000 AXNT20 KNHC 160547 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON MAY 16 2011 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ANALYZED FROM 02N42W TO 08N41W MOVING W AT 5 KT. TOTAL PRECIPITABLE WATER IMAGERY DEPICTS A NORTHWARD BULGE OF LOW-LEVEL MOISTURE IN THE VICINITY OF THE WAVE AXIS. LOW TO MIDDLE LEVEL MODEL GUIDANCE ALSO INDICATES WEAK TROUGHING BETWEEN 40W-50W. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY WITH THE WAVE AT THIS TIME. ...ITCZ... ITCZ AXIS IS ALONG 07N11W 03N23W 06N41W 05N52W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE AXIS BETWEEN 11W-22W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 01N-06N ALONG 23W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE SURFACE TROUGH AXIS. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES MOSTLY DRY NW FLOW ALOFT IS LOCATED OVER THE GULF BASIN AS AN UPPER LEVEL TROUGH SHIFTS EASTWARD INTO THE SW NORTH ATLC THIS EVENING. AS OF 16/0300 UTC...THE SOUTHERN EXTENT OF THE WEAKENING COLD FRONT WAS ANALYZED FROM KEY BISCAYNE ACROSS THE UPPER FLORIDA KEYS TO THE YUCATAN CHANNEL NEAR 22N86W. WHILE MOST OF THE CONVECTIVE ACTIVITY HAS MOVED E OF 80W...A FEW ISOLATED SHOWERS AND TSTMS ARE LINGERING ACROSS THE STRAITS OF FLORIDA BETWEEN 80W-83W. WEST OF THE FRONT ACROSS THE REMAINDER OF THE GULF...A SURFACE RIDGE IS BUILDING IN OVER WESTERN PORTIONS OF THE GULF AND IS ANCHORED BY A 1015 MB HIGH CENTERED NEAR 28N96W. WHILE NORTHERLY WINDS IN THE RANGE OF 10 TO 15 KT ARE EXPECTED THROUGH THE OVERNIGHT HOURS E OF 94W...LIGHT WINDS OVER THE NW GULF AND AREAS ALONG THE MEXICO GULF COAST W OF 96W WILL CONTINUE TO EXPERIENCE LOW-LEVEL STRATUS AND POSSIBLE AREAS OF LOWERED VISIBILITY THROUGH THE LATE MORNING HOURS. CARIBBEAN SEA... WITH BROAD UPPER LEVEL TROUGH LOCATED OVER THE SW NORTH ATLC WATERS...GENERALLY DRY W-NW FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY THIS EVENING. THIS IS PROVIDING FOR OVERALL FAIR CONDITIONS AND CLEAR SKIES OVER MUCH OF THE WESTERN GULF W OF 70W. AS NOTED IN THE GULF OF MEXICO...A WEAKENING COLD FRONT EXTENDS ACROSS THE YUCATAN CHANNEL WITH A STATIONARY FRONT ACROSS INTERIOR PORTIONS OF THE YUCATAN PENINSULA AND NORTHEASTERN GUATEMALA. MOST OF THE UPPER LEVEL DYNAMICS SUPPORTING THE COLD FRONT REMAIN N OF 25N IN THE W ATLC...WHILE ONLY A SUBTLE WIND SHIFT AND LACK OF SIGNIFICANT CONVECTION ARE ASSOCIATED WITH THE COLD FRONT THIS EVENING. OVER THE EASTERN CARIBBEAN...MOSTLY SOUTHWESTERLY FLOW ALOFT IS NOTED EAST OF THE UPPER LEVEL TROUGH AXIS AND THIS SUPPORTS A SURFACE TROUGH THAT MEANDERS FROM THE W ATLC NEAR 21N60W PASSING EAST OF PUERTO RICO NEAR 18N66W TO 14N70W. TOTAL PRECIPITABLE WATER IMAGERY INDICATES AN ABUNDANT AMOUNT OF LOW TO MIDDLE LEVEL MOISTURE IS IN PLACE TO SUSTAIN NUMEROUS SHOWERS CURRENTLY LOCATED E OF 70W. THE OVERALL DIFFLUENT PATTERN IS EXPECTED TO PERSIST OVER THE EASTERN CARIBBEAN THROUGH LATE TUESDAY WITH THE SURFACE TROUGHING FORECAST TO REMAIN NEARLY STATIONARY OVER THE CENTRAL CARIBBEAN AS WELL. ATLANTIC OCEAN... AN UPPER LEVEL LOW IS LOCATED OVER THE OHIO RIVER VALLEY THIS EVENING AND EXTENDS AN UPPER LEVEL TROUGH AXIS THROUGH 32N81W TO THE SE BAHAMAS NEAR 22N73W. THIS UPPER LEVEL TROUGH SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N78W THAT EXTENDS TO KEY BISCAYNE THEN OVER THE UPPER FLORIDA KEYS AND INTO THE STRAITS OF FLORIDA NEAR 23N83W. INFRARED SATELLITE IMAGERY AND LIGHTNING DATA SHOW WIDELY SCATTERED SHOWERS AND TSTMS OCCURRING WITHIN 120 NM EAST OF THE FRONT N OF 25N. FARTHER EAST...ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 37N49W AND SUPPORTS A SURFACE TROUGH THAT ENTERS THE DISCUSSION AREA NEAR 32N45W AND MEANDERS ALONG 27N46W 22N59W TO EAST OF PUERTO RICO NEAR 18N65W AND INTO THE NE CARIBBEAN SEA. A LARGE PORTION OF THIS SURFACE TROUGH IS LOCATED EAST OF THE BROAD UPPER LEVEL TROUGH OVER THE BAHAMAS AND ALONG WITH LOW-LEVEL CONVERGENCE IN THE VICINITY OF THE SURFACE TROUGH AXIS CONTINUES TO GENERATE A RATHER LARGE AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 360 NM EITHER SIDE OF THE SURFACE TROUGH. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1035 MB HIGH CENTERED NW OF THE IBERIAN PENINSULA NEAR 47N18W. THE SURFACE RIDGE AXIS EXTENDS FROM THE AZORES NEAR 39N30W TO 20N39W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN