|
Show Selection: |
| #859002 (Received by flhurricane at: 5:04 AM 06.Jun.2016) TCDAT3 TROPICAL STORM COLIN DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032016 400 AM CDT MON JUN 06 2016 Colin remains poorly organized this morning. Surface observations and data from NOAA and Air Force Reserve Hurricane Hunter aircraft suggest that at least two small-scale circulation centers are present, one near an intense burst of convection around 24.5N 85.5W and the other well to the west-northwest near 25.5N 89W. The low confidence initial position splits the difference between these two features. The Air Force aircraft reported 850-mb flight-level winds of 71 kt and estimated 60 kt surface winds on the SFMR instrument. However, these winds were measured in the aforementioned convection, and it is unclear how representative they are. There is sufficient data to justify increasing the initial intensity to 45 kt. The cyclone appears to be moving faster, with the initial motion now 015/12. The track forecast reasoning again has not changed from the previous advisory. Over the next day or so, Colin should move north-northeastward to northeastward in the flow between a deep-layer trough over the western and northern Gulf of Mexico and a ridge over the subtropical western Atlantic. After that time, the cyclone will become embedded in strong southwesterly flow associated with a large baroclinic low over the eastern United States. The track guidance has nudged northward since the previous advisory, and the new forecast track, which lies near the consensus models, is also nudged northward. The poor organization and the presence of moderate vertical wind shear suggest that significant strengthening is unlikely before Colin makes landfall in Florida in less than 24 hours. The global models forecast winds of near 50 kt as Colin moves over the Atlantic and begins extratropical transition, and the latter part of the intensity forecast is based on this guidance. The model guidance forecasts that extratropical transition should be complete by about 72 hours. It is important to emphasize that one should not focus on the exact forecast track of this system. Strong winds, heavy rains and coastal flooding are likely to occur well to the east of the center. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 25.2N 87.4W 45 KT 50 MPH 12H 06/1800Z 27.6N 85.8W 45 KT 50 MPH 24H 07/0600Z 30.7N 81.9W 45 KT 50 MPH...INLAND 36H 07/1800Z 33.8N 76.2W 50 KT 60 MPH...OVER WATER 48H 08/0600Z 37.6N 67.8W 50 KT 60 MPH 72H 09/0600Z 45.0N 50.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 10/0600Z 50.0N 36.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 11/0600Z 54.0N 29.9W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven |
