000
AXNT20 KNHC 191150
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUN 19 2012

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.

...SPECIAL FEATURES...

A NON-TROPICAL LOW IS LOCATED ABOUT 380 NM SE OF HALIFAX NOVA 
SCOTIA. SHOWER/THUNDERSTORM ACTIVITY HAS DECREASED THIS MORNING. 
THE CHANCES FOR DEVELOPMENT OF THIS SYSTEM ARE DECREASING AS THE 
LOW IS FORECAST TO ENCOUNTER COOLER WATERS AND A MORE STABLE 
ATMOSPHERE WITHIN A DAY OR SO. THIS SYSTEM HAS A MEDIUM CHANCE 
OF BECOMING A TROPICAL OR SUBTROPICAL CYCLONE DURING THE NEXT 48 
HOURS AS IT MOVES EAST-NORTHEASTWARD NEAR 10 KT. FOR ADDITIONAL 
INFORMATION ON THIS SYSTEM...PLEASE SEE HIGH SEAS FORECASTS 
ISSUED BY THE OCEAN PREDICTION CENTER.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 47W/48W S OF 13N MOVING W NEAR 20-25 KT. 
WAVE IS LOW AMPLITUDE AND FAST MOVING ALONG THE WESTERN EDGE OF 
AN UPPER RIDGE. NO ASSOCIATED CONVECTION. 

TROPICAL WAVE IS ALONG 60W/61W S OF 17N MOVING WNW NEAR 20 KT. 
THIS WAVE MOVING THROUGH THE LESSER ANTILLES LEADING SCATTERED 
SHOWERS THAT ARE FROM 11N-21N BETWEEN 55W-61W INCLUDING THE 
LESSER ANTILLES. 

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL 
ATLC NEAR 15N17W CONTINUING ALONG 11N21W TO 6N29W WHERE THE ITCZ 
CONTINUES ALONG 5N38W TO INLAND OVER SOUTH AMERICA NEAR 4N52W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-9N 
BETWEEN 15W-19W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE 
FROM 6N-11N BETWEEN 49W-59W AND WITHIN 120 NM OF LINE FROM 5N12W 
7N22W TO 5N38W. 

...DISCUSSION...

GULF OF MEXICO...
THE GULF IS DOMINATED BY A PAIR OF UPPER LOWS. ONE IS CENTERED 
INLAND OVER NE MEXICO NEAR 26N98W COVERING THE W GULF AND THE 
SECOND COVERING THE E GULF CENTERED NEAR 26N87W. THE UPPER RIDGE 
OVER THE W CARIBBEAN EXTENDS ACROSS CUBA OVER THE SE GULF TO 
NEAR FORT MYERS FLORIDA PROVIDING DIFFLUENCE ALOFT TO GENERATE 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 27N E OF 88W. 
SCATTERED TO ISOLATED SHOWERS WITH ISOLATED THUNDERSTORMS ARE 
POSSIBLE OVER THE NW GULF N OF 23N W OF 90W AND IN THE BAY OF 
CAMPECHE S OF 20N BETWEEN 91W-96W. THE NE GULF REMAINS UNDER 
MOSTLY CLEAR SKIES THIS MORNING. WEAK SURFACE RIDGE EXTENDS FROM 
THE W ATLC OVER THE E GULF ANCHORED BY A 1021 MB HIGH OVER SOUTH 
CAROLINA. THE SURFACE TROUGH OVER THE NW CARIBBEAN WILL MOVE 
INTO THE SE GULF WED AS AN ASSOCIATED BROAD LOW PRESSURE AREA 
MOVES THROUGH THE YUCATAN PENINSULA. A LOW WILL MOVE INTO THE S 
CENTRAL GULF FROM THE CARIBBEAN BY LATE THU THEN DRIFT NW TO 
NEAR 24N93W BY LATE SAT AS THE TROUGH MOVES ACROSS THE E GULF.

CARIBBEAN SEA...
BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED NEAR HAITI 
EXTENDING AN AXIS NW ACROSS E CUBA TO THE FLORIDA COAST NEAR 
FORT MYERS AND E TO THE LEEWARD ISLANDS. A 1009 MB LOW REMAINS 
INLAND OVER HONDURAS NEAR 15N85W WITH A SURFACE TROUGH EXTENDING 
INTO THE CARIBBEAN WATERS ALONG 19N83W TO 21N80W. THE UPPER 
RIDGE IS PROVIDING DIFFLUENCE ALOFT TO ENHANCE SCATTERED TO 
HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS N OF 17N TO INLAND 
OVER CUBA BETWEEN 77W-82W. SCATTERED SHOWERS AND POSSIBLE 
ISOLATED THUNDERSTORMS DOT THE REMAINDER OF THE NW CARIBBEAN W 
OF LINE FROM SW HAITI TO NE NICARAGUA LEAVING THE S AND E 
CARIBBEAN INCLUDING THE LESSER ANTILLES UNDER MOSTLY CLEAR SKIES 
THIS MORNING. LOW/SURFACE TROUGH WILL MOVE NW AND INTO THE GULF 
OF MEXICO WED AND THU. A TROPICAL WAVE WILL REACH THE S CENTRAL 
CARIBBEAN TONIGHT BEFORE BECOMING DIFFUSE OVER THE SW CARIBBEAN 
WED. A SECOND TROPICAL WAVE WILL INTO THE SE CARIBBEAN WED AND 
BECOME ABSORBED IN WEAK LOW PRESSURE OVER THE SW CARIBBEAN THU. 

ATLANTIC OCEAN...
THE BROAD UPPER TROUGH OVER THE W ATLC CONTINUES TO WEAKEN IN 
THE DISCUSSION AREA AS THE UPPER LOW/SURFACE LOW MOVES PULLS 
FURTHER AWAY. THE UPPER TROUGH EXTENDS E OF BERMUDA ALONG 32N62W 
TO 27N65W CONTINUING TO SUPPORT A SURFACE TROUGH THAT EXTENDS 
FROM 31N61W ALONG 28N66W TO 22N74W. SCATTERED TO HEAVY SHOWERS 
AND ISOLATED THUNDERSTORMS ARE WITHIN 400 NM SE OF THE TROUGH S 
OF 27N WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM THE 
BAHAMAS TO THE GREATER ANTILLES W OF 71W THROUGH THE STRAITS OF 
FLORIDA INTO THE SE GULF OF MEXICO. THE UPPER RIDGE OVER THE 
CARIBBEAN EXTENDS AN UPPER RIDGE AXIS FROM THE VIRGIN ISLANDS NE 
ALONG 25N58W TO BEYOND 32N58W PROVIDING DIFFLUENCE ALOFT TO 
GENERATE SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS 
WITHIN 150 NM OF A LINE FROM 26N65W TO BEYOND 32N57W. A BROAD 
SURFACE RIDGE CONTINUES TO DOMINATE THE REMAINDER OF THE ATLC E 
OF 60W ANCHORED BY A 1027 MB HIGH NEAR 31N45W. THE SURFACE 
TROUGH WILL DRIFT NW THROUGH TONIGHT APPROACHING FLORIDA WED AND 
THU. HIGH PRES WILL BUILD IN FROM THE E BEHIND THE TROUGH WED 
THROUGH SAT.

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

$$
PAW