EPAC: HILARY - Post-Tropical

[Ntxw]

Timeline of the models suggest this is probably Hilary by tomorrow (unless 10-E beats it somehow) then Irwin. Rapidly deepens it to a Hurricane and latest GFS has 928mbar. Tues-Thurs is probably peak period.

[CaliforniaResident]

This one has to beat 10-E to become a TS JUST so it can swag the name "HILLARY". A mighty storm is deserving of a mighty, noble name.

[CaliforniaResident]

What is taking Hillary so long? She was supposed to be a TS by last night. Hope that this delayed start doesn't mean she will underperform.

[Yellow Evan]

Systems this far east can take time to really take off.

[gatorcane]

Both the GFS and ECMWF ultimately show TD-10 wrapping into the large circulation of this system in what looks like a Fujiwhara effect. Just shows how large this system could become.

[Kingarabian]

Timeline of the models suggest this is probably Hilary by tomorrow (unless 10-E beats it somehow) then Irwin. Rapidly deepens it to a Hurricane and latest GFS has 928mbar. Tues-Thurs is probably peak period.

[img]http://i63.tinypic.com/4j011e.png[img]

Definetely more of a Cat.5 watch than Fernanda. Just needs to hurry and wrap up to take full advantage of the very high SST's and OHC.

[Sciencerocks]

[cycloneye]

Tropical Depression Nine-E Discussion Number 6
NWS National Hurricane Center Miami FL EP092017
400 PM CDT Sat Jul 22 2017

Recent ASCAT data confirmed that the depression has not become any
better organized and that the low-level center is on the southern
edge of the main convection. T-numbers have remain either steady or
decrease slightly, so the initial intensity has been kept at 30 kt
at this time. Despite the current lack of organization, the cyclone
is expected to be in a very favorable environment of low shear and
over warm waters. With these conditions, I have no option but to
forecast strengthening. This process will probably be slow during
the next day or so, but after that time, the cyclone should
strengthen at a faster pace and become a hurricane. This follows the
latest intensity guidance which suggest that the most rapid increase
in the winds should occur beyond 48 hours.

The depression appears to be moving toward the west-northwest or
290 degrees at 11 kt. The steering pattern has not changed, and
global models continue to forecast a strong ridge extending from
Mexico westward across the Pacific. This flow pattern will keep the
cyclone on the same general west-northwestward track for the next 5
days, as indicated by the general guidance. This solution is not
different from the previous NHC track forecasts which have been
keeping the core of the cyclone well south of the coast of Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT 22/2100Z 10.5N 99.3W 30 KT 35 MPH
12H 23/0600Z 11.2N 100.7W 30 KT 35 MPH
24H 23/1800Z 12.2N 102.5W 40 KT 45 MPH
36H 24/0600Z 13.0N 104.0W 50 KT 60 MPH
48H 24/1800Z 13.7N 105.5W 65 KT 75 MPH
72H 25/1800Z 15.0N 109.0W 85 KT 100 MPH
96H 26/1800Z 16.5N 113.0W 90 KT 105 MPH
120H 27/1800Z 17.5N 116.0W 95 KT 110 MPH

$$
Forecaster Avila

[Sciencerocks]

Boy, satellite can be a liar as by appearance alone it would lead to one making the comment that this looks better then Bret, Cindy and Don.

[Ntxw]

Boy, satellite can be a liar as by appearance alone it would lead to one making the comment that this looks better then Bret, Cindy and Don.

If there was recon the plane would probably find 50kt winds somewhere in an embedded thunderstorm . As wxman57 likes to say.

[Yellow Evan]

This is precisely the kind of system where Dvorak fails quite a bit.

[gatorcane]

Slightly less strong but still intense on the 18Z GFS:

[cycloneye]

Finnally getting it's act together.

[Yellow Evan]

EP, 09, 201707222345, 10, DVTS, CI, , 1120N, 9970W, , 3, 30, 2, , , , , , , , , , , , , , , , , E, SAB, JW, VIM, 5, 2020 /////, , , GOES13, LLCC, T, DT=2.0 BO SHR MET=2.5 PT=2.5 FTBO DT

uhh shear pattern?

