000 WTNT45 KNHC 030244 TCDAT5 TROPICAL STORM EMILY DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL052011 1100 PM AST TUE AUG 02 2011 THE AREA OF COLD CLOUD TOPS HAS EXPANDED OVER THE PAST FEW HOURS IN A CDO-LIKE PATTERN...HOWEVER A 2157 UTC SSMIS PASS SUGGESTED THAT THE LOW-LEVEL CENTER REMAINS DISPLACED TO THE WEST OF THE DEEPEST CONVECTION. DVORAK CURRENT INTENSITY ESTIMATES WERE 3.0...45 KT...FROM TAFB AND SAB AT 00Z...THAT THAT WILL REMAIN THE INTENSITY FOR THIS ADVISORY PACKAGE. ANOTHER AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE EMILY OVERNIGHT. UW-CIMSS SATELLITE ANALYSIS SHOWS ABOUT 12 KT OF WESTERLY SHEAR OVER EMILY...WHICH IS CONSISTENT WITH THE TILTED STRUCTURE OF THE CYCLONE AND THE LOCATION OF A MID-LEVEL CIRCULATION SEEN IN VELOCITY DATA FROM THE SAN JUAN DOPPLER RADAR. OVERALL THE ENVIRONMENT APPEARS FAVORABLE FOR SOME CONTINUED STRENGTHENING UNTIL THE CYCLONE REACHES HISPANIOLA IN ABOUT 24 HOURS...AND THE OFFICIAL FORECAST HAS BEEN ADJUSTED UPWARD A BIT IN AGREEMENT WITH THE IVCN INTENSITY CONSENSUS THROUGH THAT TIME. IF EMILY SURVIVES ITS TRIP ACROSS THE HIGH TERRAIN OF HISPANIOLA...THE ENVIRONMENT APPEARS SUPPORTIVE OF RE-INTENSIFICATION LATE IN THE PERIOD. THE OFFICIAL FORECAST HAS BEEN ADJUSTED UPWARD A LITTLE FROM THE PREVIOUS ADVISORY...BUT REMAINS BELOW THE GUIDANCE GIVEN THE UNCERTAINTY IN HOW EMILY WILL FARE AFTER LAND INTERACTION. THE CENTER HAS BEEN DIFFICULT TO LOCATE THIS EVENING GIVEN THE LACK OF AIRCRAFT AND MICROWAVE DATA. BASED ON THE ABOVE-MENTIONED SSMIS PASS...THE CENTER IS ASSUMED TO BE WEST OF THE COLDEST CLOUD TOPS... YIELDING AN UNCERTAIN INITIAL MOTION ESTIMATE OF 285/12...TOWARD THE WEST-NORTHWEST. THE SYNOPTIC REASONING REMAINS UNCHANGED...AS A MID-LEVEL TROUGH WILL REACH MAXIMUM AMPLITUDE OVER THE WESTERN ATLANTIC IN THE NEXT 24 HOURS...ALLOWING EMILY TO TURN NORTHWESTWARD AND MOVE ACROSS HISPANIOLA AND INTO THE SOUTHEASTERN BAHAMAS IN THE NEXT 24 TO 36 HOURS. AFTER THE TROUGH LIFTS OUT A MID-LEVEL WEAKNESS IS EXPECTED TO PERSIST OVER THE SOUTHWESTERN ATLANTIC THROUGH THE END OF THE FORECAST PERIOD...AND EMILY SHOULD TURN NORTHWARD INTO THE WEAKNESS AND EVENTUALLY ACCELERATE NORTH-NORTHEASTWARD BY DAY 5 AS A RIDGE REBUILDS TO THE SOUTHEAST OF THE CYCLONE AND A BROAD TROUGH MOVES INTO THE EASTERN UNITED STATES. THE BIGGEST CHANGE IN THE GUIDANCE FOR THIS CYCLE IS THAT THE GFDL AND HWRF NOW SHOW A LITTLE MORE RIDGING EAST OF EMILY LATE IN THE PERIOD AND HAVE SHIFTED THEIR TRACKS WESTWARD...ESPECIALLY AT DAYS 3 AND 4. THROUGH THE FIRST 36 HOURS...THE NEW NHC FORECAST IS ALONG THE OLD TRACK...BUT A LITTLE FASTER AS IT TRENDS TOWARD THE FASTER MULTI-MODEL CONSENSUS. FROM 48 TO 96 HOURS...THE NEW NHC FORECAST HAS BEEN ADJUSTED A LITTLE TO THE LEFT OF THE PREVIOUS PACKAGE...AND NOW LIES TO THE RIGHT OF THE MULTI-MODEL CONSENSUS. GIVEN THE LARGE CYCLE-TO-CYCLE VARIABILITY SEEN IN THE TRACK GUIDANCE...UNCERTAINTY IN THE TRACK FORECAST REMAINS LARGER THAN USUAL BEYOND 48 HOURS. BASED ON THE INCREASE IN FORWARD SPEED WITH THE NEW TRACK FORECAST ...A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE SOUTHEAST BAHAMAS AND TURKS AND CAICOS. FORECAST POSITIONS AND MAX WINDS INIT 03/0300Z 16.2N 66.7W 45 KT 50 MPH 12H 03/1200Z 17.0N 68.4W 50 KT 60 MPH 24H 04/0000Z 18.4N 70.5W 55 KT 65 MPH...INLAND 36H 04/1200Z 20.2N 72.6W 35 KT 40 MPH...OVER WATER 48H 05/0000Z 22.0N 74.4W 35 KT 40 MPH 72H 06/0000Z 26.0N 77.5W 45 KT 50 MPH 96H 07/0000Z 29.5N 78.5W 55 KT 65 MPH 120H 08/0000Z 33.0N 76.0W 65 KT 75 MPH $$ FORECASTER BRENNAN