EPAC: HILDA - Post-Tropical

[cycloneye]

TD or TS on Friday or Saturday.

Showers and thunderstorms are gradually becoming better organized
in association with an area of low pressure located about 600 miles
southwest of the coast of southwestern Mexico. Environmental
conditions are conducive for continued development, and a tropical
depression or tropical storm is expected to form during the next
day or two while the system moves west-northwestward at 10 to 15
mph. For more information on this system, please see High Seas
forecasts issued by the NOAA Tropical Analysis and Forecast Branch.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[Kingarabian]

[Sciencerocks]

[Yellow Evan]

TXPZ29 KNES 292354
TCSENP

A. TROPICAL DISTURBANCE (90E)

B. 29/2330Z

C. 11.1N

D. 108.0W

E. THREE/GOES-E

F. T2.0/2.0

G. IR/EIR/VIS

H. REMARKS...5/10 BANDING AROUND THE LLCC YIELDS A DT OF 2.5. MET IS
EQUAL TO 1.5 AND PT IS EQUAL TO 2.0. FT IS BASED ON PT DUE TO INCONSISTENT
CONVECTION MAKING THE BANDING NOT CLEAR CUT.

I. ADDL POSITIONS

NIL


...TUGGLE

[Yellow Evan]

18z GFS having a 3 way interaction with both 90E and the disturbance to its east moving north as a result. More realistic than the ECMWF which moves this too fast.

[Yellow Evan]

* GFS version *
* EAST PACIFIC 2021 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* INVEST EP902021 07/30/21 00 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
V (KT) NO LAND 30 32 33 36 39 48 56 63 70 70 71 72 71 69 66 64 59
V (KT) LAND 30 32 33 36 39 48 56 63 70 70 71 72 71 69 66 64 59
V (KT) LGEM 30 32 33 35 36 39 43 46 50 54 57 59 59 59 59 57 52
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 5 7 7 5 1 10 16 18 21 17 15 13 6 7 8 12 11
SHEAR ADJ (KT) 0 2 1 1 5 2 -4 -8 -9 -6 -3 -3 -4 -4 -5 -4 -6
SHEAR DIR 348 344 335 323 354 71 92 70 72 62 52 54 49 354 18 19 31
SST (C) 28.4 28.8 28.8 28.6 28.6 28.9 27.7 27.1 27.8 26.5 26.3 26.5 26.0 25.5 25.8 25.7 24.8
POT. INT. (KT) 148 153 153 151 151 154 142 136 143 128 125 127 122 117 120 119 109
200 MB T (C) -52.6 -52.7 -53.0 -52.9 -52.5 -53.5 -52.9 -53.3 -52.6 -53.1 -52.5 -52.9 -52.2 -52.5 -51.9 -52.1 -51.8
200 MB VXT (C) 0.0 0.0 0.1 0.2 0.2 0.1 0.1 0.3 0.2 0.2 0.3 0.3 0.4 0.5 0.4 0.4 0.3
TH_E DEV (C) 5 5 5 4 4 3 3 2 2 2 2 1 1 1 2 1 2
700-500 MB RH 69 72 75 77 79 83 84 82 79 77 72 71 72 67 64 61 60
MODEL VTX (KT) 9 9 9 10 11 14 15 16 19 19 20 23 23 24 25 25 23
850 MB ENV VOR -30 -29 -24 -15 -8 4 25 42 63 68 76 66 40 37 29 31 0
200 MB DIV 5 19 32 68 99 54 97 95 106 88 66 65 56 51 49 -9 -27
700-850 TADV -5 -9 -6 -7 -5 -5 -1 -4 -6 -6 -5 -9 -6 -7 -7 -7 -3
LAND (KM) 902 946 990 1045 1111 1200 1284 1415 1559 1684 1775 1830 1852 1919 2026 2116 2188
LAT (DEG N) 11.8 xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x xx.x
LONG(DEG W) 108.4 xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT) 10 10 11 12 12 12 11 12 11 9 7 5 6 7 7 7 6
HEAT CONTENT 19 32 29 13 11 18 6 3 14 1 0 1 0 0 0 0 0

FORECAST TRACK FROM OFPI INITIAL HEADING/SPEED (DEG/KT):275/ 9 CX,CY: -8/ 1
T-12 MAX WIND: 25 PRESSURE OF STEERING LEVEL (MB): 600 (MEAN=587)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 19.9 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 56.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 19.2

