WTPZ42 KNHC 060242 TCDEP2 TROPICAL STORM LORENA DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP122013 800 PM PDT THU SEP 05 2013 FOR MUCH OF THE AFTERNOON...THE CENTER OF LORENA WAS NOT WELL DEFINED AND WAS DIFFICULT TO LOCATE. HOWEVER...TWO SSMI/S PASSES WITHIN THE PAST 3 HOURS CLEARLY SHOW THAT A NEW CENTER HAS FORMED FARTHER NORTH AND IS DISPLACED JUST SOUTH OF THE DEEP CONVECTION. THE CONVECTION ITSELF WANED DURING THE PAST FEW HOURS...BUT A RECENT BURST HAS DEVELOPED NEAR THE NEW CENTER POSITION. THE INITIAL INTENSITY WILL BE HELD AT 35 KT BASED ON CURRENT INTENSITY ESTIMATES OF T2.5 FROM TAFB AND SAB. GIVEN THE REFORMATION OF THE CENTER...THE INITIAL MOTION IS SOMEWHAT UNCERTAIN...BUT A 12-HOUR MOTION YIELDS 325/11 KT. LORENA CONTINUES TO MOVE GENERALLY NORTHWESTWARD DUE TO A LOW- TO MID-LEVEL RIDGE LOCATED OVER THE SOUTHERN U.S. AND NORTHERN MEXICO. GLOBAL MODEL GUIDANCE INDICATES THAT THE MID-LEVEL VORTEX SHOULD CONTINUE MOVING NORTHWESTWARD AROUND THE RIDGE DURING THE NEXT FEW DAYS...BUT THE LOW-LEVEL CIRCULATION GETS LEFT BEHIND IN AN ENVIRONMENT OF WEAK LOW-LEVEL STEERING. AS A RESULT...THE LOW-LEVEL CENTER IS FORECAST TO SLOW DOWN CONSIDERABLY BY 36 HOURS...LINGERING NEAR THE SOUTHERN BAJA CALIFORNIA PENINSULA FOR A COUPLE OF DAYS. THE OFFICIAL FORECAST IS A LITTLE LEFT OF THE TVCE MULTI-MODEL CONSENSUS IN AN ATTEMPT TO DISCOUNT THE INFLUENCE OF THE HWRF...WHICH MAINTAINS A DEEP VORTEX THAT MOVES UP THE GULF OF CALIFORNIA. BECAUSE THE LOW- AND MID-LEVEL CIRCULATIONS ARE EXPECTED TO SEPARATE...LORENA WILL PROBABLY NOT BE ABLE TO STRENGTHEN MUCH DURING THE NEXT COUPLE OF DAYS. HOWEVER...UPPER-LEVEL OUTFLOW REMAINS GOOD AND SEA SURFACE TEMPERATURES WILL BE SUFFICIENTLY WARM...SO THE CYCLONE IS EXPECTED TO AT LEAST MAINTAIN TROPICAL STORM STRENGTH FOR 36 HOURS OR SO. AFTER THAT...LORENA WILL BE INTERACTING WITH LAND...AND THE INCREASINGLY SHALLOW CIRCULATION WILL LIKELY SPIN DOWN QUICKLY. THE UPDATED FORECAST NOW SHOWS LORENA BECOMING A REMNANT LOW IN 3 DAYS AND DISSIPATING BY DAY 4. THE NORTHWARD REFORMATION OF THE CENTER MEANS THAT TROPICAL STORM FORCE WINDS COULD REACH THE SOUTHERN BAJA CALIFORNIA PENINSULA WITHIN THE NEXT 24 HOURS OR SO...REQUIRING THE ISSUANCE OF A TROPICAL STORM WARNING. A TROPICAL STORM WATCH HAS ALSO BEEN ISSUED NORTH OF THE WARNING AREA ON THE WEST SIDE OF THE BAJA CALIFORNIA PENINSULA DUE TO THE POSSIBILITY OF TROPICAL STORM FORCE WINDS IN 36 TO 48 HOURS. FORECAST POSITIONS AND MAX WINDS INIT 06/0300Z 20.4N 107.6W 35 KT 40 MPH 12H 06/1200Z 21.6N 108.7W 40 KT 45 MPH 24H 07/0000Z 22.5N 109.8W 40 KT 45 MPH 36H 07/1200Z 23.2N 110.4W 35 KT 40 MPH 48H 08/0000Z 23.8N 110.6W 30 KT 35 MPH...INLAND 72H 09/0000Z 25.0N 111.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 10/0000Z...DISSIPATED $$ FORECASTER BERG/BRENNAN PALMBAYWEATHER.info
Posted on: Fri, 06 Sep 2013 02:42:32 +0000
Recently Viewed Topics
© 2015