000 AXNT20 KNHC 151725 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAY 15 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. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 21W S OF 11N MOVING W 10-15 KT. THIS WAVE IS MORE DISORGANIZED TODAY AS VISIBLE IMAGES ONLY INDICATE A FAINT BROAD AREA OF LOW LEVEL CYCLONIC TURNING. THE AXIS IS PLACED IN THE CENTER OF THE BROAD STRUCTURE. SCATTERED SHOWERS AND TSTMS ARE WITHIN 360 NM E OF THE WAVE AXIS. A TROPICAL WAVE HAS BEEN ADDED TO THE 12Z ANALYSIS ALONG 47W S OF 11N ESTIMATED TO BE MOVING W 15 KT. THIS WAVE HAS BEEN TRACEABLE OVER THE PAST FEW DAYS...ESPECIALLY ON THE MIMIC TPW ANIMATION...BUT WAS VERY MUCH EMBEDDED IN THE ITCZ. HOWEVER... TODAY THE WAVE IS MORE DEFINED WITH VISIBLE IMAGES SHOWING LOW-LEVEL CYCLONIC TURNING ALONG THE AXIS AND ITS ASSOCIATED MOISTURE FIELD SLIGHTLY MORE AMPLIFIED. SCATTERED SHOWERS AND TSTMS ARE WITHIN 360 NM EITHER SIDE OF THE AXIS S OF 6N... ENHANCED BY LOW-LEVEL CONVERGING FLOW ALONG THE COAST OF SOUTH AMERICA. A WEAK TROPICAL WAVE HAS BEEN ADJUSTED W ALONG 71W S OF 13N MOVING W 15 KT. THIS POSITION ADJUSTMENT WAS BASED ON A FAINT MOISTURE PLUME...EVIDENT ON THE MIMIC TPW ANIMATION...TRACKING W ALONG THE N COAST OF SOUTH AMERICA. REGARDLESS OF THE LOCATION...THE WAVE IS WEAK AND IS NOT MUCH OF A WEATHER PLAYER AT THE MOMENT. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 7N19W 3N24W 3N46W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 1N-6N BETWEEN 13W-20W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM OF THE AXIS BETWEEN 28W-34W AND BETWEEN 41W-46W. SCATTERED MODERATE TO STRONG IS FROM 6N-10N BETWEEN 52W-61W. ...DISCUSSION... GULF OF MEXICO... THE GULF LIES BETWEEN A 1021 MB SFC HIGH OVER THE W ATLC AND LOW PRES TROUGHING OVER E TEXAS AND E MEXICO. THIS PATTERN IS PRODUCING FAIRLY UNIFORM 15-20 KT SOUTHERLY WINDS OVER THE GULF. A SLIGHT INTERRUPTION IN THIS WIND REGIME IS ASSOCIATED WITH A PRE-FRONTAL TROUGH THAT EXTENDS FROM NEAR HOUSTON TO 24N97W. ALOFT...A LARGE UPPER HIGH IS CENTERED OVER THE NW CARIBBEAN AND UPPER TROUGHING EXTENDS ACROSS THE ROCKIES TO NW MEXICO. UPPER DIFFLUENCE BETWEEN THESE FEATURES COUPLED WITH SOME LOW-LEVEL LIFT ALONG THE PRE-FRONTAL SFC BOUNDARY IS PRODUCING SCATTERED TO NUMEROUS TSTM ACTIVITY OVER THE SOUTHERN U.S. AND N PORTIONS OF THE CENTRAL AND WESTERN GULF. MOST OF THE ACTIVITY OVER THE N GULF IS MOVING INLAND...HOWEVER LONG RANGE DOPPLER RADAR AND LIGHTNING DATA IS STILL DETECTING A BROKEN SQUALL LINE OVER THE AL/MS/LA COASTAL WATERS AND ISOLATED ACTIVITY ELSEWHERE N OF 28N BETWEEN 88W-94W. A COLD FRONT IS EXPECTED TO ENTER THE NW WATERS TONIGHT. CARIBBEAN SEA... THE TAIL END OF A COLD FRONT REMAINS WELL DEFINED FROM THE CENTRAL ATLC ACROSS HISPANIOLA. SAN JUAN DOPPLER RADAR AND SAT IMAGERY REVEALS A 60 NM BAND OF LOW-LEVEL CLOUDS WITHIN EMBEDDED SCATTERED SHOWERS AHEAD OF THE FRONT NEAR THE MONA PASSAGE AND OVER MUCH OF THE ISLAND OF HISPANIOLA. OTHERWISE...VERY TRANQUIL WEATHER RESIDES ACROSS THE REMAINDER OF THE BASIN IN LARGE PART DUE TO A SPRAWLING MID-UPPER RIDGE CENTERED OVER THE NW WATERS AND UPPER TROUGHING OVER THE E CARIBBEAN. THIS UPPER PATTERN IS PRODUCING MODERATE TO STRONG SUBSIDENCE SUPPRESSING THE DEVELOPMENT OF ANY SIGNIFICANT CONVECTION. TRADE WINDS ARE FAIRLY MODEST TODAY...DUE TO THE WEAKENED SFC PRES PATTERN BROUGHT ABOUT BY THE AFOREMENTIONED FRONT. THESE WINDS WILL LIKELY INCREASE SLIGHTLY OVER THE NEXT DAY OR TWO AS WEAK HIGH PRES SETTLES N OF THE AREA. ATLANTIC OCEAN... AN OCCLUDED 1001 MB LOW PRESSURE SYSTEM OVER THE N CENTRAL ATLC SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N53W AND EXTENDS SW TO HISPANIOLA. LOW-LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY COUPLED WITH UPPER DIFFLUENT FLOW IS PRODUCING A 180 NM WIDE BAND OF SCATTERED SHOWERS AND TSTMS E OF THE FRONT N OF 23N. SCATTERED SHOWERS NARROW TO WITHIN 60-90 NM E OF THE FRONT S OF 23N TO HISPANIOLA. WEAK HIGH PRES IS BUILDING SE BEHIND THE FRONT. THE REMAINDER OF THE CENTRAL AND E ATLC IS DOMINATED BY A 1025 MB SFC HIGH LOCATED NEAR 31N39W. THE TIGHT PRES PATTERN BETWEEN THE HIGH AND THE AFOREMENTIONED FRONT IS PRODUCING SLY 20-30 KT WINDS WITHIN 300 NM E OF THE COLD FRONT. IN THE UPPER LEVELS...A LONGWAVE RIDGE/TROUGH PATTERN DOMINATES. THE TROUGH IS SUPPORTING A COLD FRONT THAT CLIPS THE NE PORTION FROM FROM JUST E OF THE MADEIRA ISLANDS TO 30N20W TO 31N27W. ONLY A BROKEN NARROW LINE OF LOW CLOUDS MARK THE BOUNDARY. $$ CANGIALOSI