000 AXNT20 KNHC 131757 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 13 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 38W SOUTH OF 20N MOVING W NEAR 10 KT. A 1010 MB LOW PRESSURE CENTER IS ALONG THE WAVE NEAR 13 N. LATEST SATELLITE PICTURES SHOWS THIS AREA OF LOW PRESSURE HAS WEAKENED DUE TO STRONG UPPER-LEVEL WINDS. SCATTERED MODERATE CONVECTION IS FROM 14N-18N BETWEEN 35W-39W. A TROPICAL WAVE IS ALONG 70W SOUTH OF 20N MOVING WEST 10-15 KT. THIS WAVE HAS LEFT BEHIND A 1008 MB LOW PRESSURE CENTER WHICH IS CURRENTLY NEAR 22N65W OR A COUPLE OF HUNDRED MILES NORTH- NORTHEAST OF PUERTO RICO. THIS SYSTEM CONTINUES TO SHOW LITTLE CHANGE IN ORGANIZATION THIS MORNING...AND UPPER-LEVEL WINDS CONTINUE TO BECOME LESS CONDUCIVE FOR TROPICAL DEVELOPMENT. LINES OF LOW CLOUDS WITH EMBEDDED SHOWERS ASSOCIATED WITH THE CIRCULATION OF THE SURFACE LOW ARE APPROACHING TO THE NORTHERN COAST OF PUERTO RICO AND HISPANIOLA. A WEAK TROPICAL WAVE IS ALONG 85W/86W SOUTH OF 22N MOVING WEST 10-15 KT. THIS WAVE IS MOVING THROUGH AN AREA OF AN UPPER LEVEL RIDGE. MIDDLE TO UPPER LEVEL DRY AIR COVERS THE CARIBBEAN SEA PRACTICALLY EVERYWHERE WEST OF 70W. NO DEEP CONVECTIVE PRECIPITATION IS WITH THIS WAVE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N15W 7N25W 9N35W 8N45W 9N60W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 100/120 NM ON EITHER SIDE OF THE AXIS WEST OF 35W. SIMILAR CONVECTION IS FOUND MAINLY SOUTH OF THE AXIS BETWEEN 37W-45. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE INLAND OVER AFRICA FROM 8N-13N BETWEEN 7W-13W. ...DISCUSSION... THE GULF OF MEXICO... DEEP LAYERED TROUGH IS MOVING EASTWARD ACROSS THE EASTERN US. AS OF 1500 UTC...THE ASSOCIATED COLD FRONT CROSSES NORTHERN FLORIDA AND THE NORTHERN GULF WATERS TO A 1011 MB SURFACE LOW LOCATED NEAR 28N94W. THIS LOW HAS FORMED ALONG THE FRONT OVER THE NW CORNER OF THE GULF. THE FRONT CONTINUES MAINLY WESTWARD ACROSS NORTHERN MEXICO. DOPPLER RADAR DEPICTS SCATTERED SHOWERS AND ISOLATED TSTMS ASSOCIATED WITH THE COLD FRONT/LOW OVER THE GULF. DRY AND COLD CONTINENTAL AIR IS BEHIND THE COLD FRONT. A WEAK SURFACE TROUGH REMAINS JUST SOUTH OF THE FLORIDA KEYS AND ALONG THE STRAITS OF FLORIDA GENERATING ISOLATED SHOWERS AND TSTMS. A WEAKENING FRONTAL TROUGH EXTENDS FROM 31N73W TO OVER NORTH- CENTRAL FLORIDA WITH ISOLATED SHOWERS. UPPER LEVEL WESTERLY FLOW COVERS THE GULF WATERS. THIS WESTERLY FLOW IS ASSOCIATED WITH LARGE-SCALE UPPER LEVEL ANTICYCLONIC LOCATED OVER THE YUCATAN PENINSULA. THE COLD FRONT WILL MOVE TO THE CENTRAL FLORIDA PENINSULA TO NE MEXICO TONIGHT AND SHOULD REACH SOUTH FLORIDA SAT AFTERNOON. MODERATE ELY WINDS OF 20 KT WILL BLOW BEHIND THE COLD FRONT. THE CARIBBEAN SEA... A VERY LARGE UPPER LEVEL ANTICYCLONIC ANCHORED OVER THE YUCATAN PENINSULA EXTENDS A RIDGE FROM THE SOUTH CENTRAL MEXICO EASTWARD TO THE GREATER ANTILLES. DRY AIR...RESULTING IN MODERATE TO STRONG SUBSIDENCE COVERS THE BASIN WEST OF 70W. AN UPPER TROUGH IN THE W ATLC EXTENDS S INTO THE CARIBBEAN ACROSS PUERTO RICO TO NEAR LAKE MARACAIBO. SCATTERED SHOWERS ARE OVER THE EASTERN CARIBBEAN JUST AHEAD THIS UPPER TROUGH. BROAD RIDGE ANCHORED IN THE TROPICS NEAR 15N57W COVERING MOST OF THE CENTRAL ATLC INCLUDES THE FAR E CARIBBEAN. LIGHT EASTERLY FLOW IS EXPECTED ACROSS THE ENTIRE CARIBBEAN DURING THE NEXT SEVERAL DAYS. THE ATLANTIC OCEAN... A WEAK LOW PRESSURE AREA IS LOCATED A COUPLE OF HUNDRED MILES NORTH-NORTHEAST OF PUERTO RICO. THIS SYSTEM IS MOVING SLOWLY WESTWARD. A BAND OF SCATTERED MODERATE CONVECTION REMAINS EAST OF THE SURFACE LOW PRESSURE AND COVERS FROM 18N-31N AND BEYOND BETWEEN 55W-62W. THE VERY LARGE UPPER LEVEL ANTICYCLONIC ANCHORED OVER THE YUCATAN PENINSULA ALSO DOMINATES THE W ATLC WEST OF 68W. THE WLY FLOW ASSOCIATED WITH THIS FEATURE IS ADVECTING UPPER LEVEL MOISTURE OVER THE FLORIDA PENINSULA INTO THE W ATLC. AN UPPER TROUGH LIES ALONG 64W AND EXTENDS INTO THE CARIBBEAN ACROSS PUERTO RICO. AN UPPER HIGH CENTERED IN THE TROPICS NEAR 15N57W EXTENDS A RIDGE NWD ALONG 55W TO BEYOND 31N55W. AN UPPER TROUGH IS OVER THE E ATLC MAINLY NORTH OF THE AREA. THE ASSOCIATED COLD FRONT IS ENTERING THE REGION ALONG 30/31N BETWEEN 30W-40W. A BAND OF SHOWERS WITH EMBEDDED TSTMS IS WITHIN 60-100 NM AHEAD OF THE FRONT. AT THE SURFACE A BROAD SURFACE RIDGE COVERS THE ATLC E OF 60W. A 1021 MB SURFACE HIGH IS LOCATED OVER THE CANARY ISLANDS. AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS IS FROM 20N-27N BETWEEN 37W-46W ASSOCIATED WITH A SHORT WAVE TROUGH THAT LIES ALONG 37/38W. $$ GR