000
AXNT20 KNHC 171044
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT FRI JUN 17 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 
1030 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 11N45W TO 1N49W MOVING WNW AT 10-15 
KT. WAVE REMAINS EMBEDDED WITHIN A MOISTURE MAXIMUM AS INDICATED 
BY THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE ALSO SHOWS A GOOD 
INVERTED-V STRUCTURE ON VISIBLE NIGHT CHANNEL. THE CONVECTION IS 
MOSTLY CONFINED TO THE ITCZ FROM 4N-12N BETWEEN 42W-59W.

TROPICAL WAVE IS MOVING ACROSS THE WESTERN CARIBBEAN ANALYZED 
FROM E OF JAMAICA NEAR 18N75W TO 11N78W MOVING WNW AT 10-15 KT. 
THIS WAVE IS EMBEDDED IN A SURGE OF DEEP MOISTURE ON TOTAL 
PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS S OF 15N W OF 73W.   

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM INLAND ACROSS GUINEA-BISSAU IN 
WEST AFRICA...ENTERING THE ATLC NEAR 11N16W CONTINUING SW TO 
6N23W. THE ITCZ AXIS CONTINUES FORM THIS POINT ALONG 3N30W 2N40W 
3N45W. THEN...IT RESUMES E OF A TROPICAL WAVE FROM 8N49W TO 
7N58W. SCATTERED MODERATE TO STRONG CONVECTION MOVES OUT THE 
COAST OF SIERRA LEONE...GUINEA...AND NORTHERN LIBERIA E OF 24W 
FROM 3N-10N. SIMILAR CONVECTION IS WITHIN 180 NM N OF THE ITCZ 
AXIS W OF 45W. 

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY CONTINUES TO SHOW VERY DRY AIR AND STRONG 
SUBSIDENCE ALOFT COVERING THE GULF OF MEXICO THIS EVENING. AT 
SURFACE...A 1015 MB HIGH REMAINS CENTERED OVER THE NE BASIN NEAR 
28N85W. THIS BENIGN FEATURE IS PRODUCING FAIR WEATHER ACROSS THE 
DISCUSSION AREA...WITH ONLY A FEW ISOLATED WEAK SHOWERS NOTICED 
OFF THE WESTERN COAST OF THE YUCATAN PENINSULA AND BAY OF 
CAMPECHE AND WESTERN WATERS OF CUBA INCLUDING THE YUCATAN 
CHANNEL S OF 22N E OF 95W. OTHERWISE...A VERY RELAX PRESSURE 
GRADIENT IS OBSERVED ALMOST OVER THE ENTIRE BASIN...GENERATING 
5-10 KT ANTICYCLONIC WINDS ACROSS THE AREA...GUSTING TO 20 KT 
WITHIN 90 NM OFF THE TEXAS COAST. NO SIGNIFICANT CHANGES ARE 
EXPECTED DURING THE NEXT 24 HOURS AS THE SURFACE RIDGE WEAKENS 
AND DRIFTS TO THE NE OVER THE NEXT 24 HOURS. 

CARIBBEAN SEA...
THE WEATHER IN THE SW CARIBBEAN CONTINUES UNDER THE INFLUENCE 
OF THE MONSOON TROUGH THAT EXTENDS ACROSS CENTRAL AMERICA OVER 
COSTA RICA INTO NORTHERN COLOMBIA...AND A TROPICAL WAVE NE OF 
COLOMBIA. THE COMBINATION OF THESE TWO FEATURES IS GENERATING 
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS S OF 15N W OF 73W. 
THE NORMAL EASTERLY TRADES HAVE BEEN REPLACED FOR BROAD CYCLONIC 
TURNING AROUND THE CONVECTION REGION W OF 70W. OTHERWISE...ANTI 
CYCLONIC FLOW ALOFT CONTINUES TO DOMINATE ELSEWHERE OUT OF THE 
CONVECTION REGION...LEAVING THE AREA RELATIVELY CLEAR WITH A  
FEW ISOLATED SHOWERS S IF HISPANIOLA AND N OF HONDURAS. EXPECT 
MORE CONVECTION DEVELOPING OVER THE SW CARIBBEAN BASIN OVER THE 
NEXT 24 HOURS.

ATLANTIC OCEAN...
AN AREA OF SCATTERED MODERATE CONVECTION MOVES OFF THE COAST OF 
GEORGIA TO 100 NM EAST. THIS CLUSTER OF CONVECTION WILL WEAKEN 
AND DISSIPATE AS IT TRACKS SE IN THE NEXT 56 HOURS. A BROAD 
UPPER LEVEL TROUGH MOVES ACROSS THE NW ATLC SUPPORTING A COLD 
FRONT EXTENDING SW ALONG 32N55W 2761W TO 25N68W GENERATING 
SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 50/100 NM ON EITHER 
SIDE OF THE FRONT. IN THE MEAN TIME...AN UPPER LEVEL RIDGE OF 
HIGH PRESSURE BUILDS BEHIND THE FRONT ACROSS THE W ATLC BASIN 
ANCHORED BY A 1020 MB HIGH NEAR 35N67W. THE REMAINDER OF THE 
ATLC E OF THE FRONT IS DOMINATED BY A BROAD SURFACE RIDGE 
ANCHORED BY A STRONG 1028 MB HIGH CENTERED NEAR 35N30W.

F0R ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA