* GFS version * * ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/20/21 06 UTC * TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120 132 144 156 168 V (KT) NO LAND 60 63 65 67 66 62 57 59 61 64 65 68 71 74 75 78 79 V (KT) LAND 60 63 65 67 56 37 30 28 27 27 27 27 27 27 27 27 27 V (KT) LGEM 60 64 68 70 61 38 30 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) 11 15 13 13 16 8 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 -2 -2 0 2 8 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR DIR 351 5 358 329 328 38 27 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SST (C) 30.0 30.1 30.3 30.3 29.2 28.9 28.5 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A POT. INT. (KT) 171 172 172 171 155 151 144 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A ADJ. POT. INT. 164 163 165 165 146 142 135 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB T (C) -52.0 -52.3 -52.1 -51.7 -51.8 -52.0 -51.9 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB VXT (C) 0.8 0.6 0.4 0.4 0.6 0.7 0.4 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A TH_E DEV (C) 10 9 11 12 10 11 8 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-500 MB RH 57 58 61 62 63 70 75 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MODEL VTX (KT) 19 19 19 19 16 9 4 LOST LOST LOST LOST LOST LOST LOST LOST LOST LOST 850 MB ENV VOR -11 -4 11 40 51 72 83 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB DIV 22 9 21 23 27 66 43 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-850 TADV -7 -6 -1 -3 -5 -4 -4 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LAND (KM) 234 261 179 73 -33 -290 -157 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LAT (DEG N) 20.7 20.8 20.8 20.6 20.4 19.7 19.4 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LONG(DEG W) 92.7 93.9 95.1 96.1 97.2 99.6 101.8 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A STM SPEED (KT) 13 11 10 10 11 11 11 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A HEAT CONTENT 29 35 43 40 18 6 12 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):270/ 15 CX,CY: -14/ 0 T-12 MAX WIND: 50 PRESSURE OF STEERING LEVEL (MB): 543 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 16.8 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 69.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 5.2 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 1. 3. 4. 5. 6. 7. 9. 11. 12. 14. 16. 17. 18. 18. 18. 17. VERTICAL SHEAR MAG -0. -0. -1. -1. -0. 2. 3. 4. 5. 6. 6. 7. 7. 8. 8. 9. VERTICAL SHEAR ADJ 0. 0. 1. 1. 1. 0. 0. 1. 1. 1. 1. 1. 1. 1. 0. 0. VERTICAL SHEAR DIR 0. 0. 0. 0. 1. 2. 3. 3. 3. 4. 4. 5. 5. 5. 5. 5. PERSISTENCE 2. 2. 2. 2. 1. 1. 1. 1. 0. 0. -0. -0. 0. 1. 1. 1. 200/250 MB TEMP. -0. -1. -1. -1. -2. -3. -3. -3. -3. -3. -4. -4. -5. -5. -5. -5. THETA_E EXCESS 0. 0. 0. 1. 1. 1. 1. 1. 1. 0. 0. 0. -0. -0. -0. -1. 700-500 MB RH -0. -0. -0. -0. -1. -2. -3. -4. -4. -5. -5. -5. -6. -6. -7. -6. MODEL VTX TENDENCY -0. -1. -1. -3. -10. -18. -21. -24. -25. -27. -28. -28. -27. -27. -26. -25. 850 MB ENV VORTICITY -0. -0. -0. -0. 0. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 200 MB DIVERGENCE -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. 0. 0. 0. 0. -0. 850-700 T ADVEC 0. -0. -0. -0. -0. -1. -1. -1. -1. -0. -0. -0. -0. -0. -0. -0. ZONAL STORM MOTION -0. -0. 0. 0. 1. 1. 1. 1. 2. 2. 3. 3. 3. 3. 3. 3. STEERING LEVEL PRES 0. 0. 0. 0. 1. 0. 0. 0. 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 0. 0. -0. -0. 0. 0. 1. 1. 1. 1. 1. 1. 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 3. 5. 7. 6. 2. -3. -1. 1. 4. 5. 8. 11. 14. 15. 18. 19. CURRENT MAX WIND (KT): 60. LAT, LON: 20.7 92.7 ** 2021 ATLANTIC RI INDEX AL072021 GRACE 08/20/21 06 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 -49.5 to 33.0 0.72 6.6 850-200 MB SHEAR (KT) : 13.8 30.1 to 2.3 0.59 2.5 HEAT CONTENT (KJ/CM2) : 33.0 0.0 to 151.8 0.22 0.8 STD DEV OF IR BR TEMP : 16.8 36.6 to 2.8 0.59 2.5 MAXIMUM WIND (KT) : 60.0 22.5 to 137.5 0.98 3.4 BL DRY-AIR FLUX (W/M2) : 267.0 895.4 to -55.0 0.66 2.3 2nd PC OF IR BR TEMP : 0.4 2.9 to -2.9 0.43 1.1 POT = MPI-VMAX (KT) : 100.8 28.3 to 146.3 0.61 1.0 D200 (10**7s-1) : 20.4 -29.7 to 185.9 0.23 0.3 %area of TPW <45 mm upshear : 3.1 100.0 to 0.0 0.97 0.3 SHIPS Prob RI for 20kt/ 12hr RI threshold= 11% is 2.3 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 30% is 2.8 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 21% is 3.1 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 14% is 3.6 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= 15% is 3.4 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= 15% 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: 11.1% 30.2% 20.9% 14.0% 8.1% 15.4% 12.3% 14.5% Logistic: 9.5% 33.5% 24.5% 17.5% 10.8% 22.8% 29.2% 36.1% Bayesian: 4.0% 23.5% 7.8% 0.8% 0.5% 3.2% 3.6% 40.7% Consensus: 8.2% 29.0% 17.7% 10.8% 6.5% 13.8% 15.0% 30.5% DTOPS: 27.0% 1.0% 1.0% 0.0% 0.0% 0.0% 0.0% 0.0% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/20/21 06 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 08/20/2021 06 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 0 2( 2) 0( 2) 0( 2) <-- 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) 60 63 65 67 56 37 30 28 27 27 27 27 27 27 27 27 27 18HR AGO 60 59 61 63 52 33 26 24 23 23 23 23 23 23 23 23 23 12HR AGO 60 57 56 58 47 28 21 19 18 18 18 18 18 18 18 18 18 6HR AGO 60 54 51 50 39 20 DIS 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