000 AXNT20 KNHC 222340 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUN 22 2015 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 2315 UTC. ...SPECIAL FEATURES... A STRONG PRESSURE GRADIENT EXISTS ACROSS THE SW CARIBBEAN SEA DUE TO A MODEST 1027 MB HIGH CENTERED IN THE CENTRAL ATLC NEAR 28N48W AND LOWER PRESSURE ANALYZED ACROSS NORTHERN COLOMBIA. CURRENTLY STRONG TO NEAR GALE FORCE TRADES ARE NOTED S OF 15N BETWEEN 70W-79W PER EARLIER ASCAT PASSES AROUND 22/1352 UTC... 22/1440 UTC...AND 22/1534 UTC. THE HIGH IS FORECAST TO SHIFT WEST SLIGHTLY THROUGH TUESDAY AND INCREASE THE WIND FIELD OFF THE COAST OF COLOMBIA INTO A RANGE OF NEAR GALE TO GALE FORCE BY 23/0000 UTC. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 08N32W TO 19N30W MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH AN AMPLIFIED GLOBAL MODEL INDICATED 700 MB TROUGH BETWEEN 25W-36W. 850 MB RELATIVELY VORTICITY IS ALSO MAXIMIZED ALONG THE WAVE AXIS NEAR 13N. DUE TO THE PRESENCE OF THE SAHARAN AIR LAYER...NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 07N49W TO 15N50W MOVING W AT 15 KT. POSITION IS BASED LARGELY ON CONTINUITY AND VERY SUBTLE 700 MB TROUGHING BETWEEN 47W-54W. A 700 MB LOW-LEVEL JET MAXIMUM LIES TO THE EAST OF THE WAVE FROM 08N-14N STRETCHING EASTWARD TO THE TROPICAL WAVE ALONG 31W MENTIONED ABOVE. NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME DUE TO THE PRESENCE OF THE SAHARAN AIR LAYER. TROPICAL WAVE EXTENDS FROM 09N68W TO 17N65W MOVING W AT 15 KT. VERY SUBTLE 700 MB TROUGHING IS NOTED OVER THE EASTERN CARIBBEAN SEA AS THE WAVE INTERACTS WITH AN UPPER LEVEL CENTERED NORTH OF THE MONA PASSAGE NEAR 21N68W. LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH MIDDLE TO UPPER LEVEL DIFFLUENCE DUE TO THE UPPER LEVEL LOW IS GENERATING WIDELY SCATTERED MODERATE CONVECTION FROM 14N-22N BETWEEN 60W-68W...INCLUDING THE LEEWARD ISLANDS... PUERTO RICO...AND THE US/UK VIRGIN ISLANDS. TROPICAL WAVE EXTENDS FROM 08N87W TO 16N87W MOVING W AT 10-15 KT. WHILE MOST OF THE WAVE IS LOCATED IN THE EASTERN PACIFIC REGION...A PORTION OF THE WAVE CONTINUES TO MOVE ACROSS HONDURAS AND EL SALVADOR. A MAXIMUM IN 850 MB RELATIVE VORTICITY IS NOTED IN GLOBAL MODEL DATA OVER THE GULF ON HONDURAS. THESE AMPLE DYNAMICS ALOFT ARE GENERATING ISOLATED TO WIDELY SCATTERED MODERATE CONVECTION FROM 17N-21N BETWEEN 81W-90W ACROSS THE NW CARIBBEAN AND PORTIONS OF THE YUCATAN PENINSULA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 09N25W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N25W TO 06N34W TO 04N51W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 07N-12N BETWEEN 11W-18W. ...DISCUSSION... GULF OF MEXICO... THE BASIN IN UNDER THE INFLUENCE OF TWO UPPER LEVEL FEATURES THIS EVENING...THE FIRST AN UPPER LEVEL RIDGE CENTERED IN THE EASTERN PACIFIC REGION WITH AXIS EXTENDING OVER CENTRAL MEXICO TO OVER THE LOUISIANA COAST NEAR 30N93W. THE OTHER FEATURE IS A BROAD UPPER LEVEL LOW CENTERED OVER BELIZE AND GUATEMALA NEAR 18N89W. BETWEEN THESE FEATURES...UPPER LEVEL NORTHERLY FLOW REMAINS RELATIVELY DRY AND STABLE ACROSS THE NORTH-CENTRAL GULF AND SW GULF WATERS. OVER THE NW GULF...MIDDLE TO UPPER LEVEL MOISTURE INCREASES DUE TO DIFFLUENCE ALOFT GENERATING MOSTLY