000 AXNT20 KNHC 210006 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAY 20 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 24W S OF 8N MOVING W 15 KT. THIS WAVE CONTINUES TO BE EMBEDDED WITHIN THE ITCZ AXIS...AND ANY CYCLONIC CIRCULATION ASSOCIATED WITH THIS WAVE IS RATHER BROAD BUT LESS DISCERNIBLE THAN VISIBLE EARLIER DURING THE DAY...AND SHOULD BECOME LESS DEFINED AS IT MOVES WESTWARD UNDER A STRONG ATLC RIDGE PRODUCING STRONG SUBSIDENCE AND A DRY ENVIRONMENT NEAR THE NORTHERN EXTENSION OF THE WAVE. TROPICAL WAVE IS ALONG 49W S OF 9N MOVING W 15-20 KT. THIS WAVE CONTINUES TO EXHIBIT AN INVERTED V-PATTERN EMBEDDED WITHIN THE ITCZ ALONG WITH SCATTERED MODERATE/ISOLATED STRONG WITHIN 180 NM W OF THE WAVE AXIS FROM 5N-6N. WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE ELSEWHERE WITHIN 60 NM OF THE WAVE AXIS 4N-9N. AS STATED IN THE PREVIOUS DISCUSSION...STILL LITTLE IMPACT IS EXPECTED IN THE CARIBBEAN FROM THIS WAVE OVER THE NEXT 3-5 DAYS AS THE MAJORITY OF THE MOISTURE AND CONVECTION WITH THIS SYSTEM IS EXPECTED TO MOVE INTO SOUTH AMERICA. TROPICAL WAVE PREVIOUSLY ALONG 81W/82W S OF 11N IS RELOCATED TO ALONG 84W/85W S OF 14N MOVING W 10-15 KT BASED ON UPDATED SURFACE AND STREAMLINE ANALYSES FROM 1800 UTC. SOME ENHANCEMENT OF SCATTERED MODERATE TO STRONG CONVECTION IS SEEN OVER NICARAGUA AND SOUTHERN HONDURAS. STRONG UPPER LEVEL SW WINDS ACROSS THE NORTHERN PART OF THE WAVE ARE IMPINGING ON THE CONVECTION AT THIS TIME. WAVE IS NOT EXPECTED TO BECOME ANY BETTER DEFINED OVER THE NEXT 2 DAYS AS MOVES FURTHER WEST INTO THE EASTERN PACIFIC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 4N25W 2N31W 2N38W 3N45W TO INLAND SOUTH AMERICA NEAR 4N52W. SCATTERED STRONG CONVECTION EXISTS FROM 1N-4N BETWEEN 44W-47W...AND ALSO WITHIN 30 NM OF THE AXIS BETWEEN 31-33W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 30 NM OF THE AXIS BETWEEN 22W-24W. ...DISCUSSION... GULF OF MEXICO... HIGH PRESSURE CONTINUES TO BE THE DOMINANT WEATHER FEATURE HERE AS A 1019 MB HIGH CENTER IS ANALYZED NEAR 27N86.5W. AS A RESULT...SKIES CONTINUE TO BE MOSTLY CLEAR WITH ONLY SCATTERED LOW CLOUDS PRESENT SOUTH OF MAINLY 26N WHERE SCATTERED TO BROKEN HIGH CLOUDS ARE ALSO NOTED. IN THE UPPER LEVELS...UPPER TROUGH IS SEEN EXTENDING FROM ACROSS NORTHERN FLORIDA SOUTHWESTWARD TO EXTREME SOUTHERN TEXAS AND NE MEXICO WHERE A NEARLY STATIONARY MID/UPPER LEVEL CYCLONIC CIRCULATION IS EVIDENT. MOSTLY STRONG SUBSIDENCE AND ASSOCIATED DRY/STABLE AIR ACCOMPANIES THE TROUGH DUE TO UPPER LEVEL CONFLUENCE ACROSS THESE AREA. CONDITIONS IN THE GULF ARE EXPECTED TO CHANGE LITTLE OVER THE NEXT FEW DAYS AS HIGH PRESSURE REMAINS IN PLACE...HOWEVER TROPICAL MOISTURE JUST SOUTH OF THE GULF ACROSS THE NW