* GFS version * * ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/20/21 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 55 56 58 60 60 55 52 54 57 59 62 65 68 72 72 74 74 V (KT) LAND 55 56 58 60 60 42 32 28 27 27 27 27 27 27 27 27 27 V (KT) LGEM 55 56 58 60 61 43 32 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Storm Type TROP TROP TROP TROP TROP TROP TROP N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR (KT) 6 10 15 12 15 15 5 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR ADJ (KT) 1 0 1 0 0 1 3 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR DIR 349 342 357 355 326 358 32 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SST (C) 29.9 30.0 30.1 30.2 30.4 28.6 28.2 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A POT. INT. (KT) 169 171 172 172 172 146 140 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A ADJ. POT. INT. 161 163 164 163 168 138 133 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB T (C) -51.9 -52.1 -52.2 -52.0 -51.6 -52.0 -51.6 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB VXT (C) 0.7 0.7 0.7 0.5 0.7 0.9 0.7 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A TH_E DEV (C) 12 10 8 11 12 9 10 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-500 MB RH 56 56 56 60 60 65 74 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MODEL VTX (KT) 20 20 20 21 20 11 6 LOST LOST LOST LOST LOST LOST LOST LOST LOST LOST 850 MB ENV VOR -7 -15 -3 13 32 62 94 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB DIV 8 18 2 26 18 23 45 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-850 TADV 0 -11 -6 0 -4 -11 -5 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LAND (KM) 67 204 267 203 101 -126 -195 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LAT (DEG N) 20.8 20.8 20.8 20.8 20.7 20.2 19.2 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LONG(DEG W) 91.0 92.3 93.7 94.8 95.9 98.1 100.6 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A STM SPEED (KT) 13 13 12 10 10 12 12 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A HEAT CONTENT 39 29 33 42 43 10 10 N/A N/A N/A N/A 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: 60 PRESSURE OF STEERING LEVEL (MB): 686 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 18.7 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 65.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 5.1 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. 2. 3. 4. 5. 8. 10. 13. 15. 17. 20. 22. 24. 24. 24. 24. VERTICAL SHEAR MAG 0. 0. 1. 1. 1. 2. 3. 4. 4. 5. 5. 5. 6. 7. 7. 7. VERTICAL SHEAR ADJ 0. -0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 1. 1. 0. VERTICAL SHEAR DIR 0. 0. 0. 0. 1. 1. 2. 2. 3. 3. 3. 4. 4. 4. 4. 4. PERSISTENCE -0. -1. -1. -1. -0. -0. -0. -0. -0. 0. 0. 0. -0. -0. -1. -0. 200/250 MB TEMP. -0. -0. -1. -1. -2. -3. -3. -3. -3. -4. -4. -5. -5. -6. -6. -6. THETA_E EXCESS 0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 0. 0. -0. -0. -1. -1. 700-500 MB RH -0. -0. -0. -0. -1. -2. -2. -3. -3. -3. -4. -4. -4. -5. -5. -5. MODEL VTX TENDENCY -0. -0. 0. -0. -8. -17. -20. -22. -24. -25. -26. -26. -26. -25. -24. -24. 850 MB ENV VORTICITY -0. -0. -0. -0. -0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 200 MB DIVERGENCE -0. -0. -0. -0. -1. -0. -1. -1. -1. -0. -0. 0. 0. 0. 0. 1. 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. -1. -1. -0. -1. -1. -1. -2. -2. -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. -0. -0. -0. 0. 0. 0. 1. 1. 1. 0. -0. -0. -0. -0. OCEAN HEAT CONTENT 0. 0. 0. 0. 0. 0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. RI POTENTIAL -0. -0. -1. -1. -2. -2. -1. -1. -0. 0. 1. 2. 2. 2. 2. 2. ------------------------------------------------------------------------------ TOTAL CHANGE 1. 3. 5. 5. -0. -3. -1. 2. 4. 7. 10. 13. 17. 17. 19. 19. CURRENT MAX WIND (KT): 55. LAT, LON: 20.8 91.0 ** 2021 ATLANTIC RI INDEX AL072021 GRACE 08/20/21 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) : 0.0 -49.5 to 33.0 0.60 3.0 850-200 MB SHEAR (KT) : 11.8 30.1 to 2.3 0.66 1.5 HEAT CONTENT (KJ/CM2) : 37.2 0.0 to 151.8 0.25 0.5 STD DEV OF IR BR TEMP : 18.7 36.6 to 2.8 0.53 1.3 MAXIMUM WIND (KT) : 55.0 22.5 to 137.5 0.85 1.6 BL DRY-AIR FLUX (W/M2) : 277.6 895.4 to -55.0 0.65 1.2 2nd PC OF IR BR TEMP : -0.1 2.9 to -2.9 0.52 0.7 POT = MPI-VMAX (KT) : 108.9 28.3 to 146.3 0.68 0.6 D200 (10**7s-1) : 14.4 -29.7 to 185.9 0.20 0.2 %area of TPW <45 mm upshear : 4.6 100.0 to 0.0 0.95 0.2 SHIPS Prob RI for 20kt/ 12hr RI threshold= 6% is 1.2 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 19% is 1.8 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 11% is 1.6 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 9% is 2.4 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 7% is 3.0 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 11% is 2.4 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 12% is 2.5 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 14% is 2.7 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: 5.8% 19.2% 10.8% 9.4% 7.3% 11.2% 11.9% 14.3% Logistic: 3.9% 17.6% 12.0% 6.8% 3.8% 7.0% 13.9% 17.9% Bayesian: 0.3% 2.9% 0.8% 0.0% 0.0% 0.1% 0.3% 8.5% Consensus: 3.3% 13.2% 7.9% 5.4% 3.7% 6.1% 8.7% 13.6% DTOPS: 11.0% 16.0% 9.0% 2.0% 3.0% 0.0% 0.0% 0.0% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/20/21 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 AL072021 GRACE 08/20/2021 00 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) 55 56 58 60 60 42 32 28 27 27 27 27 27 27 27 27 27 18HR AGO 55 54 56 58 58 40 30 26 25 25 25 25 25 25 25 25 25 12HR AGO 55 52 51 53 53 35 25 21 20 20 20 20 20 20 20 20 20 6HR AGO 55 49 46 45 45 27 17 DIS DIS 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