000 AXNT20 KNHC 251051 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE JUN 25 2013 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1022 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS CROSSING THE DOMINICAN REPUBLIC WITH AXIS EXTENDING FROM 21N67W TO 14N72W. THIS WAVE IS MOVING W-NW AT 10- 15 KT IN THE SW PERIPHERY OF A BROAD SURFACE RIDGE COVERING THE ATLC...PORTIONS OF THE CARIBBEAN AND THE GULF. THE PORTION OF THE WAVE N-NE OF LA HISPANIOLA IS EMBEDDED IN A MODERATE HUMID ENVIRONMENT AT THE LOWER LEVELS. SOME OF THIS HUMIDITY HAS MOVED INLAND E OF THE AXIS AS WELL AS SE OF THE AXIS N OF 16N. A LOW HUMIDITY ENVIRONMENT AT THE LOWER LEVELS IS OBSERVED ACROSS LA HISPANIOLA WEST OF THE WAVE AXIS AND AHEAD OF THE WAVE IN THE CENTRAL CARIBBEAN. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE HAPPENING NE OF THE DOMINICAN REPUBLIC ASSOCIATED WITH THE WAVE AND BEING ENHANCED BY UPPER LEVEL DIFFLUENCE FROM A CYCLONIC CIRCULATION IN THE W ATLC AND A NARROW RIDGE THAT HAS FORMED NE OF PUERTO RICO. TROPICAL WAVE CROSSING THE SOUTHERN LESSER ANTILLES WITH AXIS EXTENDING FROM 20N59W TO 11N61W. THE WAVE AXIS IS MOVING W-NW AT 15 KT. THE ENVIRONMENT IN WHICH THE WAVE IS EMBEDDED IS CHARACTERIZED BY MODERATE MOISTURE IN THE LOWER LEVELS N OF 16N AND A LOW HUMID ENVIRONMENT S OF 16N EXTENDING ACROSS THE EASTERN CARIBBEAN. WATER VAPOR IMAGERY DEPICT THIS DRY REGION AHEAD OF THE WAVE ALSO IN THE MIDDLE LEVELS. SCATTERED SHOWERS ARE OCCURRING WITHIN 180 NM EAST OF THE WAVE AXIS COINCIDING WITH THE REGION OF MODERATE MOISTURE OBSERVED IN THE TOTAL PRECIPITABLE WATER IMAGERY. A NEW TROPICAL WAVE HAS BEEN DETECTED EMBEDDED WITHIN THE ITCZ WITH AXIS ALONG 10N34W TO 02N36W. IT IS A LOW AMPLITUDE WAVE IN THE 700 MB AND 315K POTENTIAL VORTICITY AND WIND GUIDANCE PREDICTS THIS WAVE TO MOVE W-NW ENTERING THE EASTERN CARIBBEAN IN FOUR DAYS. CURRENTLY SCATTERED MODERATE TO STRONG CONVECTION IS FROM 04N-06N BETWEEN 34W-40W COINCIDING WITH HIGH MOISTURE AT THE LOWER LEVELS WITHIN THE ITCZ AXIS. NO CONVECTION IS OCCURRING IN THE NORTHERN ENVIRONMENT OF THE WAVE DUE TO THE PRESENCE OF SAHARAN DRY AIR. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL WEST AFRICA NEAR 11N15W TO 09N22W 08N25W. THE ITCZ STARTS NEAR 08N25W AND IT CONTINUES TO 06N35W. THE ITCZ AXIS RESUMES WEST OF A TROPICAL WAVE FROM 05N36W TO 06N45W. BESIDES THE CONVECTION ALREADY DESCRIBED ABOVE WITHIN THE TROPICAL WAVE ENVIRONMENT EMBEDDED IN THE ITCZ...SCATTERED MODERATE CONVECTION IS FROM 05N-08N BETWEEN 25W-28W. ...DISCUSSION... THE GULF OF MEXICO... BROAD SURFACE RIDGING FROM A SET OF HIGH PRESSURES N OF THE AREA OVER THE NORTH ATLC EXTENDS INTO THE GULF GENERATING RETURN FLOW IN THE RANGE OF 10-15 KT ACROSS THE BASIN. MODERATE MOISTURE AT THE LOWER AND MIDDLE LEVELS COMBINED WITH UPPER LEVEL DIVERGENCE FROM AN ANTICYCLONIC CIRCULATION EAST OF 88W MAY ENHANCE ISOLATED SHOWERS IN THIS PART OF THE BASIN THIS MORNING. BOTH PRECIPITABLE WATER AND