000 AXNT20 KNHC 180535 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU MAY 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 68W S OF 13N MOVING NEAR 10 KT. THE WAVE IS RATHER ILL-DEFINED WITH THE MAJORITY OF THE WAVE INLAND OVER SOUTH AMERICA. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 5N20W 2N30W 3N42W 2N51W. SCATTERED MODERATE CONVECTION IS N OF 2N TO INLAND OVER AFRICA BETWEEN 3W-10W. A SMALL CLUSTER OF MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 19W-25W. ELSEWHERE...ISOLATED SHOWERS AND TSTMS ARE WITHIN 180 NM EITHER SIDE OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... THE DEEP LAYERED TROUGH THAT HAS BEEN OVER MUCH OF THE GULF OVER THE PAST FEW DAYS HAS RETREATED TO THE NE SECTION WITH WSW UPPER LEVEL FLOW ACROSS MUCH OF THE AREA. ALL OF THE UNSETTLED WEATHER ENHANCED BY THE UPPER TROUGH AND ASSOCIATED SFC FRONTAL BOUNDARY HAS EXITED THE REGION. FAIR WEATHER AND DRY/STABLE AIR ALOFT IS WIDESPREAD WITH STRONG SUBSIDENCE N OF 27N. A 1016 MB HIGH IS CENTERED IN THE CENTRAL/W GULF NEAR 25N92W. SKIES ARE MOSTLY CLEAR UNDER STRONG SUBSIDENCE WITH ONLY A FEW PATCHES OF LOW-MID LEVEL CLOUDS MOVING SWD IN THE S GULF. SFC WINDS ARE FAIRLY LIGHT ACROSS THE AREA. HIGH PRES WILL REMAIN ACROSS THE GULF OF MEXICO THRU THE REMAINDER OF THE WEEK INTO THIS WEEKEND CONTINUING TO PRODUCE FAIR DRY WEATHER...LIGHT WINDS AND PLEASANT TEMPS. CARIBBEAN SEA AND ATLANTIC OCEAN W OF 60W... A DEEP LAYERED TROUGH STRETCHES ACROSS THE E U.S. AND W ATLC WITH AN UPPER LEVEL SWLY JET RACING FROM CENTRAL FLORIDA TO W OF BERMUDA. AS OF 03 UTC...AN ASSOCIATED COLD FRONT ENTERS THE AREA ALONG 32N70W 25N75W TO A BROAD WEAK 1009 MB LOW OVER CENTRAL CUBA NEAR 21N79W SWD TO THE COAST OF NICARAGUA NEAR 14N83W. SCATTERED SHOWERS AND TSTMS EXTEND WITHIN 180 NM E OF THE FRONT N OF THE SFC LOW. S OF THE SFC LOW...MOISTURE IS MORE DIFFUSE. A WELL DEFINED UPPER LEVEL ANTICYCLONE IS CENTERED NEAR PUERTO RICO. UPPER RIDGING EXTENDS NEWARD FROM THE UPPER HIGH TO 32N58W. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION IS ON THE SW PERIPHERY OF THE UPPER RIDGE OVER N COLOMBIA. SOME OF THIS MOISTURE IS THEN ADVECTED NEWARD BY THE SWLY UPPER JET AND CONVERGES WITH THE FRONT IN THE W ATLC. VERY DRY STABLE AIR IS WIDESPREAD TO THE E OF THE UPPER HIGH. TRADEWINDS ARE WEAK IN THE W CARIBBEAN BETWEEN 70W AND THE FRONT WITH MODERATE TRADES E OF 70W. NLY WINDS NEAR 15 KT ARE BEHIND THE FRONT. THE COLD FRONT WILL SLOWLY WEAKEN AND LIFT NWD OVER THE NEXT COUPLE OF DAYS LIKELY DISSIPATING BY THIS WEEKEND. RAINFALL WILL BE MOST CONCENTRATED IN THE W ATLC WITH STILL A GOOD CHANCE OF SHOWERS IN NW CARIBBEAN OVER THE NEXT COUPLE OF DAYS AS THE FRONT BECOMES NEARLY STATIONARY IN THE AREA. REMNANT MOISTURE WILL BUILD BACK WWARD ACROSS THE S GULF...CUBA AND S FLORIDA LATE SUN. TRADE WINDS WILL LIKELY INCREASE THIS WEEKEND AS A LARGE SFC RIDGE STRETCHES WWARD FROM THE CENTRAL ATLC. THE REMAINDER OF ATLANTIC OCEAN... A TROUGH/RIDGE UPPER LEVEL PATTERN EXISTS ACROSS THE ATLC OCEAN E OF 60W. A SHARP DEEP LAYERED TROUGH IS OVER THE CENTRAL ATLC WITH THE AXIS EXTENDING THRU 32N36W INTO THE TROPICS NEAR 16N46W. AN UPPER LOW APPEARS TO BE FORMING NEAR 24N39W PRODUCING A FEW SHOWERS NEAR IT. THE COLD FRONT ASSOCIATED WITH THE UPPER TROUGH HAS WEAKENED TO A TROUGH WHICH EXTENDS ALONG 31N21W 23N33W 18N46W. THIS SFC TROUGH IS RATHER BENIGN MARKED ONLY BY A LINE OF CLOUDS WITH A FEW EMBEDDED SHOWERS AND A WIND SHIFT. AN UPPER RIDGE DOMINATES THE REMAINDER OF THE ATLC WITH THE AXIS ALONG 20W. AT THE SFC...WITH THE EXCEPTION OF THE WEAK SFC TROUGH A 1030 MB HIGH CENTERED NEAR 35N34W DOMINATES THE PATTERN PRODUCING MOSTLY FAIR WEATHER ACROSS THE AREA. SFC HIGH PRES WILL REMAIN ACROSS THE AREA THRU THE WEEKEND ALLOWING FAIR WEATHER TO CONTINUE ACROSS THE AREA. THE WEAK SFC TROUGH WILL LIKELY DISSIPATE IN A DAY OR SO. $$ CANGIALOSI