000 AXNT20 KNHC 161740 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1730 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ANALYZED OFF THE COASTAL WATERS OF NE BRAZIL FROM 10N44W TO 1N48W. THE WAVE IS DRIFTING WEST AT ABOUT 5-8 KT. THIS WAVE SHOWS UP WELL AS A BROAD MOISTURE SURGE ON TOTAL PRECIPITABLE WATER IMAGERY. THE MOST RECENT WINDSAT PASS REVEALS VERY LITTLE CYCLONIC CURVATURE IN THE FAR SOUTHERN EXTENSION OF THE AXIS...AND ENE WINDS UP TO 20 KT SURROUNDING THE REMAINING EXTENSION OF THE WAVE AXIS. THIS WAVE IS GENERATING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION S OF 7N BETWEEN 43W-53W AFFECTING THE COASTAL WATERS OF NE BRAZIL AND FRENCH GUIANA. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE COAST OF SIERRA LEONE NEAR 7N12W S-WESTWARD ALONG 4N20W 2N30W. THEN...IT RESUMES OFF THE COAST OF BRAZIL NEAR 3S38W AND CONTINUES NW INTERSECTING THE TROPICAL WAVE NEAR 2N47W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM ON EITHER SIDE OF THE ITCZ E OF 30W. AN EMBEDDED SURFACE TROUGH IS ANALYZED WITHIN THIS AREA OF CONVECTION EXTENDING FROM 6N24W TO 2N26W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUES TO BUILD ACROSS THE AREA THIS AFTERNOON...WITH WATER VAPOR IMAGERY INDICATING DRY SUBSIDENT NW FLOW ALOFT KEEPING A STABLE ATMOSPHERE ACROSS THE GULF E OF 96W. AT SURFACE...NORTHERLY 10-15 TK DIFFLUENT FLOW IS NOTED ACROSS THE AREA. THIS FLOW IS PACKING LOW LEVEL STRATUS AND AREAS OF LOW VISIBILITIES ACROSS THE COASTAL WATERS OF MEXICO S OF 26N W OF 96W. A WEATHER STATION LOCATED IN THE COAST OF TAMPICO...MMTM...INDICATED VISIBILITIES DOWN TO 2 1/2 SM WITH LIGHT RAIN DURING THE EARLY AFTERNOON HOURS. WEATHER CONDITIONS IN THIS REGION ARE EXPECTED TO PERSIST FOR THE NEXT 24 HOURS... WITH NO SIGNIFICANT CHANGES EXPECTED ELSEWHERE ACROSS THE GULF. CARIBBEAN SEA... AN UPPER LEVEL TROUGH MOVES ACROSS THE CARIBBEAN THIS AFTERNOON. DRY AIR ALOFT ACCOMPANIES THE TROUGHING W OF 74W. THIS PATTERN IS PROVIDING FAIR CONDITIONS ACROSS THE ENTIRE NW AND CENTRAL PORTIONS OF THE BASIN. THE UPPER LEVEL TROUGH IS INDUCING BROAD CYCLONIC TURNING COVERING PART OF THE CENTRAL BASIN BETWEEN 70W-74W. WITHIN THIS AREA OF CYCLONIC CURVATURE...A SURFACE TROUGH IS ANALYZED FROM THE ATLC BASIN ACROSS HISPANIOLA ALONG 18N71W...EXTENDING SW INTO NORTHERN COLOMBIA NEAR 11N74W... GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS N OF 15N BETWEEN 70W-74W. THE OVERALL SYNOPTIC PATTERN IS SUPPORTING A BROAD AREA OF SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS E OF 70W INCLUDING THE COASTAL WATERS SURROUNDING THE LESSER ANTILLES AND PUERTO RICO. ATMOSPHERIC MOISTURE IN THE LOW TO MID LEVELS REMAINS VERY HIGH IN THE REGION OF CONVECTION NOTED ON TOTAL PRECIPITABLE WATER IMAGERY...AND GLOBAL MODEL GUIDANCE INDICATES THIS SYNOPTIC SETUP WILL REMAIN IN PLACE OVER THE NEXT FEW DAYS. THEREFORE EXPECT SURFACE TROUGHING TO REMAIN ACROSS THE ERN CARIBBEAN WITH ENHANCED MOISTURE LEVELS SUPPORTING CONVECTION. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH MOVES OFF THE EASTERN SEABOARD SUPPORTING A COLD FRONT THAT ENTERS THE AREA ALONG 32N75W ACROSS THE NORTHERN BAHAMAS ALONG 25N77W AND DISSIPATING ACROSS CUBA ALONG 23N80W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 70 NM AHEAD OF THE FRONT N OF 25N. THIS FRONT IS EXPECTED TO TRACK ENE OVER THE NEXT 24 HOURS. FARTHER EAST...A BROAD AND ELONGATED UPPER LOW IS OVER THE CENTRAL ATLC ROTATING AROUND 37N47W. THIS SYSTEM ALONG WITH AN AREA OF DIFFLUENCE FLOW ALOFT NE OF THE LESSER ANTILLES SUPPORT A SURFACE TROUGH AXIS DEPICTING THE MAIN WIND SHIFT ACROSS THE CENTRAL ATLC ALONG 32N42W 26N45W 25N54W 23N64W. A BROAD AREA OF WIDELY SCATTERED SHOWERS AND THUNDERSTORMS IS FOUND WITHIN 150 NM ON EITHER SIDE OF THE TROUGH. SURFACE RIDGING COVERS THE REMAINDER OF THE EASTERN ATLC E OF 40W PROVIDING FAIR WEATHER CONDITIONS ACROSS THIS AREA. AN UPPER LEVEL LOW CONTINUES TO SPIN OVER THE MADEIRA ISLANDS SUPPORTING A WEAK 1014 MB LOW NEAR 34N17W. MINIMAL ACTIVE WEATHER IS ASSOCIATED WITH THIS SYSTEM. EXPECT CONVECTIVE WEATHER TO REMAIN ACROSS THE CENTRAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA