000 WTPZ41 KNHC 260256 TCDEP1 TROPICAL DEPRESSION JULIO DISCUSSION NUMBER 11 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112008 800 PM PDT MON AUG 25 2008 VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT THE LOW-LEVEL AND MID- TO UPPER-LEVEL CIRCULATIONS HAVE DECOUPLED... WITH THE LOW-LEVEL CIRCULATION HUGGING THE COASTLINE OF EAST-CENTRAL BAJA CALIFORNIA WHILE THE MID- TO UPPER-LEVEL CIRCULATIONS MOVE NORTHEASTWARD TOWARD THE SOUTHWESTERN COAST OF MAINLAND MEXICO. SATELLITE INTENSITY ESTIMATES FROM BOTH TAFB AND SAB NO LONGER SUPPORT TROPICAL STORM STRENGTH AND...THEREFORE... JULIO HAS BEEN DOWNGRADED TO A TROPICAL DEPRESSION. JULIO HAS DECREASED ITS FORWARD SPEED NOW THAT THE CYCLONE IS DECOUPLING AND IT IS NO LONGER A DEEP SYSTEM. THE LOW-LEVEL CIRCULATION IS EXPECTED TO MOVE SLOWLY NORTH-NORTHWESTWARD ALONG OR NEAR THE EAST COAST OF BAJA CALIFORNIA AS IT GETS DRAWN INTO THE BROADER CYCLONIC GYRE OF A THERMAL LOW OVER THE REGION. THE LATEST MODEL GUIDANCE IS WIDELY DIVERGENT AFTER 24 HOURS...SUGGESTING THAT STEERING CURRENTS WILL COLLAPSE. THE OFFICIAL TRACK FORECAST IS VERY CLOSE TO THE PREVIOUS ADVISORY TRACK. CONTINUED WEAKENING IS FORECAST DUE TO MODERATE VERTICAL SHEAR AND TERRAIN INTERACTION...AND JULIO SHOULD STEADILY SPIN DOWN AS A TROPICAL CYCLONE. HOWEVER...MOISTURE FROM JULIO WILL STILL CREATE A HEAVY RAINFALL THREAT ALONG THE WEST COAST OF MAINLAND MEXICO...AND THAT MOISTURE IS EXPECTED TO REACH THE SOUTHWESTERN UNITED STATES OVER THE NEXT COUPLE OF DAYS...WHICH COULD ENHANCE RAINFALL OVER THAT REGION. FORECAST POSITIONS AND MAX WINDS INITIAL 26/0300Z 28.0N 112.7W 30 KT 12HR VT 26/1200Z 28.8N 112.9W 30 KT 24HR VT 27/0000Z 29.4N 113.2W 25 KT 36HR VT 27/1200Z 29.8N 113.4W 25 KT...REMNANT LOW 48HR VT 28/0000Z 29.9N 113.5W 20 KT...REMNANT LOW 72HR VT 29/0000Z...REMNANT LOW $$ FORECASTER STEWART/RHOME