000
AXNT20 KNHC 061752
TWDAT 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EDT SUN APR 06 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...THE ITCZ...
THE ITCZ AXIS IS PRETTY ACTIVE. IT AXIS IS CENTERED ALONG 9N13W 
4N20W 2N30W...CROSSING THE EQUATOR AT 40W INTO NE BRAZIL NEAR 
3N46W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION ARE FROM THE EQUATOR TO 7N BETWEEN 20W-29W...AND 
WITHIN 360 NM N OF AXIS BETWEEN 30W-40W. SIMILAR CONVECTION IS 
ALSO FOUND FROM EQUATOR TO 4N BETWEEN 42W AND 51W.

...DISCUSSION...

THE GULF OF MEXICO...
A SHORTWAVE TROUGH OVER THE NE CORNER OF THE GULF SUPPORTS A 
WEAK STATIONARY FRONT ACROSS THE AREA. AS OF 1500 UTC...THE 
FRONTAL BOUNDARY EXTENDS FROM A 1012 MB LOW NEAR 30N86W THROUGH 
THE NORTH-CENTRAL GULF TO THE MEXICAN COAST NEAR 24N98W. A 
PRE-FRONTAL TROUGH RUNS FROM 29N85W TO 25N87W. A QUIKSCAT PASS 
FROM AROUND 12Z DEPICTS THE WIND SHIFT ASSOCIATED WITH THE FRONT 
MAINLY OVER THE CENTRAL GULF. THESE DATA SHOWED MODERATE TO 
STRONG SE TO S WINDS AHEAD OF THE FRONT...PARTICULARLY OVER THE 
NE PORTION OF THE REGION BUT MOST OF THEM ARE RAIN-CONTAMINATED. 
WINDS ARE MOSTLY LIGHT BEHIND THE FRONT. DOPPLER RADAR INDICATES 
A WELL-ORGANIZED AREA OF SHOWERS AND TSTMS RELATED TO THE 
LOW/FRONT/TROUGH OVER THE NE PORTION OF THE GULF. ANOTHER AREA 
OF CONVECTION HAS MOVED WELL AHEAD OF THE FRONT AND IS CURRENTLY 
AFFECTING THE NW BAHAMAS. THE ABOVE MENTIONED SFC LOW IS 
FORECAST TO MOVE ACROSS N FLORIDA TONIGHT WHILE THE FRONT WILL 
EXTEND FROM THE FLORIDA BIG BEND TO THE CENTRAL GULF NEAR 24N90W 
INTO THE BAY OF CAMPECHE. A 1009 MB LOW IS ANALYZED OVER THE 
WESTERN GULF NEAR 23N96W. SATELLITE PHOTOS INDICATE A SWIRL OF 
MAINLY LOW CLOUDS WITH ISOLATED SHOWERS ASSOCIATED WITH THIS LOW 
THAT IS FORECAST TO WEAKEN DURING THE NEXT 12-24 HOURS. 

CARIBBEAN SEA...
WATER VAPOR IMAGERY REVEALS HIGH-LEVEL WESTERLY FLOW DOMINATING 
MUCH OF THE BASIN...WITH THE REMAINS OF A WEAKENING UPPER-LEVEL 
TROUGH LYING OVER THE NW CARIBBEAN BETWEEN WESTERN CUBA AND THE 
GULF OF HONDURAS. THIS TROUGH COMBINED WITH A MOIST SLY FLOW AT 
LOW LEVELS IS ENHANCING SOME SHOWER ACTIVITY OVER WEST-CENTRAL 
CUBA...INCLUDING THE ISLE OF YOUTH. MODERATE TO STRONG UPPER 
SUBSIDENCE ASSOCIATED WITH A LARGE AND DOMINANT MID-TO UPPER- 
LEVEL ANTICYCLONE IN THE TROPICAL E PACIFIC CONTINUES TO BE 
OBSERVED AS FAR E AS THE WESTERN CARIBBEAN W OF THE DISSIPATING 
TROUGH AXIS. A PLUME OF MOISTURE WITH ORIGINS FROM CONVECTIVE 
DEBRIS OVER THE AMAZON IS BEING DRAWN NORTHWARD FROM NORTHERN 
COLOMBIA TO JUST SOUTH OF HISPANIOLA AND PUERTO RICO.  
OTHERWISE...A 1025 MB SURFACE HIGH PRESSURE LOCATED NEAR 29N61W  
IS PROVIDING A CONTINUED FRESH TRADE WIND FLOW ACROSS THE 
EASTERN AND CENTRAL PART OF THE BASIN. A QUIKSCAT PASS FROM THIS 
MORNING SHOWED ELY WINDS OF 20 TO 25 KT WITH THE STRONGEST 
WINDS...AS USUAL...JUST OFF THE COLOMBIAN COAST. 
THE SURFACE RIDGE OVER THE WEST-CENTRAL ATLANTIC SHOULD 
GRADUALLY WEAKEN WHILE SHIFTING SSE...WHICH SHOULD CAUSE THE 
FRESH TRADE WIND FLOW ACROSS THE AREA TO RELAX.

ATLANTIC OCEAN....
A HIGH AMPLITUDE RIDGE-TROUGH PATTERN DOMINATES THE ENTIRE 
FORECAST AREA. THE RIDGE AXIS EXTENDS NWD ALONG 65W CROSSING 
OVER BERMUDA. A BROAD DEEP-LAYERED TROUGH IS E OF 50 AND N OF 
ABOUT 15N...WITH AN ASSOCIATED CLOSED CYCLONIC CIRCULATION NEAR 
37N28W. THE ATTENDANT COLD FRONT ENTERS THE AREA NEAR 31N19W 
THEN CONTINUES SW ALONG 24N24W 20N35W. A BAND OF BROKEN LOW TO 
MID CLOUDS IS ASSOCIATED WITH THE FRONT. THIS FEATURE IS 
FOLLOWED BY A LARGE DOME OF SURFACE HIGH PRESSURE CENTERED NEAR 
29N61W. THE STRONG PRESSURE GRADIENT BETWEEN THE HIGH AND THE 
LOWER LATITUDES IS ENHANCED THE TRADE WINDS...MOSTLY OVER THE 
AREA S OF 20N AND W OF 50W TO THE LESSER ANTILLES. IN FACT... AN 
EARLIER QUIKSCAT PASS REVEALED 20-25-KT NE WINDS OVER MUCH OF 
THE ABOVE AREA...WITH SEAS GENERALLY 9 TO 12 FT IN NE SWELL. 
WITH THE SURFACE RIDGE FORECAST TO GRADUALLY WEAKEN AND SHIFT 
SSE...THE FRESH TRADES SHOULD RELAX GOING INTO EARLY NEXT WEEK.
W OF 50W...A BROAD SURFACE CYCLONIC FLOW COVERS THE AREA N OF 
ABOUT 25N...DIRECTLY BEHIND THE AFOREMENTIONED COLD FRONT. A 
FAIRLY THICK DECK OF STRATOCUMULUS IS ALSO FOUND BEHIND THE 
FRONT. ELSEWHERE...WATER VAPOR IMAGERY AND CLOUD-TRACKED WINDS 
INDICATE A NARROW MID TO UPPER-LEVEL RIDGE S OF ABOUT 12N FROM 
THE NW COAST OF AFRICA TO JUST SE OF THE WINDWARD ISLANDS.  

$$
GR