* GFS version * * ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/18/21 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 50 54 59 64 71 79 84 84 84 77 63 62 62 64 65 67 68 V (KT) LAND 50 54 59 64 71 62 47 47 47 35 29 28 27 27 27 27 27 V (KT) LGEM 50 53 57 62 68 65 47 55 64 49 33 29 27 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) 10 13 14 10 8 15 7 17 15 17 8 5 4 N/A N/A N/A N/A SHEAR ADJ (KT) -4 -4 -3 -4 -4 0 0 3 0 0 -3 4 5 N/A N/A N/A N/A SHEAR DIR 243 294 311 298 286 345 348 6 353 355 34 45 142 N/A N/A N/A N/A SST (C) 30.2 30.0 29.9 29.8 30.0 29.8 29.8 29.9 30.1 29.4 29.1 28.6 29.3 N/A N/A N/A N/A POT. INT. (KT) 173 171 170 168 172 167 167 168 172 158 153 145 156 N/A N/A N/A N/A ADJ. POT. INT. 173 170 168 166 171 163 158 160 164 147 140 133 142 N/A N/A N/A N/A 200 MB T (C) -52.7 -52.9 -52.9 -52.5 -52.4 -52.6 -52.2 -52.5 -52.0 -52.0 -51.6 -52.0 -51.4 N/A N/A N/A N/A 200 MB VXT (C) 0.7 0.9 0.8 0.7 0.7 0.8 0.7 0.3 0.7 0.9 0.7 0.2 0.0 N/A N/A N/A N/A TH_E DEV (C) 11 11 10 11 11 9 10 8 11 8 11 7 9 N/A N/A N/A N/A 700-500 MB RH 55 54 54 57 58 58 60 64 65 68 74 78 78 N/A N/A N/A N/A MODEL VTX (KT) 17 16 16 16 20 20 19 20 20 17 7 6 LOST LOST LOST LOST LOST 850 MB ENV VOR 26 11 -1 5 5 -16 -9 12 51 77 95 96 88 N/A N/A N/A N/A 200 MB DIV 44 27 31 29 29 8 15 11 14 -2 35 52 56 N/A N/A N/A N/A 700-850 TADV -1 -3 -6 -6 -4 -12 -7 -6 -2 -8 -9 -4 0 N/A N/A N/A N/A LAND (KM) 34 194 354 323 278 -75 37 244 112 -109 -293 -278 -169 N/A N/A N/A N/A LAT (DEG N) 18.3 18.6 18.8 19.1 19.3 19.9 20.4 20.7 20.9 20.8 20.5 20.5 20.8 N/A N/A N/A N/A LONG(DEG W) 78.6 80.1 81.6 83.2 84.8 88.1 90.8 93.2 95.9 98.3 100.2 101.9 103.6 N/A N/A N/A N/A STM SPEED (KT) 13 14 15 15 16 14 12 12 12 10 8 8 8 N/A N/A N/A N/A HEAT CONTENT 76 84 85 81 84 34 46 29 44 15 8 14 19 N/A N/A N/A N/A FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):275/ 12 CX,CY: -11/ 1 T-12 MAX WIND: 45 PRESSURE OF STEERING LEVEL (MB): 536 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 13.5 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 93.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 44.7 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. 1. 2. 3. 4. 8. 12. 15. 18. 21. 24. 26. 29. 29. 30. 29. VERTICAL SHEAR MAG 0. 0. 1. 1. 2. 3. 3. 3. 2. 2. 4. 5. 6. 6. 6. 7. VERTICAL SHEAR ADJ 0. 1. 1. 2. 2. 3. 3. 3. 3. 3. 2. 1. 1. 1. 1. 1. VERTICAL SHEAR DIR -0. -0. -0. -1. -1. -1. -0. 0. 0. 1. 2. 2. 2. 2. 2. 2. PERSISTENCE 1. 1. 1. 1. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 0. 200/250 MB TEMP. -0. -0. -0. -1. -1. -2. -2. -2. -3. -3. -3. -4. -4. -4. -4. -5. THETA_E EXCESS 0. 0. 1. 1. 1. 1. 1. 1. 1. 0. 0. 0. -0. -0. -0. -0. 700-500 MB RH 0. 