000
AXNT20 KNHC 271746
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
205 PM EDT TUE APR 27 2010

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 
1740 UTC...

...THE ITCZ...

FROM THE LIBERIA COAST NEAR 6.5N11W WESTWARD ALONG 4N20W 3.5N30W 
3N40W INTO THE NORTHEASTERN COAST OF BRAZIL NEAR 2N52W. MODERATE 
TO STRONG CONVECTION IS IN THE COASTAL WATERS OF AFRICA BETWEEN 
THE PRIME MERIDIAN AND 5W...INCLUDING LIBERIA...SIERRA LEONE AND 
GUINEA. WEAK TO MODERATE CONVECTION IS WITHIN 35 NM ON EITHER 
SIDE OF THE ITCZ WEST OF 33W.
 
...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL ZONAL FLOW COVERS THE ENTIRE REGION. WATER VAPOR 
IMAGERY SHOWS DRY AND STABLE AIR DOMINATING THE MID AND LOWER 
LEVELS OF THE ATMOSPHERE. HOWEVER...A WEAKENING COLD FRONT 
CONTINUES TO SLIDE ACROSS THE NORTHERN GULF...ENTERING THROUGH 
THE FLORIDA PANHANDLE NEAR PANAMA CITY AND EXITING THROUGH 
BROWNSVILLE TEXAS ALONG 28N88W 26N93W. WEAK ISOLATED SHOWERS ARE 
WITHIN 30 NM ON EITHER SIDE OF THE FRONT. MARINE OBSERVATIONS 
SHOW WEAK PRESSURE GRADIENT ACROSS THE REGION. COMPUTER MODELS 
ARE HINTING AT MID LEVEL MOISTURE ADVECTING FROM THE FAR EASTERN 
TROPICAL PACIFIC INTO THE SOUTHERN GULF BASIN BY WEDNESDAY 
MORNING...WITH A WEAK SURFACE LOW DEVELOPING OVER THE BAY OF 
CAMPECHE BRINGING SHOWERS SOUTH OF 22N. 

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS MID TO UPPER DRY STABLE AIR ACROSS THE 
REGION. AT SURFACE...A STATIONARY FRONT ENTERS THE REGION 
THROUGH CENTRAL CUBA NEAR 22N79W CONTINUING WEST-SOUTHWEST TO 
THE FAR NORTHWEST BASIN NEAR 20N86W. SCATTERED WEAK TO MODERATE 
SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 70 NM ON EITHER 
SIDE OF THE FRONT. PART OF THE ITCZ CROSSES THE FAR SOUTHWEST 
BASIN FROM THE NORTHWEST COLOMBIA COAST TO THE EASTERN COAST OF 
COSTA RICA ALONG 9N76W 10N80W 10N83W. THIS FEATURE IS PRODUCING 
SCATTERED SHOWERS SOUTH OF 12N WEST OF 72W. COMPUTER MODELS 
CONTINUE TO SHOW CONVECTION IN THIS REGION OVER THE NEXT 24 
HOURS. ELSEWHERE ACROSS THE CARIBBEAN SEA...THE SURFACE PRESSURE 
GRADIENT IS COMPARATIVELY WEAK...WITH WEAK TO MODERATE TRADE 
WINDS.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH PASSES THROUGH THE WESTERN ATLANTIC. ALONG 
WITH THIS FEATURE...AN UPPER LEVEL SHORTWAVE SUPPORTS A COLD 
BOUNDARY THAT ENTERS THE AREA OF DISCUSSION THROUGH 32N70W 
CONTINUING SOUTHWEST THROUGH THE CENTRAL BAHAMAS NEAR 24N75W TO 
CENTRAL CUBA NEAR 22N78W. NO PRECIPITATION IS READILY APPARENT 
NEAR THE FRONT JUST FROM SATELLITE IMAGERY. INSTEAD...THE 
CONVECTION SEEMS TO BE FOUND FAR EAST OF THE SYSTEM NORTH OF 25N 
BETWEEN 60 AND 70. AN UPPER LEVEL RIDGE OF HIGH PRESSURE COVERS 
MOST OF THE CENTRAL AND EASTERN BASIN SUPPRESSING DEEP 
CONVECTION EAST OF 60W. HOWEVER...A STATIONARY FRONT IS ANALYZED 
ENTERING THROUGH 32N23W EXTENDING SOUTHWEST ALONG 26N30W 20N37W 
16N42W. SCATTERED SHOWERS ARE WITHIN 60 NM ON EITHER SIDE OF THE 
FRONT. OVER THE NEXT 24 HOURS LOOK FOR THE WESTERN COLD FRONT TO 
CONTINUE TO MOVE EASTWARD WITH CONVECTION AHEAD OF IT...WHILE 
THE STATIONARY FRONT OVER THE EASTERN BASIN SLOWLY DIMINISHES.

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

$$

GARCIA