000
AXNT20 KNHC 141136
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT SAT MAY 14 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1115 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED FROM SIERRA LEONE NEAR 8N11W ALONG 5N20W 
3N34W CROSSING THE EQUATOR NEAR 39W AND INTO NRN BRAZIL NEAR 
1S50W. SCATTERED MODERATE/STRONG CONVECTION IS OFF THE W COAST 
OF AFRICA FROM 2N-7N BETWEEN 11W-16W. SIMILAR ACTIVITY IS S OF 
5N BETWEEN 31W-40W.

...DISCUSSION...

GULF OF MEXICO...
A SHORTWAVE UPPER LEVEL TROUGH CONTINUES TO IMPACT THE NE GULF 
OF MEXICO SUPPORTING A SURFACE TROUGH ALONG 31N84W TO 26N88W. 
ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 100 NM AHEAD OF THE 
TROUGH. THE UPPER SHORTWAVE IS EMBEDDED WITHIN A LONGWAVE UPPER 
TROUGH EXTENDING DOWN MUCH OF THE CENTRAL CONUS SUPPORTING A 
COLD FRONT THAT EXTENDS FROM NEAR PENSACOLA FLORIDA TO THE 
BROWNSVILLE TEXAS...AS OF 0900 UTC. RADAR IMAGERY INDICATES A 
LINE OF STRONG SHOWERS WITH 45 NM AHEAD OF THE FRONT N OF 28N. 
DUE TO STRONG SUBSIDENCE ALOFT BEHIND THE UPPER TROUGH NO ACTIVE 
WEATHER IS ALONG THE REMAINDER OF THE FRONTAL BOUNDARY. THIS 
AREA OF DRY AIR AND SUBSIDENCE IS SUPPORTING FAIR CONDITIONS 
ACROSS THE REMAINDER OF THE BASIN. EXPECT STRONG SHOWERS TO 
CONTINUE TO IMPACT THE NE GULF AND NRN FLORIDA AS THE FRONT AND 
TROUGH MOVE EWD.

CARIBBEAN SEA...
BROAD UPPER TROUGHING SITS ACROSS THE ENTIRE CARIBBEAN EXTENDING 
FROM AN UPPER LEVEL LOW OVER THE NW ATLC. WATER VAPOR IMAGERY 
INDICATES MOSTLY DRY AIR ACROSS THE NRN CARIBBEAN WITH MOISTER 
CONDITIONS S OF 14N. THIS PATTERN IS PROVIDING FAIR CONDITIONS 
ACROSS THE ENTIRE NW PORTION OF THE BASIN WITH A FEW POSSIBLE 
ISOLATED SHOWERS S OF JAMAICA AND WRN CUBA. A SURFACE TROUGH 
EXTENDS ACROSS THE ERN CARIBBEAN FROM NEAR ANGUILLA TO THE SW 
CARIBBEAN ALONG 14N70W 10N82W. TOTAL PRECIPITABLE WATER IMAGERY 
SHOWS ENHANCED MOISTURE VALUES IN THIS AREA WITH ISOLATED 
SHOWERS/THUNDERSTORMS WITHIN 120 NM EITHER SIDE OF THE 
AXIS...WITH STRONG ACTIVITY ACROSS NRN VENEZUELA AND THE COASTAL 
WATERS. EXPECT SURFACE TROUGHING TO REMAIN ACROSS THE ERN 
CARIBBEAN WITH ENHANCED MOISTURE LEVELS SUPPORTING CONVECTION.

ATLANTIC OCEAN...
A WEAK 1012 MB HIGH SITS OFF THE FLORIDA E COAST N OF THE 
BAHAMAS NEAR 27N76W. HOWEVER...A DEEP LAYER LOW CONTINUES TO 
COVER THE MAJORITY OF THE W ATLC WITH A MID-UPPER LEVEL TROUGH 
EXTENDING FROM AN UPPER LOW NEAR 36N62W TO THE CENTRAL 
CARIBBEAN. A SERIES OF SURFACE TROUGHS ARE ASSOCIATED WITH THE 
SYSTEM. THE FIRST EXTENDS FROM NEAR 31N57W TO 25N68W DEPICTING 
THE MAIN WIND SHIFT. A SECOND SURFACE TROUGH EXTENDS FROM 30N53W 
TO 21N68W SUPPORTING ISOLATED SHOWERS WITHIN 60 NM OF THE AXIS. 
A BROAD AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IS S 
AND E OF THE SECOND TROUGH TO 45W INFLUENCED MOSTLY BY UPPER 
LEVEL DIFFLUENCE AROUND THE E SIDE OF THE UPPER TROUGH. FARTHER 
E...A BROAD UPPER LEVEL RIDGE COVERS THE MAJORITY OF THE ERN 
ATLC EXTENDING FROM NEAR 7N43W TO 36N39W SUPPORTING A SURFACE 
HIGH CENTERED WELL NORTH OF THE DISCUSSION AREA WITH SURFACE 
RIDGE AXIS EXTENDING DOWN 35W. AN UPPER LEVEL TROUGH COVERS THE 
FAR E ATLC ALONG 19W SUPPORTING A WEAK 1012 MB LOW W OF THE 
CANARY ISLANDS. A SURFACE TROUGH EXTENDS ALMOST HORIZONTALLY 
THROUGH THE LOW CENTER FROM 31N23W TO 29N17W.

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

$$
WALTON