* ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * SAM AL182021 09/25/21 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 85 92 98 101 105 108 110 109 109 108 106 103 106 103 104 104 102 V (KT) LAND 85 92 98 101 105 108 110 109 109 108 106 103 106 103 104 104 102 V (KT) LGEM 85 93 98 101 104 108 110 108 106 104 102 101 97 90 85 82 80 Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP SHEAR (KT) 1 1 3 3 3 5 3 10 6 10 11 15 15 18 16 9 17 SHEAR ADJ (KT) 1 2 0 0 0 1 0 -2 -2 -4 -4 1 -1 5 5 10 16 SHEAR DIR 352 306 316 347 18 304 308 285 317 297 285 260 243 246 214 203 176 SST (C) 28.8 28.6 28.5 28.5 28.5 28.7 28.6 28.5 28.6 28.5 28.6 28.7 28.8 28.7 28.6 28.9 28.3 POT. INT. (KT) 149 145 143 142 142 145 144 142 144 143 145 147 148 148 147 151 142 ADJ. POT. INT. 149 143 139 137 136 138 138 134 136 134 135 138 139 139 136 139 127 200 MB T (C) -53.3 -53.5 -53.5 -53.3 -53.5 -53.9 -54.0 -54.0 -53.9 -54.0 -53.8 -53.7 -53.5 -53.8 -53.7 -53.4 -53.2 200 MB VXT (C) 0.0 0.1 0.1 0.1 0.2 0.3 0.3 0.3 0.4 0.7 0.7 0.7 0.6 0.9 0.8 0.9 0.8 TH_E DEV (C) 9 9 9 9 9 9 9 9 10 9 9 9 9 9 9 8 7 700-500 MB RH 57 56 55 56 58 56 55 51 52 49 50 53 54 56 61 56 49 MODEL VTX (KT) 17 17 18 17 18 20 21 22 23 25 26 27 30 30 33 34 35 850 MB ENV VOR -4 -13 -23 -28 -25 -28 -27 -34 -26 -31 -30 -26 -5 1 15 21 89 200 MB DIV 51 31 27 34 57 41 30 53 66 46 52 54 79 73 59 66 54 700-850 TADV -2 -2 -2 0 -2 -2 -1 3 3 3 2 0 4 11 14 25 18 LAND (KM) 1124 1070 1016 1001 991 966 975 1039 980 945 954 907 717 609 663 816 1024 LAT (DEG N) 12.3 12.5 12.6 12.9 13.1 13.4 14.0 14.9 15.6 16.5 17.6 18.6 19.5 xx.x xx.x xx.x xx.x LONG(DEG W) 45.4 46.4 47.4 48.0 48.7 49.9 51.1 52.3 53.4 54.5 55.6 57.1 59.0 xxx.x xxx.x xxx.x xxx.x STM SPEED (KT) 11 10 8 7 7 6 7 7 7 7 8 9 10 12 13 13 13 HEAT CONTENT 23 23 23 26 32 43 40 47 53 39 36 52 57 34 48 51 26 FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):285/ 12 CX,CY: -11/ 3 T-12 MAX WIND: 65 PRESSURE OF STEERING LEVEL (MB): 608 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 9.0 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 91.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 23.6 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. 10. 11. 12. 12. 13. 14. 15. 15. 16. SST POTENTIAL 1. 3. 4. 4. 3. -0. -4. -6. -8. -9. -10. -11. -13. -14. -15. -16. VERTICAL SHEAR MAG 1. 2. 3. 4. 5. 8. 10. 12. 13. 14. 14. 14. 15. 15. 15. 15. VERTICAL SHEAR ADJ -0. -0. 0. 0. 0. 0. 1. 2. 2. 2. 2. 2. 2. 1. 1. -0. VERTICAL SHEAR DIR 0. -0. 0. 0. 0. 0. -0. -1. -1. -1. -2. -3. -4. -4. -4. -3. PERSISTENCE 3. 4. 4. 3. 2. 1. 2. 1. 0. -1. -2. -1. -0. 1. 1. 1. 200/250 MB TEMP. -0. -0. -1. -1. -1. -1. -1. -1. -1. -1. -1. -1. -0. -0. -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. -0. -0. -1. -0. -0. -0. -1. -1. -1. -1. -1. MODEL VTX TENDENCY 0. 0. -0. 0. 2. 3. 4. 4. 6. 6. 7. 11. 10. 12. 12. 12. 850 MB ENV VORTICITY -0. -0. -0. -1. -1. -2. -2. -2. -3. -3. -3. -4. -4. -4. -4. -4. 200 MB DIVERGENCE 0. 0. 0. 0. 0. 0. 0. 1. 1. 1. 0. -0. -0. -1. -1. -2. 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. 0. 1. 1. 1. 1. 2. 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. 1. 1. 2. 2. 2. 2. 1. 2. 2. 2. 2. 2. OCEAN HEAT CONTENT 0. 0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. RI POTENTIAL 1. 1. 3. 4. 5. 5. 3. 2. 0. -1. -2. -3. -3. -3. -4. -4. ------------------------------------------------------------------------------ TOTAL CHANGE 7. 13. 16. 20. 23. 25. 24. 24. 23. 21. 18. 21. 18. 19. 19. 17. CURRENT MAX WIND (KT): 85. LAT, LON: 12.3 45.4 ** 2022 ATLANTIC RI INDEX AL182021 SAM 09/25/21 00 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) : 20.0 -45.0 to 30.0 0.87 13.8 850-200 MB SHEAR (KT) : 2.2 25.9 to 2.2 1.00 7.4 HEAT CONTENT (KJ/CM2) : 25.4 0.0 to 147.0 0.17 1.3 STD DEV OF IR BR TEMP : 9.0 33.3 to 3.1 0.80 4.8 MAXIMUM WIND (KT) : 85.0 25.0 to 125.0 0.62 3.3 2nd PC OF IR BR TEMP : 0.7 2.6 to -2.7 0.37 1.3 BL DRY-AIR FLUX (W/M2) : 487.4 814.0 to -65.0 0.37 1.6 POT = MPI-VMAX (KT) : 55.9 30.0 to 128.0 0.26 0.6 D200 (10**7s-1) : 40.0 -28.0 to 171.0 0.34 1.0 %area of TPW <45 mm upshear : 0.0 95.0 to 0.0 1.00 0.6 SHIPS Prob RI for 20kt/ 12hr RI threshold= 24% is 4.9 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 41% is 3.7 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 36% is 5.3 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 26% is 6.7 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 8% is 3.3 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 25% is 5.4 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 0% is 0.0 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: 24.0% 40.7% 35.7% 25.9% 7.9% 24.8% 0.0% 0.0% Logistic: 13.8% 46.0% 35.9% 24.4% 12.8% 21.4% 10.8% 4.9% Bayesian: 23.4% 61.4% 41.1% 4.7% 5.0% 6.3% 0.8% 0.0% Consensus: 20.4% 49.4% 37.6% 18.3% 8.6% 17.5% 3.9% 1.6% ## ANNULAR HURRICANE INDEX (AHI) AL182021 SAM 09/25/21 00 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 AL182021 SAM 09/25/2021 00 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 10 21( 29) 27( 48) 28( 63) <-- PROB BASED ON INTENSITY ONLY PROB(%) 1 2( 3) 7( 10) 11( 20) <-- 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) 85 92 98 101 105 108 110 109 109 108 106 103 106 103 104 104 102 18HR AGO 85 84 90 93 97 100 102 101 101 100 98 95 98 95 96 96 94 12HR AGO 85 82 81 84 88 91 93 92 92 91 89 86 89 86 87 87 85 6HR AGO 85 79 76 75 79 82 84 83 83 82 80 77 80 77 78 78 76 NOW 85 76 70 67 66 69 71 70 70 69 67 64 67 64 65 65 63 IN 6HR 85 92 83 77 74 73 75 74 74 73 71 68 71 68 69 69 67 IN 12HR 85 92 98 89 83 79 81 80 80 79 77 74 77 74 75 75 73