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000
AXNT20 KNHC 290606 RRA
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI MAY 29 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC.


...TROPICAL WAVES...

A TROPICAL WAVE IS E OF THE LESSER ANTILLES S OF 19N WITH AXIS NEAR 59W...MOVING W AT 15 KT DURING THE LAST 24 HOURS. SSMI TPW IMAGERY SHOW MODERATE MOISTURE BEHIND THE WAVE AXIS AND ABUNDANT MOISTURE AHEAD OF IT IN THE SE CARIBBEAN. A SLIGHT MIDDLE-LEVEL DIFFLUENT ENVIRONMENT SUPPORT SCATTERED MODERATE CONVECTION N OF THE WAVE AXIS FROM 15N TO 18N BETWEEN 41W AND 63W. SIMILAR CONVECTION IS WITHIN 200 NM EITHER SIDE OF THE WAVE AXIS S OF 11N. FURTHER CONVECTION IS BEING HINDERED IN PART BY STRONG DEEP LAYER WIND SHEAR IN THIS REGION OF THE TROPICAL ATLC AND EASTERN CARIBBEAN.


...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL ATLANTIC NEAR 11N16W TO 06N21W. THE ITCZ BEGINS NEAR 06N21W AND CONTINUES ALONG 04N32W TO 03N41W TO THE COAST OF NORTHERN BRAZIL NEAR 03N51W. A CLUSTER OF MODERATE CONVECTION ASSOCIATED WITH A TROPICAL WAVE OVER THE E ATLC IS FROM 01N TO 07N BETWEEN 21W AND 29W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 03N TO 10N E OF 20W. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM EITHER SIDE OF THE ITCZ W OF 32W. FOR CONVECTION ASSOCIATED WITH THE TROPICAL WAVE E OF THE LESSER ANTILLES SEE THE SECTION ABOVE.


...DISCUSSION...

GULF OF MEXICO...

SURFACE LOW PRESSURE PREVAILS ACROSS MEXICO...INCLUDING THE YUCATAN PENINSULA WHERE A SURFACE TROUGH IS ANALYZED ALONG 21N88W TO 14N92W WITH NO CONVECTION ASSOCIATED WITH IT. BROAD SURFACE HIGH PRESSURE OVER THE ATLANTIC ANCHORED BY A 1032 MB CENTER NEAR 38N48W CONTINUES TO EXTEND A RIDGE AXIS SW ACROSS THE FLORIDA PENINSULA AND INTO THE REMAINDER GULF. OVER THE FAR EASTERN GULF...A WEAKNESS IN THE RIDGE IS ANALYZED AS A SURFACE TROUGH WITH AXIS FROM 31N83W TO 25N82W BEING SUPPORTED BY AN UPPER LEVEL LOW. STRONG DRY AIR SUBSIDENCE FROM ALOFT HAS DECREASED THE LOW LEVEL MOISTURE BEING ADVECTED TO THE BASIN FROM THE ATLC AND THE CARIBBEAN...THUS FAVORING STABLE CONDITIONS AND FAIR WEATHER ACROSS THE GULF. 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. SURFACE RIDGING WILL CONTINUE TO BE THE DOMINANT FEATURE DURING THE NEXT THREE DAYS.

CARIBBEAN SEA...

ABUNDANT MOISTURE IS OVER THE SW CARIBBEAN DUE TO ADVECTION FROM NORTHERN SOUTHERN AMERICA AND THE E PAC WATERS. THE SE BASIN IS BEING MOISTEN BY UPPER LEVEL SOUTHERLY FLOW FROM NORTHERN SOUTH AMERICA AND BY A TROPICAL WAVE WITH AXIS E OF THE LESSER ANTILLES. THE MOISTURE ENHANCES SCATTERED MODERATE TO ISOLATED SHOWERS ACROSS THE EASTERN CARIBBEAN S OF 18N AND OVER THE SW BASIN S OF 15N. AN UPPER TROUGH IS OVER THE N-NW BASIN THAT ALONG WITH PATCHES OF MODERATE LOW LEVEL MOISTURE SUPPORT CLOUDINESS AND ISOLATED SHOWERS AND TSTMS OVER HISPANIOLA...CUBA AND ADJACENT WATERS. MOISTURE AND SHOWER ACTIVITY OVER THE EASTERN AND CENTRAL BASIN WILL CONTINUE TO INCREASE AS THE TROPICAL WAVE MOVES ACROSS THE LESSER ANTILLES FRIDAY. FAIR WEATHER IS ELSEWHERE BEING SUPPORTED BY DRY AIR SUBSIDENCE FROM ALOFT.


...HISPANIOLA...

MIDDLE TO UPPER LEVEL TROUGHING ASSOCIATED WITH A LOW ALOFT OVER THE SW N ATLC ALONG WITH SHALLOW MOISTURE SUPPORT CLOUDINESS AND ISOLATED SHOWERS AND TSTMS ACROSS THE ISLAND AND ADJACENT WATERS. THIS CONVECTION IS FORECAST THROUGH FRIDAY MORNING...RESUMING AGAIN FRIDAY NIGHT ASSOCIATED WITH MOISTURE FROM A TROPICAL WAVE ENTERING THE E CARIBBEAN DURING THE MORNING HOURS.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL LOW ANCHORED NEAR 28N60W CONTINUE TO SUPPORT A 1016 MB LOW NEAR 27N60W WITH SCATTERED TO ISOLATED MODERATE CONVECTION N OF 24N BETWEEN 51W AND 62W. THIS LOW IS FORECAST TO DISSIPATE BY FRIDAY EVENING LEAVING A SURFACE TROUGH TO DRIFT W OVER THE SW N ATLC THE NEXT THREE DAYS. NE OF THE SOUTHERN BAHAMAS...A 1015 MB LOW IS ANALYZED WITH A SURFACE TROUGH FROM 29N66W TO THE LOW CENTER NEAR 25N67W. NO CONVECTION IS ASSOCIATED WITH THIS SECOND LOW THAT IS FORECAST TO DISSIPATE FRIDAY AFTERNOON. A TROPICAL WAVE IS E OF THE LESSER ANTILLES. SEE THE TROPICAL WAVES SECTION ABOVE. ELSEWHERE SURFACE HIGH PRESSURE AND FAIR WEATHER PREVAILS. THE TROPICAL WAVE WILL ENTER THE EASTERN CARIBBEAN BASIN FRIDAY.

FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE

$$ NR

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