000 WTPZ43 KNHC 030852 TCDEP3 TROPICAL STORM JIMENA DISCUSSION NUMBER 23 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP132009 200 AM PDT THU SEP 03 2009 ALTHOUGH THE LOW-LEVEL CENTER OF JIMENA HAS BEEN DIFFICULT TO LOCATE OVER LAND...THE 37 GHZ CHANNEL FROM A TIMELY 0516 UTC TRMM OVERPASS SUGGESTED THAT THE CENTER HAS CONTINUED TO MOVE NORTHWARD AND IS LOCATED NEAR THE EAST COAST OF THE BAJA PENINSULA. ALL THE DEEP CONVECTION IS NOW DISPLACED EAST OF THE CENTER OVER THE GULF OF CALIFORNIA AND THE COAST OF NORTHWESTERN MAINLAND MEXICO. A 0415 UTC ASCAT PASS SHOWED AN AREA OF 40-45 KT WINDS OVER THE GULF OF CALIFORNIA...BUT IT IS ASSUMED THAT THERE COULD BE WINDS TO 50 KT CLOSER TO THE COAST WHERE THE SCATTEROMETER DOES NOT PROVIDE DATA. THE INITIAL INTENSITY IS THEREFORE LOWERED TO 50 KT. INTERACTION WITH LAND AND INCREASING VERTICAL SHEAR ARE EXPECTED TO WEAKEN JIMENA FAIRLY QUICKLY...AND THE FORECAST CALLS FOR THE CYCLONE TO WEAKEN TO A DEPRESSION WITHIN 24 HOURS. ALTHOUGH THE CENTER MAY MOVE OVER THE WATERS OF THE GULF OF CALIFORNIA FOR A BRIEF PERIOD DURING THE DAY...RE-STRENGTHENING IS NOT LIKELY. CONVECTIONAL SATELLITE AND MICROWAVE FIXES INDICATE THAT THE CENTER OF JIMENA IS MOVING ALONG THE EAST COAST OF THE BAJA PENINSULA... AND THE INITIAL MOTION IS ESTIMATED AT 350/6. THE MODEL GUIDANCE CONTINUES TO SHOW A CESSATION OF THIS NORTHWARD MOTION LATER TODAY WITH JIMENA PREDICTED TO TURN TOWARD THE WEST AND MOVE BACK INLAND OVER BAJA CALIFORNIA. THE REMNANT LOW OF JIMENA IS EXPECTED TO MOVE SLOWLY SOUTHWESTWARD AFTER 24 HOURS WITH DISSIPATION ANTICIPATED BY 96 HOURS. TROPICAL STORM WARNINGS HAVE BEEN EXTENDED NORTHWARD ALONG THE EAST COAST OF BAJA CALIFORNIA AND ALONG THE COAST OF NORTHWESTERN MAINLAND MEXICO. FORECAST POSITIONS AND MAX WINDS INITIAL 03/0900Z 27.7N 112.4W 50 KT 12HR VT 03/1800Z 28.2N 112.7W 35 KT 24HR VT 04/0600Z 28.2N 113.2W 30 KT...INLAND 36HR VT 04/1800Z 27.8N 113.7W 25 KT...REMNANT LOW INLAND 48HR VT 05/0600Z 27.3N 114.2W 20 KT...REMNANT LOW INLAND 72HR VT 06/0600Z 27.0N 115.0W 20 KT...REMNANT LOW OVER WATER 96HR VT 07/0600Z...DISSIPATED $$ FORECASTER BERG