je.st
news
Tropical Storm BERTHA Forecast Discussion Number 8
2014-08-02 22:51:30| National Hurricane Center (Atlantic)
Issued at 500 PM AST SAT AUG 02 2014 000 WTNT43 KNHC 022050 TCDAT3 TROPICAL STORM BERTHA DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032014 500 PM AST SAT AUG 02 2014 Bertha has maintained some organized convection over the eastern semicircle during the past several hours. However, the system barely qualifies as a tropical cyclone, as a combination of NOAA Hurricane Hunter aircraft and surface data cannot definitively close off the circulation. The initial intensity is reduced to 40 kt based on a combination of surface observations and data from the San Juan WSR-88D Doppler radar. It should be noted that Bertha continues to suffer from dry air entrainment and northwesterly vertical shear, and advisories could be discontinued tonight or Sunday if the system becomes any less organized. The initial motion is now 300/19. Bertha is approaching the southwestern edge of the subtropical ridge and should turn northwestward during the next several hours. A turn toward the north should occur in about 48 hours as Bertha moves between the ridge and a deep-layer trough over the southeastern United States. After that, the cyclone should turn northeastward as it enters the mid-latitude westerlies. The track guidance remains in good agreement on this scenario, and the new forecast track is again generally similar to the previous track. There are now three possible scenarios for the intensity of Bertha. The scenario for the official forecast is that Bertha survives its current lack of structure, land interaction, and dry air entrainment long enough to reach a more favorable environment in about 36 hours. At that point, it would likely intensify until the onset of extratropical transition in 96-120 hours. Using this scenario, the new intensity forecast is similar to the previous forecast and calls for Bertha to become a hurricane in about 96 hours. The second scenario is that Bertha degenerates to a tropical wave as it passes over Hispaniola, with possible regeneration later when the system reaches the more favorable environment. A new third possibility involves a low pressure area currently developing over the northwestern Bahamas. The UKMET and NAVGEM forecast this low to get strong enough to absorb Bertha in 48 hours or so, while the other models are less bullish on the its development. Later model runs should help determine the likelihood of this scenario. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 18.4N 68.5W 40 KT 45 MPH 12H 03/0600Z 20.0N 70.3W 40 KT 45 MPH 24H 03/1800Z 22.5N 72.7W 40 KT 45 MPH 36H 04/0600Z 25.1N 74.1W 45 KT 50 MPH 48H 04/1800Z 28.0N 74.1W 50 KT 60 MPH 72H 05/1800Z 34.0N 70.5W 60 KT 70 MPH 96H 06/1800Z 38.5N 63.0W 65 KT 75 MPH 120H 07/1800Z 43.5N 53.0W 50 KT 60 MPH $$ Forecaster Beven
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||