Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #712626 (Received by flhurricane at: 11:00 AM 24.Aug.2014) TCDAT4 TROPICAL STORM CRISTOBAL DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL042014 1100 AM EDT SUN AUG 24 2014 The overall cloud pattern of Cristobal has changed little since the previous advisory. Flight-level wind data from the Air Force Reserve and NOAA reconnaissance aircraft investigating Cristobal earlier this morning indicated that the low-level and mid-level circulations were not vertically aligned, suggesting that the inner-core wind field of the cyclone is still trying to form. The initial intensity of 40 kt is based on 1000-ft flight-level winds of 49 kt and a few reliable SFMR winds of near 40 kt. The initial motion is an uncertain 345/6 kt. There are significant differences noted between the various NHC models. The GFS model and the GFS ensemble mean shear the mid-level circulation southward from the current position, and take the remaining shallow and weak low-level circulation quickly northeastward, which seems unlikely at this time given the overall large structure of the cyclone noted in recon, satellite, and upper-air data. In contrast, the ECMWF, UKMET, and NAVGEM models keep Cristobal as a deeper, stronger, and more vertically coherent cyclone, moving the system only slowly north-northwestward or northwestward for the next 72 hours or so as a strong mid-latitude trough over the Carolinas lifts out to the northeast. As the trough lifts out, the subtropical ridge is expected to build back in to the north of Cristobal until a second trough moves off the U.S. east coast in 4-5 days and weakens the ridge again, allowing Cristobal to move slowly northward and then accelerate off to the northeast. More weight has been placed the on the ECMWF-UKMET-NAVGEM solutions, and the official forecast track remains near the left side of the guidance envelope. Light to moderate northwesterly to northerly shear is expected to affect Cristobal throughout the forecast period. However, the shear is not forecast to be strong enough to prevent at least slow strengthening, especially given that the upper-level flow is expected to be quite diffluent and divergent through at least 48 hours, which will act to enhance convective development. The NHC intensity forecast remains close to SHIPS guidance. FORECAST POSITIONS AND MAX WINDS INIT 24/1500Z 23.6N 73.1W 40 KT 45 MPH 12H 25/0000Z 24.2N 73.4W 45 KT 50 MPH 24H 25/1200Z 24.9N 73.6W 50 KT 60 MPH 36H 26/0000Z 25.7N 73.8W 55 KT 65 MPH 48H 26/1200Z 26.6N 74.1W 60 KT 70 MPH 72H 27/1200Z 29.3N 74.9W 65 KT 75 MPH 96H 28/1200Z 32.2N 73.3W 70 KT 80 MPH 120H 29/1200Z 35.0N 67.3W 75 KT 85 MPH $$ Forecaster Stewart |
