000 WTPZ44 KNHC 220244 TCDEP4 TROPICAL DEPRESSION NINE-E DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092010 800 PM PDT SAT AUG 21 2010 SATELLITE IMAGERY INDICATES THAT THE DEPRESSION HAS BECOME A LITTLE BETTER ORGANIZED DURING THE PAST FEW HOURS AS AN IRREGULAR CENTRAL CONVECTIVE FEATURE HAS FORMED WITH SOME OUTER BANDING. THE INITIAL INTENSITY IS RAISED TO 30 KT IN AGREEMENT WITH A SATELLITE INTENSITY ESTIMATE FROM TAFB. THE DEPRESSION IS CURRENTLY IN A LIGHT VERTICAL WIND SHEAR ENVIRONMENT FAIR TO GOOD CIRRUS OUTFLOW IN ALL DIRECTIONS EXCEPT TO THE NORTH. THE INITIAL INTENSITY IS A SOMEWHAT ERRATIC 270/3. THE CYCLONE REMAINS IN A WEAK STEERING FLOW ENVIRONMENT...AND IN THE SHORT-TERM SOME ADDITIONAL ERRATIC MOTION MAY BE SUPERIMPOSED ON A WESTWARD DRIFT. AFTER 24 HOURS OR SO...A BUILDING LOW/MID-LEVEL RIDGE OVER MEXICO SHOULD STEER THE SYSTEM SLOWLY TOWARD THE WEST AND WEST-NORTHWEST. THERE REMAINS SOME SPREAD IN THE GUIDANCE. THE GFS AND THE HWRF SHOW THE CYCLONE MOVING ONSHORE NEAR OR OVER THE ISTHMUS OF TEHUANTEPEC...WHILE THE UKMET HAS A WEST-NORTHWESTWARD TRACK ALONG OR CLOSE TO THE COAST OF MEXICO. THE REMAINDER OF THE GUIDANCE FORECASTS A MOTION PARALLEL TO...BUT OFFSHORE OF...THE COAST OF MEXICO. THE NEW FORECAST TRACK FOLLOWS THAT SCENARIO AND IS SIMILAR TO...BUT SOMEWHAT FASTER THAN THE PREVIOUS FORECAST. THE FORECAST TRACK IS IN BEST OVERALL AGREEMENT WITH THE ECMWF. VERTICAL WIND SHEAR AND SEA SURFACE TEMPERATURES CONDITIONS APPEAR CONDUCIVE FOR DEVELOPMENT...AND THE SHIPS AND LGEM MODELS FORECAST THE DEPRESSION TO BECOME A HURRICANE IN 48-60 HOURS. THE SHIPS RAPID INTENSIFICATION INDEX HAS A 85-90 PERCENT CHANCE OF 25 KT OF INTENSIFICATION DURING THE NEXT 24 HOURS...AND A 40-45 PERCENT CHANCE OF 40 KT OF INTENSIFICATION. ON THE OTHER HAND...ANY MOTION THAT BRINGS THE CENTER NEAR THE COAST OF MEXICO WOULD LIKELY PREVENT RAPID INTENSIFICATION. ALSO...THE GFDL MODEL...WHICH KEEPS THE CENTER OFFSHORE...DOES NOT FORECAST HURRICANE STRENGTH DURING THE FORECAST PERIOD. DUE TO THESE THINGS...THE INTENSITY FORECAST DOES NOT CALL FOR RAPID INTENSIFICATION. INSTEAD...IT WILL BE SIMILAR TO...BUT A LITTLE BELOW...THE SHIPS/LGEM MODELS. TROPICAL STORM WARNINGS COULD BE REQUIRED FOR PORTIONS OF THE PACIFIC COAST OF MEXICO ON SUNDAY IF THE DEPRESSION TRACKS CLOSE TO LAND OR BECOMES LARGER THAN CURRENTLY FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 22/0300Z 13.8N 93.8W 30 KT 12HR VT 22/1200Z 13.8N 94.5W 35 KT 24HR VT 23/0000Z 13.8N 95.6W 45 KT 36HR VT 23/1200Z 13.8N 96.6W 55 KT 48HR VT 24/0000Z 13.9N 97.9W 60 KT 72HR VT 25/0000Z 14.5N 100.0W 65 KT 96HR VT 26/0000Z 15.5N 102.0W 65 KT 120HR VT 27/0000Z 17.0N 104.5W 65 KT $$ FORECASTER BEVEN