000 AXNT20 KNHC 181708 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 73W S OF 14N MOVING W NEAR 15-20 KT. THE WAVE IS COMBINING WITH THE FRONT IN THE W CARIBBEAN TO PRODUCE ISOLATED TSTMS S OF 15N W OF 73W. THE WAVE IS BEST TRACKED USING LONG-TERM SATELLITE LOOPS AND CONVECTIVE CLUSTERS OVER S AMERICA. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N11W 4N23W 1N36W 1N50W. SOME EVIDENCE OF A WEAK WAVE NEAR 32W ENHANCING CONVECTION. ISOLATED MODERATE CONVECTION S OF 2.5N BETWEEN 32W-40W. WIDELY SCATTERED MODERATE CONVECTION FROM 2N-6.5N BETWEEN 10W-19W. ...DISCUSSION... GULF OF MEXICO... UNSEASONABLY DEEP UPPER TROUGH CONTINUES TO DOMINATE THE WEATHER OVER THE GULF. VERY DRY AIR ALOFT AND AT THE SURFACE IS KEEPING THINGS VERY QUIET WITH ONLY A FEW CUMULUS CLOUDS AND SOME HIGH CLOUDS MOVING OVER THE SOUTHERN GULF AS REMNANTS OF YESTERDAYS REMAINING FROM THE AFTERMATH OF YESTERDAYS TSTMS OVER MEXICO. 1017 MB HIGH NEAR 24N95W WITH FAIRLY LIGHT WINDS THROUGHOUT THE AREA. NO BIG CHANGES ARE LIKELY WITH SLOW MOISTURE RETURN DURING THE NEXT FEW DAYS AND MAYBE A CHANCE OF RAIN IN THE FAR SE GULF ON SUN. CARIBBEAN SEA AND ATLANTIC OCEAN W OF 55W... AHEAD OF THE DEEP LAYERED TROUGH OVER THE USA.. COLD FRONT LIES FROM NEAR BERMUDA TO THE CENTRAL BAHAMAS NEAR 23N75W SW THRU E CUBA BETWEEN THE CAYMANS AND JAMAICA SOUTHWARD TO 15N80W. SCATTERED SHOWERS AND TSTMS ARE WITHIN 180 NM SE OF THE FRONT IN THE ATLC AND WITHIN 240 NM SE OF THE FRONT IN THE N CARIBBEAN. HEAVY RAINS ARE POSSIBLE IN E CUBA AND HAITI TODAY AHEAD OF THE FRONT. FARTHER W.. MOSTLY CLEAR SKIES ARE IN THE NW CARIBBEAN AND NW ATLC BEHIND THE FRONT WITH DRIER AIR FILTERING INTO THE REGION. IN THE SW CARIBBEAN... UPPER DIVERGENCE COMBINED WITH A WEAK TROPICAL WAVE AND NLY WINDS ARE FORCING SCATTERED SHOWERS/TSTMS S OF 13N W OF 78W. THE LARGE AREA OF DISTURBED WEATHER IN THE CARIBBEAN IS NOT EXPECTED TO MAKE MUCH MORE PROGRESS TO THE EAST.. BECOMING STATIONARY OVERNIGHT THEN DRIFTING W TOMORROW. E CUBA IS LIKELY TO GET HEAVY RAINS FOR THE NEXT COUPLE OF DAYS IN ADDITION TO CENTRAL AMERICA AND THE NW CARIBBEAN BY SAT. FARTHER EAST...A WELL DEFINED UPPER LEVEL ANTICYCLONE IS CENTERED N OF VENEZUELA NEAR 13.5N74W RIDGING NE TO BEYOND 31N55W. MODERATE/STRONG SUBSIDENCE IS KEEPING CONDITIONS QUIET IN THE E CARIBBEAN. TRADE WINDS WILL LIKELY INCREASE THIS WEEKEND OVER THE ENTIRE AREA AS A LARGE SFC RIDGE STRETCHES WWARD FROM THE CENTRAL ATLC AND THE FRONTAL SYSTEM TO THE N BREAKS DOWN. THE REMAINDER OF ATLANTIC OCEAN... SHARP MID/UPPER TROUGH IS IN THE CENTRAL ATLC FROM 30N31W INTO AN UPPER LOW NEAR 22N40W CONTINUING SOUTHWARD TO 11N46W. TROUGH IS ENHANCING SHOWERS AND A FEW TSTMS ALONG A DISSIPATING FRONT.. NOW A SURFACE TROUGH FROM 28N26W TO 19N40W 16N50W. ISOLATED SHOWERS/TSTMS ARE WITHIN 90 NM EITHER SIDE OF THE TROUGH BETWEEN 30W-41W. THE SURFACE TROUGH IS THE ONLY DENT IN THE SPRAWLING 1034 MB HIGH OVER THE ATLC CENTERED JUST S OF THE AZORES. RIDGE AXIS COMES INTO THE AREA NEAR 31N44W SW TO 25N58W TO 22N68W. AS THE SURFACE TROUGH WEAKENS S OF THE HIGH.. TRADES ARE FORECAST TO INCREASE AND BECOME STRONGER-THAN-AVERAGE IN THE ENTIRE AREA BY THE WEEKEND. MID/UPPER HIGH DOMINATES THE E ATLC AS WELL WITH RIDGE AXIS W-E FROM 7N12W IN W AFRICA TO 9N37W AND NORTHWARD FROM JUST E OF THE CAPE VERDES NE TO BEYOND THE CANARY ISLANDS. MODERATE/STRONG SUBSIDENCE DOMINATES MOST OF THE ATLC S OF 25N WITH SOME PASSING HIGH CLOUDS AND ISOLATED TSTMS NEAR THE SURFACE TROUGH. $$ BLAKE