000 AXNT20 KNHC 221757 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAY 22 2014 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 1715 UTC. ...TROPICAL WAVES... THE TROPICAL WAVE THAT MOVED YESTERDAY OUT OF AFRICA NOW EXTENDS FROM 13N17W TO 4N18W BASED ON THE 1024 UTC ASCAT PASS THAT SHOWED PRETTY WELL THE WIND SHIFT ASSOCIATED WITH THE WAVE AXIS AS WELL AS E TO SE WINDS OF 20-30 KT NEAR THE SOUTHERN END OF THE WAVE LIKELY ASSOCIATED WITH A CLUSTER OF MODERATE TO STRONG CONVECTION PREVIOUSLY SEEN ON SATELLITE IMAGERY. CURRENTLY... SCATTERED MODERATE CONVECTION IS NOTE ON EITHER SIDE OF THE WAVE AXIS MAINLY FROM 4N TO 7N BETWEEN 15N AND 21W. IN ADDITION... THE WAVE COINCIDES WITH A BULGE OF MOISTURE IN THE TOTAL PRECIPITABLE WATER ANIMATION. THE WAVE WILL MOVE WESTWARD AT 10- 15 KT. ANOTHER TROPICAL WAVE IS NOTED ALONG 38W FROM 2N TO 10N. THIS WAVE WAS PREVIOUSLY ANALYZED AS A SURFACE TROUGH. HOWEVER...THE HOVMOLLER DIAGRAM SHOWS THE WESTWARD MOVEMENT OF THIS FEATURE THAT APPARENTLY MOVED OUT OF AFRICA THE 19TH OF MAY. CURRENTLY...VISIBLE SATELLITE IMAGERY INDICATES SOME INVERTED-V PATTERN ASSOCIATED WITH THIS WAVE. UNFORTUNATELY THE ASCAT PASS MISSED THIS SYSTEM. THERE ARE FEW SHOWERS ON EITHER SIDE OF THE WAVE AXIS. THIS FEATURE WILL ALSO MOVE WESTWARD AT 10-15 KT. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ANALYZED MAINLY ACROSS AFRICA. THE ITCZ EXTENDS FROM 3N20W TO 1N25W TO 3N36W THEN CONTINUES WEST OF THE SECOND TROPICAL WAVE FROM 2N41W TO 1N50W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 150 NM N OF AXIS BETWEEN 20W AND 30W...AND WITHIN 60 NM S OF AXIS BETWEEN 30W AND 33W. SIMILAR CONVECTION IS NOTED S OF 1.5N W OF 41W. ...DISCUSSION... GULF OF MEXICO... A 1022 MB HIGH PRES LOCATED NEAR THE MOUTH OF THE MISSISSIPPI RIVER EXTENDS A RIDGE ACROSS THE ENTIRE GULF REGION PRODUCING MOSTLY FAIR WEATHER. ANOTHER WEAK HIGH PRES OF 1019 MB IS INLAND MEXICO BETWEEN TAMPICO AND TUXPAN. S OF THE RIDGE...AN EARLIER ASCAT PASS SHOWED FRESH TO LOCALLY STRONG EASTERLY WINDS OVER THE SOUTH-CENTRAL GULF JUST N OF THE YUCATAN PENINSULA. W OF THE RIDGE...SOUTHERLY RETURN FLOW HAS ESTABLISHED OVER THE WESTERN GULF AND WILL PERSIST DURING THE UPCOMING WEEKEND. THE HIGH PRESSURE WILL REMAIN OVER THE NORTHEAST AND NORTH CENTRAL GULF THROUGH EARLY NEXT WEEK. ALOFT...A RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS S MEXICO TO ALONG THE MEXICO AND TEXAS COASTLINES TO OVER THE CENTRAL PLAIN STATES GIVING THE GULF NW FLOW IN THE MID/UPPER LEVELS. MODERATE TO STRONG MID/UPPER LEVEL SUBSIDENCE AND IMPLIED DRY AIR MASS IS OBSERVED ON WATER VAPOR IMAGERY ACROSS MOST OF THE GULF REGION. CARIBBEAN SEA... A MID/UPPER LEVEL TROUGH FROM THE ATLC EXTENDS ACROSS EASTERN CUBA AND THE WEST-CENTRAL CARIBBEAN. SW TO W WINDS AHEAD OF THE TROUGH AXIS ARE HELPING TO INDUCE CONVECTION ACROSS PARTS OF THE CENTRAL CARIBBEAN...JAMAICA AND HISPANIOLA. IT SHOULD BE NOTED THAT THE TROUGH HAS SLIGHTLY MOVED EASTWARD FROM YESTERDAY BUT WILL REMAIN NEARLY STATIONARY ACROSS THE FAR EAST CUBA AND THE CENTRAL CARIBBEAN ON FRI WHILE DEEPENING. VISIBLE SATELLITE IMAGERY CONTINUES TO SHOW A BROKEN BAND OF MULTILAYERED CLOUDS EXTENDING FROM NE HONDURAS ALL THE WAY NE CROSSING JUST S OF JAMAICA INTO HISPANIOLA. THE WEATHER SERVICE IN DOMINICAN REPUBLIC HAS ISSUED A FLASH FLOOD WATCH DUE TO THE PERSISTENT RAINFALL DURING THE PREVIOUS DAYS. THIS MID/UPPER LEVEL TROUGH WILL CONTINUE TO AFFECT HISPANIOLA AND PUERTO RICO AS IT DRIFTS SLOWLY EASTWARD TOWARD THE EASTERN CARIBBEAN EARLY NEXT WEEK. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS NOTED OVER THE SW CARIBBEAN MAINLY S OF 11N BETWEEN 78W AND 81W. A DIFFLUENT PATTERN ALOFT NEAR THE BASE OF THE AFOREMENTIONED UPPER TROUGH IS HELPING TO ENHANCE THIS CONVECTIVE ACTIVITY. PATCHES OF LOW LEVEL CLOUDS EMBEDDED IN THE TRADE WIND FLOW ARE CROSSING THE LEEWARD ISLANDS PRODUCING ISOLATED TO SCATTERED PASSING SHOWERS. HIGH PRESSURE NORTH OF THE AREA WILL MAINTAIN FRESH TO STRONG TRADEWINDS IN THE CENTRAL CARIBBEAN OFF NE COLOMBIA AND NW VENEZUELA WITH MODERATE TO FRESH TRADES ELSEWHERE THROUGH SUNDAY. ...HISPANIOLA... THE ABOVE MENTIONED MID/UPPER LEVEL TROUGH WILL COMBINE WITH DAYTIME HEATING...A MOIST SOUTHEASTERLY FLOW AND LOCAL EFFECTS TO INDUCE THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS PARTS OF THE ISLAND MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS THROUGH AT LEAST FRI. DUE TO THE CONTINUOUS RAINFALL OVER THE PAST FEW DAYS...THE POSSIBILITY OF LOCALIZED FLOODING COULD OCCUR ESPECIALLY IN THE MOUNTAINOUS TERRAIN. ATLANTIC OCEAN... A 1024 MB HIGH PRES LOCATED NEAR 29N61W EXTENDS A RIDGE ACROSS MUCH OF THE W ATLC. THIS HIGH CENTER IN FORECAST TO DISSIPATE IN ABOUT 24 HOURS AS A TROUGH MOVES OFF THE SE CONUS INTO THE NW PART OF THE FORECAST AREA BY TONIGHT. FRESH TO STRONG SWLY FLOW IS SEEN AHEAD OF THE TROUGH PER THE MOST RECENT SCATTEROMETER DATA. THIS TROUGH IS FORECAST TO DISSIPATE BY FRI NIGHT. A SURFACE TROUGH...REFLECTION OF THE PREVIOUSLY MENTIONED MID/UPPER LEVEL TROUGH EXTENDS FROM 24N68W TO HAITI NEAR 19N73W. SCATTERED SHOWERS WITH EMBEDDED TSTMS ARE NOTED ON THE EAST SIDE OF THE TROUGH WHERE A MOIST SOUTHEASTERLY FLOW PREVAILS. SIMILAR CONVECTION IS NEAR THE ENTRANCE OF THE WINDWARD PASSAGE. LIGHT TO MODERATE NE FLOW AHEAD OF THE TROUGH AXIS AND ON THE S PERIPHERY OF THE RIDGE CONTINUES TO ADVECT SHALLOW MOISTURE ACROSS THE BAHAMAS INTO CUBA. A COLD FRONT ENTERS THE FORECAST AREA NEAR 31N52W THEN CONTINUES SW TO NEAR 28N58W WHERE IT BECOMES STATIONARY TO NEAR 27N65W. SHOWER ACTIVITY IS LIMITED ALONG THE FRONTAL BOUNDARY FORECAST TO DISSIPATE ON FRI. E OF FRONT...A SECOND SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC ANCHORED BY A HIGH LOCATED WELL N OF THE REGION. ALOFT...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE FORECAST REGION. BROAD UPPER TROUGH EXTENDS FROM NEAR BERMUDA TO EASTERN CUBA. SWLY FLOW AHEAD OF THE TROUGH IS PRODUCING A NEARLY 400 NM WIDE BAND OF MULTILAYERED CLOUDS THAT EXTEND FROM HISPANIOLA ALL THE WAY NE TO BEYOND 31N45W. TRANSVERSE HIGH CLOUDS ARE ALSO NOTED IN ASSOCIATION WITH THE STRONGEST UPPER-LEVEL WINDS. ANOTHER UPPER LEVEL TROUGH IS OVER THE E ATLC EXTENDING FROM 31N19W TO ABOUT 13N36W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR