000
AXNT20 KNHC 092336
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON APR 09 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 
SECTIONS OF SOUTH AMERICA...AND THE 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 8N10W 5N20W 1N35W CROSSING THE 
EQUATOR AT 45W INTO NE BRAZIL NEAR 1S48W. SCATTERED MODERATE 
CONVECTION IS WITHIN 100 NM N OF THE AXIS BETWEEN 21W-28W. 
WIDELY SCATTERED MODERATE CONVECTION IS WITHIN AROUND 120 NM N 
OF AXIS W OF 37W.

...DISCUSSION...

THE GULF OF MEXICO...
A MID/UPPER LEVEL RIDGE ANCHORED ON A HIGH OVER LAKE MARACAIBO 
IN NW VENEZUELA EXTENDS NW ACROSS THE CARIBBEAN INTO THE GULF OF 
MEXICO...WHILE A SHORT WAVE TROUGH LIES ACROSS NORTHERN TEXAS 
AND NE MEXICO. SWLY WINDS AHEAD OF THE SHORT WAVE TROUGH ARE 
TRANSPORTING UPPER LEVEL MOISTURE/HIGH CLOUDS FROM THE EPAC 
ACROSS SOUTH MEXICO INTO THE GULF AND THE FLORIDA PENINSULA. LOW 
AND MID LEVEL CLOUDS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS 
COVER MUCH OF REGION N OF 26N. THIS ACTIVITY IS ASSOCIATED WITH 
A WARM FRONT THAT STRETCHES FROM 28N83W TO A 1011 MB SFC LOW 
SITUATED NEAR 26N95W. THE INTERACTION BETWEEN THE SFC LOW AND 
HIGH PRES OVER THE SOUTHEASTERN STATES IS PRODUCING NELY WINDS 
OF 15 TO 20 KT OVER THE NORTHERN GULF WATERS. A SFC TROUGH ALSO 
EXTENDS FROM THE LOW TO THE BAY OF CAMPECHE. MAINLY FAIR WEATHER 
CONTINUES ACROSS THE SE GULF THANKS TO A WEAK HIGH PRES CENTERED 
N OF THE BAHAMAS. ACCORDING TO THE COMPUTER MODELS...THE LOW 
WILL MOVE INLAND TX LATE TONIGHT WHILE THE WARM FRONT MOVES 
SLOWLY N OVER THE NORTHERN GULF WATERS. IN ADDITION...ANOTHER 
SFC LOW IS FORECAST TO DEVELOP ALONG THE FRONTAL BOUNDARY OVER 
THE NE CORNER OF THE GULF TUE AFTERNOON...THEN WILL MOVE EWD 
CROSSING N-CENTRAL FLORIDA INTO THE W ATLC.

THE CARIBBEAN SEA...
A BROAD MID TO UPPER LEVEL RIDGE COVERS THE REGION ANCHORED BY 
AN UPPER HIGH CENTERED OVER LAKE MARACAIBO. A DIFFLUENT PATTERN 
ON THE W SIDE OF THIS UPPER ANTICYCLONE IS ENHANCING THE 
DEVELOPMENT OF CLUSTERS OF MODERATE TO STRONG CONVECTION OVER 
PANAMA AND THE SW CARIBBEAN S OF 12N. AFTERNOON HEAT INDUCED 
SHOWERS ARE SEEN OVER E CUBA. A WEAK HIGH PRES N OF THE AREA IS 
PRODUCING LIGHT TO MODERATE TRADES ACROSS THE REGION. A 
STATIONARY FRONTAL BOUNDARY COMBINED WITH LOCAL EFFECTS ARE 
GENERATING SOME SHOWER ACTIVITY OVER HISPANIOLA THE NORTHERN  
COASTAL WATERS. TYPICAL PATCHES OF LOW LEVEL MOISTURE ARE SEEN 
OVER THE AREA. THE TRADES MAY INCREASE SLIGHTLY AS THE FRONT 
DISSIPATES AND A NARROW WEAK SFC RIDGE BUILDS N OF THE AREA.

THE ATLANTIC OCEAN...
A 1021 MB SFC HIGH PRES LOCATED NE OF THE BAHAMAS NEAR 27N70W... 
DOMINATES THE W ATLC BEHIND A STATIONARY FRONT THAT ENTERS THE 
AREA NEAR 32N50W AND THEN CONTINUES SW TO THE N SHORE OF 
HISPANIOLA NEAR 20N70W. BROKEN TO OVERCAST MULTILAYERED CLOUDS 
ARE RELATED TO THE FRONTAL SYSTEM WITH MOST OF THE SHOWER 
ACTIVITY WITHIN 150-200 NM AHEAD OF THE FRONT N OF 26N. AN UPPER 
TROUGH LOCATED N OF THE FORECAST ARE SUPPORTS THIS FRONT THAT IS 
FORECAST TO GRADUALLY DISSIPATE THROUGH MID-WEEK WITH A WEAK E-W 
SFC RIDGE TAKING ITS PLACE. A STRONGLY TITLED RIDGE AXIS GOES 
FROM THE E CARIB TO BEYOND 32N40W COVERING THE CENTRAL ATLC. AN 
UPPER TROUGH EXTENDS FROM 32N20W TO THE DEEP TROPICS WITH THE 
BASE OF THE TROUGH NEAR 5N45W. EAST OF THE TROUGH...A BROAD 
RIDGE COVERS W AFRICA. AT THE SURFACE...A RIDGE IS IN CONTROL OF 
THE WEATHER PATTERN ACROSS MOST OF THE E-CENTRAL ATLC. THIS 
FEATURE IS PRODUCING MODERATE TRADE WINDS S OF 20N. ONLY 
FRAGMENTS OF LOW/MID CLOUDS ARE SEEN UNDER THE INFLUENCE OF THIS 
SYSTEM.  

$$
GR