000 AXNT20 KNHC 090004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU MAY 08 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N11W SW TO 04N13W 02N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS NEAR 02N19W AND CONTINUES ALONG 02N36W TO THE NORTHERN COAST OF BRAZIL NEAR 0N50W. CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION AND TSTMS ARE FROM 02S-05N E OF 15W. SCATTERED MODERATE CONVECTION IS FROM 03S-05N BETWEEN 17W-34W AND FROM 01S- 04N W OF 44W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH SUPPORTING A LOW PRESSURE SYSTEM OVER THE NORTHERN-CENTRAL U.S. HAS ITS BASE OVER SOUTHERN MEXICO. EAST OF THE TROUGH...A MIDDLE TO UPPER LEVEL RIDGE EXTENDS ACROSS THE EASTERN CONUS INTO THE GULF AND GENERATES DIFFLUENCE ALOFT OVER THE NW GULF. SOUTHWESTERLY FLOW ASSOCIATED WITH THE RIDGE ALOFT AS WELL AS AN AREA OF LOW PRESSURE ON THE E PACIFIC HAVE BEEN ADVECTING VERY MOIST AIR INTO MEXICO AND THE A PORTION OF THE WESTERN GULF. THE SYNOPTIC PATTERN ALOFT ALONG WITH THE DEEP LAYER MOIST AIR ARE SUPPORTING HEAVY SHOWERS AND TSTMS OVER EASTERN AND CENTRAL MEXICO. SCATTERED SHOWERS EXTEND INTO THE GULF W OF 92W. A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH OVER THE W ATLC EXTENDS SW INTO THE GULF...THUS PROVIDING WITH SOUTHEASTERLY FLOW OF 10-15 KT. THIS WIND FLOW IS SUPPORTING ADVECTION FOG OVER THE NW GULF N OF 27N W OF 91W. DEEP LAYER DRY AIR ACROSS THE REMAINDER BASIN ALONG WITH SURFACE RIDGING SUPPORT FAIR WEATHER ELSEWHERE IN THE BASIN. SURFACE RIDGING AND SOUTHEASTERLY WINDS IN THE RANGE OF 10-20 KT WILL PERSIST THROUGH SUNDAY NIGHT. SCATTERED SHOWERS ARE FORECAST FOR THE WESTERN GULF THROUGH SATURDAY NIGHT. CARIBBEAN SEA... A BROAD MIDDLE TO UPPER LEVEL TROUGH COVERING PORTIONS OF THE WESTERN ATLC AND THE CENTRAL ATLC EXTENDS SOUTHWARD TO A BASE OVER THE NE CARIBBEAN TO SUPPORT A SURFACE TROUGH ALONG 23N63W TO 17N65W. BOTH THE SURFACE TROUGH AND DIFFLUENCE ALOFT ARE SUPPORTING SHOWERS AND TSTMS ACROSS PUERTO RICO AND ADJACENT WATERS AS WELL AS THE VIRGIN ISLANDS. THE TROUGH ALOFT ALONG WITH LOW LEVEL MOISTURE SUPPORT SIMILAR CONVECTION ACROSS SOUTHERN HISPANIOLA. LINGERING MOISTURE ASSOCIATED WITH THE PASSAGE OF A FORMER FRONT SUPPORT RAINSHOWERS OVER JAMAICA. ELSEWHERE...DEEP LAYER DRY AIR SUPPORT FAIR WEATHER. A RELAXED PRESSURE GRADIENT CONTINUES TO SUPPORT TRADES OF 10-15 KT ACROSS THE BASIN. RAINSHOWERS ARE EXPECTED TO CONTINUE FOR HISPANIOLA AND PUERTO RICO THROUGH FRIDAY MORNING. PRECIPITATION ACTIVITY THEN WILL SHIFT TO THE LESSER ANTILLES SUPPORTED BY UPPER LEVELS DYNAMICS. ...HISPANIOLA... A DEEP LAYER TROUGH OVER THE WESTERN ATLC HAS ITS BASE OVER THE NE CARIBBEAN. RIDGING ALOFT EAST OF THE TROUGH IS GENERATING DIFFLUENCE WHICH ALONG LOW LEVEL MOISTURE SUPPORT SHOWERS AND TSTMS ACROSS SOUTHERN HISPANIOLA. THE UPPER LEVEL DYNAMICS AND THE MOISTURE WILL CONTINUE TO SUPPORT RAINSHOWERS THROUGH FRIDAY MORNING. ATLANTIC OCEAN... A DEEP LAYER TROUGH COVERING PORTIONS OF THE W ATLC AND THE CENTRAL ATLC SUPPORT A COLD FRONT ALONG 30N51W SW TO 26N59W TO 25N68W. AHEAD OF THE FRONT A DISSIPATING STATIONARY FRONT IS ANALYZED FROM 30N46W SW TO 26N53W TO 22N60W. THE TROUGH ALOFT ALSO SUPPORTS A SURFACE TROUGH ALONG 23N63W TO 17N65W. THESE SURFACE FEATURES ARE SUPPORTING SCATTERED SHOWERS WITHIN A LINE FROM 30N45W SW TO 16N62W AND A LINE FROM 30N53W SW TO 18N66W. OTHERWISE...SURFACE RIDGING COVERS THE REMAINDER WESTERN AND EASTERN ATLC WATERS...THE WESTERN RIDGE BEING ANCHORED BY A 1027 MB HIGH NEAR 32N66W AND THE EASTERN RIDGE BY A 1028 MB HIGH NEAR 34N24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR