* ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/17/21 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 45 51 57 62 66 75 84 87 88 87 79 69 66 69 71 74 74 V (KT) LAND 45 51 57 62 66 75 58 53 54 53 40 31 28 27 27 27 27 V (KT) LGEM 45 52 58 64 70 82 64 56 65 71 59 37 30 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) 12 7 7 11 14 4 17 6 17 14 15 7 5 N/A N/A N/A N/A SHEAR ADJ (KT) 0 1 -1 -4 -3 0 2 0 5 1 3 2 13 N/A N/A N/A N/A SHEAR DIR 293 267 249 293 322 299 345 2 357 351 4 23 2 N/A N/A N/A N/A SST (C) 29.8 30.4 30.1 30.0 29.8 30.1 29.0 29.5 30.2 30.1 30.2 29.8 28.8 N/A N/A N/A N/A POT. INT. (KT) 167 173 173 172 168 173 153 161 172 171 171 166 149 N/A N/A N/A N/A ADJ. POT. INT. 164 173 172 171 165 172 147 153 164 159 161 153 136 N/A N/A N/A N/A 200 MB T (C) -53.3 -53.0 -52.8 -53.1 -53.2 -52.5 -52.5 -52.0 -52.1 -51.7 -51.7 -51.3 -51.6 N/A N/A N/A N/A 200 MB VXT (C) 0.4 0.4 0.6 0.8 0.7 0.6 0.7 0.8 0.6 0.7 0.8 0.7 0.0 N/A N/A N/A N/A TH_E DEV (C) 11 11 10 10 10 11 9 11 8 12 9 12 8 N/A N/A N/A N/A 700-500 MB RH 54 56 57 55 54 58 55 57 61 65 68 70 73 N/A N/A N/A N/A MODEL VTX (KT) 12 14 16 15 16 19 21 20 21 21 16 8 5 LOST LOST LOST LOST 850 MB ENV VOR 7 23 22 1 -6 0 -24 0 9 36 66 74 80 N/A N/A N/A N/A 200 MB DIV 25 30 46 34 21 48 17 8 18 8 42 14 56 N/A N/A N/A N/A 700-850 TADV -6 -5 -12 -13 -13 -8 -7 -8 -8 -3 -7 -11 -5 N/A N/A N/A N/A LAND (KM) 29 1 101 266 326 192 -93 114 321 114 -39 -249 -309 N/A N/A N/A N/A LAT (DEG N) 18.2 18.5 18.7 19.0 19.2 19.9 20.6 21.1 21.4 21.7 22.0 22.2 22.2 N/A N/A N/A N/A LONG(DEG W) 76.1 77.6 79.1 80.7 82.3 85.4 88.5 91.4 93.9 96.1 98.2 100.3 102.4 N/A N/A N/A N/A STM SPEED (KT) 14 14 15 15 15 15 14 12 11 10 10 10 10 N/A N/A N/A N/A HEAT CONTENT 48 68 82 88 84 76 10 28 42 41 31 28 15 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: 30 PRESSURE OF STEERING LEVEL (MB): 617 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 22.5 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 74.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 38.6 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 0. 1. 1. 2. 3. 8. 13. 17. 20. 23. 27. 30. 33. 34. 35. 35. VERTICAL SHEAR MAG 0. 1. 2. 2. 4. 5. 5. 5. 5. 4. 5. 5. 6. 6. 6. 7. VERTICAL SHEAR ADJ 0. 0. 0. 1. 1. 2. 2. 1. 1. 1. 1. -0. -0. -0. -0. -0. VERTICAL SHEAR DIR -0. -0. -1. -1. -1. -1. -1. -0. -0. 0. 1. 1. 1. 1. 1. 1. PERSISTENCE 3. 4. 4. 4. 2. 1. 1. 1. 1. 1. 0. 0. 1. 2. 3. 3. 200/250 MB TEMP. -0. -0. -0. -0. -1. -1. -2. -2. -3. -3. -3. -4. -4. -4. -5. -5. THETA_E EXCESS 0. 0. 1. 1. 1. 1. 1. 1. 1. 1. 0. 0. -0. -0. -1. -1. 700-500 MB RH 0. -0. -0. -0. -0. -0. -1. -1. -2. -2. -3. -4. -4. -4. -5. -4. MODEL VTX TENDENCY 0. 1. 2. 2. 4. 8. 7. 8. 7. 0. -13. -17. -17. -17. -17. -17. 850 MB ENV VORTICITY -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -1. -0. -0. -0. -0. -0. 200 MB DIVERGENCE -0. -0. -0. -0. 0. -0. -0. -0. -1. -0. -0. 0. 0. 0. 0. 0. 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. 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 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 0. OCEAN HEAT CONTENT 0. -0. -0. -1. -1. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. RI POTENTIAL 1. 3. 5. 8. 11. 11. 7. 4. 1. -2. -4. -6. -7. -8. -8. -8. ------------------------------------------------------------------------------ TOTAL CHANGE 6. 12. 17. 21. 30. 39. 42. 43. 42. 34. 24. 21. 24. 26. 29. 29. CURRENT MAX WIND (KT): 45. LAT, LON: 18.2 76.1 ** 2022 ATLANTIC RI INDEX AL072021 GRACE 08/17/21 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) : 15.0 -45.0 to 30.0 0.80 9.0 850-200 MB SHEAR (KT) : 10.3 25.9 to 2.2 0.66 3.4 HEAT CONTENT (KJ/CM2) : 74.0 0.0 to 147.0 0.50 2.6 STD DEV OF IR BR TEMP : 22.5 33.3 to 3.1 0.36 1.5 MAXIMUM WIND (KT) : 45.0 25.0 to 125.0 0.56 2.1 2nd PC OF IR BR TEMP : 1.0 2.6 to -2.7 0.30 0.7 BL DRY-AIR FLUX (W/M2) : 294.8 814.0 to -65.0 0.59 1.8 POT = MPI-VMAX (KT) : 124.1 30.0 to 128.0 0.96 1.5 D200 (10**7s-1) : 31.2 -28.0 to 171.0 0.30 0.6 %area of TPW <45 mm upshear : 5.8 95.0 to 0.0 0.94 0.4 SHIPS Prob RI for 20kt/ 12hr RI threshold= 12% is 2.5 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 38% is 3.4 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 24% is 3.5 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 13% is 3.5 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 7% is 2.8 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 26% is 5.6 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 32% is 6.8 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 37% is 7.0 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: 12.1% 37.6% 23.7% 13.5% 6.6% 25.8% 31.9% 37.3% Logistic: 15.7% 43.8% 29.0% 24.2% 14.3% 49.4% 54.3% 60.5% Bayesian: 23.9% 61.0% 25.7% 3.5% 1.7% 21.6% 39.1% 8.5% Consensus: 17.2% 47.5% 26.1% 13.7% 7.5% 32.3% 41.8% 35.4% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/17/21 12 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 12 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 0 0( 0) 3( 3) 5( 8) <-- 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) 45 51 57 62 66 75 58 53 54 53 40 31 28 27 27 27 27 18HR AGO 45 44 50 55 59 68 51 46 47 46 33 24 21 20 20 20 20 12HR AGO 45 42 41 46 50 59 42 37 38 37 24 15 DIS DIS DIS DIS DIS 6HR AGO 45 39 36 35 39 48 31 26 27 26 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