CARIBBEAN MAY PUSH FURTHER NORTH AND BEGIN TO INFLUENCE THE SOUTHERN PORTIONS OF THE GULF ON SUNDAY...AND POSSIBLE BECOME MORE WIDESPREAD OVER THE CENTRAL AND EASTERN GULF WITH TIME AS SUGGESTED BY COMPUTER MODELS. CARIBBEAN SEA AND ATLANTIC OCEAN W OF 55W... AN UPPER LEVEL TROUGH/RIDGE PATTERN REMAINS IN PLACE ACROSS THIS AREA. AT THE SURFACE...A DISSIPATING STATIONARY FRONT EXTENDS FROM 32N61W SOUTHWEST TO 27N68.5W WHERE IT BECOMES A TROUGH SOUTHWESTWARD TO THE CENTRAL BAHAMAS AND CONTINUES SOUTHWEST INTO THE W CARIBBEAN TO NEAR THE CAYMAN ISLANDS AND SOUTHWARD TO NEAR SAN ANDRES ISLAND. BROKEN TO OVERCAST MOSTLY MID/HIGH CLOUDS ALONG WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM SE OF THE FRONT/TROUGH N OF 22N. WIDELY SCATTERED SHOWERS AND TSTMS ARE WITHIN 75-90 NM W OF THE TROUGH OVER THE CARIBBEAN. SCATTERED STRONG TSTMS ARE ENHANCED OVER CENTRAL AND ADJACENT WATERS. FARTHER E...MID/UPPER HIGH IS LOCATED JUST N OF HISPANIOLA NEAR 21N71W WITH RIDGING EXTENDING SW TO HONDURAS/NICARAGUA BORDER AND NE TO BEYOND 32N45W. A JET STREAM BRANCH EXTENDS FROM THE E BAY OF CAMPECHE NORTHEASTWARD THROUGH 24N84W TO ACROSS S FLORIDA AND CONTINUES NORTHEASTWARD THROUGH 27N70W TO BEYOND THE AREA NEAR 32N59W. WINDS IN THE RANGE OF 60-80 KT ARE NOTED WITHIN THIS JET MAINLY W OF 65W. STRONG MID/UPPER SUBSIDENCE IS NOTED S OF ABOUT 19N AND E OF 80W WHERE EASTERLY FLOW AT MID AND UPPER LEVELS PREVAILS. MOISTURE RELATED TO THE SURFACE TROUGH SHOULD GRADUALLY INCREASE CHANCES OF RAIN FOR THE NW CARIBBEAN INCLUDING THE YUCATAN PENINSULA AND CUBA OVER THE NEXT 2-3 DAYS AS IT ADVECTS WESTWARD. THE LARGE VOLCANIC ASH CLOUDS EARLIER DETECTED OVER THE E CARIBBEAN DUE TO AN ERUPTION OF THE MONTSERRAT VOLCANO THIS MORNING CONTINUES TO BE SEEN ON SATELLITE IMAGERY FROM 13N-17N BETWEEN 64W-69W. SMALL ISOLATED SHOWERS AND TSTMS ARE EMBEDDED WITHIN THE AS CLOUD FROM 15N-17N BETWEEN 63.5W-65W. THE REMAINDER OF ATLANTIC OCEAN... A SHARP UPPER LEVEL TROUGH IS OVER THE CNTRL ATLC WITH THE AXIS EXTENDING THRU 30N43W THROUGH AN UPPER LOW NEAR 23N47W AND INTO THE DEEP TROPICS NEAR 9N51W. THE LOW IS HELPING TO TRANSPORT UPPER MOISTURE FROM THE DEEP TROPICS NORTHEASTWARD TO S OF 26N BETWEEN 35W-42.5W. AN UPPER HIGH IS NEAR 16N30W WITH MID/UPPER LEVEL RIDGING COVERING THE AREA S OF 17N AND E OF 33W. DIFFLUENCE S OF THE RIDGE IS ENHANCING ITCZ CONVECTION. MODERATE/STRONG SUBSIDENCE NOTED FROM 7N-17N E OF 33W. UPPER TROUGH IS MOVING SE OVER EXTREME NW AFRICA. AT THE SFC...STRONG 1030 MB HIGH CENTERED NEAR 32N36W COVERS THE ENTIRE REGION SUPPLYING FAIR WEATHER ACROSS A GOOD PORTION OF THE ATLANTIC OCEAN. TRADE WINDS ARE RATHER STRONG ACROSS THE AREA AND WILL LIKELY REMAIN THAT WAY FOR THE NEXT FEW DAYS. $$ AGUIRRE