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. -2. -3. -4. -4.
SST POTENTIAL 0. 0. 1. 2. 6. 11. 17. 22. 25. 26. 27. 27. 27. 27. 26. 26.
VERTICAL SHEAR MAG 1. 1. 2. 3. 5. 4. 3. 1. -1. -1. -2. -0. 1. 2. 1. 1.
VERTICAL SHEAR ADJ -0. -0. -0. -1. -1. -1. 0. 1. 1. 0. 0. 0. 0. 0. 1. 1.
VERTICAL SHEAR DIR -0. -0. -1. -1. 1. 3. 4. 6. 7. 7. 7. 7. 6. 4. 4. 3.
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. -2. -3. -3. -3. -3. -2. -1. -0. 1. 1.
THETA_E EXCESS -0. -0. -1. -1. -2. -3. -5. -6. -7. -8. -8. -9. -10. -10. -12. -14.
700-500 MB RH 0. 0. 0. 0. 1. 1. 1. 2. 2. 2. 2. 2. 2. 3. 4. 5.
MODEL VTX TENDENCY 0. 0. 1. 2. 4. 6. 9. 13. 14. 16. 18. 17. 16. 15. 14. 11.
850 MB ENV VORTICITY -0. -0. -0. -0. -0. 0. 0. 0. 0. 0. 0. -0. -0. -0. -0. 0.
200 MB DIVERGENCE -0. -0. -0. 0. 0. 1. 2. 3. 4. 4. 4. 3. 2. 1. -0. -1.
850-700 T ADVEC 0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. -1. -1. -1. -2. -2.
ZONAL STORM MOTION 0. 0. 0. 0. 0. 1. 1. 0. 0. 0. 0. 0. 0. 0. 0. -0.
STEERING LEVEL PRES 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 1. 1. 0. 0. 0. 0.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -0. -0.
GOES PREDICTORS -0. -0. -0. -0. -1. -1. -2. -3. -3. -3. -4. -4. -5. -4. -3. -3.
OCEAN HEAT CONTENT 0. 0. 0. 0. 0. -0. -0. -0. -0. -0. 0. 0. 1. 2. 3. 4.
RI POTENTIAL 0. 1. 1. 2. 2. 2. 1. 0. -0. -0. -0. -0. -0. -0. -0. -0.
------------------------------------------------------------------------------
TOTAL CHANGE 2. 3. 6. 9. 18. 26. 33. 40. 40. 41. 42. 41. 39. 36. 34. 29.

CURRENT MAX WIND (KT): 30. LAT, LON: 11.8 108.4

** 2021 E. Pacific RI INDEX EP902021 INVEST 07/30/21 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
POT = MPI-VMAX (KT) : 121.3 40.5 to 149.3 0.74 5.7
12 HR PERSISTENCE (KT) : 5.0 -22.0 to 44.0 0.41 3.6
D200 (10**7s-1) : 44.6 -33.0 to 159.5 0.40 2.9
850-200 MB SHEAR (KT) : 5.3 19.6 to 1.3 0.78 5.4
MAXIMUM WIND (KT) : 30.0 22.5 to 132.0 0.21 1.1
STD DEV OF IR BR TEMP : 19.9 37.8 to 2.1 0.50 2.4
BL DRY-AIR FLUX (W/M2) : 50.8 800.8 to -82.5 0.85 -4.6
HEAT CONTENT (KJ/CM2) : 20.8 2.7 to 106.7 0.17 0.7
%area of TPW <45 mm upshear : 0.0 56.6 to 0.0 1.00 1.5
2nd PC OF IR BR TEMP : 0.5 2.2 to -2.3 0.38 0.3

SHIPS Prob RI for 20kt/ 12hr RI threshold= 8% is 1.3 times climatological mean ( 6.3%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 21% is 1.7 times climatological mean (12.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 19% is 2.2 times climatological mean ( 8.6%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 18% is 2.9 times climatological mean ( 6.2%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times climatological mean ( 4.2%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 18% is 2.7 times climatological mean ( 6.7%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 16% is 2.6 times climatological mean ( 5.9%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 13% is 2.8 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: 8.3% 21.3% 19.1% 18.2% 0.0% 18.4% 15.6% 13.0%
Logistic: 1.7% 14.8% 6.8% 3.2% 0.4% 6.3% 6.1% 11.7%
Bayesian: 0.2% 4.9% 0.8% 0.1% 0.0% 0.3% 0.2% 0.1%
Consensus: 3.4% 13.7% 8.9% 7.2% 0.1% 8.3% 7.3% 8.3%
DTOPS: 0.0% 5.0% 2.0% 1.0% 1.0% 3.0% 12.0% 33.0%

