000 AXNT20 KNHC 182353 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUN 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2245 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION TWO IS CENTERED NEAR 18.3N 91.9W AT 18/2100 UTC OR 20 NM SSW OF CARMEN MEXICO...OR ABOUT 140 NM E OF COATZACOALAS MEXICO MOVING WNW AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. SCATTERED MODERATE CONVECTION IS FROM 17N-23N BETWEEN 85W-89W...AND FROM 20N-22N BETWEEN 89W-93W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 13N26W TO 6N25W MOVING WEST AT 15-20 KT. THE WAVE LIES ON THE WESTERN SIDE OF A SURGE IN DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. THERE IS ALSO A CLEARING IN THE LARGE AREA OF SAHARAN DUST THAT SPREADS ACROSS THE TROPICAL ATLC. DUE TO THE PRESENCE OF THE DUST...CONVECTION IS LIMITED TO THE MONSOON TROUGH/ITCZ REGION...AND IS SPARSE THERE AS WELL. TROPICAL WAVE EXTENDS FROM 15N68W TO 8N68W MOVING W NEAR 20 KT. THE WAVE COINCIDES WITH A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. AN UPPER LEVEL TROUGH TO THE EAST OF THE WAVE AND THE LESSER ANTILLES IS ALSO ADVECTING MOISTURE NORTHWARD CAUSING A LARGE AREA OF MOISTURE TO BE PRESENT EAST OF THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 12N-14N BETWEEN 61W-66W. CONVECTION CONTINUE TO THE EAST...BUT IS MORE LIKELY CONNECTED TO THE UPPER TROUGH AND WILL BE DISCUSSED IN THE ATLC SECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF SENEGAL NEAR 15N17W TO 7N23W. THE ITCZ BEGINS ON THE WEST SIDE OF A TROPICAL WAVE ALONG 7N27W 5N53W. A LARGE CLUSTER OF STRONG CONVECTION IS MOVING OFF THE AFRICAN COAST FROM 7N-12N BETWEEN 12W-15W. ISOLATED MODERATE CONVECTION IS FROM 7N-9N BETWEEN 22W- 24W...FROM 6N-8N BETWEEN 34W-37W...AND FROM 5N-8N BETWEEN 42W- 45W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING DOMINATES THE NORTHERN HALF OF THE GULF OF MEXICO WITH AXIS ALONG 27N CONTINUING INTO THE WEST ATLC. TROPICAL DEPRESSION TWO IS IMPACTING THE SOUTHERN GULF. SEE SPECIAL FEATURES FOR MORE DETAILS. NORTH OF THE CIRCULATION OF THE DEPRESSION...WINDS ARE LIGHT AND ANTI-CYCLONIC. SKIES ARE MOSTLY CLEAR DUE TO DRY AIR ALOFT IN WESTERLY FLOW AROUND AN UPPER LEVEL RIDGE TO THE SOUTH THAT EXTENDS INTO THE CARIBBEAN. THE UPPER RIDGE IS ADVECTING MOISTURE OVER THE YUCATAN PENINSULA FROM T.D. TWO. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE MAINLY SOUTH OF 23N BETWEEN 85W-94W. CLUSTERS OF SHOWERS/THUNDERSTORMS ARE ALSO OVER THE SOUTHERN HALF OF THE FLORIDA PENINSULA. T.D. TWO WILL CONTINUE TO IMPACT THE SW GULF...WHILE SURFACE RIDGING REMAINS OVER THE NORTHERN GULF. CARIBBEAN SEA... MOISTURE ASSOCIATED WITH T.D TWO CONTINUES TO IMPACT THE FAR NW CARIBBEAN SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS NORTH OF 14N WEST OF 84W. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. ALOFT...AN UPPER LEVEL RIDGE COVERS THE MAJORITY OF THE BASIN...WHILE AN UPPER LEVEL TROUGH SINKS INTO THE EASTERN CARIBBEAN ALONG 66W. BESIDES CONVECTION ASSOCIATED WITH THE DEPRESSION...HEAVY SHOWERS/THUNDERSTORMS ARE SOUTH OF 11N BETWEEN 77W-85W ASSOCIATED WITH THE MONSOON TROUGH THAT EXTENDS THROUGH COSTA RICA TO NORTHERN COLOMBIA. THE CENTRAL CARIBBEAN IS FAIRLY CLEAR ELSEWHERE. A TROPICAL WAVE ALONG 68W IS DRAGGING MOISTURE WESTWARD WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS SOUTH OF 16N EAST OF THE WAVE AXIS. THE UPPER TROUGH ALONG 66W IS ALSO PROVIDING DIFFLUENT FLOW OVER THE FAR EASTERN CARIBBEAN...WHICH IS DRAWING MOISTURE TOWARDS THE NE. AS THE WAVE MOVES WESTWARD...A LARGE AREA OF MOISTURE WILL SPREAD OVER THE EASTERN CARIBBEAN BEHIND THE WAVE. TRADEWIND FLOW OF 15-20 KT IS PRESENT OVER THE EASTERN CARIBBEAN INCREASING TO 25 KT OVER THE CENTRAL PORTIONS. BESIDES THE MOISTURE EXPECTED OVER THE EASTERN CARIBBEAN...MOIST CONDITIONS ARE EXPECTED TO REMAIN OVER THE FAR NW CARIBBEAN AS WELL. HISPANIOLA... HISPANIOLA REMAINS RATHER TRANQUIL EXCEPT FOR A FEW WIDELY ISOLATED SHOWERS/THUNDERSTORMS OVER SOUTHERN HAITI. CONSIDERABLY LESS ACTIVITY IS OCCURRING COMPARED TO MOST AFTERNOONS. THIS IS LIKELY TO DUE TO DRY AIR ALOFT AROUND AN UPPER TROUGH TO THE EAST...AND THE PRESENCE OF DUST IN THE LOWER ATMOSPHERE. MOISTURE EAST OF A TROPICAL WAVE TO THE SOUTH WILL BEGIN TO IMPACT THE EASTERN PORTIONS OF THE ISLAND WITHIN 24 HOURS...AND WILL SPREAD OVER THE ISLAND THROUGH 48 HOURS. ATLANTIC OCEAN... A BROAD RIDGE COVERS MUCH OF THE ATLC BASIN EXTENDING FROM A 1033 MB AZORES HIGH. DRY AIR ALOFT AROUND THE WEST SIDE OF AN UPPER LOW NEAR 23N65W IS PROVIDING FAIR CONDITIONS OVER THE FAR WEST ATLC. THE UPPER LOW IS ADVECTING MOISTURE AROUND THE EAST SIDE EXTENDING FROM THE FAR EASTERN CARIBBEAN. SCATTERED SHOWERS/THUNDERSTORMS ARE NOTED EAST OF THE LESSER ANTILLES FROM 11N-19N BETWEEN 55W-61W. FARTHER EAST...AN UPPER LEVEL RIDGE IS ALONG 52W...WHILE ANOTHER UPPER LOW IS CENTERED NEAR 28N42W. THE UPPER LOW SUPPORTS A BROAD SURFACE TROUGH ALONG 32N44W TO 27N41W. NO SHOWERS ARE ASSOCIATED WITH THE TROUGH. BROAD UPPER RIDGING DOMINATES THE TROPICAL ATLC...WHILE A THIRD WEAK UPPER LOW IS OVER THE EASTERN ATLC NEAR 25N23W. A SAHARAN AIR LAYER CONTINUES TO BE PRESENT OVER MUCH OF THE TROPICAL ATLC...EXCEPT NEAR THE TROPICAL WAVE...EXTENDING TO NEAR 55W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON