Show Selection: |
#713249 (Received by flhurricane at: 10:43 PM 26.Aug.2014) TCDAT4 HURRICANE CRISTOBAL DISCUSSION NUMBER 14 NWS NATIONAL HURRICANE CENTER MIAMI FL AL042014 1100 PM EDT TUE AUG 26 2014 A NOAA Hurricane Hunter aircraft investigated Cristobal earlier this evening, and found that the hurricane had strengthened a bit. Based on SFMR-observed surface winds and dropsonde data from the aircraft, the intensity was increased to 70 kt. Since the time of the aircraft mission, the convective cloud tops have warmed somewhat -- but this is likely a diurnal fluctuation. The dynamical guidance indicates that the vertical shear over Cristobal will remain modest through about 36 hours, but increase substantially thereafter. Therefore the hurricane has a window of opportunity for strengthening that should last through tomorrow night. The official wind speed forecast is close to the latest intensity model consensus. Later in the forecast period, as Cristobal nears and undergoes extratropical transition, strong baroclinic forcing should result in a powerful post-tropical storm with hurricane-force winds over the north Atlantic later this week. Aircraft fixes indicate a northward motion of about 360/13 kt. The track forecast philosophy is essentially unchanged from the previous advisory package. Over the next day or two, Cristobal should move through a weakness between 2 subtropical anticyclones. Thereafter, the cyclone should turn northeastward ahead of a mid-tropospheric shortwave trough moving off of the northeastern United States, and accelerate in the mid-latitude westerlies. The latest track model guidance has shifted a bit to the left, and the official forecast remains near the right side of the guidance suite. FORECAST POSITIONS AND MAX WINDS INIT 27/0300Z 30.4N 71.5W 70 KT 80 MPH 12H 27/1200Z 32.0N 71.2W 70 KT 80 MPH 24H 28/0000Z 34.3N 69.7W 75 KT 85 MPH 36H 28/1200Z 36.6N 66.5W 75 KT 85 MPH 48H 29/0000Z 39.5N 60.0W 75 KT 85 MPH 72H 30/0000Z 47.5N 45.5W 70 KT 80 MPH...POST-TROP/EXTRATROP 96H 31/0000Z 54.0N 33.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 01/0000Z 62.0N 23.0W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch |