ATL: MARCO - Models

[Steve]

ICON at 18z (TT has only to 120 hours) shows 97L is likely to miss Central America to the NE. It could still hit Belize or the Yucatan. Or it might could go through the Channel. We'll have to wait until about 10:30 tonight to see the next 60 hours.

https://www.tropicaltidbits.com/analysi ... 618&fh=120

What’s really important is how it’s showing 97L as a developed TC by 120 hours out, as well as future-98L. Both systems could get bumped up to 70-80% in 5 days in the next TWO, or that of tomorrow morning.

What it doesn't show crossing the Caribbean is much strengthening. Relative (to the model) pressure output only drops about 5mb from the islands. I'm assuming that the forward speed is the biggest inhibitor in the 5 day timeframe.

Edit to say that the 12Z CMC is similar. Slow pressure drops toward the Western Caribbean then maybe dropping a little faster moving toward and into the Gulf.

[DestinHurricane]

GFS Para has weak TS Charley track

[cycloneye]

* GFS version *
* ATLANTIC 2020 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* INVEST AL972020 08/17/20 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 25 26 27 27 29 33 40 49 53 58 64 68 74 78 78 79 78
V (KT) LAND 25 26 27 27 29 33 40 49 53 58 64 68 74 78 78 79 78
V (KT) LGEM 25 25 26 26 27 28 30 32 33 36 42 48 55 62 67 68 67
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 7 6 5 7 8 13 11 14 1 8 7 8 10 13 20 20 22
SHEAR ADJ (KT) 2 6 7 7 5 0 -1 -4 -3 -5 -6 -4 -4 0 9 6 3
SHEAR DIR 295 296 296 306 286 304 291 308 151 294 173 236 176 213 199 238 218
SST (C) 28.6 28.9 29.0 29.1 29.2 29.3 29.4 29.2 29.0 29.3 29.2 29.9 29.9 30.4 30.1 30.7 30.8
POT. INT. (KT) 148 152 154 155 157 158 160 157 154 159 157 170 169 172 171 170 169
ADJ. POT. INT. 148 152 154 155 157 158 160 157 154 159 157 170 165 168 156 166 161
200 MB T (C) -52.5 -52.7 -52.9 -52.5 -52.5 -52.9 -52.5 -52.8 -52.3 -52.8 -52.4 -53.0 -52.2 -52.8 -51.8 -52.1 -51.6
200 MB VXT (C) 0.0 0.1 0.1 0.1 0.0 0.1 0.1 0.1 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
TH_E DEV (C) 7 6 6 8 8 9 9 8 10 9 9 9 9 9 9 9 10
700-500 MB RH 59 60 60 60 62 62 63 63 64 65 65 65 69 69 67 64 57
MODEL VTX (KT) 8 8 8 7 8 8 8 9 7 LOST LOST LOST LOST LOST LOST LOST LOST
850 MB ENV VOR 42 39 41 45 42 31 23 32 19 25 23 22 19 12 14 -4 3
200 MB DIV 28 47 32 44 51 46 47 26 36 47 73 70 94 72 54 25 27
700-850 TADV -11 -16 -12 -11 -7 -7 -8 0 1 0 2 3 2 3 3 6 5
LAND (KM) 765 734 607 459 327 253 318 298 273 267 123 208 325 137 83 196 323
LAT (DEG N) 12.4 12.5 12.5 12.6 12.7 13.0 13.5 14.0 14.8 15.6 16.6 17.7 19.1 xx.x xx.x xx.x xx.x
LONG(DEG W) 52.4 54.1 55.7 57.2 58.7 61.7 64.6 67.8 70.8 74.0 77.1 80.2 83.0 xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT) 17 16 15 15 15 14 15 16 15 16 15 16 14 11 8 8 5
HEAT CONTENT 33 47 54 60 59 45 41 65 74 92 74 92 138 80 41 43 46

FORECAST TRACK FROM TABM INITIAL HEADING/SPEED (DEG/KT):275/ 18 CX,CY: -17/ 2
T-12 MAX WIND: 25 PRESSURE OF STEERING LEVEL (MB): 699 (MEAN=620)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 17.8 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 77.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 12.1

INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
------------------------------------------------------------------------------
SAMPLE MEAN CHANGE 1. 2. 3. 4. 6. 8. 9. 10. 11. 12. 12. 13. 14. 14. 15. 16.
SST POTENTIAL -0. -1. -1. -1. 1. 7. 15. 21. 26. 29. 33. 38. 42. 44. 47. 47.
VERTICAL SHEAR MAG 1. 2. 3. 4. 6. 7. 7. 8. 8. 9. 9. 9. 9. 8. 6. 5.
VERTICAL SHEAR ADJ -0. -1. -1. -1. -2. -1. -0. 1. 1. 2. 2. 2. 2. 1. 1. 0.
VERTICAL SHEAR DIR -0. -0. -0. -1. -1. -2. -3. -3. -3. -3. -4. -5. -6. -6. -6. -6.
PERSISTENCE -0. -1. -1. -1. -0. -0. -0. -0. -0. 0. 0. 0. -0. -0. -1. -0.
200/250 MB TEMP. -0. -1. -1. -1. -2. -2. -2. -2. -2. -2. -2. -2. -2. -1. 0. 1.
THETA_E EXCESS -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. 0. 0. 0. 0. -0.
700-500 MB RH -0. -0. -0. -0. -1. -1. -2. -3. -3. -3. -3. -3. -4. -4. -4. -4.
MODEL VTX TENDENCY 0. -0. -1. -1. -1. -2. -1. -5. -6. -7. -8. -8. -8. -9. -9. -9.
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. 0. 0. 0. 0. 0. -0. -1. -1. -1. -2. -2.
850-700 T ADVEC 0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -0. -0. -0. -0. -0. -0.
ZONAL STORM MOTION -0. -0. 0. 0. 1. 1. 2. 2. 3. 4. 5. 5. 5. 5. 5. 5.
STEERING LEVEL PRES -0. -0. -0. -0. -1. -1. -0. -1. -1. -1. -2. -2. -1. -1. -1. -1.
DAYS FROM CLIM. PEAK -0. 0. 0. 0. 0. -0. -0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
GOES PREDICTORS 0. 1. 1. 1. 1. 0. -0. -0. -1. -1. -1. -0. 0. 1. 1. 1.
OCEAN HEAT CONTENT 0. 0. 0. 0. 0. 0. -0. -0. -0. 0. 1. 3. 3. 2. 1. 0.
RI POTENTIAL 0. 0. 1. 1. 1. 1. 0. 0. 0. -0. -0. -0. 0. 0. 0. 0.
------------------------------------------------------------------------------
TOTAL CHANGE 1. 2. 2. 4. 8. 15. 24. 28. 33. 39. 43. 49. 53. 53. 54. 53.

CURRENT MAX WIND (KT): 25. LAT, LON: 12.4 52.4

** 2020 ATLANTIC RI INDEX AL972020 INVEST 08/17/20 00 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
12 HR PERSISTENCE (KT) : 0.0 -49.5 to 33.0 0.60 5.0
850-200 MB SHEAR (KT) : 6.6 30.1 to 2.3 0.84 2.7
HEAT CONTENT (KJ/CM2) : 50.6 0.0 to 151.8 0.33 1.0
STD DEV OF IR BR TEMP : 17.8 36.6 to 2.8 0.56 2.0
MAXIMUM WIND (KT) : 25.0 22.5 to 137.5 0.07 0.1
2nd PC OF IR BR TEMP : -1.4 2.9 to -2.9 0.73 1.6
BL DRY-AIR FLUX (W/M2) : 130.8 895.4 to -55.0 0.80 1.8
POT = MPI-VMAX (KT) : 128.2 27.5 to 139.6 0.90 0.7
D200 (10**7s-1) : 40.4 -29.7 to 185.9 0.33 0.2
%area of TPW <45 mm upshear : 15.0 100.0 to 0.0 0.85 0.2

SHIPS Prob RI for 20kt/ 12hr RI threshold= 7% is 1.3 times climatological mean ( 5.0%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 25% is 2.3 times climatological mean (10.9%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 15% is 2.2 times climatological mean ( 6.9%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 11% is 2.7 times climatological mean ( 3.9%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times climatological mean ( 2.5%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 0% is 0.0 times climatological mean ( 4.6%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 14% is 3.1 times climatological mean ( 4.6%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 0% is 0.0 times climatological mean ( 5.2%)

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: 6.6% 25.2% 15.3% 10.6% 0.0% 0.0% 14.3% 0.0%
Logistic: 10.1% 29.0% 27.9% 9.0% 2.0% 6.9% 7.5% 14.8%
Bayesian: 0.6% 0.9% 2.7% 0.1% 0.1% 0.4% 3.0% 4.1%
Consensus: 5.8% 18.4% 15.3% 6.6% 0.7% 2.4% 8.3% 6.3%
DTOPS: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%

## ANNULAR HURRICANE INDEX (AHI) AL972020 INVEST 08/17/20 00 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) ##

** PROBLTY OF AT LEAST 1 SCNDRY EYEWL FORMTN EVENT AL972020 INVEST 08/17/2020 00 UTC **
TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48)
CLIMO(%) 0 0( 0) 0( 0) 0( 0) <-- PROB BASED ON INTENSITY ONLY
PROB(%) 0 0( 0) 0( 0) 0( 0) <-- FULL MODEL PROB (RAN NORMALLY)

