* GFS version * * ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/18/21 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 70 77 82 86 90 93 95 88 77 69 64 63 64 67 68 70 70 V (KT) LAND 70 77 82 71 53 54 56 49 33 29 27 27 27 27 27 27 27 V (KT) LGEM 70 79 86 77 56 58 67 72 43 32 28 N/A N/A N/A N/A N/A N/A Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP N/A N/A N/A N/A N/A N/A SHEAR (KT) 12 15 16 18 14 10 11 18 14 4 1 N/A N/A N/A N/A N/A N/A SHEAR ADJ (KT) 0 -2 -1 3 0 0 1 0 0 8 7 N/A N/A N/A N/A N/A N/A SHEAR DIR 311 300 327 351 6 337 2 339 24 72 169 N/A N/A N/A N/A N/A N/A SST (C) 29.7 30.0 29.8 29.1 29.3 30.0 30.1 30.3 29.7 28.5 29.6 N/A N/A N/A N/A N/A N/A POT. INT. (KT) 166 172 168 155 158 171 172 172 165 145 163 N/A N/A N/A N/A N/A N/A ADJ. POT. INT. 162 169 164 149 151 163 161 167 158 136 154 N/A N/A N/A N/A N/A N/A 200 MB T (C) -52.5 -52.3 -52.6 -52.6 -52.4 -52.3 -52.0 -51.8 -51.8 -51.7 -51.3 N/A N/A N/A N/A N/A N/A 200 MB VXT (C) 0.6 0.6 0.7 0.7 0.8 0.7 0.5 1.1 0.8 0.4 0.0 N/A N/A N/A N/A N/A N/A TH_E DEV (C) 11 11 10 8 10 9 10 9 10 8 9 N/A N/A N/A N/A N/A N/A 700-500 MB RH 55 59 56 56 59 58 63 66 73 77 80 N/A N/A N/A N/A N/A N/A MODEL VTX (KT) 19 19 20 20 20 19 20 16 9 5 3 LOST LOST LOST LOST LOST LOST 850 MB ENV VOR -9 -6 -25 -29 -25 -20 21 51 72 95 95 N/A N/A N/A N/A N/A N/A 200 MB DIV 42 50 30 14 13 17 31 0 46 51 86 N/A N/A N/A N/A N/A N/A 700-850 TADV -4 -5 -13 -8 -7 -19 -2 -5 -11 -5 7 N/A N/A N/A N/A N/A N/A LAND (KM) 274 211 105 -42 -63 170 244 53 -212 -256 -102 N/A N/A N/A N/A N/A N/A LAT (DEG N) 19.6 19.9 20.2 20.5 20.7 20.9 21.0 20.8 20.6 20.3 20.1 N/A N/A N/A N/A N/A N/A LONG(DEG W) 83.0 84.6 86.2 87.7 89.2 92.0 94.5 96.5 99.3 101.9 104.3 N/A N/A N/A N/A N/A N/A STM SPEED (KT) 15 15 15 14 14 13 10 11 13 12 11 N/A N/A N/A N/A N/A N/A HEAT CONTENT 84 87 49 26 20 30 43 38 5 13 21 N/A N/A N/A N/A N/A N/A FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):285/ 14 CX,CY: -13/ 4 T-12 MAX WIND: 50 PRESSURE OF STEERING LEVEL (MB): 588 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 12.2 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 98.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 40.2 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. 8. 9. 10. 11. 12. 12. 13. 14. 15. 15. 16. SST POTENTIAL 2. 3. 5. 6. 6. 7. 8. 9. 9. 10. 11. 13. 13. 13. 13. 12. VERTICAL SHEAR MAG -1. -2. -3. -3. -2. -1. -0. 0. 2. 5. 6. 7. 8. 9. 9. 9. VERTICAL SHEAR ADJ 0. 0. 0. 0. 1. 0. 0. 1. 0. -0. -0. -0. -0. -0. -0. -0. VERTICAL SHEAR DIR -0. -0. -0. 0. 0. 1. 1. 2. 2. 2. 2. 3. 3. 3. 3. 3. PERSISTENCE 3. 4. 4. 4. 2. 2. 2. 1. 0. -0. -1. -1. 0. 1. 2. 2. 200/250 MB TEMP. -0. -0. -1. -1. -1. -2. -2. -3. -3. -3. -4. -4. -5. -5. -5. -5. THETA_E EXCESS 0. 0. 0. 0. 1. 0. 1. 0. 0. 0. 0. 0. -0. -0. -0. -0. 700-500 MB RH -0. -0. -0. -0. -0. -1. -2. -2. -4. -5. -5. -5. -6. -7. -7. -6. MODEL VTX TENDENCY -0. 0. 