000 AXNT20 KNHC 210520 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN MAY 21 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 0500 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 25W S OF 7N MOVING W 15 KT. THIS LOW-LATITUDE WAVE IS EMBEDDED WITHIN THE ITCZ AXIS. THERE IS STILL SOME CYCLONIC TURNING ASSOCIATED WITH THIS WAVE BUT IT IS RATHER BROAD AND LESS DISCERNIBLE THAN YESTERDAY. THE WAVE WILL LIKELY REMAIN ILL DEFINED AS IT MOVES WESTWARD IN A DRY ENVIRONMENT NEAR THE NORTHERN EXTENSION OF THE WAVE. TROPICAL WAVE IS ALONG 50W S OF 9N MOVING W 15-20 KT. THIS WAVE CONTINUES TO EXHIBIT AN INVERTED V-PATTERN EMBEDDED WITHIN THE ITCZ. MUCH OF THE WAVE IS NOW MOVING INLAND OVER S AMERICA. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM W OF THE WAVE AXIS FROM 5N-7N. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE ELSEWHERE. LITTLE IMPACT IS EXPECTED IN THE CARIBBEAN FROM THIS WAVE OVER THE NEXT 3-5 DAYS AS THE MAJORITY OF THE MOISTURE ASSOCIATED WITH THE WAVE IS EXPECTED TO MOVE ACROSS S AMERICA. TROPICAL WAVE ALONG 86W S OF 13N MOVING W 10-15 KT. THE WAVE IS MAINLY IN THE EPAC BUT ITS NORTHERN EXTENSION LIES OVER CENTRAL AMERICA. SOME SLIGHT CURVATURE IS EVIDENT ON SATELLITE IMAGERY NEAR THE AXIS. A 1009 MB LOW HAS DEVELOPED JUST TO THE WAVE AXIS. THIS WAVE IN CONJUNCTION WITH STRONG SWLY FLOW AND A SFC TROUGH IS PRODUCING CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ACROSS THE SW CARIBBEAN AND CENTRAL AMERICA. WAVE IS NOT EXPECTED TO BECOME ANY BETTER DEFINED OVER THE NEXT COUPLE OF DAYS AS MOVES FURTHER W ACROSS THE EPAC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 4N25W 2N37W 4N51W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 20W-27W ASSOCIATED WITH THE TROPICAL WAVE ALONG 25W. SIMILAR CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 31W-40W. SCATTERED SHOWERS/ISOLATED TSTMS ARE W OF 44W WITHIN 180 NM EITHER SIDE OF THE AXIS ENHANCED BY THE TROPICAL WAVE ALONG 50W. ...DISCUSSION... GULF OF MEXICO... PLEASANT WEATHER CONTINUES ACROSS THE GULF AS A 1017 MB HIGH PRES SYSTEM CENTERED 180 NM E OF TAMPA NEAR 27N86W DOMINATES. AS IN THE UPPER LEVELS...UPPER TROUGH EXTENDS FROM A SMALL UPPER LOW ABOVE N MEXICO NEAR 25N98W TO NORTHERN FLORIDA. STRONG SUBSIDENCE AND ASSOCIATED DRY/STABLE AIR ALOFT ACCOMPANIES THE TROUGH DUE TO UPPER LEVEL CONFLUENCE KEEPING SKIES FAIR TO MOSTLY CLEAR ACROSS THE N GULF. BROKEN MID-HIGH LEVEL CLOUDINESS IS STREAMING NEWARD FROM S MEXICO TO S FLORIDA ON THE W PERIPHERY OF AN UPPER ANTICYCLONE IN THE CARIBBEAN. WEAK HIGH PRESSURE WILL REMAIN ACROSS THE GULF FOR THE NEXT FEW DAYS...HOWEVER TROPICAL MOISTURE 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...THE FRONT HAS WEAKENED TO A TROUGH AND EXTENDS FROM 32N59W SWARD TO THE BAHAMAS NEAR 23N76W THEN CONTINUES SSWWARD INTO THE W CARIBBEAN TO NEAR NICARAGUA. BROKEN TO OVERCAST MOSTLY MID/HIGH CLOUDS ALONG WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM SE OF THE TROUGH N OF 21N. CLUSTERS OF STRONG TSTMS ARE OVER THE W CARIBBEAN WITHIN 120 NM W OF THE TROUGH AXIS S OF 21N. FARTHER E...A MID/UPPER HIGH IS LOCATED JUST N OF HAITI NEAR 21N72W WITH RIDGING EXTENDING SW TO HONDURAS AND NE TO BEYOND 32N50W. A 60-80 KT SWLY JET STREAM IS RIDING OVER THE THE UPPER ANTICYCLONE AND EXTENDS FROM THE E BAY OF CAMPECHE NORTHEASTWARD T0 S FLORIDA AND CONTINUES NEWARD BEYOND 32N59W. WINDS IN THE RANGE OF 60-80 KT ARE NOTED WITHIN THIS JET MAINLY W OF 65W. STRONG SUBSIDENCE IS ENCOMPASSING MUCH OF THE CARIBBEAN S OF 19N AND CURRENTLY E OF 82W...PUSHING WWARD. TRADEWINDS ARE GENERALLY IN THE 15-20 KT RANGE E OF 80W...LIGHTER WINDS W OF THERE DUE TO THE WEAKNESS IN THE RIDGE. TRADES WILL BECOME MORE UNIFORM AND INCREASE SLIGHTLY AS THE CNTRL ATLC SFC RIDGE CONTINUES TO NOSE CLOSER. MOISTURE RELATED TO THE SURFACE TROUGH WILL MOVE WWD TOWARDS THE YUCATAN TOMORROW AND WILL LIKELY AFFECT THE NW CARIBBEAN AND THE W ATLC OVER THE NEXT FEW DAYS. 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 12N-16N BETWEEN 65W-71W...MOVING SWWARD. SMALL ISOLATED SHOWERS AND TSTMS ARE EMBEDDED WITHIN THE ASH CLOUDS. 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 22N48W AND INTO THE DEEP TROPICS NEAR 9N50W. THE UPPER LOW IS HELPING TO TRANSPORT UPPER MOISTURE FROM THE DEEP TROPICS NEWARD WITHIN 180 NM TO THE RIGHT OF A LINE ALONG 10N50W 20N44W 28N40W. AN UPPER HIGH IS NEAR 16N31W WITH MID/UPPER LEVEL RIDGING COVERING THE AREA S OF 17N AND E OF 35W. DIFFLUENCE S OF THE RIDGE IS ENHANCING ITCZ CONVECTION. MODERATE/STRONG SUBSIDENCE COVERS THE AREA FROM 6N-17N E OF 35W. UPPER TROUGH IS MOVING SE OVER EXTREME NW AFRICA. THIS TROUGH IS CARRYING MOISTURE FROM THE UPPER TROUGH IN THE CENTRAL ATLC OVER THE UPPER HIGH INTO W AFRICA. AT THE SFC...A STRONG 1026 MB HIGH CENTERED NEAR 31N39W 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. $$ CANGIALOSI