|
Show Selection: |
| #375685 (Received by flhurricane at: 10:50 PM 12.Sep.2010) TCDAT2 TROPICAL STORM JULIA DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1100 PM AST SUN SEP 12 2010 INFRARED AND MICROWAVE SATELLITE IMAGERY SHOW THAT THE CENTER OF THE CYCLONE IS LOCATED NEAR THE EASTERN EDGE OF A CURVED BAND OF CONVECTION THAT WRAPS AROUND THE WESTERN SEMICIRCLE OF THE SYSTEM. SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE 35 KT FROM TAFB AND 30 KT FROM SAB. OBJECTIVE DVORAK ESTIMATES FROM UW/CIMMS ARE SLIGHTLY HIGHER. A BLEND OF THESE ESTIMATES SUPPORT AN UPGRADE OF THE DEPRESSION TO A 35-KT TROPICAL STORM...THE TENTH OF THE 2010 ATLANTIC HURRICANE SEASON. THE EASTERLY SHEAR IS EXPECTED TO WEAKEN DURING THE NEXT 12 HOURS AND IS FORECAST TO REMAIN LIGHT OVER THE NEXT COUPLE OF DAYS. DURING THAT TIME JULIA WILL BE TRAVERSING WARM WATER AND AS A RESULT...STEADY STRENGTHENING IS ANTICIPATED. THE SHIPS...LGEM... AND GFDL MODELS ALL BRING JULIA TO HURRICANE STATUS WITHIN TWO DAYS AND THE NHC FORECAST IS IN GOOD AGREEMENT. THEREAFTER...JULIA WILL BE MOVING OVER SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND INTO AN AREA OF INCREASING SOUTHWESTERLY SHEAR TO THE EAST OF AN UPPER-LEVEL LOW/TROUGH BETWEEN 30W AND 40W. IT IS A BIT SURPRISING GIVEN THESE NEGATIVE FACTORS THAT THE INTENSITY GUIDANCE SHOWS LITTLE...IF ANY...WEAKENING. BECAUSE OF THAT...THE OFFICIAL FORECAST WILL KEEP JULIA AT 65 KT AT DAYS 3-5 FOR NOW. THE CENTER OF JULIA WAS RELOCATED A LITTLE EAST OF THE PREVIOUS ADVISORY POSITION BASED ON THE EARLIER MICROWAVE DATA. THE INITIAL MOTION ESTIMATE IS 285/10. THE TRACK FORECAST REASONING REMAINS THE SAME AS THE PREVIOUS ADVISORY. JULIA IS FORECAST TO MOVE WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A MID-LEVEL RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN ATLANTIC. IN A COUPLE OF DAYS...THE CYCLONE IS FORECAST TO TURN NORTHWESTWARD TOWARD A WEAKNESS IN THE RIDGE. MOST OF THE GUIDANCE INDICATES A TURN BACK TOWARD THE WEST-NORTHWEST LATE IN THE PERIOD AS JULIA MOVES AROUND THE NORTH SIDE OF AN UPPER-LEVEL LOW THAT CUTS OFF NEAR 40W. THE OFFICIAL FORECAST TRACK IS GOOD AGREEMENT WITH THE PREVIOUS ADVISORY AND A BLEND OF THE LATEST RUNS OF THE GFS... UKMET...GFDL...HWRF...AND ECMWF MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 13/0300Z 13.5N 23.5W 35 KT 12HR VT 13/1200Z 14.0N 25.3W 45 KT 24HR VT 14/0000Z 14.9N 27.6W 50 KT 36HR VT 14/1200Z 15.9N 29.5W 55 KT 48HR VT 15/0000Z 17.1N 31.1W 65 KT 72HR VT 16/0000Z 20.9N 35.1W 65 KT 96HR VT 17/0000Z 24.5N 41.0W 65 KT 120HR VT 18/0000Z 27.5N 46.5W 65 KT $$ FORECASTER BROWN |
