* GFS version * * ATLANTIC 2023 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * SEVENTEEN AL172023 09/23/23 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 35 38 43 46 49 55 59 61 61 66 69 70 70 72 71 75 74 V (KT) LAND 35 38 43 46 49 55 59 61 61 66 69 70 70 72 71 75 74 V (KT) LGEM 35 38 40 42 44 48 50 52 55 58 62 63 63 63 62 62 63 Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP SHEAR (KT) 4 5 6 7 9 11 9 12 18 20 25 27 29 25 23 16 14 SHEAR ADJ (KT) 2 3 5 4 1 4 10 13 8 4 0 1 -4 2 0 3 2 SHEAR DIR 253 251 259 246 239 253 264 243 238 239 234 229 219 227 235 263 255 SST (C) 28.5 28.7 29.1 28.8 28.8 29.0 29.2 29.3 29.5 29.5 29.7 29.5 29.2 29.4 28.7 27.5 26.8 POT. INT. (KT) 145 148 155 149 149 152 154 156 159 160 163 160 154 157 145 128 120 200 MB T (C) -52.3 -52.4 -52.6 -52.5 -52.2 -52.4 -52.4 -52.5 -52.3 -52.4 -52.3 -52.7 -52.9 -53.1 -53.0 -53.2 -53.4 200 MB VXT (C) 0.0 0.0 0.0 0.1 0.2 0.2 0.3 0.3 0.3 0.4 0.7 0.9 0.6 0.7 1.0 1.2 0.8 TH_E DEV (C) 9 9 9 9 9 9 10 9 9 9 9 9 9 8 8 8 7 700-500 MB RH 56 57 58 56 58 57 57 63 63 63 60 56 53 53 54 58 56 MODEL VTX (KT) 14 15 16 16 15 16 15 15 14 18 20 21 22 23 23 26 26 850 MB ENV VOR 62 65 56 53 43 43 35 36 45 59 66 65 47 36 19 17 9 200 MB DIV 56 63 63 36 49 74 76 35 30 38 34 38 20 26 36 -3 11 700-850 TADV 0 -1 3 1 0 -2 0 -3 0 0 2 4 4 3 5 9 8 LAND (KM) 1841 1734 1635 1556 1473 1340 1177 1050 940 915 876 931 1072 1218 1362 1490 1616 LAT (DEG N) 15.6 15.7 15.7 15.8 15.8 16.0 16.4 16.8 17.5 18.7 20.3 22.1 23.8 xx.x xx.x xx.x xx.x LONG(DEG W) 39.1 40.6 42.0 43.3 44.5 47.0 49.0 50.4 51.9 53.1 53.9 54.2 53.8 xxx.x xxx.x xxx.x xxx.x STM SPEED (KT) 13 14 13 12 12 11 8 7 8 8 9 9 8 7 6 5 6 HEAT CONTENT 35 38 58 48 39 35 53 47 44 53 63 59 41 36 29 12 3 FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):270/ 12 CX,CY: -11/ 0 T-12 MAX WIND: 30 PRESSURE OF STEERING LEVEL (MB): 669 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 15.9 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 69.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 23.2 INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE 6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168 -------------------------------------------------------------------------------------------- SAMPLE MEAN CHANGE 1. 2. 3. 4. 6. 7. 9. 10. 10. 11. 11. 12. 13. 14. 15. 16. SST POTENTIAL 1. 1. 2. 3. 6. 12. 19. 26. 32. 37. 40. 42. 42. 38. 36. 33. VERTICAL SHEAR MAG 1. 2. 3. 4. 5. 5. 5. 3. 0. -4. -8. -11. -12. -13. -13. -12. VERTICAL SHEAR ADJ -0. -0. -1. -1. -1. -3. -5. -6. -6. -4. -4. -3. -2. -1. -1. -1. VERTICAL SHEAR DIR -0. -1. -1. -1. -2. -3. -3. -3. -2. -1. -1. -1. -1. -0. 1. 1. PERSISTENCE 1. 1. 1. 1. 1. 1. 0. 0. 0. 0. 0. 0. 0. 1. 1. 1. 200/250 MB TEMP. -0. -1. -1. -2. -2. -2. -2. -2. -2. -2. -2. -2. -2. -1. -0. -0. 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. -0. -1. -1. -2. -3. -3. -3. -3. -3. -3. -2. -2. MODEL VTX TENDENCY 0. 1. 1. 0. 1. -1. -2. -3. 1. 2. 4. 4. 5. 4. 7. 6. 850 MB ENV VORTICITY 0. 0. 0. 0. 1. 1. 1. 1. 1. 1. 2. 2. 2. 2. 2. 2. 200 MB DIVERGENCE 0. 0. 0. 0. 1. 1. 1. 1. 0. -0. -1. -1. -1. -2. -2. -2. 850-700 T ADVEC 0. -0. -0. -0. -0. -0. -1. -1. -1. -1. -1. -0. -0. -0. -0. -0. ZONAL STORM MOTION -0. 0. 0. 1. 1. 1. 1. 1. 1. 2. 2. 2. 2. 2. 2. 2. STEERING LEVEL PRES -0. -0. -0. -0. -1. -0. -0. -1. -1. -1. -1. -1. -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. 0. 1. 0. 0. -0. -1. -1. -1. -1. -1. -1. -1. -0. -0. -0. OCEAN HEAT CONTENT 0. 0. 0. 0. 0. 0. -0. -0. -0. -1. -1. -0. -0. 0. 0. 0. RI POTENTIAL 1. 2. 3. 4. 6. 5. 4. 2. -0. -2. -3. -4. -3. -4. -4. -4. -------------------------------------------------------------------------------------------- TOTAL CHANGE 3. 8. 11. 14. 20. 24. 26. 26. 31. 34. 35. 35. 37. 36. 40. 39. CURRENT MAX WIND (KT): 35. LAT, LON: 15.6 39.1 ** 2023 ATLANTIC RI INDEX AL172023 SEVENTEEN 09/23/23 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 12 HR PERSISTENCE (KT) : 5.0 -49.5 to 33.0 0.66 4.4 MULTI-LAYER SHEAR (KT) : 18.4 45.1 to 6.7 0.70 2.4 HEAT CONTENT (KJ/CM2) : 43.6 0.0 to 161.7 0.27 0.7 STD DEV OF IR BR TEMP : 15.9 36.6 to 2.8 0.61 1.7 MAXIMUM WIND (KT) : 35.0 22.5 to 126.5 0.33 0.5 2nd PC OF IR BR TEMP : 1.3 2.9 to -3.0 0.27 0.4 POT = MPI-VMAX (KT) : 112.2 27.0 to 144.1 0.73 0.6 D200 (10**7s-1) : 53.4 -30.8 to 188.1 0.38 0.6 BL DRY-AIR FLUX (W/M2) : 196.0 895.4 to -71.5 0.72 1.0 %area of TPW <45 mm upshear : 11.7 109.3 to 0.0 0.89 0.2 SHIPS Prob RI for 20kt/ 12hr RI threshold= 5% is 1.0 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 21% is 1.9 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 12% is 1.8 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 9% is 2.0 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 7% is 3.6 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 12% is 2.6 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 14% is 2.9 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 15% is 2.9 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: 5.0% 21.1% 12.4% 9.4% 7.2% 11.9% 13.7% 15.3% Logistic: 4.1% 11.4% 6.6% 4.3% 1.3% 6.1% 5.5% 6.6% Bayesian: 2.5% 4.0% 4.5% 0.5% 0.1% 3.2% 4.1% 2.3% Consensus: 3.9% 12.2% 7.8% 4.7% 2.9% 7.1% 7.8% 8.1% DTOPS: 2.0% 7.0% 4.0% 2.0% 0.0% 1.0% 1.0% 1.0% ## ANNULAR HURRICANE INDEX (AHI) AL172023 SEVENTEEN 09/23/23 18 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) ## ** PROBLTY OF AT LEAST 1 SCNDRY EYEWL FORMTN EVENT AL172023 SEVENTEEN 09/23/2023 18 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) 35 38 43 46 49 55 59 61 61 66 69 70 70 72 71 75 74 18HR AGO 35 34 39 42 45 51 55 57 57 62 65 66 66 68 67 71 70 12HR AGO 35 32 31 34 37 43 47 49 49 54 57 58 58 60 59 63 62 6HR AGO 35 29 26 25 28 34 38 40 40 45 48 49 49 51 50 54 53 NOW CURRENT INTENSITY < 83 KT IN 6HR INTENSITY IN 6HR < 83 KT IN 12HR INTENSITY IN 12HR < 83 KT