[Tropical] Tropical Weather Discussion

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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




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