[Sciencerocks]

Any Pro met:

Why do storms like Bret and Don manage to produce tropical storm force winds, while appearing less impressive on satellite compared to 8E and 9E. It is my observation that Eastern Pacific systems appear to need deeper convection to produce the same winds. Is there something different in pressure set up that causes this difference like a stronger pressure gradient in the Atlantic between the subtropical high to the north and the area of low pressure(cyclone).

[RL3AO]

Any Pro met:

Why do storms like Bret and Don manage to produce tropical storm force winds, while appearing less impressive on satellite compared to 8L and 9L. It is my observation that Eastern Pacific systems appear to need deeper convection to produce the same winds. Is there something different in pressure set up that causes this difference like a stronger pressure gradient in the Atlantic between the subtropical range and the area of low pressure(cyclone).

These early season Atlantic waves are moving at 20 to 25 knots. It means it doesn't take that much organization to produce tropical storm force winds on the north side of the low where the winds are easterly with respect to the center. These easterly winds get added to the strong background flow to produce 40+ knot winds despite poor organization.

[cycloneye]

Still no TS??

22/2345 UTC 11.2N 99.7W T2.0/2.0 09E -- East Pacific

[cycloneye]

* EAST PACIFIC SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* NINE EP092017 07/23/17 00 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 30 32 35 38 46 59 72 87 94 98 99 99 95
V (KT) LAND 30 32 35 38 46 59 72 87 94 98 99 99 95
V (KT) LGEM 30 31 33 35 37 44 53 67 82 93 94 89 83
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 3 1 2 1 4 3 6 7 7 7 11 12 13
SHEAR ADJ (KT) 5 2 0 0 -1 -1 -6 -3 0 -1 -1 -3 -4
SHEAR DIR 76 329 307 243 75 99 85 56 57 30 20 8 14
SST (C) 29.1 29.2 29.3 29.3 29.2 29.0 28.9 28.9 28.6 27.9 26.9 26.5 26.3
POT. INT. (KT) 157 157 158 157 156 154 153 153 151 143 133 127 124
200 MB T (C) -52.9 -53.3 -53.3 -52.8 -52.3 -52.7 -52.0 -52.1 -51.3 -51.4 -50.7 -50.9 -50.4
200 MB VXT (C) 0.0 0.0 -0.1 -0.1 0.0 0.3 0.4 0.6 0.6 0.7 0.7 1.0 1.1
TH_E DEV (C) 7 7 6 7 8 7 8 8 7 7 6 5 5
700-500 MB RH 71 73 75 76 78 80 78 78 76 75 74 74 76
MODEL VTX (KT) 15 16 18 17 19 21 21 25 27 29 32 35 36
850 MB ENV VOR 21 17 3 -2 -4 -10 -3 -15 1 8 13 34 51
200 MB DIV 53 52 55 64 106 99 111 65 97 72 61 53 56
700-850 TADV 0 -1 -2 -1 -1 0 -1 -1 0 -4 -2 -7 -7
LAND (KM) 564 551 542 532 522 508 526 561 665 738 734 790 861
LAT (DEG N) 11.2 11.7 12.2 12.7 13.1 13.8 14.5 15.2 15.8 16.5 17.4 17.9 18.1
LONG(DEG W) 99.7 100.7 101.6 102.4 103.2 104.7 106.3 108.0 110.0 111.9 113.9 115.4 116.5
STM SPEED (KT) 12 11 10 9 8 9 9 9 10 10 9 6 5
HEAT CONTENT 17 24 39 50 44 24 23 28 17 11 7 4 3

FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):300/ 13 CX,CY: -10/ 7
T-12 MAX WIND: 30 PRESSURE OF STEERING LEVEL (MB): 561 (MEAN=550)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 20.2 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 77.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 55 KT IN 48 HR): 21.7

