earlier ASCAT overpass
revealed a couple of wind vectors slightly higher than that value.
Based on the continued increase in organization, the advisory
intensity has been set at 40 kt. Genevieve becomes the seventh
named storm in the eastern Pacific basin this hurricane season.

Although there are a few dry slots noted within the bands of deep
convection, environmental conditions of warm water, low shear, and
plenty of low- to mid-level moisture along the forecast track
suggest that Genevieve will intensify quite rapidly over the next
couple of days. The statistical and dynamical guidance, along with
the global models, deepen the cyclone rapidly over the next 2-3
days. The latest SHIPS Rapid Intensification Index shows about a
65-percent chance of 65-kt increase in wind speed over the next 72
hours, and DTOPS gives a 90-percent chance of a similar increase in
intensity over that same time period. All of this leads to an
unusually high level of confidence that Genevieve will rapidly
strengthen, likely becoming a hurricane in 24 hours and a major
hurricane within 48 hours. The NHC intensity forecast is similar to
both the SHIPS and HFIP corrected consensus models. After 72 h,
Genevieve is expected to reach cooler waters, and a fairly quick
rate of weakening is forecast after that time.

Recent satellite fixes suggest that the center is located slightly
north of the previous track, but Genevieve's motion remains
west-northwestward at a brisk 17 kt. The track forecast philosophy
is unchanged from before. Genevieve should move west-northwestward
to the south of a deep layer ridge over the western United States
during the next couple of days. After that time, the cyclone will
be approaching the western portion of the ridge and a slightly
slower northwestward motion is expected. The new NHC track forecast
is slightly north of the previous advisory through 24 hours due to
the more northward initial position, otherwise the updated forecast
is similar to the previous advisory, and is close to the HFIP
corrected consensus model.

Although the tropical cyclone is forecast to remain well offshore
the southern coast of Mexico, large swells generated by the
strengthening system are expected to begin affecting portions of
the coast of southern Mexico over the next day or so.


FORECAST POSITIONS AND MAX WINDS

INIT 16/2100Z 12.2N 99.2W 40 KT 45 MPH
12H 17/0600Z 12.9N 101.5W 50 KT 60 MPH
24H 17/1800Z 14.3N 104.5W 65 KT 75 MPH
36H 18/0600Z 15.7N 107.2W 85 KT 100 MPH
48H 18/1800Z 17.2N 109.3W 100 KT 115 MPH
60H 19/0600Z 18.6N 110.9W 110 KT 125 MPH
72H 19/1800Z 20.2N 112.4W 105 KT 120 MPH
96H 20/1800Z 22.5N 115.3W 80 KT 90 MPH
120H 21/1800Z 24.7N 119.1W 55 KT 65 MPH

$$
Forecaster Brown

[Visioen]

Officially forecasted to go from tropical storm to major hurricane in 48h. Not something you see every day. This should be fun to watch.

[aspen]

^Some of the most aggressive RI probabilities I've seen in a long time. This SHOULD be a beastly storm. The key word is should, however the Epac has had other plans this season.

Fingers crossed this is more like Douglas and not another Cristina. This will probably be the last notable EPac system in a while, with the Atlantic likely taking center stage in a week or so.

[Yellow Evan]

There's a part of me that thinks this is basically Marie 14 all over again but hard to justify getting that bullish in the year 2020 in this basin just because the models have so little credibility this year.

[DestinHurricane]

And we thought the name Isaias was bad...

[EquusStorm]

Definitely has 'the look' of something about to bomb out, if it can overcome the hostile base state with the help of the MJO this could be the big one this year in the EPac (alongside Douglas)

[AnnularCane]

And we thought the name Isaias was bad...

What's wrong with Genevieve? I like this name.

[aspen]

It seems like Genevieve is developing a decently tight and compact core. It also has a lot of outflow and banding features. If she can develop a solid inner core without pesky dry air intrusions, her small size coupled with a favorable environment will lead to RI like the NHC is anticipating.

Edit: and it does look like it’s in the beginning stages of developing a core.

[gatorcane]

Looking really impressive. Will be fun to watch the RI expected since this one won’t be impacting land.

Here is a floater to watch this bomb out:

http://rammb.cira.colostate.edu/ramsdis ... display=12

[EquusStorm]

Definitely getting its act together ridiculously fast. Wouldn't be shocked to see Douglas challenged if it avoids dry air.