CPAC: LINDA - Post-Tropical

[aspen]

Why has the EPac IR imagery on Tropical Tidbits all of a sudden become so low-res?

[cycloneye]

Tropical Storm Linda Discussion Number 6
NWS National Hurricane Center Miami FL EP122021
1000 AM CDT Wed Aug 11 2021

Despite a continuation of moderate deep-layer shear, Linda is
becoming better organized. Upper-level outflow appears to be
expanding over the system, but even more notably, an 1109 UTC SSMIS
microwave pass revealed that a well-defined mid-level eye has
formed. Dvorak T-numbers have increased to T3.5 from both TAFB and
SAB, and given the significantly improved microwave structure,
Linda's initial intensity has been increased to 55 kt.

The latest fixes, including from the microwave pass, indicate that
Linda is moving a little faster and more south of due west, or
265/10 kt. This motion is being caused by a large mid-level ridge
located over Mexico, and the ridging is expected to maintain Linda
on a westward and then west-northwestward track for the next 5
days. There is very tight clustering among the track models for
the entire forecast period, and the updated NHC track forecast lies
very close to the HCCA consensus aid. This new forecast has been
shifted a bit to the left of the previous official forecast to
account for the updated initial position.

Linda will be moving through an environment of mixed favorability
for strengthening. On the positive side, sea surface temperatures
will hover around 28 degrees Celsius, mid-level moisture will
remain high, and upper-level divergence should be strong for the
next day or two. On the negative side, the deep-layer shear is not
expected to abate much for several days. That being said, the
system has still been able to strengthen, and the intensity models
support further intensification. The NHC intensity forecast
generally lies between the HCCA aid and the IVCN consensus, and
brings Linda to hurricane strength tonight with a peak intensity
occurring in 2-3 days.

FORECAST POSITIONS AND MAX WINDS

INIT 11/1500Z 13.8N 105.9W 55 KT 65 MPH
12H 12/0000Z 13.8N 106.9W 60 KT 70 MPH
24H 12/1200Z 14.3N 108.4W 70 KT 80 MPH
36H 13/0000Z 15.2N 110.1W 75 KT 85 MPH
48H 13/1200Z 16.2N 112.0W 80 KT 90 MPH
60H 14/0000Z 17.2N 114.1W 85 KT 100 MPH
72H 14/1200Z 17.9N 116.2W 85 KT 100 MPH
96H 15/1200Z 18.7N 120.0W 80 KT 90 MPH
120H 16/1200Z 19.1N 123.8W 65 KT 75 MPH

$$
Forecaster Berg

[InfernoFlameCat]

Linda is clearing an eye out rapidly.

[Yellow Evan]

Linda is clearing an eye out rapidly.

While also having remarkably warm convection. Needs to become more CDO dominant if it wants to become strong.

[Yellow Evan]

TXPZ23 KNES 111755
TCSENP

A. 12E (LINDA)

B. 11/1730Z

C. 13.5N

D. 105.5W

E. THREE/GOES-E

F. T4.0/4.0

G. IR/EIR/VIS

H. REMARKS...SYSTEM HAS A DISTINCT DOUBLE BANDING LIKE FEATURE THAT
CAN BE SEEN ON VISIBLE SATELLITE IMAGERY WHICH RESULTS TO 9/10 MAKING
THE DT 3.5. THE 24 HR DEVELOPING TREND IS DEVELOPING RAPIDLY. MET IS 3.5
AND PT IS 4.0. FT IS BASED ON PT DUE TO CLOUD FEATURES NOT BEING CLEAR
CUT FOR ACTIVE CONVECTION.

I. ADDL POSITIONS

NIL


...PATEL

[Yellow Evan]

EP, 12, 202108111800, 10, DVTS, CI, , 1350N, 10570W, , 2, 55, 2, 994, 2, DVRK, , , , , , , , , , , , , , E, TAFB, NR, VI, 3, 3535 /////, , , GOES17, CSC, T,

[Yellow Evan]

[Hurricane Mike]

Linda appears to have formed an eye, so it may be at or near hurricane strength. It also appears to have almost stalled briefly unless it's just a satellite illusion.

[Sciencerocks]

[Kingarabian]

12z Euro track for Linda means that this would be the highest EPAC ACE maker so far

[Yellow Evan]

* GFS version *
* EAST PACIFIC 2021 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* LINDA EP122021 08/11/21 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 60 66 72 76 81 88 90 88 86 84 81 75 70 67 62 59 54
V (KT) LAND 60 66 72 76 81 88 90 88 86 84 81 75 70 67 62 59 54
V (KT) LGEM 60 66 71 74 76 80 82 83 83 81 75 67 58 51 47 44 40
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 13 15 19 16 15 17 17 14 15 17 13 13 6 3 4 4 11
SHEAR ADJ (KT) 0 1 5 5 1 5 -3 0 -1 0 2 3 1 -2 0 0 -3
SHEAR DIR 24 4 5 2 352 2 43 49 57 73 53 64 53 359 275 199 244
SST (C) 28.3 28.2 28.3 28.5 28.8 28.4 28.0 28.6 28.0 27.3 26.2 25.5 24.4 24.3 24.9 23.6 23.4
POT. INT. (KT) 146 145 146 149 152 149 145 151 144 136 125 118 106 105 112 99 97
200 MB T (C) -53.4 -53.1 -53.6 -53.8 -53.6 -53.7 -53.8 -53.4 -53.2 -53.2 -52.8 -52.8 -52.6 -52.6 -52.6 -52.2 -52.2
200 MB VXT (C) 0.1 0.2 0.3 0.4 0.6 0.6 0.7 0.4 0.4 0.6 0.6 0.8 1.0 1.0 0.8 0.5 0.4
TH_E DEV (C) 5 5 5 4 5 5 5 5 4 4 3 3 3 3 2 2 1
700-500 MB RH 78 79 80 81 80 81 80 76 76 70 66 59 54 49 45 41 35
MODEL VTX (KT) 19 19 21 21 22 26 28 29 30 31 33 32 32 31 28 27 24
850 MB ENV VOR -66 -53 -44 -31 -12 -7 -10 -16 9 21 33 47 63 93 111 118 111
200 MB DIV 79 95 93 112 118 99 66 18 23 20 18 -4 16 -7 -7 1 -10
700-850 TADV -3 -4 -12 -11 -13 -25 -12 -2 0 2 1 3 2 0 1 6 11
LAND (KM) 589 618 653 661 673 746 755 781 893 978 1092 1240 1377 1496 1615 1744 1881
LAT (DEG N) 13.6 13.7 13.8 14.2 14.6 15.5 16.6 17.5 18.0 18.4 18.7 18.9 19.0 xx.x xx.x xx.x xx.x
LONG(DEG W) 105.9 106.6 107.3 108.1 108.9 110.7 112.7 114.8 116.9 118.8 120.6 122.5 124.5 xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT) 7 7 8 9 9 10 11 11 10 9 9 9 9 9 9 11 11
HEAT CONTENT 11 11 13 17 24 12 9 14 10 6 0 0 0 0 0 0 0

FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):255/ 8 CX,CY: -7/ -1
T-12 MAX WIND: 45 PRESSURE OF STEERING LEVEL (MB): 508 (MEAN=587)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 11.0 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 96.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 53.2

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 1. 2. 3. 4. 5. 5. 5. 6. 6. 5. 4. 3. 0. -2. -4. -7.
VERTICAL SHEAR MAG -1. -2. -2. -3. -3. -4. -4. -4. -5. -5. -5. -4. -2. -1. 0. 0.
VERTICAL SHEAR ADJ -0. -0. -1. -1. -2. -1. -1. -0. -0. -0. -0. -0. -0. -0. 0. 0.
VERTICAL SHEAR DIR 0. 0. 0. 1. 1. 1. 2. 2. 2. 2. 2. 1. 1. 0. 0. 0.
PERSISTENCE 3. 5. 5. 5. 4. 3. 2. 1. 1. 1. 1. 1. 1. 1. 1. 1.
200/250 MB TEMP. 0. 0. 0. -0. -0. -0. -1. -0. 0. 1. 2. 3. 5. 6. 7. 7.
THETA_E EXCESS -0. -0. -1. -1. -2. -2. -2. -3. -3. -4. -5. -5. -6. -6. -7. -9.
700-500 MB RH 0. 0. 0. 1. 1. 1. 1. 2. 2. 2. 2. 2. 2. 2. 2. 2.
MODEL VTX TENDENCY -0. 1. 1. 2. 5. 8. 12. 15. 17. 18. 17. 14. 12. 8. 7. 3.
850 MB ENV VORTICITY -0. -0. -0. -0. -0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 0. 0.
200 MB DIVERGENCE 0. 0. 1. 1. 2. 2. 3. 3. 3. 3. 2. 1. 1. 0. -0. -0.
850-700 T ADVEC 0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. -0. -1. -1. -1. -1.
ZONAL STORM MOTION 0. 0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. -0. -0. -0. 0.
STEERING LEVEL PRES -0. -0. -0. -1. -1. -1. -1. -1. -1. -1. -1. -2. -1. -1. -1. -0.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 0. 1. 1. 1. 2. 2. 2. 3. 3. 3.
GOES PREDICTORS 1. 1. 2. 2. 2. 2. 2. 2. 2. 2. 3. 3. 3. 2. 2. 2.
OCEAN HEAT CONTENT -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. 0. 0. 1. 2. 3. 4.
RI POTENTIAL 2. 4. 6. 10. 15. 14. 8. 2. -2. -5. -7. -8. -8. -8. -8. -8.
------------------------------------------------------------------------------
TOTAL CHANGE 6. 12. 16. 21. 28. 30. 28. 26. 24. 21. 15. 10. 7. 2. -1. -6.

CURRENT MAX WIND (KT): 60. LAT, LON: 13.6 105.9

** 2021 E. Pacific RI INDEX EP122021 LINDA 08/11/21 18 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) : 87.8 40.5 to 149.3 0.43 3.6
12 HR PERSISTENCE (KT) : 15.0 -22.0 to 44.0 0.56 5.3
D200 (10**7s-1) : 99.4 -33.0 to 159.5 0.69 5.3
850-200 MB SHEAR (KT) : 15.6 19.6 to 1.3 0.22 1.6
MAXIMUM WIND (KT) : 60.0 22.5 to 132.0 0.97 5.6
STD DEV OF IR BR TEMP : 11.0 37.8 to 2.1 0.75 3.9
BL DRY-AIR FLUX (W/M2) : 71.0 800.8 to -82.5 0.83 -4.8
HEAT CONTENT (KJ/CM2) : 15.2 2.7 to 106.7 0.12 0.5
%area of TPW <45 mm upshear : 0.0 56.6 to 0.0 1.00 1.6
2nd PC OF IR BR TEMP : -0.7 2.2 to -2.3 0.65 0.6

SHIPS Prob RI for 20kt/ 12hr RI threshold= 15% is 2.3 times climatological mean ( 6.3%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 38% is 3.0 times climatological mean (12.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 23% is 2.7 times climatological mean ( 8.6%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 23% is 3.7 times climatological mean ( 6.2%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 14% is 3.3 times climatological mean ( 4.2%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 20% is 2.9 times climatological mean ( 6.7%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 14% is 2.4 times climatological mean ( 5.9%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 9% is 1.9 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: 14.7% 38.0% 23.4% 22.8% 13.7% 19.6% 14.2% 9.1%
Logistic: 5.5% 13.7% 5.4% 3.3% 0.8% 4.5% 4.6% 4.7%
Bayesian: 2.1% 8.4% 6.1% 2.5% 0.3% 2.0% 0.4% 0.1%
Consensus: 7.4% 20.0% 11.6% 9.5% 4.9% 8.7% 6.4% 4.6%
DTOPS: 48.0% 68.0% 63.0% 47.0% 38.0% 46.0% 13.0% 7.0%

## ANNULAR HURRICANE INDEX (AHI) EP122021 LINDA 08/11/21 18 UTC ##
## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=4 NFAIL=3 ##
## AHI= 0 (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##

[Kingarabian]

Tropical Storm Linda Discussion Number 7
NWS National Hurricane Center Miami FL EP122021
300 PM MDT Wed Aug 11 2021

After the issuance of the previous advisory, Linda showed hints of
an eye in visible and infrared satellite imagery. That feature
is no longer apparent, and it appears that some dry air has
infiltrated into the circulation. That being said, earlier
microwave data indicated that the storm has a robust structure, and
new convection is developing near the center. The latest Dvorak
T-numbers are T3.5 from TAFB and T4.0 from SAB, and as a result,
the initial intensity is raised to 60 kt.

Linda has been losing latitude for the past 12-18 hours, and the
initial motion is south of due west, or 260/8 kt. The mid-level
ridge that is steering Linda extends over northern Mexico, reaching
as far as the Baja California peninsula. With Linda approaching
the western edge of the ridge, it should begin to gain latitude
again soon and turn toward the west-northwest by 24 hours. General
ridging should remain in control through the 5-day forecast period,
maintaining Linda on a west-northwestward or westward track with
minimal changes in speed. There were no noteworthy changes to the
guidance on this cycle, and the updated NHC track forecast is very
close to the HCCA consensus aid and not too different from the
previous forecast.

As mentioned earlier today, the environment ahead of Linda consists
of a mix of positives and negatives for intensification.
North-northeasterly shear of 15-20 kt is not expected to decrease
much in the coming days, which could allow some dry air to continue
penetrating into the circulation. On the other hand, Linda's track
will keep it over warm 28 degree Celsius waters for several days,
and strong upper-level divergence should support deep convective
development for another couple of days. Therefore, steady
strengthening is shown in the official forecast, which indicates a
slightly higher peak intensity compared to this morning's forecast.
An important note is that several dynamical and statistical models
are showing the intensity peaking near or at major hurricane
intensity in 2 to 3 days. However, given the presence of the shear,
I'd prefer to keep the forecast on the conservative side and only
nudge the forecast up for now. Future upward adjustments may
be required if Linda strengthens more in the short term than what is
shown in the official forecast. Weakening should occur by days 4
and 5 due to Linda moving over cooler waters.


FORECAST POSITIONS AND MAX WINDS

INIT 11/2100Z 13.6N 106.2W 60 KT 70 MPH
12H 12/0600Z 13.8N 107.2W 70 KT 80 MPH
24H 12/1800Z 14.5N 109.0W 80 KT 90 MPH
36H 13/0600Z 15.4N 110.9W 85 KT 100 MPH
48H 13/1800Z 16.4N 112.9W 90 KT 105 MPH
60H 14/0600Z 17.4N 115.0W 90 KT 105 MPH
72H 14/1800Z 18.1N 117.0W 90 KT 105 MPH
96H 15/1800Z 18.7N 120.9W 80 KT 90 MPH
120H 16/1800Z 18.9N 124.6W 65 KT 75 MPH

$$
Forecaster Berg

[Yellow Evan]

[Kingarabian]

Odd shear setup.

[Yellow Evan]

18z GFS coming in with more shear over Linda in the short term.

[Kingarabian]

This thing needs to move west ASAP. It'll do better once the shear turns easterly.

[Yellow Evan]

TXPZ23 KNES 112351
TCSENP

A. 12E (LINDA)

B. 11/2330Z

C. 13.6N

D. 106.5W

E. THREE/GOES-W

F. T3.5/4.0

G. IR/EIR/VIS/AMSR2

H. REMARKS...6/10 BANDING AROUND LLCC YIELDS DT OF 3.0. MET AGREES AND
PT IS 3.5. FT IS BASED ON PT DUE TO BANDING NOT BEING CLEAR-CUT.

I. ADDL POSITIONS

11/2036Z 13.6N 105.9W AMSR2


...MLEVINE

[Yellow Evan]

Okay this is a sheared mess.

[aspen]

https://cdn.discordapp.com/attachments/733552978572869632/875172764569440306/20210811.png

Okay this is a sheared mess.

At least it tried lol

[Kingarabian]

18z Euro doesn't drop it below 990mb until 36 hours from now. Very likely it struggles for the next day or so.