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Hurricane SIMON Forecast Discussion Number 13
2014-10-04 22:47:00| National Hurricane Center (East Pacific)
Issued at 200 PM PDT SAT OCT 04 2014 000 WTPZ44 KNHC 042046 TCDEP4 HURRICANE SIMON DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP192014 200 PM PDT SAT OCT 04 2014 A NOAA Hurricane Hunter Aircraft, carrying meteorologists from the Meteorological Service of Mexico, reports that Simon has become a major hurricane. The aircraft measured 700 mb flight-level winds of 114 kt, and the Stepped Frequency Microwave Radiometer estimated surface winds of 104 kt. The minimum reported pressure was 950 mb inside a 7 n mi wide eye. Based on this information, the initial intensity is increased to 105 kt. The initial motion is 295/12. Simon is expected to move generally northwestward for the next 24-36 hours or so as is approaches a weakness in the subtropical ridge to its north. After that, the system is expected to turn northward and northeastward. There have been some changes in the track guidance since the last advisory. The ECMWF and Canadian models have shifted to the right and show a faster northward motion, with the ECMWF now calling for landfall on the Baja California peninsula in about four days. The GFS, NAVGEM, and the GFDL continue show Simon moving quickly to the northeast, with the GFS forecasting landfall on the Baja California peninsula in about three days. The new forecast track has not changed much in direction since the last advisory, but it has a faster forward speed. That being said, the new forecast is still slower than the consensus models, and additional adjustments to the speed could be required on later advisories. A combination of microwave imagery and aircraft data suggest that Simon is about to start an eyewall replacement cycle. Some additional strengthening could occur in the next few hours before the eyewall replacement and decreasing sea surface temperatures end intensification. A weakening trend should begin after 12 hours due to the cooler water, and this trend should accelerate after 36 hours as the cyclone encounters increasing shear and a very dry air mass. The new intensity forecast follows the trend of the previous forecast in making Simon a remnant low by the end of the forecast period. An alternative scenario is that Simon could make landfall in Mexico as a weakening tropical cyclone if it moves as fast as the GFS is forecasting. Simon is the eighth major hurricane of the 2014 Eastern North Pacific Hurricane season. This ties the record for major hurricanes set in 1983, 1992, and 1993. FORECAST POSITIONS AND MAX WINDS INIT 04/2100Z 20.6N 115.0W 105 KT 120 MPH 12H 05/0600Z 21.5N 116.4W 105 KT 120 MPH 24H 05/1800Z 22.7N 117.4W 100 KT 115 MPH 36H 06/0600Z 23.5N 117.6W 85 KT 100 MPH 48H 06/1800Z 24.1N 117.6W 75 KT 85 MPH 72H 07/1800Z 25.5N 117.0W 50 KT 60 MPH 96H 08/1800Z 26.5N 116.0W 35 KT 40 MPH 120H 09/1800Z 27.5N 115.0W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven
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