0. -0. -0. -0. -1. -1. -2. -3. -3. -4. -5. -6. -6. -7. -6. MODEL VTX TENDENCY -0. -1. -1. 1. 1. -0. -0. 0. -5. -20. -22. -25. -24. -24. -23. -22. 850 MB ENV VORTICITY -0. -0. -0. -0. -1. -1. -1. -1. -1. -0. 0. 1. 1. 1. 1. 1. 200 MB DIVERGENCE 0. -0. -0. -0. -0. -0. -1. -1. -1. -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. 0. 1. 1. 1. 1. 2. 2. 2. 2. 2. 2. 2. STEERING LEVEL PRES 0. 0. 0. 0. 1. 1. 0. 1. 1. 1. 1. 1. 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 1. 1. 1. 1. 1. 1. 2. 2. 2. 1. 1. 2. 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. 4. 6. 10. 14. 13. 9. 5. 1. -3. -5. -8. -9. -9. -10. -10. ------------------------------------------------------------------------------ TOTAL CHANGE 4. 9. 14. 21. 29. 34. 34. 34. 27. 13. 12. 12. 14. 15. 17. 18. CURRENT MAX WIND (KT): 50. LAT, LON: 18.3 78.6 ** 2021 ATLANTIC RI INDEX AL072021 GRACE 08/18/21 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) : 5.0 -49.5 to 33.0 0.66 7.5 850-200 MB SHEAR (KT) : 11.3 30.1 to 2.3 0.68 3.6 HEAT CONTENT (KJ/CM2) : 82.0 0.0 to 151.8 0.54 2.6 STD DEV OF IR BR TEMP : 13.5 36.6 to 2.8 0.68 3.7 MAXIMUM WIND (KT) : 50.0 22.5 to 137.5 0.72 3.1 BL DRY-AIR FLUX (W/M2) : 301.2 895.4 to -55.0 0.63 2.7 2nd PC OF IR BR TEMP : 0.5 2.9 to -2.9 0.41 1.3 POT = MPI-VMAX (KT) : 119.4 28.3 to 146.3 0.77 1.6 D200 (10**7s-1) : 32.0 -29.7 to 185.9 0.29 0.5 %area of TPW <45 mm upshear : 0.0 100.0 to 0.0 1.00 0.4 SHIPS Prob RI for 20kt/ 12hr RI threshold= 13% is 2.6 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= 27% is 4.0 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 19% is 4.8 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 14% is 5.7 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 21% is 4.5 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 27% is 5.8 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 17% is 3.2 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: 12.7% 40.9% 27.1% 18.8% 13.7% 20.6% 27.1% 16.9% Logistic: 23.9% 48.3% 36.5% 34.7% 24.3% 33.8% 43.8% 37.9% Bayesian: 12.7% 77.2% 50.2% 9.4% 10.6% 28.3% 23.5% 10.8% Consensus: 16.4% 55.5% 37.9% 21.0% 16.2% 27.6% 31.5% 21.9% DTOPS: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/18/21 00 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 00 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 0 0( 0) 4( 4) 0( 4) <-- PROB BASED ON INTENSITY ONLY PROB(%) 0 0( 0) 1( 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) 50 54 59 64 71 62 47 47 47 35 29 28 27 27 27 27 27 18HR AGO 50 49 54 59 66 57 42 42 42 30 24 23 22 22 22 22 22 12HR AGO 50 47 46 51 58 49 34 34 34 22 16 15 DIS DIS DIS DIS DIS 6HR AGO 50 44 41 40 47 38 23 23 23 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