000
AXNT20 KNHC 181729
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT FEB 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF 
SIERRA LEONE NEAR 8N13W TO 4N18W. THE ITCZ CONTINUES FROM 4N18W 
TO 1N40W TO BRAZIL NEAR 1S47W. SCATTERED MODERATE CONVECTION IS 
FROM 1N-4N BETWEEN 18W-30W...AND FROM 2N-5N BETWEEN 30W-36W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 1500 UTC... A 1007 MB LOW IS CENTERED 0FF THE COAST OF 
HOUSTON TEXAS. A COLD FRONT EXTENDS SW FROM THE LOW THROUGH 
BROWNSVILLE TEXAS TO NE MEXICO AT 22N101W. A WARM FRONT EXTENDS 
NE FROM THE LOW THROUGH S LOUISIANA TO PANAMA CITY FLORIDA. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 45 NM 
OF THE FRONTS. THE LIGHTNING DETECTION SYSTEM SHOWS A MULTITUDE 
OF ACTIVITY ALONG THE FRONTS BETWEEN S ALABAMA AND S TEXAS. 
15-25 KT SOUTHERLY WINDS ARE S OF THE FRONT OVER THE NW GULF OF 
MEXICO. 20 KT NORTHERLY WINDS ARE N OF THE FRONTS. AIR 
TEMPERATURES ARE IN THE 60'S AND 70'S OVER THE GULF S OF THE 
FRONTS. IN THE UPPER LEVELS...SW FLOW LINGERS OVER THE GULF WITH 
SIGNIFICANT UPPER LEVEL MOISTURE. EXPECT OVER THE NEXT 24 HOURS 
FOR THE LOW TO MOVE NE TO GEORGIA NEAR 33N85W. A COLD FRONT WILL 
EXTEND S FROM THE LOW TO THE BAY OF CAMPECHE WITH CONVECTION. 
ALSO EXPECT A GOOD AMOUNT OF COLD AIR ADVECTION OVER THE NW GULF 
N OF THE FRONT.   

CARIBBEAN SEA...
10-25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST 
WINDS ALONG THE COAST OF N COLOMBIA AND WEAKEST WINDS OVER THE W 
CARIBBEAN W OF 80W. PATCHES OF BROKEN LOW CLOUDS AND SCATTERED 
SHOWERS ARE N OF PUERTO RICO AND THE VIRGIN ISLANDS....ALONG THE 
COAST OF S HAITI...AND OVER INLAND HONDURAS AND EL SALVADOR. 
MOSTLY FAIR WEATHER IS ELSEWHERE. IN THE UPPER LEVELS...AN UPPER 
LEVEL HIGH IS CENTERED OVER HONDURAS. STRONG SUBSIDENCE COVERS 
THE ENTIRE CARIBBEAN AND CENTRAL AMERICA. EXPECT PREFRONTAL RAIN 
AND SHOWERS OVER THE YUCATAN PENINSULA AND THE NW CARIBBEAN 
WITHIN THE NEXT 24 HOURS. EXPECT LITTLE CHANGE ELSEWHERE.    

ATLANTIC OCEAN...
THE TAIL END OF A COLD FRONT IS OVER THE W ATLANTIC FROM 32N64W 
TO 30N70W TO 29N78W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE 
FRONT. A 1020 MB HIGH IS FURTHER SE NEAR 26N63W. A SURFACE 
TROUGH IS OVER THE CENTRAL ATLANTIC FROM 31N44W TO 20N48W TO 
15N50W. A 1031 MB HIGH IS OVER THE E ATLANTIC NEAR THE AZORES AT 
39N24W. A SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 27N35W. 
IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE CENTRAL 
ATLANTIC N OF 10N BETWEEN 40W-55W PRODUCING WIDELY SCATTERED 
MODERATE CONVECTION IS N OF 20N BETWEEN 40W-45W. EXPECT OVER THE 
NEXT 24 HOURS FOR RAIN AND SHOWERS TO BE OVER THE W ATLANTIC N 
OF 27N AND W OF 60W. ALSO EXPECT THE MORE CONVECTION OVER THE 
CENTRAL ATLANTIC DUE TO THE UPPER LEVEL TROUGH.    

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

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FORMOSA