CLOUDY SKIES THIS EVENING. ON THE NORTHERN PERIPHERY OF THE UPPER LEVEL LOW...SCATTERED SHOWERS AND TSTMS CONTINUE TO BLOSSOM ACROSS THE SE GULF WATERS S OF 24N AND ACROSS PORTIONS OF THE YUCATAN PENINSULA FUELED BY PEAK DAYTIME HEATING AND INSTABILITIES. ELSEWHERE AT THE SURFACE ACROSS THE BASIN...A 1021 MB HIGH REMAINS ANCHORED ACROSS THE NORTHERN HALF OF THE GULF PROVIDING GENERALLY GENTLE TO MODERATE EASTERLY FLOW FROM THE FLORIDA PENINSULA TO THE TEXAS AND MEXICO COAST. THE RIDGE IS ANTICIPATED TO REMAIN RELATIVELY STATIONARY AND WEAKEN SLIGHTLY BY LATE WEDNESDAY INTO THURSDAY. WINDS ACROSS THE WESTERN GULF ARE EXPECTED TO HAVE MORE OF A SOUTHERLY COMPONENT FOR THE LATTER PART OF THE WEEK. CARIBBEAN SEA... AN UPPER LEVEL LOW IS CENTERED OVER BELIZE AND GUATEMALA NEAR 18N89W WHICH IS PROVIDING THE NW CARIBBEAN WITH SOUTH- SOUTHWESTERLY WINDS ALOFT ADVECTING MOISTURE AND MIDDLE TO UPPER LEVEL CLOUDINESS NORTHWARD TOWARD CUBA. THIS OVERALL DIFFLUENT ENVIRONMENT ALOFT IS GENERATING A FEW SCATTERED SHOWERS AND ISOLATED TSTMS IN THE VICINITY OF 16N85W OFF THE COAST OF HONDURAS AND A FEW SCATTERED SHOWERS AND ISOLATED TSTMS N OF 18N W OF 76W. CONVECTION COVERAGE AND INTENSITY INCREASES SLIGHTLY ACROSS MUCH OF CUBA AND PORTIONS OF THE YUCATAN PENINSULA DUE TO DIFFERENTIAL HEATING AND PEAK DAYTIME INSTABILITY. THE SOUTHWESTERLY FLOW ALOFT ALSO EXTENDS OVER PORTIONS OF THE SW CARIBBEAN WATERS GENERATING A FEW ISOLATED SHOWERS AND TSTMS S OF 13N W OF 80W INCLUDING INLAND PORTIONS OF COSTA RICA AND SE NICARAGUA. FINALLY...INTERACTION BETWEEN A TROPICAL WAVE ALONG 67W AND AN UPPER LEVEL LOW CENTERED NORTH OF THE MONA PASSAGE NEAR 21N68W IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS THE NE CARIBBEAN N OF 14N BETWEEN 60W-69W...INCLUDING THE LEEWARD ISLANDS...PUERTO RICO...AND THE US/UK VIRGIN ISLANDS. THE WAVE IS FORECAST TO MOVE WESTWARD AND IMPACT THE EASTERN GREATER ANTILLES THROUGH WEDNESDAY. ...HISPANIOLA... CURRENTLY A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE DOMINICAN REPUBLIC THIS EVENING AS A TROPICAL WAVE APPROACHES FROM THE EAST. AN UPPER LEVEL LOW IS ALSO NOTED ON WATER VAPOR IMAGERY CENTERED NORTH OF THE ISLAND NEAR 21N68W THAT CONTINUES TO PROVIDE RELATIVELY DRY AND STABLE AIR DUE TO NORTH-NORTHWESTERLY FLOW ON THE WESTERN PERIPHERY OF THE UPPER LEVEL LOW. WHILE THE UPPER LEVEL LOW IS FORECAST TO MOVE VERY LITTLE OVER THE NEXT FEW DAYS...LOW-LEVEL MOISTURE IS EXPECTED TO INCREASE ACROSS HISPANIOLA THROUGH THURSDAY BRINGING INCREASED PROBABILITY OF PRECIPITATION FOR THE WEEK DUE TO THE PASSING OF THE TROPICAL WAVE TO THE SOUTH. ATLANTIC OCEAN... ASIDE FROM THE A FEW ISOLATED SHOWERS ACROSS THE WESTERN BAHAMAS AND FLORIDA STRAITS THIS EVENING...AND THE PRECIPITATION AND CONVECTION OCCURRING IN ASSOCIATION WITH AN UPPER LEVEL LOW CENTERED NEAR 21N68W...THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED IN THE CENTRAL ATLC NEAR 28N48W. THE RIDGE AXIS EXTENDS WESTWARD TO THE FLORIDA PENINSULA ALONG 28N WITH MOSTLY CLEAR SKIES AND FAIR CONDITIONS EXPECTED. ON THE EASTERN PERIPHERY OF THIS RIDGE...THE RIDGE AXIS EXTENDS ALONG 28N TO 25W THEN NE TO THE MADEIRA ISLANDS NEAR 33N17W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN