Tropical Weather Discussion
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000 AXNT20 KNHC 281026 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU MAY 28 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS W OF THE ITCZ FROM 5N TO 14N WITH AXIS NEAR 54W/55W...MOVING W AT 15-20 KT DURING THE LAST 24 HOURS. SSMI TPW IMAGERY SHOW THE WAVE CONTINUES EMBEDDED WITHIN ABUNDANT MOISTURE IN THE MIDDLE TO LOWER LEVELS. SATELLITE DERIVED WINDS AND MODEL GUIDANCE SHOW A DIVERGENT ENVIRONMENT ALOFT THAT SUPPORT SCATTERED MODERATE CONVECTION FROM 04N TO 15N BETWEEN 50W AND 60W. FURTHER CONVECTION IS BEING HINDERED IN PART BY STRONG DEEP LAYER WIND SHEAR IN THIS REGION OF THE TROPICAL ATLC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL ATLANTIC NEAR 08N13W TO 06N20W. THE ITCZ BEGINS NEAR 06N20W AND CONTINUES ALONG 03N36W TO THE COAST OF NORTHERN BRAZIL NEAR 00N50W. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS FROM 02N TO 08N E OF 20W. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM EITHER SIDE OF THE ITCZ. FOR CONVECTION ASSOCIATED WITH THE TROPICAL WAVE SEE THE SECTION ABOVE. ...DISCUSSION... GULF OF MEXICO... SURFACE LOW PRESSURE OVER MEXICO EXTENDS E-SE TO THE GULF OF CAMPECHE WHERE A SURFACE TROUGH IS ANALYZED FROM 22N92W TO 16N94W WITH NO CONVECTION ASSOCIATED WITH IT. BROAD SURFACE HIGH PRESSURE OVER THE ATLANTIC CONTINUES TO EXTEND A RIDGE AXIS SW ACROSS THE FLORIDA PENINSULA AND INTO THE REMAINDER GULF. OVER THE N-NE BASIN...A FORMER SQUALL LINE WEAKENED LEAVING AN ELONGATED AREA OF LOW PRESSURE BEING SUPPORTED BY A SHORT-WAVE MIDDLE TO UPPER LEVEL TROUGH. ISOLATED SHOWERS AND TSTMS ARE N OF 26N BETWEEN 85W AND 89W. AN UPPER LEVEL LOW OVER THE SE GULF SUPPORTS SIMILAR CONVECTION S OF 26N E OF 86W. EASTERLY TO SOUTHEASTERLY WIND FLOW OF 10 TO 15 KT ASSOCIATED WITH THE RIDGE DOMINATES THE GULF...EXCEPT OVER THE STRAITS OF FLORIDA...THE YUCATAN CHANNEL AND ALONG THE WESTERN YUCATAN PENINSULA WHERE WINDS INCREASE TO 20 KT DUE TO A TIGHTER PRESSURE GRADIENT. STRONG DRY AIR SUBSIDENCE FROM ALOFT HAS DECREASED THE LOW LEVEL MOISTURE BEING ADVECTED TO THE BASIN...THUS FAVORING STABLE CONDITIONS AND FAIR WEATHER ELSEWHERE. SURFACE RIDGING WILL CONTINUE TO BE THE DOMINANT FEATURE DURING THE NEXT THREE DAYS. CARIBBEAN SEA... LOW PRESSURE OVER NORTHERN COLOMBIA AND A SLIGHTLY HIGHER PRESSURE ACROSS THE CARIBBEAN GENERATE A TIGHTER PRESSURE GRADIENT ALONG THE COAST OF COLOMBIA...RESULTING IN NE TO E WINDS OF 20 TO 25 KT FROM 11N TO 13N BETWEEN 74W AND 76W WITH SEAS TO 8 FT. ELSEWHERE...TRADES OF 10 TO 15 KT AND SEAS LESS THAN 8 FT DOMINATE. SSMI TPW IMAGERY SHOW PATCHES OF MODERATE LOW LEVEL MOISTURE ALONG THE NORTHERN BASIN SUPPORTING CLOUDINESS AND POSSIBLE ISOLATED SHOWERS OVER PUERTO RICO AND HISPANIOLA AND SCATTERED MODERATE CONVECTION AND TSTMS OVER CUBA SOUTHERN ADJACENT WATERS. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE WITHIN 20 NM OFF THE COLOMBIA AND SOUTHERN PANAMA COASTS. ABUNDANT MOISTURE STARTS TO REACH THE WINDWARD ISLANDS ASSOCIATED WITH A TROPICAL WAVE FORECAST TO ENTER THE EASTERN BASIN BY FRIDAY NIGHT. FAIR WEATHER IS ELSEWHERE BEING SUPPORTED BY DEEP LAYER DRY AIR. ...HISPANIOLA... MIDDLE TO UPPER LEVEL TROUGHING ALONG WITH SHALLOW MOISTURE OVER HISPANIOLA COASTAL WATERS SUPPORT CLOUDINESS AND POSSIBLE ISOLATED SHOWERS ACROSS THE ISLAND...INTENSIFYING IN THE AFTERNOON AND EARLY EVENING HOURS. HOWEVER...UPPER LEVEL SUBSIDENCE CONTINUE TO SUPPRESS THE FORMATION OF THUNDERSTORMS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW ANCHORED NEAR 25N62W CONTINUE TO SUPPORT A SURFACE TROUGH WITH AXIS EXTENDING FROM 31N62W TO A 1015 MB LOW NEAR 25N66W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE N OF 25N BETWEEN 48W AND 61W. A TROPICAL WAVE IS W OF THE ITCZ. SEE THE TROPICAL WAVES SECTION ABOVE. ELSEWHERE SURFACE HIGH PRESSURE AND FAIR WEATHER PREVAILS. THE SURFACE TROUGH WILL REMAIN OVER THE SW N ATLC DURING THE NEXT THREE DAYS. SURFACE RIDGING WILL DOMINATE ELSEWHERE. THE TROPICAL WAVE WILL ENTER THE EASTERN CARIBBEAN BASIN FRIDAY NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR

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