* ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/17/21 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 45 51 55 61 66 75 79 82 82 77 67 65 64 68 71 74 74 V (KT) LAND 45 54 59 65 70 79 47 51 51 41 32 28 27 27 27 27 27 V (KT) LGEM 45 53 58 63 69 80 48 56 64 70 39 30 28 N/A N/A N/A N/A Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP N/A N/A N/A N/A SHEAR (KT) 6 7 13 14 8 13 14 12 14 16 16 7 3 N/A N/A N/A N/A SHEAR ADJ (KT) 1 -2 -6 -2 -1 -1 0 0 1 0 0 11 10 N/A N/A N/A N/A SHEAR DIR 269 254 298 328 353 328 30 11 31 352 18 36 284 N/A N/A N/A N/A SST (C) 30.3 30.1 30.0 29.8 29.9 29.8 29.5 29.9 30.1 30.0 29.9 28.8 29.2 N/A N/A N/A N/A POT. INT. (KT) 173 173 171 168 170 168 162 169 172 170 168 149 156 N/A N/A N/A N/A ADJ. POT. INT. 173 172 170 166 167 164 156 161 163 159 155 138 145 N/A N/A N/A N/A 200 MB T (C) -53.0 -52.8 -53.1 -53.1 -52.7 -52.6 -52.4 -52.2 -52.3 -51.9 -51.9 -52.0 -51.9 N/A N/A N/A N/A 200 MB VXT (C) 0.4 0.6 0.8 0.6 0.6 0.8 0.8 0.7 0.4 0.5 0.8 0.1 0.0 N/A N/A N/A N/A TH_E DEV (C) 11 10 10 10 11 9 10 9 10 9 11 9 10 N/A N/A N/A N/A 700-500 MB RH 55 57 54 54 57 58 58 58 62 63 68 71 73 N/A N/A N/A N/A MODEL VTX (KT) 14 14 14 15 16 19 18 18 18 15 9 7 5 LOST LOST LOST LOST 850 MB ENV VOR 23 19 0 -6 1 -9 -15 6 32 65 77 90 90 N/A N/A N/A N/A 200 MB DIV 30 36 30 25 36 33 19 -1 25 32 28 38 42 N/A N/A N/A N/A 700-850 TADV -5 -8 -11 -15 -9 -13 -9 -14 -3 -10 -10 -12 2 N/A N/A N/A N/A LAND (KM) -2 94 254 336 281 60 -57 241 181 -10 -191 -355 -106 N/A N/A N/A N/A LAT (DEG N) 18.4 18.7 18.9 19.1 19.3 19.9 20.6 20.9 21.0 21.3 21.5 21.5 21.3 N/A N/A N/A N/A LONG(DEG W) 77.5 79.1 80.6 82.2 83.8 86.8 89.8 92.7 95.2 97.5 99.6 101.8 104.2 N/A N/A N/A N/A STM SPEED (KT) 14 15 15 15 15 15 14 13 11 11 10 11 11 N/A N/A N/A N/A HEAT CONTENT 66 82 88 84 85 41 30 29 47 29 22 15 19 N/A N/A N/A N/A FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):280/ 13 CX,CY: -12/ 2 T-12 MAX WIND: 35 PRESSURE OF STEERING LEVEL (MB): 591 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 8.5 (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): 42.4 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 0. 0. 1. 1. 3. 8. 13. 17. 20. 23. 27. 30. 33. 34. 35. 35. VERTICAL SHEAR MAG 1. 1. 2. 2. 4. 4. 5. 5. 5. 4. 4. 5. 6. 6. 6. 7. VERTICAL SHEAR ADJ 0. 0. 1. 1. 1. 2. 2. 2. 2. 1. 1. -0. -0. -0. -0. -0. VERTICAL SHEAR DIR -0. -0. -0. -0. -1. -0. 0. 1. 1. 2. 2. 2. 2. 2. 2. 2. PERSISTENCE 2. 2. 2. 2. 1. 1. 1. 1. 0. 0. 0. 0. 0. 1. 2. 2. 200/250 MB TEMP. -0. -0. -0. -1. -1. -1. -2. -2. -2. -3. -3. -3. -4. -4. -4. -4. THETA_E EXCESS 0. 0. 0. 1. 1. 1. 1. 1. 1. 0. 0. 0. -0. -0. -0. -0. 700-500 MB RH -0. -0. -0. -0. -0. -1. -1. -1. -2. -2. -3. -4. -4. -5. -5. -5. MODEL VTX TENDENCY 0. -0. 0. 1. 2. 2. 1. 1. -4. -13. -17. -20. -20. -20. -19. -19. 850 MB ENV VORTICITY -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -0. 0. 0. 0. 0. 0. 200 MB DIVERGENCE -0. -0. -0. -0. 0. -0. -0. -1. -0. -0. -0. 0. 0. 0. 0. 0. 850-700 T ADVEC 0. -0. -0. -0. -1. -1. -2. -1. -1. -1. -0. -0. -0. -0. -0. -0. ZONAL STORM MOTION -0. -0. 0. 0. 1. 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. 1. 0. GOES PREDICTORS 1. 2. 2. 2. 1. 1. 1. 1. 1. 0. 0. 1. 2. 2. 3. 2. OCEAN HEAT CONTENT -0. -0. -1. -1. -1. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. RI POTENTIAL 1. 3. 6. 9. 13. 12. 8. 4. 1. -2. -5. -7. -8. -9. -9. -9. ------------------------------------------------------------------------------ TOTAL CHANGE 6. 11. 16. 21. 30. 35. 37. 37. 32. 22. 20. 19. 23. 26. 29. 29. CURRENT MAX WIND (KT): 45. LAT, LON: 18.4 77.5 ** 2022 ATLANTIC RI INDEX AL072021 GRACE 08/17/21 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 12 HR PERSISTENCE (KT) : 10.0 -45.0 to 30.0 0.73 11.9 850-200 MB SHEAR (KT) : 9.9 25.9 to 2.2 0.68 5.1 HEAT CONTENT (KJ/CM2) : 81.0 0.0 to 147.0 0.55 4.2 STD DEV OF IR BR TEMP : 8.5 33.3 to 3.1 0.82 5.0 MAXIMUM WIND (KT) : 45.0 25.0 to 125.0 0.56 3.0 2nd PC OF IR BR TEMP : 1.1 2.6 to -2.7 0.28 1.0 BL DRY-AIR FLUX (W/M2) : 266.4 814.0 to -65.0 0.62 2.7 POT = MPI-VMAX (KT) : 124.6 30.0 to 128.0 0.97 2.1 D200 (10**7s-1) : 31.4 -28.0 to 171.0 0.30 0.9 %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= 21% is 4.3 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 50% is 4.6 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 36% is 5.4 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 25% is 6.5 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 8% is 3.4 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 36% is 7.8 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 28% is 6.0 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 30% is 5.6 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: 21.2% 50.2% 36.5% 25.5% 8.2% 36.0% 28.2% 29.8% Logistic: 28.5% 54.1% 42.8% 45.7% 31.8% 55.1% 51.1% 46.0% Bayesian: 20.9% 79.0% 50.3% 11.8% 6.3% 28.3% 36.0% 10.5% Consensus: 23.6% 61.1% 43.2% 27.6% 15.5% 39.8% 38.4% 28.8% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/17/21 18 UTC ## ## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=3 NFAIL=4 ## ## 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 AL072021 GRACE 08/17/2021 18 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 0 0( 0) 4( 4) 7( 11) <-- PROB BASED ON INTENSITY ONLY PROB(%) 0 0( 0) 1( 1) 2( 3) <-- 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) 45 54 59 65 70 79 47 51 51 41 32 28 27 27 27 27 27 18HR AGO 45 44 49 55 60 69 37 41 41 31 22 18 17 17 17 17 17 12HR AGO 45 42 41 47 52 61 29 33 33 23 DIS DIS DIS DIS DIS DIS DIS 6HR AGO 45 39 36 35 40 49 17 21 21 DIS DIS DIS DIS DIS DIS DIS DIS NOW CURRENT INTENSITY < 83 KT IN 6HR INTENSITY IN 6HR < 83 KT IN 12HR INTENSITY IN 12HR < 83 KT