000 AXNT20 KNHC 030004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT AUG 02 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... TROPICAL STORM BERTHA IS CENTERED NEAR 18.4N 68.5W AT 02/2100 UTC OR ABOUT 81 NM E OF SANTO DOMINGO DOMINICAN REPUBLIC MOVING WNW AT 19 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1010 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. NUMEROUS MODERATE CONVECTION IS OVER PUERTO RICO AND ADJACENT WATERS WITH THE HEAVIEST RAINFALL BEING OVER THE WESTERN ISLAND AND THE MONA PASSAGE. SIMILAR CONVECTION WITH EMBEDDED TSTMS EXTENDS TO THE EASTERN DOMINICAN REPUBLIC AND COASTAL WATERS. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT3/ WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AXIS EXTENDING FROM 20N34W TO 11N36W MOVING W AT 20 KT DURING THE PAST 24 HOURS. EXCEPT FOR THE SOUTHERN PORTION OF THE WAVE CLOSE TO THE ITCZ AXIS...THE REMAINDER WAVE IS EMBEDDED IN THE DRY SAHARAN AIR LAYER...WHICH INHIBITS CONVECTION AT THE TIME. A TROPICAL WAVE IS ABOUT 400 NM E OF THE LESSER ANTILLES WITH AXIS EXTENDING FROM 17N49W TO 10N46W MOVING W AT 20-25 KT. METEOSAT SAL TRACKING IMAGERY INDICATE THE WAVE IS ALSO EMBEDDED IN THE DRY SAHARAN AIRMASS...WHICH IS HINDERING CONVECTION AT THE TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR 12N16W TO 9N25W TO 10N33W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N33W AND CONTINUES ALONG 7N45W TO 4N52W. SCATTERED MODERATE CONVECTION IS FROM 7N-11N E OF 17W AND FROM 5N-12N BETWEEN 26W-41W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH OVER THE EASTERN CONUS WITH BASE EXTENDING TO NORTHERN GULF COASTAL WATERS SUPPORT A FRONTAL SYSTEM ASSOCIATED WITH A 1013 MB LOW LOCATED OVER SOUTHERN LOUISIANA. A STATIONARY FRONT EXTENDS EASTWARD FROM THE LOW ACROSS SOUTHERN MISSISSIPPI TO SOUTHERN ALABAMA. A COLD FRONT EXTENDS SW FROM THE LOW ALONG 26N93W TO SOUTHERN TEXAS NEAR 26N97W. THE UPPER LEVEL TROUGH IS ALSO SUPPORTING A LINE OF SHOWERS AND TSTMS ALONG THE FLORIDA PENINSULA. AN UPPER LEVEL CYCLONE OVER THE YUCATAN PENINSULA SUPPORT A SURFACE TROUGH ALONG 21N88W TO 16N92W...WHICH IS SUPPORTING HEAVY SHOWERS AND TSTMS OVER THE GREAT PORTIONS OF IT. MIDDLE TO UPPER LEVEL DIVERGENT FLOW OVER THE CENTRAL BASIN ALONG WITH ABUNDANT MOISTURE BEING ADVECTED FROM THE SW N ATLC ENHANCE SCATTERED SHOWERS AND TSTMS ASSOCIATED WITH A SURFACE PRE-FRONTAL TROUGH ALONG 29N90W TO 26N91W 23N93W. THE FRONTAL BOUNDARY WILL LINGER ACROSS THE NORTHERN GULF THROUGH TUESDAY MORNING WHEN IT IS FORECAST TO DISSIPATE. CARIBBEAN SEA... THE HIGHLIGHT IN THE BASIN TONIGHT IS TROPICAL STORM BERTHA WHICH IS AFFECTING THE ISLAND OF PUERTO RICO WITH HEAVY RAINFALL...FLOODING AND POSSIBLE MUDSLIDES. HEAVY SHOWERS AND TSTMS ARE ALSO ACROSS THE MONA PASSAGE AND EASTERN DOMINICAN REPUBLIC AS THE STORM CONTINUES A WNW TRACK. SEE SPECIAL FEATURES ABOVE FOR MORE INFORMATION ABOUT BERTHA. LOW-LEVEL MOISTURE CONVERGENCE AS WELL AS UPPER LEVEL DIVERGENCE OVER CUBA IS SUPPORTING HEAVY SHOWERS AND TSTMS ALONG THE ISLAND AS WELL AS ADJACENT WATERS. THE MONSOON TROUGH MOVES ACROSS COSTA RICA AND PANAMA TO A 1006 MB LOW OVER COLOMBIA AND SUPPORT SCATTERED MODERATE CONVECTION AND TSTMS S OF 11N BETWEEN 75W-83W. OTHERWISE...DEEP LAYER DRY AIR IS ELSEWHERE IN THE BASIN SUPPORTING FAIR WEATHER. BERTHA WILL MOVE ACROSS THE E-NE DOMINICAN REPUBLIC TONIGHT AND WILL ENTER ATLC WATERS EARLY SUNDAY MORNING. HOWEVER RAINFALL ASSOCIATED WITH IT WILL LINGER ACROSS HISPANIOLA SUNDAY NIGHT. NEXT TROPICAL WAVE WILL MOVE ACROSS THE EASTERN CARIBBEAN TUE MORNING. ...HISPANIOLA... HEAVY RAINFALL AND TSTMS ARE OCCURRING OVER THE MONA PASSAGE AND EASTERN DOMINICAN REPUBLIC ASSOCIATED WITH TROPICAL STORM BERTHA. THE STORM IS FORECAST TO MOVE ACROSS THE E-NE HISPANIOLA TONIGHT...ENTERING THE ATLC WATERS EARLY ON SUNDAY. FLASH FLOODING AND MUDSLIDES ARE POSSIBLE AS THIS ACTIVITY IS EXPECTED TO LAST THROUGH SUNDAY NIGHT. SEE SPECIAL FEATURES ABOVE FOR MORE INFORMATION ON BERTHA. ATLANTIC OCEAN... A MIDDLE-LEVEL INVERTED TROUGH IS ACROSS THE BAHAMAS...THUS SUPPORTING A SURFACE TROUGH ALONG 27N76W TO 22N79W AS WELL AS SCATTERED HEAVY SHOWERS AND TSTMS OVER THE NORTHERN AND CENTRAL BAHAMAS. FARTHER TO THE SE...NUMEROUS SHOWERS AND ISOLATED TSTMS ARE WITHIN 260 NM NORTH OF PUERTO RICO AND EASTERN DOMINICAN REPUBLIC ASSOCIATED WITH TROPICAL STORM BERTHA. AN EARLIER SCATTEROMETER PASS INDICATED THE PRESENCE OF A 1019 MB LOW PRESSURE NEAR 28N55W WITH NO CONVECTION ASSOCIATED WITH IT. OTHERWISE...BESIDES THE TROPICAL WAVES ALREADY DISCUSSED...SURFACE RIDGING ANCHORED BY A 1028 MB NEAR 39N37W DOMINATES ELSEWHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR