CPAC: LINDA - Post-Tropical

[Kingarabian]

Two hour old GMI pass
Still a little dry and ragged at this mid levels but ominous and well defined cyan ring:

[Kingarabian]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 13 AUG 2021 Time : 083035 UTC
Lat : 16:17:59 N Lon : 110:31:11 W


CI# /Pressure/ Vmax
4.7 / 974.9mb/ 82.2kt


Final T# Adj T# Raw T#
4.7 5.2 5.7

Estimated radius of max. wind based on IR : 10 km

Center Temp : -1.1C Cloud Region Temp : -63.1C

Scene Type : EYE

Subtropical Adjustment : OFF

Extratropical Adjustment : OFF

Positioning Method : ARCHER POSITIONING

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : MW AdjEnd
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

[Yellow Evan]

Assuming the eye can sustain itself, Linda should reach Category 2 status at the next package, and Category 3 by this afternoon or evening.

[Yellow Evan]

T4.5 until the DG junk goes away. OW eye surrounded by LG embedded in MG.

[Yellow Evan]

Seems clearing eye attempt #4 has failed though each attempt has been more successful than its last.

[Shell Mound]

Warmer SST to its west notwithstanding, given persistent northerly shear, Linda seems unlikely to become much stronger than 80 kt. The eye remains obscured.

[aspen]

Eye clearing attempt number…I lost count lol. Maybe Linda will finally find some luck with intensification.

[Subtrop]

EP, 12, 2021081312, , BEST, 0, 166N, 1112W, 90, 971, HU,

[Yellow Evan]

TXPZ23 KNES 131204
TCSENP

A. 12E (LINDA)

B. 13/1130Z

C. 16.6N

D. 111.1W

E. ONE/GOES-W

F. T4.5/4.5

G. IR/EIR/SWIR

H. REMARKS...SYSTEM HAS A DARK GRAY EYE THAT IS SURROUNDED BY A LG RING
TEMP AND IS EMBEDDED IN MG RESULTING TO AN EYE PATTERN DT OF 4.5. THE
24 HR DEVELOPING TREND RESULTS IN DEVELOPING RAPIDLY. MET IS 5.0 AND PT
IS 4.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...PATEL

[Yellow Evan]

* GFS version *
* EAST PACIFIC 2021 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* LINDA EP122021 08/13/21 12 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
V (KT) NO LAND 90 93 94 93 94 89 85 82 81 79 77 75 71 67 62 56 49
V (KT) LAND 90 93 94 93 94 89 85 82 81 79 77 75 71 67 62 56 49
V (KT) LGEM 90 93 94 94 92 87 80 74 68 63 60 59 56 50 43 36 30
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 15 13 8 6 6 6 5 6 6 6 2 4 3 2 5 6 4
SHEAR ADJ (KT) 1 0 1 2 0 3 2 0 -3 -4 0 1 1 6 3 4 4
SHEAR DIR 21 24 21 11 20 76 92 16 26 52 342 35 321 108 165 138 214
SST (C) 27.6 27.4 27.8 28.2 28.5 26.9 26.6 26.3 25.1 25.3 26.0 26.0 25.5 24.1 23.5 22.8 23.2
POT. INT. (KT) 141 139 143 147 150 133 129 126 114 116 123 123 119 104 98 91 96
200 MB T (C) -53.4 -53.4 -53.0 -53.2 -53.2 -52.7 -52.9 -52.6 -52.9 -52.5 -52.9 -52.3 -52.5 -52.5 -52.7 -52.5 -52.3
200 MB VXT (C) 0.2 0.6 0.7 0.7 0.5 0.4 0.6 0.6 0.8 0.5 0.6 0.5 0.8 0.5 0.6 0.5 0.3
TH_E DEV (C) 5 5 6 6 6 5 4 4 4 4 3 4 3 2 2 1 1
700-500 MB RH 78 76 75 71 71 66 63 57 56 53 53 49 47 43 42 37 31
MODEL VTX (KT) 23 25 25 24 26 25 26 26 27 28 27 27 26 23 20 15 11
850 MB ENV VOR -16 -15 -16 -24 -18 -10 -2 2 21 35 53 60 67 58 55 45 48
200 MB DIV 39 57 40 32 16 20 -19 3 -18 6 -19 -13 -32 0 -3 -1 -9
700-850 TADV -16 -8 -1 1 0 4 6 1 2 2 0 0 0 0 0 2 4
LAND (KM) 711 693 704 743 799 903 1046 1218 1419 1581 1734 1881 2060 2139 1955 1738 1494
LAT (DEG N) 16.6 17.1 17.6 18.0 18.3 18.8 18.9 18.7 18.4 18.1 17.8 17.9 18.3 xx.x xx.x xx.x xx.x
LONG(DEG W) 111.2 112.5 113.7 114.8 115.9 118.2 120.2 122.1 124.4 126.3 128.0 129.9 132.3 xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT) 12 13 12 11 11 10 9 10 11 9 9 10 11 10 11 13 14
HEAT CONTENT 8 7 8 10 11 4 2 1 0 0 0 0 0 0 0 0 0

FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):300/ 11 CX,CY: -9/ 6
T-12 MAX WIND: 75 PRESSURE OF STEERING LEVEL (MB): 577 (MEAN=587)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 11.5 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 87.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 4.4

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. 0. 0. -3. -9. -14. -20. -24. -28. -30. -32. -35. -38. -43. -48.
VERTICAL SHEAR MAG -1. -2. -2. -2. -1. 1. 3. 5. 7. 8. 9. 10. 10. 11. 11. 12.
VERTICAL SHEAR ADJ -0. -0. -0. -0. -1. -1. -1. -0. 0. 0. 0. 0. -0. -0. -0. -0.
VERTICAL SHEAR DIR 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -0. -1. -1. -1. -1.
PERSISTENCE 4. 5. 5. 5. 3. 2. 0. -1. -1. -1. -1. -2. -2. -2. -1. -1.
200/250 MB TEMP. 0. 0. -0. -0. 0. 0. 1. 2. 2. 3. 3. 4. 4. 5. 5. 5.
THETA_E EXCESS -0. -0. -0. -0. -1. -2. -2. -3. -4. -4. -5. -5. -6. -6. -8. -10.
700-500 MB RH 0. 0. 0. 0. 1. 1. 0. 0. 0. 0. 0. -0. -0. -1. -1. -2.
MODEL VTX TENDENCY 1. 1. 1. 2. 1. 3. 4. 6. 6. 5. 5. 3. -0. -4. -7. -10.
850 MB ENV VORTICITY -0. -0. -0. -0. -0. 0. 0. 1. 1. 1. 1. 0. 0. 0. 0. 0.
200 MB DIVERGENCE 0. 0. 0. -0. -0. -1. -1. -2. -3. -3. -3. -3. -2. -1. 0. 1.
850-700 T ADVEC 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1.
ZONAL STORM MOTION 0. 0. 0. 0. 1. 1. 1. 1. 1. 0. 0. 0. 0. 0. 0. -0.
STEERING LEVEL PRES -0. -0. -0. -0. -0. 0. 0. 0. 0. 0. 0. 0. -0. -0. -0. -0.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 1. 1. 1. 2. 2. 2. 3. 3. 3. 4.
GOES PREDICTORS -0. -0. -1. -1. -0. 1. 1. 1. 1. 1. 2. 1. 2. 2. 2. 3.
OCEAN HEAT CONTENT -0. -0. -0. -0. -0. -1. -1. -1. -0. -0. 0. 1. 2. 2. 4. 6.
RI POTENTIAL -0. -1. -1. -2. -3. -3. -2. -1. 1. 2. 3. 3. 3. 3. 3. 3.
------------------------------------------------------------------------------
TOTAL CHANGE 3. 4. 3. 4. -1. -5. -8. -9. -11. -13. -15. -19. -23. -28. -34. -40.

CURRENT MAX WIND (KT): 90. LAT, LON: 16.6 111.2

** 2021 E. Pacific RI INDEX EP122021 LINDA 08/13/21 12 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) : 54.0 40.5 to 149.3 0.12 0.9
12 HR PERSISTENCE (KT) : 15.0 -22.0 to 44.0 0.56 4.7
D200 (10**7s-1) : 36.8 -33.0 to 159.5 0.36 2.5
850-200 MB SHEAR (KT) : 9.5 19.6 to 1.3 0.55 3.6
MAXIMUM WIND (KT) : 90.0 22.5 to 132.0 0.57 2.9
STD DEV OF IR BR TEMP : 11.5 37.8 to 2.1 0.74 3.4
BL DRY-AIR FLUX (W/M2) : 272.8 800.8 to -82.5 0.60 -3.1
HEAT CONTENT (KJ/CM2) : 8.8 2.7 to 106.7 0.06 0.2
%area of TPW <45 mm upshear : 0.0 56.6 to 0.0 1.00 1.4
2nd PC OF IR BR TEMP : 0.7 2.2 to -2.3 0.33 0.3

SHIPS Prob RI for 20kt/ 12hr RI threshold= 12% is 1.9 times climatological mean ( 6.3%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 18% is 1.4 times climatological mean (12.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 17% is 2.0 times climatological mean ( 8.6%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 16% is 2.6 times climatological mean ( 6.2%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 10% is 2.4 times climatological mean ( 4.2%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 12% is 1.8 times climatological mean ( 6.7%)
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 ( 4.7%)

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: 11.7% 18.0% 16.8% 15.9% 10.1% 12.3% 0.0% 0.0%
Logistic: 3.8% 6.7% 3.1% 2.0% 0.7% 1.4% 0.5% 0.1%
Bayesian: 0.7% 2.1% 0.3% 0.1% 0.1% 0.0% 0.0% 0.0%
Consensus: 5.4% 8.9% 6.8% 6.0% 3.6% 4.6% 0.2% 0.0%
DTOPS: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%

