When you have a sheared storm though, sometimes it might get further west than anticipated. Here is the HWRF, GFDL and also DSHP: http://hurricanecity.com/models/models.cgi?basin=al&year=2016&storm=06&display=google_map&latestrun=1&models=HWRF,GFDL,DSHP The NHC talks about the GFDL and HWRF at 11pm Wednesday: "TROPICAL STORM FIONA DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062016 1100 PM AST WED AUG 17 2016 For a time late this afternoon, it seemed that Fiona might lose all its deep convection. However, a new burst developed around 2300 UTC and has persisted since that time. An 0026 UTC ASCAT-B pass revealed that the cyclone is still producing a small area of tropical-storm-force winds, and the intensity remains 35 kt. Fiona has a tough road ahead. Vertical shear right now is relatively low, but it is expected to begin increasing within the next 24 hours and then become belligerent out of the southwest by days 3 and 4. In addition, the cyclone is surrounded by dry air, and any negative impacts that the dry air is already having on the convection is likely to be compounded once the shear increases in a few days. With the exception of the GFDL, which makes Fiona a hurricane by the end of the forecast period, the rest of the intensity models respond to the unfavorable environment by showing relatively little strengthening. The NHC forecast follows this same thinking, and it shows Fiona only modestly strengthening during the next 36 hours, with some weakening probable by day 3. Based on the latest intensity guidance, the new NHC forecast has been adjusted downward from the previous forecast, but it still lies above the consensus at most forecast times. The recent ASCAT data helped to fix the center, and the initial motion estimate is now west-northwestward, or 300/14 kt. A break in the mid-tropospheric ridge to the north of Fiona is expected to to migrate westward during the next few days, but the cyclone's shallow nature is expected to help maintain a west-northwestward motion for much of the forecast period. The bulk of the track models are tightly clustered on such a heading. However, the GFDL (which makes Fiona hurricane) shows a sharp northward turn, while the HWRF (which essentially shows no intensification) takes a much more southern track. Since these two scenarios appear to cancel each other out, the NHC official forecast closely follows the consensus models, requiring a westward adjustment to the previous forecast. FORECAST POSITIONS AND MAX WINDS INIT 18/0300Z 15.5N 39.0W 35 KT 40 MPH 12H 18/1200Z 16.3N 40.4W 35 KT 40 MPH 24H 19/0000Z 17.1N 41.9W 40 KT 45 MPH 36H 19/1200Z 17.8N 43.5W 45 KT 50 MPH 48H 20/0000Z 18.6N 45.2W 45 KT 50 MPH 72H 21/0000Z 20.6N 49.1W 40 KT 45 MPH 96H 22/0000Z 22.5N 53.0W 40 KT 45 MPH 120H 23/0000Z 24.5N 57.0W 40 KT 45 MPH $$ Forecaster Berg" And here is the shear forecast following the DSHP track noted at the link above (DSHP taking land into account, although in this case it is over water for the duration): * ATLANTIC SHIPS INTENSITY FORECAST * * IR SAT DATA AVAILABLE, OHC AVAILABLE * * FIONA AL062016 08/18/16 00 UTC * TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120 V (KT) NO LAND 35 35 37 38 39 42 42 42 43 45 45 48 50 V (KT) LAND 35 35 37 38 39 42 42 42 43 45 45 48 50 V (KT) LGEM 35 36 36 38 39 40 39 38 36 35 34 35 38 Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP SHEAR (KT) 3 5 8 12 12 12 17 22 22 20 13 11 7 SHEAR ADJ (KT) -1 -2 -2 -1 0 0 3 4 3 3 4 1 1 SHEAR DIR 163 172 171 185 196 227 238 250 258 269 257 275 279 SST (C) 26.8 26.8 26.7 26.7 26.8 27.0 27.3 27.6 27.8 27.8 28.1 28.4 28.7 POT. INT. (KT) 123 122 120 120 121 124 127 131 134 134 138 142 147 ADJ. POT. INT. 119 117 113 111 113 116 117 122 124 124 126 128 131 200 MB T (C) -53.1 -53.3 -53.3 -53.2 -53.3 -53.5 -53.2 -53.6 -53.9 -54.2 -54.1 -54.2 -54.2 200 MB VXT (C) -0.1 -0.1 -0.1 -0.1 -0.2 -0.1 0.0 0.2 0.2 0.1 0.3 0.2 0.1 TH_E DEV (C) 7 7 7 7 8 7 8 8 9 9 10 10 11 700-500 MB RH 57 58 56 55 55 47 42 40 38 39 43 47 47 MODEL VTX (KT) 13 13 13 13 13 13 12 11 10 10 8 8 7 850 MB ENV VOR 53 40 31 26 34 32 28 19 -2 -25 -37 -47 -49 200 MB DIV -12 -4 4 16 26 23 -6 5 6 -5 13 -1 -5 700-850 TADV 0 -1 0 1 3 5 7 9 11 14 9 9 6 LAND (KM) 1865 1845 1833 1815 1799 1772 1751 1740 1706 1613 1452 1327 1208 LAT (DEG N) 15.2 15.9 16.5 16.9 17.2 18.2 19.0 19.7 20.7 21.8 23.1 24.1 24.9 LONG(DEG W) 38.5 39.4 40.3 41.0 41.7 43.4 45.1 46.8 48.8 50.7 52.7 54.5 56.4 STM SPEED (KT) 13 11 9 8 8 10 9 10 10 11 10 10 9 HEAT CONTENT 9 6 5 9 13 15 9 9 9 19 25 27 24 FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):300/ 14 CX,CY: -11/ 7 T-12 MAX WIND: 35 PRESSURE OF STEERING LEVEL (MB): 520 (MEAN=618) GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 17.2 (MEAN=14.5) % GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 13.0 (MEAN=65.0) PRELIM RI PROB (DV .GE. 30 KT IN 24 HR): 5.1 INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE 6 12 18 24 36 48 60 72 84 96 108 120 ---------------------------------------------------------- SAMPLE MEAN CHANGE 1. 2. 3. 4. 6. 8. 9. 11. 11. 12. 13. 13. SST POTENTIAL 1. 1. 1. 2. 4. 7. 10. 13. 16. 18. 19. 20. VERTICAL SHEAR MAG 1. 2. 3. 4. 5. 5. 4. 2. 0. -1. -1. 0. VERTICAL SHEAR ADJ 0. 0. 1. 1. 1. 1. 1. 0. 0. -1. -1. -1. VERTICAL SHEAR DIR 0. 0. -1. -1. -2. -4. -5. -7. -7. -7. -8. -8. PERSISTENCE 0. -1. -1. -1. -1. -1. -1. -1. 0. 0. 0. 0. 200/250 MB TEMP. 0. -1. -1. -2. -2. -2. -2. -2. -2. -1. -1. 0. THETA_E EXCESS 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 700-500 MB RH 0. 0. 0. 0. 0. 0. 1. 1. 2. 2. 2. 2. MODEL VTX TENDENCY 0. 0. 0. 0. -1. -3. -5. -7. -7. -10. -12. -13. 850 MB ENV VORTICITY 0. 0. 0. 0. 0. 0. 0. 0. 0. -1. -1. -2. 200 MB DIVERGENCE 0. 0. -1. -1. -1. -1. -1. -1. -1. 0. 1. 2. 850-700 T ADVEC 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 1. 0. ZONAL STORM MOTION 0. 0. 0. 1. 1. 1. 2. 2. 2. 2. 3. 3. STEERING LEVEL PRES 0. 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. GOES PREDICTORS -1. -2. -3. -3. -4. -5. -5. -5. -5. -4. -2. -2. OCEAN HEAT CONTENT 0. 0. 0. 0. -1. -1. -1. -1. -1. -1. -1. -1. ---------------------------------------------------------- TOTAL CHANGE 0. 2. 3. 4. 7. 7. 7. 8. 10. 10. 13. 15. CURRENT MAX WIND (KT): 35. LAT, LON: 15.2 38.5 ** 2015 ATLANTIC RI INDEX AL062016 FIONA 08/18/16 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 3.7 850-200 MB SHEAR (KT) : 8.2 28.8 to 2.9 0.80 2.1 HEAT CONTENT (KJ/cm2) : 8.4 0.0 to 155.1 0.05 0.1 STD DEV OF IR BR TEMP : 17.2 37.5 to 2.9 0.59 1.6 2nd PC OF IR BR TEMP : -0.4 2.8 to -3.1 0.54 1.4 MAXIMUM WIND (kt) : 35.0 22.5 to 121.0 0.35 0.3 D200 (10**7s-1) : 6.0 -23.1 to 181.5 0.14 0.2 POT = MPI-VMAX (KT) : 79.6 28.4 to 139.1 0.46 0.7 % AREA WITH TPW <45 mm: 0.0 100.0 to 0.0 1.00 0.6 BL DRY-AIR FLUX (w/m2): 230.2 960.3 to -67.1 0.71 0.0 SHIPS Prob RI for 20kt/ 12hr RI threshold= 6% is 1.1 times sample mean ( 5.5%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 15% is 1.3 times sample mean (11.6%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 11% is 1.5 times sample mean ( 7.2%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 10% is 2.3 times sample mean ( 4.2%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times sample mean ( 2.8%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 9% is 1.8 times sample mean ( 4.9%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 15% is 3.0 times sample mean ( 5.1%) Matrix of RI probabilities --------------------------------------------------------------------- RI (kt / h) | 20/12 | 25/24 | 30/24 | 35/24 | 40/24 | 45/36 | 55/48 --------------------------------------------------------------------- SHIPS-RII: 5.8% 15.5% 10.7% 9.8% 0.0% 9.0% 15.4% Logistic: 4.6% 17.1% 9.1% 4.6% 0.0% 0.9% 0.2% Bayesian: 0.1% 0.3% 0.1% 0.0% 0.0% 0.0% 0.0% Consensus: 3.5% 11.0% 6.6% 4.8% 0.0% 3.3% 5.2% ## ANNULAR HURRICANE INDEX (AHI) AL062016 FIONA 08/18/16 00 UTC ## ## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=4 NFAIL=3 ## ## 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 AL062016 FIONA 08/18/2016 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 >24HR AGO (DSHIPS) 35 35 37 38 39 42 42 42 43 45 45 48 50 18HR AGO 35 34 36 37 38 41 41 41 42 44 44 47 49 12HR AGO 35 32 31 32 33 36 36 36 37 39 39 42 44 6HR AGO 35 29 26 25 26 29 29 29 30 32 32 35 37 NOW CURRENT INTENSITY < 83 KT IN 6HR INTENSITY IN 6HR < 83 KT IN 12HR INTENSITY IN 12HR < 83 KT From: ftp://ftp.nhc.noaa.gov/atcf/stext/ You can see the shear forecast. It seems to be what is often the case. Stronger, more north. Weaker, more west. Many days to see if Bermuda could see any impact at all, even waves. |