000
AXNT20 KNHC 191152
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT MAY 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 
1015 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 16N23W TO 6N26W MOVING W NEAR 10-15 
KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED 
MOISTURE AS EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. 
HOWEVER...NO DEEP CONVECTION IS OBSERVED. 
 
...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF 
MAURITANIA JUST N OF SENEGAL. THE ITCZ AXIS BEGINS W OF THE 
TROPICAL WAVE NEAR 6N32W ALONG 5N42W TO INLAND OVER SOUTH 
AMERICA NEAR 4N51W. SMALL CLUSTERS OF SCATTERED MODERATE/ 
ISOLATED STRONG CONVECTION ARE FROM 1N-5N E OF 9W TO ACROSS THE 
PRIME MERIDIAN AND WITHIN 120 NM ALONG THE COAST OF GUINEA AND 
SIERRA LEONE BETWEEN 8N-10N.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER RIDGE IS INLAND OVER NE MEXICO ACROSS TEXAS INTO THE 
CENTRAL PLAIN STATES COVERING THE NW GULF. A BROAD UPPER TROUGH 
COVERS THE REMAINDER OF THE N GULF WHILE A BROAD UPPER RIDGE 
REMAINS OVER THE S GULF GIVING THE MOST OF THE GULF NEAR ZONAL 
WESTERLY FLOW ALOFT. A WEAK SURFACE RIDGE EXTENDS FROM A 1022 MB 
HIGH OVER N GEORGIA TO OVER THE W GULF TO THE W BAY OF CAMPECHE 
WITH STRONG SUBSIDENCE AND DRY STABLE AIR COVERING ALL BUT THE 
FAR SE GULF. A SURFACE TROUGH ENTERS THE E GULF AT 19/0900 UTC 
OVER THE E TIP OF THE YUCATAN PENINSULA NEAR 21N87W TO 24N86W 
WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 
25N E OF 88W TO OVER CUBA...S FLORIDA...THE FLORIDA KEYS AND 
THROUGH THE STRAITS OF FLORIDA. THE REMAINDER OF THE GULF IS 
UNDER MOSTLY CLEAR SKIES. THE WEAK SURFACE RIDGE WILL PERSIST 
ACROSS THE AREA THROUGH WED.

CARIBBEAN SEA...
BROAD UPPER RIDGE COVERS THE ENTIRE CARIBBEAN BASIN ANCHORED 
OVER CENTRAL AMERICA. DIFFLUENCE ALOFT OVER PUERTO RICO AND 
HISPANIOLA ARE GENERATING SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS N OF 17N BETWEEN THE MONA PASSAGE AND 71W. A 1009 
MB LOW IS IN THE GULF OF HONDURAS AT 19/0900 UTC NEAR 17N87W 
WITH A SURFACE TROUGH EXTENDING N ALONG 19N88W INTO THE E GULF 
OF MEXICO OVER THE E TIP OF THE YUCATAN PENINSULA NEAR 21N87W. 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE E OF THE TROUGH AND 
W OF A LINE FROM CUBA NEAR 21N77W TO THE NE NICARAGUA NEAR 
13N84W. MODERATE TO FRESH EASTERLY TRADE WINDS ARE ACROSS THE 
BASIN USHERING IN SOME ISOLATED SHOWERS ACROSS THE NE CARIBBEAN 
N OF 15N E OF 71W TO OVER THE LEEWARD ISLANDS. THE TRADE WINDS 
WILL PERSIST THROUGH WED. THE SURFACE LOW WILL MOVE INLAND OVER 
CENTRAL AMERICA AND DISSIPATE TODAY. 

ATLANTIC OCEAN...
THE BROAD UPPER TROUGH OVER THE GULF OF MEXICO EXTENDS INTO THE 
W ATLC N OF 25N W OF 67W SUPPORTING A DISSIPATING COLD FRONT 
THAT AT 19/0900 UTC ENTERS THE REGION NEAR 32N71W ALONG 28N75W 
TO 27N80W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 60 NM N OF 
THE FRONT W OF 75W. THE UPPER TROUGH IS ALSO SUPPORTING A 1010 
MB LOW AT 19/0900 UTC OFF SOUTH CAROLINA NEAR 33N79W WITH A 
SURFACE TROUGH EXTENDING TO 30N81W WITH CLUSTERS OF SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS N OF 30N BETWEEN 74W-81W. A WEAK 
SURFACE TROUGH EXTENDS FROM 24N72W ACROSS THE S BAHAMA ISLANDS 
TO OVER E CUBA NEAR 20N77W. AN UPPER RIDGE AXIS IS E OF THE 
ABOVE UPPER TROUGH EXTENDING FROM THE BROAD UPPER RIDGE OVER THE 
CARIBBEAN NEAR 22N67W TO BEYOND 32N61W. CLUSTERS OF SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 25N TO OVER HISPANIOLA 
BETWEEN 67W-72W. SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS ARE WITHIN 120 NM OF 65W N OF 22N TO BEYOND 32N. A 
VERY BROAD SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC N 
OF 15N BETWEEN AFRICA AND 70W ANCHORED BY A 1034 MB HIGH ABOUT 
500 NM W OF THE AZORES. THE W ATLC FRONT WILL DRIFT E AND 
GRADUALLY DISSIPATE TODAY.

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

$$
PAW