** DSHIPS INTENSITY FORECAST ADJUSTED RELATIVE TO ONSET OF ERC WEAKENING PHASE **
TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168
>24HR AGO (DSHIPS) 25 26 27 27 29 33 40 49 53 58 64 68 74 78 78 79 78
18HR AGO 25 24 25 25 27 31 38 47 51 56 62 66 72 76 76 77 76
12HR AGO 25 22 21 21 23 27 34 43 47 52 58 62 68 72 72 73 72
6HR AGO 25 19 16 15 17 21 28 37 41 46 52 56 62 66 66 67 66
NOW CURRENT INTENSITY < 83 KT
IN 6HR INTENSITY IN 6HR < 83 KT
IN 12HR INTENSITY IN 12HR < 83 KT

[Evil Jeremy]

There is a trof in the gulf that will likely bring this north eventually.

https://cdn1.bbcode0.com/uploads/2020/8 ... 6-full.png

No thanks. I would not like to play this same game again already.

[gatorcane]

Both the Euro and GFS don’t do a lot with this even in the Western Caribbean. In fact the GFS looks a bit more organized but still weak. Conditions look like they should be favorable there but nothing suggests anything significant with this invest just yet:

[stormlover2013]

Ensembles, pay to attention to them, there is a reason why nhc has bumped it to 50 percent

[gatorcane]

Ensembles, pay to attention to them, there is a reason why nhc has bumped it to 50 percent

Yes I look at those too. The 12Z Euro ensembles are all weak too. Looks like they are in the 1003MB to 1009MB range in the Western Caribbean with one in the 990s. 50% chance of development could mean a tropical storm or a depression not necessarily a hurricane. In this case NHC states a depression.

[stormlover2013]

Ensembles, pay to attention to them, there is a reason why nhc has bumped it to 50 percent

Yes I look at those too. The 12Z Euro ensembles are all weak too. Looks like they are in the 1003MB to 1009MB range in the Western Caribbean with one in the 990s. 50% chance of development could mean a tropical storm or a depression not necessarily a hurricane. In this case NHC states a depression.

Euro and other models don’t really do get with the strength till something forms

[cycloneye]

[sma10]

https://i.imgur.com/3z9kppI.png

Yep - notice the shallower the system, the further SW and quicker the motion.

[Steve]

ICON is coming in. It’s out to 57. I’m not on my pc so I can’t link images at the moment. Looks to be only slowly organizing so far. This run will take 97L through landfall, so it’s the first hint from the 00Z models. Maybe it is on a slightly farther north track so far? Sort of toward Jamaica?

Edit it goes south of Jamaica by 72 hours.
https://www.tropicaltidbits.com/analysi ... 1700&fh=57

[AutoPenalti]

In before magic trough suddenly appears literally out of NOWHERE and makes us bite our nails again.

[eastcoastFL]

[eastcoastFL]

ICON is coming in. It’s out to 57. I’m not on my pc so I can’t link images at the moment. Looks to be only slowly organizing so far. This run will take 97L through landfall, so it’s the first hint from the 00Z models. Maybe it is on a slightly farther north track so far? Sort of toward Jamaica?

Edit it goes south of Jamaica by 72 hours.
https://www.tropicaltidbits.com/analysi ... 1700&fh=57

Here it is at 120 hrs

[eastcoastFL]

Ensembles, pay to attention to them, there is a reason why nhc has bumped it to 50 percent

Yes I look at those too. The 12Z Euro ensembles are all weak too. Looks like they are in the 1003MB to 1009MB range in the Western Caribbean with one in the 990s. 50% chance of development could mean a tropical storm or a depression not necessarily a hurricane. In this case NHC states a depression.

Euro and other models don’t really do get with the strength till something forms

Have any models actually been on point with intensity this year or even last year? A few years ago they were over doing intensity and this year and last year they seem to be under doing it. I have zero confidence in modeling intensity right now.

[Steve]

In before magic trough suddenly appears literally out of NOWHERE and makes us bite our nails again.

It’s on the map. First one is now. Next one is mid-late week. System is still in the Catlrivbean.

https://www.tropicaltidbits.com/analysi ... 700&fh=114

[Steve]

ICON at 180. No landfall. Relatively weak. Maybe moving toward Panama City-ish?

[Steve]

GFS starts out much farther south and pinballs into Honduras before jumping up into the Yucatan Channel and to the NE tip of the Yucatan peninsula. Nice to see if finally caught on that we might have low pressure in the Gulf next week. It also shows a weaker solution

[Steve]

GFS treats 97L as a sacrificial lamb for the next system which it has coming up toward the YC at 994mb in low-res.

[Steve]

Finally GFS peters this out as it heads toward Brownsville.