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. 1. -0. -1. -1. -2.
SST POTENTIAL -0. -0. 0. 2. 7. 13. 20. 25. 28. 29. 29. 28.
VERTICAL SHEAR MAG 1. 2. 4. 5. 8. 10. 10. 10. 10. 9. 9. 8.
VERTICAL SHEAR ADJ -0. -0. -0. -0. -0. 0. 0. 0. 0. 0. 0. 0.
VERTICAL SHEAR DIR 0. 0. -1. -0. 0. 2. 4. 5. 5. 5. 5. 4.
PERSISTENCE -0. -0. -0. -1. -1. -1. -1. -0. -0. -0. 0. 1.
200/250 MB TEMP. 0. -0. -0. -1. -2. -2. -3. -4. -4. -4. -4. -4.
THETA_E EXCESS 0. 0. 0. 0. 1. 1. 2. 2. 2. 2. 2. 1.
700-500 MB RH 0. 0. 0. 0. 1. 1. 2. 3. 3. 4. 5. 6.
MODEL VTX TENDENCY 0. 2. 2. 4. 7. 8. 14. 16. 19. 20. 22. 22.
850 MB ENV VORTICITY 0. 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 1.
200 MB DIVERGENCE 0. 0. 1. 1. 2. 4. 4. 4. 4. 4. 3. 2.
850-700 T ADVEC 0. -0. 0. -0. 0. 0. 0. 0. -0. -0. -0. -1.
ZONAL STORM MOTION 0. 0. 1. 1. 1. 2. 2. 1. 1. 1. 1. 1.
STEERING LEVEL PRES 0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0.
DAYS FROM CLIM. PEAK -0. -0. -0. -0. 0. -0. -0. -0. -1. -1. -1. -1.
GOES PREDICTORS 0. 1. 1. 1. 1. 1. 0. -0. -0. -1. -1. -1.
OCEAN HEAT CONTENT 0. 0. 1. 1. 2. 1. 1. 1. 1. 0. 0. -0.
----------------------------------------------------------
TOTAL CHANGE 2. 5. 8. 16. 29. 42. 57. 64. 68. 69. 69. 65.

CURRENT MAX WIND (KT): 30. LAT, LON: 11.2 99.7

** 2017 E.PACIFIC RI INDEX EP092017 NINE 07/23/17 00 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
12 HR PERSISTENCE (KT): 0.0 -22.0 to 44.0 0.33 3.2
POT = MPI-VMAX (KT) : 127.0 40.5 to 149.3 0.79 4.7
850-200 MB SHEAR (KT) : 2.1 18.9 to 1.4 0.96 7.8
HEAT CONTENT (KJ/cm2) : 34.8 0.0 to 106.7 0.33 2.1
MAXIMUM WIND (kt) : 30.0 22.5 to 132.0 0.21 1.3
D200 (10**7s-1) : 66.0 -33.0 to 156.2 0.52 2.8
STD DEV OF IR BR TEMP : 20.2 37.8 to 2.1 0.49 2.9
% AREA WITH TPW <45 mm: 0.0 62.3 to 0.0 1.00 -1.6
2nd PC OF IR BR TEMP : -0.1 2.2 to -1.9 0.56 0.4
BL DRY-AIR FLUX (w/m2): 26.6 735.9 to -82.5 0.87 0.0

SHIPS Prob RI for 20kt/ 12hr RI threshold= 13% is 1.7 times sample mean ( 7.7%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 29% is 1.9 times sample mean (15.3%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 24% is 2.3 times sample mean (10.4%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 20% is 2.7 times sample mean ( 7.5%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times sample mean ( 5.2%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 25% is 3.1 times sample mean ( 8.1%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 32% is 4.4 times sample mean ( 7.4%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 40% is 7.2 times sample mean ( 5.5%)

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: 13.0% 29.2% 23.6% 20.0% 0.0% 25.2% 32.3% 39.6%
Logistic: 5.6% 39.1% 25.7% 11.6% 4.8% 42.7% 58.1% 44.3%
Bayesian: 0.3% 8.8% 1.5% 0.7% 0.1% 2.0% 4.3% 8.6%
Consensus: 6.3% 25.7% 16.9% 10.8% 1.6% 23.3% 31.6% 30.8%

## ANNULAR HURRICANE INDEX (AHI) EP092017 NINE 07/23/17 00 UTC ##
## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=5 NFAIL=2 ##
## AHI= 0 (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##

[cycloneye]

Even thou this Tropical Cyclone has taken much time not turning into a Tropical Storm,the models continue bullish.

[Yellow Evan]

[Div]EP, 09, 201707222345, 10, DVTS, CI, , 1170N, 9980W, , 3, 35, 2, 1005, 2, DVRK, , , , , , , , , , , , , , E, TAFB, HC, VI, 5, 2525 /////, , , GOES13, CSC, T, Position weighed toward AMSR-E pass at 2149Z

[/Div]