0. -0. -1. -1. -6. -17. -24. -28. -29. -29. -28. -28. -27. -26. 850 MB ENV VORTICITY -0. -0. -0. -1. -1. -1. -1. -1. -0. 0. 0. 0. 0. 0. 0. 0. 200 MB DIVERGENCE 0. 0. 0. -0. -0. -0. -1. -0. -0. 0. 0. -0. -0. -0. -0. -0. 850-700 T ADVEC 0. -0. -0. -0. -1. -1. -1. -1. -1. -0. -0. -0. -0. -0. -0. -0. ZONAL STORM MOTION -0. -0. 0. 0. 1. 1. 1. 1. 1. 2. 2. 3. 3. 2. 3. 3. 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. 2. 2. 3. 3. 2. 2. 3. 3. 3. 3. 2. OCEAN HEAT CONTENT -0. -0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. RI POTENTIAL 1. 3. 6. 8. 12. 11. 8. 4. 1. -2. -5. -7. -8. -8. -9. -9. ------------------------------------------------------------------------------ TOTAL CHANGE 7. 12. 16. 20. 23. 25. 18. 7. -1. -6. -7. -6. -3. -2. 0. 0. CURRENT MAX WIND (KT): 70. LAT, LON: 19.6 83.0 ** 2021 ATLANTIC RI INDEX AL072021 GRACE 08/18/21 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) : 20.0 -49.5 to 33.0 0.84 9.6 850-200 MB SHEAR (KT) : 14.9 30.1 to 2.3 0.55 2.9 HEAT CONTENT (KJ/CM2) : 53.2 0.0 to 151.8 0.35 1.7 STD DEV OF IR BR TEMP : 12.2 36.6 to 2.8 0.72 3.9 MAXIMUM WIND (KT) : 70.0 22.5 to 137.5 0.88 3.8 BL DRY-AIR FLUX (W/M2) : 365.2 895.4 to -55.0 0.56 2.4 2nd PC OF IR BR TEMP : 1.4 2.9 to -2.9 0.26 0.8 POT = MPI-VMAX (KT) : 89.1 28.3 to 146.3 0.52 1.1 D200 (10**7s-1) : 29.8 -29.7 to 185.9 0.28 0.5 %area of TPW <45 mm upshear : 8.9 100.0 to 0.0 0.91 0.4 SHIPS Prob RI for 20kt/ 12hr RI threshold= 33% is 6.8 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 37% is 3.4 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 27% is 4.0 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 22% is 5.7 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 16% is 6.9 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 18% is 3.9 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 12% is 2.6 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 13% is 2.5 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: 33.3% 37.0% 27.2% 22.0% 16.5% 17.7% 12.1% 13.2% Logistic: 27.5% 33.1% 29.7% 40.5% 19.2% 30.6% 25.9% 21.8% Bayesian: 31.3% 18.8% 20.0% 1.8% 1.4% 9.4% 9.4% 2.3% Consensus: 30.7% 29.6% 25.6% 21.4% 12.4% 19.2% 15.8% 12.4% DTOPS: 30.0% 1.0% 1.0% 0.0% 0.0% 0.0% 0.0% 0.0% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/18/21 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 08/18/2021 18 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 4 8( 12) 0( 12) 0( 12) <-- PROB BASED ON INTENSITY ONLY PROB(%) 0 1( 1) 0( 1) 0( 1) <-- 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) 70 77 82 71 53 54 56 49 33 29 27 27 27 27 27 27 27 18HR AGO 70 69 74 63 45 46 48 41 25 21 19 19 19 19 19 19 19 12HR AGO 70 67 66 55 37 38 40 33 17 DIS DIS DIS DIS DIS DIS DIS DIS 6HR AGO 70 64 61 60 42 43 45 38 22 18 16 16 16 16 16 16 16 NOW CURRENT INTENSITY < 83 KT IN 6HR INTENSITY IN 6HR < 83 KT IN 12HR INTENSITY IN 12HR < 83 KT