ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM HURRICANE NORBERT DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014 200 PM PDT THU SEP 04 2014 Norbert has changed little on satellite images today, with the central dense overcast remaining fairly solid, and only faint hints of an eye. An Air Force Reserve Hurricane Hunter Aircraft found maximum 700 mb winds of 84 kt, with peak SFMR values of 78 kt. These data support an initial intensity of 80 kt for this advisory, which happen to correspond well to a blend of all the currently available Dvorak estimates. The hurricane is probably near its peak intensity since it will soon move over somewhat cooler SSTs and become more influenced by drier stable air from the subtropical eastern Pacific waters. Model guidance is in fairly good agreement on the cyclone gradually losing strength over the next few days, and little change has been made to the previous forecast, which remains close to the model consensus. The cyclone is expected to transition into a remnant low in about 4 days when it moves over waters cooler than 24C. Norbert is moving northwestward at about 7 kt. A mid-level ridge is expected to persist over northwestern Mexico, keeping Norbert on the same general course during the next few days. Model guidance has shifted a bit closer to the southern Baja California peninsula during the first couple of days, but all of the guidance keeps the center a relatively safe distance offshore. Thereafter, the key to the long range forecast appears to be how much ridging rebuilds in over northwestern Mexico in the wake of a weak shortwave. The ECMWF and the UKMET have a stronger ridge, which keeps Norbert, or its remnants, farther offshore of southern California. The GFS-based guidance moves Norbert closer to northwestern Mexico or southern California, mostly due to a weaker ridge. The dynamical model consensus has changed little during the past few cycles, so I have elected to keep the previous forecast almost the same at days 4-5, which is just a bit south of the latest consensus aids. Moisture from the remnants of Dolly and the Pacific ITCZ is being advected northward by the outer circulation of Norbert across northern Mexico and into the southwestern United States. This could result in heavy rains and life-threatening flash flooding in these areas during the next few days. Please see information from your local weather office for more details. FORECAST POSITIONS AND MAX WINDS INIT 04/2100Z 21.2N 110.8W 80 KT 90 MPH 12H 05/0600Z 22.0N 111.5W 80 KT 90 MPH 24H 05/1800Z 23.0N 112.5W 75 KT 85 MPH 36H 06/0600Z 23.9N 113.5W 70 KT 80 MPH 48H 06/1800Z 24.8N 114.7W 60 KT 70 MPH 72H 07/1800Z 26.4N 117.0W 45 KT 50 MPH 96H 08/1800Z 28.1N 118.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 09/1800Z 29.0N 119.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Blake NNNN