## ANNULAR HURRICANE INDEX (AHI) EP902021 INVEST 07/30/21 00 UTC ##
## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=6 NFAIL=1 ##
## AHI= 0 (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##

[Yellow Evan]

[Yellow Evan]

An area of low pressure located about 650 miles southwest of the
coast of southwestern Mexico continues to produce showers and
thunderstorms. This system is gradually becoming better organized,
but the latest satellite wind data shows that the low lacks a
well-defined center. Environmental conditions are conducive for
further development, and a tropical depression or tropical storm is
expected to form by Saturday while the system moves west-
northwestward at 10 to 15 mph. For more information on this system,
please see High Seas forecasts issued by the NOAA Tropical Analysis
and Forecast Branch.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[Sciencerocks]

[Yellow Evan]

Showers and thunderstorms continue to show signs of organization in
association with an elongated area of low pressure located about 650
miles southwest of the coast of southwestern Mexico. Environmental
conditions are conducive for development, and a tropical depression
or tropical storm is expected to form later today or Saturday while
the system moves west-northwestward at 10 to 15 mph. For more
information on this system, please see High Seas forecasts issued by
the NOAA Tropical Analysis and Forecast Branch.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[Yellow Evan]

TXPZ29 KNES 301203
TCSENP

A. TROPICAL DISTURBANCE (90E)

B. 30/1130Z

C. 11.9N

D. 111.6W

E. FIVE/GOES-E

F. T1.5/2.0

G. IR/EIR/SWIR

H. REMARKS...0921Z AMSR2 SHOWED A POORLY DEFINED LOW LEVEL
CIRCULATION. IT ALSO SUGGESTED A POSSIBLE CENTER FARTHER WEST AND SLIGHTLY
NORTH OF PREVIOUS TRACK SO 1130Z FIX REPRESENTS A REPOSITIONING OF THE
CENTER. 3/10 BANDING RESULTS IN A DT OF 1.5. PT AGREES WHILE MET IS
2.0 BASED ON SLOW DEVELOPMENT OVER THE LAST 24 HOURS. FT IS BASED ON PT
BECAUSE BANDING WAS NOT CLEAR CUT.

I. ADDL POSITIONS

NIL


...TURK

[Yellow Evan]

6z GFS still keeping 90E and 99E separate.

[Yellow Evan]

0z ECMWF keeps 90E and the disturbance to its east separate now.

[Yellow Evan]

No northerly wind.

[cycloneye]

Satellite wind data indicate that tropical-storm-force winds are
occuring on the east side of an elongated low pressure system
located about 700 miles south-southwest of the southern tip of the
Baja California peninsula. Any improvement in the organization of
the circulation would lead to the system being designated a
tropical storm, and that is expected to occur later today or
Saturday. For more information on this system, please see
High Seas forecasts issued by the NOAA Tropical Analysis and
Forecast Branch.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[aspen]

https://cdn.discordapp.com/attachments/733552978572869632/870720843683098675/image0.jpg

No northerly wind.

It is getting quite close despite being broad. That large size could make it difficult for “future Hilda” to intensify, similar to Guillermo.

[Yellow Evan]

TXPZ29 KNES 301800
TCSENP

A. TROPICAL DISTURBANCE (90E)

B. 30/1730Z

C. 12.8N

D. 113.0W

E. FIVE/GOES-W

F. T1.0/1.5

G. IR/EIR/VIS/GMI

H. REMARKS...CENTER IS REPOSITIONED BASED ON EXPOSED CIRCULATION CENTER
NW OF CONVECTION. SLIGHTLY MORE THAN 2/10 BANDING RESULTS IN A DT OF
1.0. MET AND PT ARE ALSO 1.0. FT IS BASED ON DT.

I. ADDL POSITIONS

30/1205Z 13.5N 111.6W GMI


...TURK

[Yellow Evan]

There’s an upper trough shearing both this and 99E and until that goes away, I wouldn’t expect much development.

[Sciencerocks]

[aspen]

18z BT is up to 40 kt. This is one of the strongest invests I’ve seen, so close to going straight to TS status.