000
AXNT20 KNHC 191758
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST SAT FEB 19 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND 
RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ...

THE ITCZ IS ANALYZED FROM SW AFRICA AT 9N12W TO THE EQUATOR AT 
30W CONTINUING SW TO THE COAST OF SOUTH AMERICA AT 3S43W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 3S 
NORTHWARD TO THE AFRICAN COAST BETWEEN 10E AND 11W. SIMILAR 
CONVECTION IS OBSERVED FROM 4N SOUTHWARD TO THE COAST OF SOUTH 
AMERICA BETWEEN 40W AND 50W. 

...DISCUSSION...

GULF OF MEXICO...
THE UPPER LEVELS ARE DOMINATED BY AN ANTICYCLONE CENTERED OVER 
THE SW GULF AT 22N95W WITH AN UPPER RIDGE EXTENDING ENE AND 
COLLAPSING SE ACROSS FLORIDA BAY. THE UPPER LEVELS APPEAR VERY 
DRY EXCEPT FOR A NARROW MOISTURE PLUME THAT EXTENDS ACROSS 
CENTRAL TEXAS ALONG THE NW PERIPHERY OF THE RIDGE...WITH SOME OF 
THE MOISTURE NOW SPREADING E OVER THE NW GULF OF MEXICO NEAR THE 
TEXAS AND LOUISIANA BORDER. AT THE LOW LEVELS HIGH PRESSURE... 
1025 MB...IS CENTERED OVER THE BORDERS OF ALABAMA...GEORGIA AND 
FLORIDA...WITH A RIDGE EXTENDING SW DISSECTING THE GULF TO THE 
COAST OF MEXICO AT 20N97W. OVERCAST LOW CLOUDS WITH PATCHES OF 
FOG THAT DEVELOPED OVER THE NW GULF OVERNIGHT HAS ALMOST 
DISSIPATED OVER THE TEXAS AND LOUISIANA COASTAL WATERS...BUT IS 
STILL EVIDENT OVER THE COASTAL PLAINS. THE SURFACE HIGH IS 
EXPECTED TO SHIFT E LATE THIS WEEKEND INTO EARLY NEXT WEEK IN 
ADVANCE OF A COLD FRONT MOVING OFF THE TEXAS COAST MON NIGHT.

CARIBBEAN SEA...
AN UPPER RIDGE COVERS THE CARIBBEAN W OF ABOUT 80W WITH DRY 
UPPER AIR AND THE ASSOCIATED SUBSIDENCE. AN UPPER CYCLONE IS 
OVER THE E CARIBBEAN JUST S OF PUERTO RICO WITH THE CYCLONE 
SHIFTING SE WITH TIME. AN AREA OF LOW TO MID LEVEL CLOUDS IS 
NOTED S OF HAITI WITH EMBEDDED SHOWERS OCCASIONALLY FLARING.
SIMILAR CLOUDINESS AND PRECIPITATION IS NOTED PASSING ACROSS 
WINDWARD ISLANDS TODAY. OTHERWISE ONLY TRADE WIND CUMULUS IS 
NOTED OVER THE EASTERN WATERS WITH THE NE TO E TRADES EXPECTED 
TO INCREASE EARLY THIS WEEK WEEK AS THE HIGH PRESSURE 
STRENGTHENS TO THE N.
  
ATLANTIC OCEAN...
A BROAD UPPER TROUGH DOMINATES THE SUBTROPICAL ATLANTIC W OF 35W 
WHILE A BROAD UPPER RIDGE IS NOTED OVER THE AREA E OF 35W. A 
BAND OF UPPER MOISTURE EXTENDS FROM 22N50W TO 30N30W THEN TURNS 
SE ACROSS NW AFRICA. AT THE LOW LEVELS RIDGING EXTENDS ACROSS 
THE ENTIRE ATLANTIC ALONG 28N. A TROUGH ORIENTATED N TO S IS 
PASSING W THROUGH THE SE BAHAMAS ACCOMPANIED BY A NE TO SE WIND 
SHIFT AT 20 TO 25 KT BUT ONLY RAIN SHOWERS. OTHERWISE THE UPPER 
LEVELS APPEAR DRY AND IS SUPPRESSING CONVECTION.

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

$$
NELSON