000
AXNT20 KNHC 051540
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED APR 05 2006

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...WEATHER OBSERVATIONS... 
RADAR...AND METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1115 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N12W 1N20W EQ30W 2S47W.  WEAK 
TROUGH IS EMBEDDED IN THE ITCZ NEAR S AMERICA ALONG 49-50W 
WITH A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION FROM 2N-4N 
BETWEEN 49W-51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION 
IS ALSO JUST NORTH OF THE ITCZ AXIS BETWEEN 37W-45W. SIMILAR 
CONVECTION IS FOUND ALONG THE NORTH COAST OF BRAZIL AND THE 
ADJACENT COASTAL WATERS BETWEEN 35W-38W AND 42W-45W. 

...DISCUSSION...

GULF OF MEXICO...
AS OF 0900 UTC...A COLD FRONT FROM THE W ATLC CROSSES SOUTH 
FLORIDA INTO THE GULF ALONG 26N82W 26N87W. VERY LITTLE WEATHER 
IS CURRENTLY ASSOCIATED WITH THIS FRONT OVER THE GULF. IT WILL 
BECOME DIFFUSE AS THE DAY GOES BY. WEAK HIGH PRESSURE CONTROLS 
THE REMAINDER OF THE AREA WITH A 1018 MB CENTER NEAR 28N88W. THE 
NEXT COLD FRONT MIGHT ENTER THE NW GULF EARLY SAT WITH A CHANCE 
OF RAIN.  IN THE UPPER LEVELS...A RIDGE COVERS THE ENTIRE GULF 
WITH MODERATE/STRONG SUBSIDENCE ESPECIALLY IN THE BAY OF 
CAMPECHE. SOUTHERLY RETURN FLOW WILL INCREASE OVER THE WEST GULF 
LATE TODAY AS A LOW PRESSURE CENTER DEVELOPS OVER THE GREAT 
PLAINS. 

CARIBBEAN SEA...
A MID-UPPER LEVEL TROUGH IS DEEPENING SLIGHTLY OVER THE NW 
CARIBBEAN. SWLY UPPER LEVEL FLOW IS DRAWING MOISTURE FROM THE 
EPAC ACROSS CENTRAL AMERICA INTO THE CENTRAL CARIBBEAN AND 
HISPANIOLA. PATCHES OF LOW-LEVEL CLOUDS WITH EMBEDDED ISOLATED 
SHOWERS ARE SCATTERED ACROSS THE AREA DRIVEN BY LIGHT TO 
MODERATE TRADE WINDS. ONE OF THEM IS AFFECTING PUERTO RICO AND 
THE U.S. VIRGIN ISLANDS. THE SAN JUAN DOPPLER RADAR IS SHOWING 
SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE ISLANDS AND THE 
COASTAL WATERS. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION ARE SEEN OVER COLOMBIA. THE TROUGH IS FORECAST TO 
MOVE TOWARD THE CENTRAL CARIBBEAN TODAY... ENHANCING THE 
SHOWER/TSTM ACTIVITY FIRST OVER HISPANIOLA AND AFTERWARDS OVER 
PUERTO RICO AND THE VIRGIN ISLANDS. IT WILL ALSO ASSIST THE 
DEVELOPMENT OF SHOWERS/TSTMS OVER COSTA RICA AND PANAMA DURING 
THE NEXT COUPLE OF DAYS. EASTERLY TRADE WINDS WILL PERSIST 
ACROSS THE BASIN THROUGH SUN.

ATLANTIC OCEAN...
A TROUGH/RIDGE/TROUGH PATTERN IS OVER THE ATLC OCEAN. ZONAL FLOW 
CONTROLS MOST OF THE TROPICAL ATLC. A COLD FRONT ENTERS THE W 
ATLC NEAR 31N70W EXTENDING SW TO SOUTH FLORIDA. A PATCH OF 
SHOWERS/ISOLATED TSTMS IS ALONG THE FRONT JUST NORTH OF THE 
WESTERN BAHAMAS. AHEAD OF THE FRONT...A WEAK TROUGH LOCATED 
ALONG 70-71W IS HELPING THE DEVELOPMENT OF SCATTERED SHOWERS AND 
ISOLATED TSTMS FROM 21N-27N BETWEEN 64W-71W. A PERSISTENT 1018 
MB SURFACE LOW IS NEAR 21N46W SUPPORTED BY AN UPPER TROUGH. MOST 
OF THE SHOWER ACTIVITY ASSOCIATED WITH THIS LOW HAS MOVED 
EASTWARD AND AWAY FROM THE SURFACE CENTER. THE LOW SHOULD 
DISSIPATE AS IT LOSES UPPER SUPPORT DUE TO THE TROUGH BYPASSING 
THE LOW. AN UPPER HIGH IS IN THE DEEP TROPICS NEAR 7N42W. 

$$
GR