000
AXNT20 KNHC 232340
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT FEB 23 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
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 
2300 UTC

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N11W EQ30W EQ50W. SCATTERED MODERATE
CONVECTION WITHIN 240 NM S OF THE AXIS BETWEEN 25W AND 33W.

...DISCUSSION...
GULF OF MEXICO...
A SHEARING UPPER TROUGH SWEEPING EWD ACROSS THE SE CONUS EXTENDS 
INTO THE NE GULF TO NEAR 26N88W. DRY UPPER AIR IS NOTED ALONG THE
TROUGH. WEAK SHORTWAVE RIDGE WITH AXIS ALONG 93W IS MOVING ACROSS
THE NORTHERN GULF STATES. THE PERIPHERY OF A LARGE ANTICYCLONE 
OVER HISPANIOLA AND SE BAHAMAS CONTINUES TO EXERT AN INFLUENCE 
ON THE SE GULF OF MEXICO AND IS A MAJOR FACTOR IN THE SHEARING 
OUT OF THE UPPER TROUGH MOVING ACROSS THE SE. UPPER LEVEL 
MOISTURE FROM THE BAY OF CAMPECHE REGION IS STREAMING NE AROUND 
THE PERIPHERY OF THE RIDGE. A COLD FRONT EXTENDS FROM NORTHERN 
FLORIDA TO THE CENTRAL GULF NEAR 25N90W THEN BECOMES STATIONARY 
AND DIFFUSE IN THE SW GULF. WEAKENING UPPER DIFFLUENCE E OF THE 
THE UPPER TROUGH HAS ALLOWED CONVECTION TO DECREASE AHEAD OF THE 
SURFACE FRONT WITH SCATTERED SHOWERS NOTED OVER CENTRAL FLORIDA.
THE ATLC SUBTROPICAL RIDGE EXTENDS W OVER THE AREA WITH ITS AXIS 
ALONG 25N TO 84W.

CARIBBEAN...
A LARGE PERSISTENT UPPER ANTICYCLONE CENTERED NEAR HISPANIOLA 
DOMINATES THE MOST OF THE REGION. THE TAIL END OF A CENTRAL ATLC 
UPPER TROUGH EXTENDS INTO THE FAR EASTERN CARIBBEAN BUT APPEARS 
TO BE FILLING WITH TIME. THIN BROKEN CIRRIFORM CLOUDS ARE NOTED 
OVER THE FAR NW CARIBBEAN ALONG THE PERIPHERY OF THE ANTICYCLONE.
STRONG SUBSIDENCE FROM THE ANTICYCLONE HAS SUPPRESSED CONVECTIVE 
ACTIVITY. AT LOW LEVELS THE ATLC SUBTROPICAL RIDGE EXTENDS ACROSS
THE NW CARIBBEAN WITH ITS AXIS JUST N OF THE AREA ALONG 25N. 
LOCALLY BROKEN LOW TRADE WIND CLOUDS WITH EMBEDDED SHOWERS ARE 
NOTED E OF 70W WITH CLOUDINESS BECOMING BROKEN TO OVERCAST IN 
PATCHES FROM JAMAICA TO W CUBA AND THE YUCATAN CHANNEL.

ATLANTIC...
AN UPPER ANTICYCLONE IS CENTERED OVER THE SE BAHAMAS WITH A RIDGE
EXTENDING NE TO BEYOND 32N65W. A MOISTURE PLUME SPILLING OVER THE
RIDGE AXIS IS MAINLY N OF 25N. THE CENTRAL ATLC IS DOMINATED BY A
TROUGH EXTENDING THROUGH UPPER LEVEL CYCLONIC CIRCULATIONS NEAR 
38N15W 24N34W AND 17N50W. DRY UPPER AIR IS EVIDENT SW OF EACH OF 
THESE CYCLONES...WHILE CLOUDS AND SHOWERS ARE ENHANCED IN THE NE 
SEMICIRCLE. THE E ATLC IS DOMINATED BY AN UPPER LEVEL ANTICYCLONE
NEAR 5N23W WITH A RIDGE EXTENDING ALONG 5N TO 40W. DIFFLUENCE S 
OF THE RIDGE AXIS IS ENHANCING ITCZ CONVECTION BETWEEN 25W AND 
33W WITH DEBRIS MOISTURE SPREADING N BETWEEN 15W AND 35W. AT THE 
SURFACE A LARGE 1029 MB HIGH PRES IS CENTERED NEAR 33N35W WITH A 
RIDGE EXTENDING SW TO THE STRAITS OF FLORIDA. PATCHES OF BROKEN 
STRATOCUMULUS ARE MOVING W IN THE TRADES S OF THE SURFACE RIDGE.

$$
MUNDELL