## ANNULAR HURRICANE INDEX (AHI) EP122021 LINDA 08/13/21 12 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) ##

[Yellow Evan]

000
WTPZ42 KNHC 131444
TCDEP2

Hurricane Linda Discussion Number 14
NWS National Hurricane Center Miami FL EP122021
900 AM MDT Fri Aug 13 2021

Linda's structure has continued to improve since early this morning.
An eye was evident in longwave and shortwave IR imagery from GOES-17
and GOES-15 near 1200 UTC, though it has since become obscured by
cold cloud tops associated with eyewall convection. An earlier AMSR
overpass showed evidence of a ring of shallow to moderate
convection, often associated with rapidly intensifying cyclones.
Intensity estimates at 1200 UTC ranged from 77 kt to 97 kt, so the
initial intensity was set at 90 kt, in closest agreement with the
U-W CIMSS SATCON. It is worth noting that Linda's intensity is in a
range where estimates can range greatly, so confidence in that
assessment is not particularly high.

Computational problems with the GFS this morning has limited the
guidance available for the forecast, particularly with respect to
the intensity. Therefore, despite the higher initial intensity and
recent improvement in convective structure, the official intensity
forecast was only modestly increased in the short term. It does not
appear that wind shear will be a major inhibiting factor during the
next day or two. Environmental moisture and SSTs should also be
sufficient for further strengthening. The NHC forecast is a little
above the model consensus and previous forecast for the next
24-36 h. After that time, Linda should move over cooler SSTs which
should cause at least gradual weakening. By the end of the 5-day
period, the NHC forecast is in line with the consensus and identical
to the previous advisory.

Only small tweaks were made to the NHC track forecast. Linda
continues to move toward the west-northwest with an estimated
forward speed of 11 kt. The global models unanimously forecast that
a deep-layer ridge to the north of Linda will build over the
weekend, causing the hurricane to turn westward, and then
west-southwestward by early next week. Confidence in the track
forecast is quite high due to the agreement among the track models.

FORECAST POSITIONS AND MAX WINDS

INIT 13/1500Z 16.9N 111.8W 90 KT 105 MPH
12H 14/0000Z 17.6N 113.6W 100 KT 115 MPH
24H 14/1200Z 18.4N 115.9W 105 KT 120 MPH
36H 15/0000Z 18.8N 118.2W 105 KT 120 MPH
48H 15/1200Z 18.8N 120.3W 100 KT 115 MPH
60H 16/0000Z 18.6N 122.3W 90 KT 105 MPH
72H 16/1200Z 18.2N 124.2W 80 KT 90 MPH
96H 17/1200Z 17.5N 128.0W 65 KT 75 MPH
120H 18/1200Z 18.5N 132.0W 60 KT 70 MPH

$$
Forecaster Zelinsky

[Yellow Evan]

Still battling dry air but CDO trying to smooth out. Should be a major before too long.

[Sciencerocks]

[Yellow Evan]

Would explain the recent deepening.

[psyclone]

I like to pop in to the EPAC on occasion to see what a real storm looks like. Linda is impressive today

[Yellow Evan]

----- Current Analysis -----
Date : 13 AUG 2021 Time : 155032 UTC
Lat : 17:00:00 N Lon : 111:45:36 W


CI# /Pressure/ Vmax
5.5 / 959.1mb/102.0kt


Final T# Adj T# Raw T#
5.5 5.6 5.6

Estimated radius of max. wind based on IR : 14 km

Center Temp : +2.9C Cloud Region Temp : -61.4C

Scene Type : EYE

[Yellow Evan]

Still struggling to mix out dry air at times which seems to be allowing for only gradual intensification.

[dexterlabio]

Linda was almost written off as another bust but she made it.

[Kingarabian]

SAB up to 5.5/5.5. Should be enough for a major since ADT is at 5.5 as well.

[Yellow Evan]

TXPZ23 KNES 131800
TCSENP

A. 12E (LINDA)

B. 13/1730Z

C. 17.1N

D. 112.1W

E. ONE/GOES-W

F. T5.5/5.5

G. IR/EIR/VIS/SSMIS

H. REMARKS...SYSTEM HAS A WMG EYE TEMP SURROUNDED BY LG RING TEMP AND
IS EMBEDDED IN LG RESULTING IN AN EYE PATTERN DT OF 5.5. ADDITIONALLY,
SYSTEM HAS A DISTINCT COMMA LIKE SHAPE IN EIR IMAGERY. THE 24 HR
DEVELOPING TREND RESULTS IN DEVELOPING RAPIDLY. MET IS 5.5 AND PT IS
5.0. FT IS BASED ON DT.

I. ADDL POSITIONS

13/1203Z 16.6N 111.2W SSMIS


...PATEL

Too high. Embedded in MG not LG.