WATER VAPOR IMAGERY SHOW A DRY ENVIRONMENT IN THE LOWER AND MIDDLE LEVELS W OF 88W WHICH IS SUPPRESSING ANY TYPE OF CONVECTIVE ACTIVITY. NO SIGNIFICANT CHANGES ARE EXPECTED DURING THE NEXT 24 HOURS AS THE CURRENT WEATHER PATTERNS IN THE LOWER AND UPPER LEVELS ARE EXPECTED TO PREVAIL. THE CARIBBEAN SEA... A TROPICAL WAVE IS CROSSING THE DOMINICAN REPUBLIC WITH AXIS EXTENDING FROM 21N67W TO 14N72W. A LOW HUMIDITY ENVIRONMENT AT THE LOWER LEVELS IS OBSERVED ACROSS LA HISPANIOLA WEST OF THE WAVE AXIS AND AHEAD OF THE WAVE IN THE CENTRAL CARIBBEAN. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE HAPPENING NE OF THE DOMINICAN REPUBLIC ASSOCIATED WITH THE WAVE AND BEING ENHANCED BY UPPER LEVEL DIFFLUENCE. UPPER LEVEL DIFFLUENT FLOW FROM A CYCLONIC CIRCULATION OVER THE FAR WEST CARIBBEAN AND THE BROAD UPPER RIDGE EXTENDING ACROSS THE REMAINDER OF THE BASIN COMBINED WITH LOWER AND MIDDLE LEVEL MODERATE TO HIGH MOISTURE SUPPORT A CLUSTER OF MODERATE/STRONG CONVECTION AND THUNDERSTORMS WITHIN 240 NM OFF THE COAST OF BELIZE...SIMILAR CONVECTION WITHIN 120 NM OFF THE NICARAGUA COAST AND ISOLATED THUNDERSTORMS NE OF JAMAICA. CLUSTERS OF MODERATE/STRONG CONVECTION WITH THUNDERSTORM ACTIVITY CAN BE FOUND IN THE SOUTHERN CARIBBEAN S OF 12N IN ASSOCIATION WITH THE MONSOON TROUGH AXIS AND A 1011 MB LOW CLOSE TO THE COAST OF NORTHERN COLOMBIA. TRADEWINDS CONTINUE TO SPREAD ACROSS THE BASIN SUBSIDING TO 20 KT OVER THE CENTRAL CARIBBEAN WHILE 10-15 KT WINDS PREVAIL ELSEWHERE. A TRAILING TROPICAL WAVE IS ENTERING THE EASTERN CARIBBEAN. SEE THE WAVES SECTION ABOVE FOR A DETAILED DESCRIPTION OF ITS ENVIRONMENT. OTHERWISE...THE TROPICAL WAVE OVER LA HISPANIOLA WILL MOVE OUT OF HAITI BY TUESDAY AFTERNOON AND IS LIKELY TO VANISH IN THE WAKE OF INTERACTION WITH A VERY DRY ENVIRONMENT AT THE LOWER LEVELS. THE TRAILING WAVE IS EXPECTED TO MOVE OVER PUERTO RICO THIS EVENING. MODERATE SHOWERS CAN BE EXPECTED IN ASSOCIATION TO THIS WAVE. A LOW PRESSURE IS EXPECTED TO DEVELOP OVER THE SOUTHERN CARIBBEAN BY WEDNESDAY AND HEAVY SHOWERS WILL BE ASSOCIATED TO IT. HISPANIOLA... DRY SURFACE CONDITIONS ARE OVER THE ISLAND W OF 70W WHILE LIGHT TRADEWINDS OF 5-10 KT CONTINUES. TROPICAL WAVE IS CROSSING THE DOMINICAN REPUBLIC WITH AXIS EXTENDING FROM 21N67W TO 14N72W. IT WILL MOVE OUT OF HAITI BY TUESDAY AFTERNOON AND IS LIKELY TO VANISH IN THE WAKE OF INTERACTION WITH A VERY DRY ENVIRONMENT AT THE LOWER LEVELS. THE TROPICAL WAVE WITH AXIS CURRENTLY LOCATED NEAR 57W IS EXPECTED TO ENTER THE DOMINICAN REPUBLIC WEDNESDAY AFTERNOON GENERATING RAINSHOWERS ACROSS THIS PORTION OF THE ISLAND. THE ATLANTIC OCEAN... BROAD SURFACE RIDGING DOMINATES ACROSS THE BASIN N OF 16N FROM A SET OF HIGH PRESSURE CENTERS N OF THE AREA OF DISCUSSION. EXCEPT FOR THE AREAS DISCUSSED ABOVE...TOTAL PRECIPITABLE WATER IMAGERY SHOW AN OVERALL DRY ENVIRONMENT AT THE LOWER LEVELS WHICH IS SUPPORTING FAIR WEATHER BASIN WIDE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS