ATL: FERNAND - Models

[TomballEd]

https://ftp.nhc.noaa.gov/atcf/stext/25082112AL9025_ships.txt

* GFS version *
* ATLANTIC 2025 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC CLIMO USED *
* INVEST AL902025 08/21/25 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 25 27 30 32 36 43 54 63 71 76 84 87 89 89 83 74 66
V (KT) LAND 25 27 30 32 36 43 54 63 71 76 84 87 89 89 83 74 66
V (KT) LGEM 25 26 27 29 31 36 41 47 53 59 67 74 78 78 72 62 55
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 8 5 4 4 2 2 9 4 7 4 13 15 12 14 14 15 15
SHEAR ADJ (KT) -4 -3 -4 -2 3 1 1 0 1 2 -2 -5 1 2 -2 0 -1
SHEAR DIR 180 176 162 186 228 121 272 291 327 352 19 73 73 74 55 57 81
SST (C) 28.6 28.8 28.8 28.9 28.7 28.5 28.4 28.9 28.9 29.2 29.5 29.7 29.6 29.3 28.2 28.2 27.2
POT. INT. (KT) 147 150 150 151 148 144 142 149 149 154 160 164 162 157 140 141 128
200 MB T (C) -53.7 -53.4 -53.3 -53.4 -53.3 -53.5 -53.6 -53.1 -53.2 -52.6 -52.6 -52.1 -52.7 -53.0 -53.5 -54.0 -54.2
200 MB VXT (C) -0.1 -0.1 -0.2 -0.3 -0.5 -0.5 -0.4 -0.3 0.2 0.3 0.7 0.7 0.4 0.0 0.0 0.0 0.0
TH_E DEV (C) 9 9 10 10 10 11 11 11 11 11 11 11 9 8 7 8 6
700-500 MB RH 54 55 57 58 56 54 55 56 55 54 56 59 64 64 64 62 65
MODEL VTX (KT) 8 8 7 7 8 9 12 13 15 16 19 21 22 23 21 14 9
850 MB ENV VOR 49 40 31 16 -5 -31 -58 -65 -91 -88 -90 -77 -38 -90 -76 -34 -36
200 MB DIV 31 23 14 -1 -14 29 28 32 17 23 2 1 19 49 30 39 40
700-850 TADV 0 -2 -1 4 5 0 5 2 3 7 1 -1 4 0 6 10 14
LAND (KM) 607 486 345 226 183 215 283 456 597 731 897 1110 1209 1269 1223 1148 1029
LAT (DEG N) 17.1 17.5 18.0 18.5 19.1 20.2 21.3 22.7 24.1 25.6 27.2 28.9 30.5 xx.x xx.x xx.x xx.x
LONG(DEG W) 55.5 57.1 58.5 59.8 60.9 62.7 64.4 65.6 66.5 66.9 66.8 65.8 64.3 xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT) 15 15 14 13 12 9 10 8 9 7 9 10 10 10 11 13 15
HEAT CONTENT 46 49 53 54 53 53 55 47 42 40 31 26 20 15 12 9 7

FORECAST TRACK FROM TABM INITIAL HEADING/SPEED (DEG/KT):280/ 15 CX,CY: -14/ 3
T-12 MAX WIND: 15 PRESSURE OF STEERING LEVEL (MB): 622 (MEAN=620)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 17.5 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 81.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 12.6

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. 11. 12. 12. 13. 13. 14. 15. 15. 16.
SST POTENTIAL 0. -0. 0. 1. 4. 9. 15. 20. 24. 26. 29. 31. 32. 31. 30. 27.
VERTICAL SHEAR MAG 1. 2. 4. 5. 7. 9. 11. 13. 14. 13. 12. 11. 10. 9. 9. 10.
VERTICAL SHEAR ADJ 0. 1. 1. 1. 1. 1. 1. 1. 1. 2. 2. 2. 2. 2. 2. 2.
VERTICAL SHEAR DIR -0. -0. -0. -1. -1. -1. -2. -2. -1. -1. -1. -2. -2. -2. -3. -3.
PERSISTENCE -0. -1. -1. -1. -0. -0. -0. -0. -0. 0. 0. 0. -0. -0. -0. -0.
200/250 MB TEMP. -0. -0. -1. -1. -1. -0. -0. -0. -1. -1. -1. -1. -1. 0. 1. 1.
THETA_E EXCESS 0. 0. 0. 0. 1. 1. 1. 1. 2. 2. 1. 1. 1. 1. 0. 0.
700-500 MB RH 0. -0. -0. -0. -0. -0. -1. -1. -1. -1. -1. -2. -2. -3. -3. -3.
MODEL VTX TENDENCY -0. -0. -1. -0. -0. 2. 3. 6. 6. 10. 11. 12. 11. 8. -1. -8.
850 MB ENV VORTICITY 0. 0. 0. -0. -0. -1. -2. -2. -3. -3. -4. -4. -5. -5. -6. -6.
200 MB DIVERGENCE -0. -0. -0. -1. -1. -1. -1. -1. -1. -0. 0. 0. 1. 1. 1. 1.
850-700 T ADVEC 0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. 0.
ZONAL STORM MOTION -0. -0. 0. 0. 1. 1. 1. 1. 1. 1. 2. 2. 2. 2. 2. 2.
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. -0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
GOES PREDICTORS 1. 1. 1. 1. 0. -0. -0. -0. -1. -1. -1. -0. 0. 1. 1. 1.
OCEAN HEAT CONTENT 0. 0. 0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. -0. -0. -0.
RI POTENTIAL 0. 0. 1. 1. 1. 1. 1. 0. 0. -0. -0. -0. -0. -0. -0. -0.
--------------------------------------------------------------------------------------------
TOTAL CHANGE 3. 5. 7. 11. 18. 29. 38. 46. 51. 59. 62. 64. 64. 58. 49. 41.

CURRENT MAX WIND (KT): 25. LAT, LON: 17.1 55.5

** 2025 ATLANTIC RI INDEX AL902025 INVEST 08/21/25 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
12 HR PERSISTENCE (KT) : 0.0 -49.5 to 33.0 0.60 3.8
MULTI-LAYER SHEAR (KT) : 11.0 46.9 to 6.8 0.90 3.0
HEAT CONTENT (KJ/CM2) : 51.0 0.0 to 155.1 0.33 0.9
STD DEV OF IR BR TEMP : 17.5 36.6 to 2.8 0.57 1.4
MAXIMUM WIND (KT) : 25.0 22.5 to 137.5 0.07 0.1
2nd PC OF IR BR TEMP : 0.6 2.9 to -3.0 0.39 0.5
BL DRY-AIR FLUX (W/M2) : 150.4 895.4 to -69.3 0.77 1.2
D200 (10**7s-1) : 10.6 -29.7 to 189.2 0.18 0.2
POT = MPI-VMAX (KT) : 120.3 30.0 to 151.8 0.74 0.7
%area of TPW <45 mm upshear : 1.5 100.0 to 0.0 0.99 -0.1

SHIPS Prob RI for 20kt/ 12hr RI threshold= 3% is 0.7 times climatological mean ( 4.9%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 17% is 1.6 times climatological mean (10.9%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 12% is 1.7 times climatological mean ( 6.8%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 9% is 2.3 times climatological mean ( 3.9%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times climatological mean ( 2.4%)
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 3.0 times climatological mean ( 4.7%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 0% is 0.0 times climatological mean ( 5.3%)

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: 3.5% 17.2% 11.7% 8.8% 0.0% 0.0% 14.2% 0.0%
Logistic: 12.2% 37.4% 28.3% 18.3% 9.6% 32.9% 32.9% 25.5%
Bayesian: 4.3% 22.0% 17.2% 2.1% 1.2% 11.3% 13.4% 3.4%
Consensus: 6.6% 25.5% 19.1% 9.7% 3.6% 14.7% 20.2% 9.7%
DTOPS: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%
SDCON: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%

## ANNULAR HURRICANE INDEX (AHI) AL902025 INVEST 08/21/25 12 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 AL902025 INVEST 08/21/2025 12 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 27 30 32 36 43 54 63 71 76 84 87 89 89 83 74 66
18HR AGO 25 24 27 29 33 40 51 60 68 73 81 84 86 86 80 71 63
12HR AGO 25 22 21 23 27 34 45 54 62 67 75 78 80 80 74 65 57
6HR AGO 25 19 16 15 19 26 37 46 54 59 67 70 72 72 66 57 49
NOW CURRENT INTENSITY < 83 KT
IN 6HR INTENSITY IN 6HR < 83 KT
IN 12HR INTENSITY IN 12HR < 83 KT

[USTropics]

This will be interesting to continue following, this is the northern wave axis that models initially developed last week. This should recurve east of Erin, but could potentially be a threat to our members in Bermuda. GFS operational and its ensembles are the more western outlier here (supported by the icon), and develops a very compact 'microcane' on the 6z forecast:



Meanwhile, the other operational models are to the east of Bermuda and much weaker. I will add to this though, while the ECMWF ensembles are 'lukewarm' on development, the members that are showing strong hurricanes take a similar path to the GFS operational in the last 2 runs (closer to Bermuda):

00z ECMWF ensembles


06z ECMWF ensembles

[ElectricStorm]

12z GFS has 965mb right over Bermuda, starts developing in less than 48 hours

[Travorum]

Graphical SHIPS forecast:

[Teban54]

[Hurricane2022]

 https://x.com/WeatherProf/status/1958702209270522223

[Teban54]

Intensity guidance has trended downwards over the past day. Some of the hurricane models (not shown here explicitly) are still calling for a Cat 1, however.