* GFS version * * ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/20/21 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 75 81 84 85 82 76 71 70 70 70 69 70 74 77 79 82 82 V (KT) LAND 75 81 84 71 53 35 29 28 27 27 27 27 27 27 27 27 27 V (KT) LGEM 75 83 88 76 56 35 29 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) 16 12 12 14 12 9 6 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR ADJ (KT) 0 -1 -1 0 3 0 3 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR DIR 360 359 332 333 7 55 57 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SST (C) 29.9 30.1 30.1 28.9 28.5 28.2 28.9 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A POT. INT. (KT) 169 172 172 150 144 140 151 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A ADJ. POT. INT. 161 163 162 141 135 133 144 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB T (C) -52.3 -52.2 -51.7 -51.8 -52.0 -51.7 -52.0 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB VXT (C) 0.6 0.3 0.3 0.6 0.6 0.6 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) 8 10 12 10 9 11 7 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-500 MB RH 58 61 63 62 67 71 77 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MODEL VTX (KT) 20 19 19 17 13 6 4 LOST LOST LOST LOST LOST LOST LOST LOST LOST LOST 850 MB ENV VOR 0 14 39 50 64 77 76 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB DIV 15 26 40 34 28 35 54 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-850 TADV -5 -2 -2 -6 -8 -5 3 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LAND (KM) 246 185 75 -35 -146 -222 -84 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LAT (DEG N) 20.6 20.5 20.4 20.2 20.0 19.5 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) 93.7 94.9 96.0 97.1 98.2 100.6 103.2 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A STM SPEED (KT) 12 11 10 11 11 12 12 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A HEAT CONTENT 30 37 36 17 10 9 15 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):265/ 13 CX,CY: -12/ 0 T-12 MAX WIND: 55 PRESSURE OF STEERING LEVEL (MB): 534 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 6.5 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 100.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 9.6 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 2. 4. 5. 6. 5. 4. 3. 3. 3. 3. 4. 4. 3. 2. 1. 1. VERTICAL SHEAR MAG -1. -2. -2. -3. -2. 0. 2. 4. 5. 7. 8. 8. 10. 11. 11. 11. VERTICAL SHEAR ADJ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. VERTICAL SHEAR DIR 0. 0. 0. 0. 1. 3. 3. 4. 4. 5. 5. 6. 7. 7. 7. 7. PERSISTENCE 3. 4. 4. 3. 2. 2. 2. 1. 0. -1. -1. -1. -0. 1. 2. 2. 200/250 MB TEMP. -0. -1. -1. -1. -2. -3. -3. -3. -3. -3. -4. -4. -5. -5. -4. -5. THETA_E EXCESS 0. 0. 0. 0. 1. 1. 1. 1. 0. 0. 0. 0. -0. -0. -0. -0. 700-500 MB RH -0. -0. -0. -0. -1. -2. -3. -4. -5. -5. -6. -6. -7. -7. -8. -7. MODEL VTX TENDENCY -0. -1. -2. -5. -12. -19. -22. -25. -26. -28. -29. -29. -28. -28. -27. -26. 850 MB ENV VORTICITY -0. -0. -0. 0. 0. 1. 1. 1. 1. 1. 1. 2. 2. 2. 2. 2. 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. -0. -0. -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. 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. 2. 2. 2. 2. 2. 2. 2. 1. 1. 1. 2. 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 0. 0. 0. -0. -0. -0. -0. -0. -0. 0. 0. 1. 1. 1. 1. 1. ------------------------------------------------------------------------------ TOTAL CHANGE 6. 9. 10. 7. 1. -4. -5. -5. -5. -6. -5. -1. 2. 4. 7. 7. CURRENT MAX WIND (KT): 75. LAT, LON: 20.6 93.7 ** 2021 ATLANTIC RI INDEX AL072021 GRACE 08/20/21 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) : 20.0 -49.5 to 33.0 0.84 11.0 850-200 MB SHEAR (KT) : 13.2 30.1 to 2.3 0.61 3.7 HEAT CONTENT (KJ/CM2) : 26.0 0.0 to 151.8 0.17 0.9 STD DEV OF IR BR TEMP : 6.5 36.6 to 2.8 0.89 5.5 MAXIMUM WIND (KT) : 75.0 22.5 to 137.5 0.82 4.0 BL DRY-AIR FLUX (W/M2) : 290.4 895.4 to -55.0 0.64 3.2 2nd PC OF IR BR TEMP : -0.1 2.9 to -2.9 0.52 1.9 POT = MPI-VMAX (KT) : 77.2 28.3 to 146.3 0.41 1.0 D200 (10**7s-1) : 28.6 -29.7 to 185.9 0.27 0.6 %area of TPW <45 mm upshear : 4.4 100.0 to 0.0 0.96 0.4 SHIPS Prob RI for 20kt/ 12hr RI threshold= 36% is 7.3 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 45% is 4.1 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 32% is 4.7 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 26% is 6.7 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 19% is 7.9 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 22% is 4.7 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 15% is 3.1 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 14% is 2.6 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: 35.9% 45.2% 32.2% 26.3% 19.1% 21.7% 14.6% 13.7% Logistic: 48.6% 66.9% 62.1% 58.2% 45.8% 47.7% 45.6% 37.4% Bayesian: 36.2% 54.1% 32.9% 14.3% 5.2% 5.1% 2.4% 28.6% Consensus: 40.2% 55.4% 42.4% 32.9% 23.4% 24.8% 20.8% 26.6% DTOPS: 32.0% 1.0% 1.0% 0.0% 0.0% 0.0% 0.0% 0.0% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/20/21 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 08/20/2021 12 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 5 9( 14) 0( 14) 0( 14) <-- PROB BASED ON INTENSITY ONLY PROB(%) 1 14( 15) 0( 15) 0( 15) <-- 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) 75 81 84 71 53 35 29 28 27 27 27 27 27 27 27 27 27 18HR AGO 75 74 77 64 46 28 22 21 20 20 20 20 20 20 20 20 20 12HR AGO 75 72 71 58 40 22 16 15 DIS DIS DIS DIS DIS DIS DIS DIS DIS 6HR AGO 75 69 66 65 47 29 23 22 21 21 21 21 21 21 21 21 21 NOW CURRENT INTENSITY < 83 KT IN 6HR INTENSITY IN 6HR < 83 KT IN 12HR 75 81 84 75 69 65 59 58 57 57 57 57 57 57 57 57 57