000 AXNT20 KNHC 081801 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT MAR 08 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 1N20W 1S40W 2S52W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE N OF 3N TO THE AFRICAN COAST BETWEEN THE PRIME MERIDIAN AND 11W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM FROM EQ-3N BETWEEN 18W-24W...AND FROM 3N-7N BETWEEN 37W-43W. ...DISCUSSION... THE GULF OF MEXICO... THE STRONG COLD FRONT THAT YESTERDAY MOVED ACROSS THE GULF CROSSED SOUTH FLORIDA EARLY THIS MORNING WITH A WELL DEFINED LINE OF SHOWERS AND TSTMS. THIS FRONTAL SYSTEM IS CURRENTLY OVER THE WEST ATLANTIC...JUST EAST OF FLORIDA AND THE NW CARIBBEAN. BEHIND THE FRONT...HIGH PRES IS GRIPPING THE GULF AND NE MEXICO USHERING A COLD AND MORE STABLE AIR MASS. A 1028 MB HIGH IS NEAR TAMPICO MEXICO WHILE ANOTHER HIGH PRES CENTER IS OVER EASTERN TEXAS. COLD AIR HAS PENETRATED INTO THE SIERRA MADRE MOUNTAINS AS DEPICTED BY A RATHER UNIFORM STRATUS CLOUDS COVER AND STATIONARY FRONT IS ANALYZED ACROSS SOUTH-CENTRAL MEXICO. THIS TYPE OF CLOUDINESS ALSO COVERS THE BAY OF CAMPECHE. CONVECTIVE CLOUDS STREETS ARE FORMING PARALLEL TO THE WINDS OVER THE EASTERN GULF DUE TO THE ADVECTION OF COLD AIR OVER RELATIVELY WARM WATERS. GALE FORCE WINDS WERE BLOWING BEHIND THE FRONT OVER PARTS OF THE EASTERN AND CENTRAL GULF THIS MORNING BUT THEY ARE DIMINISHING NOW. A WIND ADVISORY REMAINS IN EFFECT FOR SOUTH FLORIDA UNTIL 4 PM EST THIS AFTERNOON. AS OF 1500 UTC...A SFC TROUGH IS ANALYZED OVER THE NW QUADRANT OF THE GULF PROBABLY ASSOCIATED WITH A SECONDARY FRONT. HIGH PRES WILL REMAIN IN CONTROL OF THE WEATHER PATTERN ACROSS THE GULF DURING THE NEXT FEW DAYS PRODUCING MODERATE TO FRESH EASTERLY WINDS MAINLY SOUTH OF 25N THROUGH MON. THE CARIBBEAN SEA... A STRONG COLD FRONT FROM THE ATLC EXTENDS ACROSS WESTERN CUBA...THE CAYMAN ISLANDS AND THE NW CARIBBEAN INTO HONDURAS. A DEEP LAYERED TROUGH EXTENDING FROM THE GREAT LAKES TO SE LOUISIANA AND THE NORTHERN GULF OF MEXICO WATERS SUPPORTS THE FRONTAL ZONE. THE LEADING EDGE OF THIS FRONT IS MARKED BY A LINE OF SHOWERS AND TSTMS. LIGHTING DATA INDICATES THAT TSTMS ARE MORE CONCENTRATED OVER AND JUST N OF THE NW BAHAMAS. HAVANA REPORTED LIGHT RAIN AND NLY SUSTAINED WINDS OF 15-20 KT WITH THE PASSAGE OF THE FRONT THIS MORNING. THE FRONT WILL MOVE ACROSS CENTRAL CUBA THIS AFTERNOON THROUGH SUNDAY MONDAY THEN STALL AND WEAKEN. COMPUTER MODELS SUGGEST THAT AN AREA OF MOISTURE ASSOCIATED WITH THIS FRONT WILL PERSIST OVER THE GULF OF HONDURAS AND BELIZE ON SUNDAY. ALOFT...A MID TO UPPER RIDGE ANCHORED ON A HIGH LOCATED SOUTH OF JAMAICA DOMINATES MOST OF THE BASIN BUT PARTICULARLY THE CENTRAL CARIBBEAN. AN UPPER LEVEL TROUGH INDUCED BY A LARGE CUT OFF LOW SITUATED IN THE EASTERN ATLANTIC REACHES THE FAR E CARIBBEAN. WIDESPREAD SUBSIDENCE IS ASSOCIATED WITH THESE UPPER SYSTEMS E OF 80W. FRAGMENTS OF LOW LEVEL CLOUDS WITH EMBEDDED MAINLY LIGHT SHOWERS DOT THE AREA EAST OF THE AFOREMENTIONED COLD FRONT. THE ATLANTIC OCEAN.... THE MAIN WEATHER FEATURE IS THE STRONG COLD FRONT THAT MOVED THROUGH SOUTH FLORIDA THIS MORNING. AS OF 1500 UTC...THE FRONT ENTERS THE DISCUSSION AREA NEAR 31N78W THEN CONTINUES SWWD ACROSS THE NW BAHAMAS AND WESTERN CUBA INTO THE CARIBBEAN SEA. GALE FORCE WINDS AHEAD OF THE FRONT WILL DIMINISH THIS AFTERNOON. A LINE OF SHOWERS AND TSTMS MARKS THE LEADING EDGE OF THIS FRONTAL SYSTEM. THE OTHER FEATURE OF INTEREST IS A 1011 MB LOW SPINNING NEAR 28N37W. THIS LOW REMAINS QUASI-STATIONARY AND HAS WEAKENED SINCE YESTERDAY. A SWIRL OF LOW CLOUDS DEFINES THE CYCLONE CENTER WITH SCATTERED SHOWERS AND PROBABLY ISOLATED TSTMS TO THE NE OF THE LOW. A SFC TROUGH EXTENDS FROM THE LOW SWWD TO 18N43W. TIGHT PRES GRADIENT BETWEEN THIS CYCLONIC CIRCULATION AND A 1031 MB HIGH PRES OVER THE CENTRAL ATLC IS PRODUCING A LARGE AREA OF MODERATE TO STRONG NE WINDS IN THE NW QUADRANT OF THE LOW. ACCORDING TO THE GFS COMPUTER MODEL...THE LOW WILL SLOWLY DRIFT SW AND CONTINUE TO WEAKEN DURING THE REST OF THE WEEKEND LEAVING AN OPEN SFC TROUGH. ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE AREA. A JET STREAM BRANCH WITH CORE WINDS OF 90-110 KT LIES BETWEEN THE PREVIOUSLY MENTIONED LARGE CUT-OFF LOW OVER THE EASTERN ATLC AND A BROAD UPPER-LEVEL HIGH LOCATED SE OF THE CAPE VERDE ISLANDS NEAR 12N21W. UPPER S AND SW FLOW ON THE WESTERN SIDE OF THE HIGH IS ADVECTING PATCHY HIGH LEVEL CLOUDS FROM N SOUTH AMERICA ACROSS THE TROPICAL ATLC. THESE WINDS ARE ALSO ENHANCING SCATTERED MODERATE CONVECTION EITHER SIDE OF THE ITCZ AXIS AND WEST OF 30W. $$ GR