* GFS version * * ATLANTIC 2021 SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * GRACE AL072021 08/20/21 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 80 86 87 84 81 74 69 67 67 66 66 67 70 74 77 79 79 V (KT) LAND 80 86 87 60 45 33 29 27 27 27 27 27 27 27 27 27 27 V (KT) LGEM 80 87 89 63 46 33 N/A 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 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR (KT) 12 17 16 13 8 8 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR ADJ (KT) -2 -4 0 3 2 3 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SHEAR DIR 340 322 333 6 41 72 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SST (C) 30.0 30.2 29.5 28.5 29.1 28.5 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A POT. INT. (KT) 170 172 161 145 155 146 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A ADJ. POT. INT. 159 164 151 137 149 142 N/A 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 -51.6 -51.7 -51.9 -51.8 -51.8 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB VXT (C) 0.4 0.6 0.8 0.6 0.5 0.4 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A TH_E DEV (C) 11 12 10 9 11 8 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-500 MB RH 61 63 62 67 70 75 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MODEL VTX (KT) 21 20 18 12 9 3 LOST LOST LOST LOST LOST LOST LOST LOST LOST LOST LOST 850 MB ENV VOR 14 40 50 65 73 79 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 200 MB DIV 27 29 17 30 48 23 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 700-850 TADV -3 -3 -7 -8 -6 -2 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LAND (KM) 222 114 7 -121 -248 -133 N/A 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 20.3 20.1 19.8 19.2 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A LONG(DEG W) 94.5 95.6 96.7 97.9 99.2 102.3 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A STM SPEED (KT) 10 10 11 12 13 15 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A HEAT CONTENT 36 40 23 12 5 13 N/A 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/ 9 CX,CY: -8/ 0 T-12 MAX WIND: 60 PRESSURE OF STEERING LEVEL (MB): 542 (MEAN=620) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 3.2 (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): 5.0 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. 3. 2. 1. 0. -0. 0. 0. -0. -2. -2. -3. VERTICAL SHEAR MAG -1. -3. -4. -3. -2. -1. 1. 3. 4. 6. 7. 8. 10. 11. 11. 11. VERTICAL SHEAR ADJ 0. 0. 0. 0. 0. 0. 0. 0. 1. 0. 0. 0. 0. 0. 0. 0. VERTICAL SHEAR DIR 0. 0. 0. 0. 1. 2. 3. 3. 4. 4. 4. 5. 6. 6. 5. 5. PERSISTENCE 3. 4. 4. 3. 2. 1. 2. 1. 0. -1. -2. -1. -0. 1. 2. 1. 200/250 MB TEMP. -0. -1. -1. -1. -2. -3. -3. -3. -3. -4. -4. -5. -5. -5. -5. -5. THETA_E EXCESS 0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 0. 0. -0. -0. -0. -1. 700-500 MB RH -0. -0. -0. -1. -2. -2. -3. -4. -5. -5. -6. -6. -7. -7. -8. -7. MODEL VTX TENDENCY -0. -2. -6. -9. -16. -21. -24. -27. -29. -30. -31. -31. -30. -30. -29. -28. 850 MB ENV VORTICITY -0. 0. 0. 0. 1. 1. 1. 1. 2. 2. 2. 2. 2. 2. 3. 3. 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. 0. 0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 1. STEERING LEVEL PRES 0. 0. 0. 0. 1. 1. 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 1. 2. 2. 2. 2. 1. 1. 1. 1. 0. 0. 1. 2. 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. -1. -1. -2. -2. -2. -1. -0. 0. 1. 2. 2. 2. 2. 2. ------------------------------------------------------------------------------ TOTAL CHANGE 6. 7. 4. 1. -6. -11. -13. -13. -14. -14. -13. -10. -6. -3. -1. -1. CURRENT MAX WIND (KT): 80. LAT, LON: 20.6 94.5 ** 2021 ATLANTIC RI INDEX AL072021 GRACE 08/20/21 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 12.0 850-200 MB SHEAR (KT) : 13.2 30.1 to 2.3 0.61 4.0 HEAT CONTENT (KJ/CM2) : 23.2 0.0 to 151.8 0.15 0.9 STD DEV OF IR BR TEMP : 3.2 36.6 to 2.8 0.99 6.7 MAXIMUM WIND (KT) : 80.0 22.5 to 137.5 0.75 4.1 BL DRY-AIR FLUX (W/M2) : 255.0 895.4 to -55.0 0.67 3.7 2nd PC OF IR BR TEMP : -0.3 2.9 to -2.9 0.55 2.2 POT = MPI-VMAX (KT) : 71.9 28.3 to 146.3 0.37 1.0 D200 (10**7s-1) : 30.2 -29.7 to 185.9 0.28 0.6 %area of TPW <45 mm upshear : 1.5 100.0 to 0.0 0.99 0.5 SHIPS Prob RI for 20kt/ 12hr RI threshold= 36% is 7.4 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 48% is 4.4 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 36% is 5.3 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 29% is 7.5 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 20% is 8.4 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 23% is 4.9 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= 0% is 0.0 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: 36.0% 47.8% 35.8% 29.2% 20.2% 22.7% 12.2% 0.0% Logistic: 53.0% 70.0% 66.6% 64.8% 53.4% 48.3% 40.1% 28.1% Bayesian: 37.1% 54.6% 29.7% 15.4% 4.4% 7.7% 1.3% 30.4% Consensus: 42.1% 57.5% 44.0% 36.5% 26.0% 26.2% 17.9% 19.5% DTOPS: 21.0% 3.0% 3.0% 2.0% 0.0% 0.0% 0.0% 0.0% ## ANNULAR HURRICANE INDEX (AHI) AL072021 GRACE 08/20/21 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 08/20/2021 18 UTC ** TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48) CLIMO(%) 7 10( 16) 0( 16) 0( 16) <-- PROB BASED ON INTENSITY ONLY PROB(%) 4 1( 5) 0( 5) 0( 5) <-- 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) 80 86 87 60 45 33 29 27 27 27 27 27 27 27 27 27 27 18HR AGO 80 79 80 53 38 26 22 20 20 20 20 20 20 20 20 20 20 12HR AGO 80 77 76 49 34 22 18 16 16 16 16 16 16 16 16 16 16 6HR AGO 80 74 71 70 55 43 39 37 37 37 37 37 37 37 37 37 37 NOW CURRENT INTENSITY < 83 KT IN 6HR 80 86 77 71 68 63 59 57 57 57 57 57 57 57 57 57 57 IN 12HR 80 86 87 78 72 68 64 62 62 62 62 62 62 62 62 62 62