[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261749
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT MAY 26 2012

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURE...

SUBTROPICAL STORM BERYL LOCATED NEAR 31.6N 76.3W AT 26/1500
UTC...AROUND 230 MILES/375 KM ESE OF CHARLESTON SOUTH
CAROLINA...AND 330 MILES/535 KM ENE OF JACKSONVILLE FLORIDA.
BERYL IS MOVING SW AT 8 KT. MAX SUSTAINED WINDS ARE 40 KT WITH
GUSTS TO 50 KT. MINIMUM CENTRAL PRES IS ESTIMATED AT 1001 MB. NO
DEEP CONVECTION IS NOTED ON SATELLITE IMAGERY CURRENTLY...BUT
SCATTERED MODERATE CONVECTION IS APPARENT MAINLY WITHIN 75 NM SE
SEMICIRCLE FROM THE STORM CENTER. EASTERLY SWELL GENERATED FROM
BERYL WILL IMPACT THE COASTAL AREAS FROM SOUTH CAROLINA TO NE
FLORIDA...BRINGING HEIGHTENED RISK OF RIP CURRENTS AND COASTAL
FLOODING. PLEASE REFER TO THE FORECAST ADVISORY BULLETIN UNDER
THE AWIPS/WMO HEADERS...MIATCMAT2/ WTNT22 KNHC...AND THE PUBLIC
ADVISORY MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS ON BERYL.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ANALYZED ALONG 19N43W TO
10N49W TO 04N50W. THE WAVE IS INTERACTING WITH AN UPPER TROUGH
EXTENDING FROM 35N37W TO 20N50W...GIVING THE SURFACE WAVE A NE
TO SW ORIENTATION. MODEST CONVECTION IS NOTED TO THE
NORTH OF THE WAVE...LIKELY INFLUENCED BY THE UPPER TROUGH TO THE
NW. THE WAVE IS NEAR THE LEADING EDGE A DRIER SAHARAN
AIRMASS...EVIDENT N OF 11N E OF 40W. THE NORTHERN PORTION OF THE
WAVE WAS EXTENDED A FURTHER NORTH IN THE 12 UTC SURFACE ANALYSIS
TO REFLECT BETTER CYCLONIC TURNING NOTED BY SHIP AND BUOY
OBSERVATIONS. THE WAVE WILL SHIFT WEST REACHING 50W BY EARLY
SUN...55W BY EARLY MON...AND 59W BY EARLY TUE.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 16571W ACROSS THE GUAJIRA
PENINSULA IN NE COLOMBIA INTO WESTERN VENEZUELA NEAR LAKE
MARACAIBO. WIND DATA FROM BUOY AND LAND BASED OBSERVATIONS
INDICATE THE WAVE IS VERY BROAD...BUT STACKS WELL WITH CYCLONIC
TURING NOTED IN LOW LEVEL SATELLITE DERIVED WIND DISPLAYS.
CONVECTION REMAINS MINIMAL DESPITE DECENT PRECIPITABLE WATER
VALUES IN THE S CENTRAL CARIBBEAN NOTED ON SATELLITE AND
REGIONAL SOUNDING DATA. THE MAIN IMPACT OF THE WAVE SO FAR ON
SENSIBLE WEATHER IS TO ENHANCE TRADE WIND FLOW SLIGHTLY...AS FAR
N AS THE N SIDE OF HISPANIOLA WHERE 20 KT WINDS ARE NOTED IN
SHIP AND SCATTEROMETER DATA. CONVECTION WILL LIKELY INCREASE
SLIGHTLY AS THE WAVE SHIFTS WESTWARD INTO THE SW CARIBBEAN
THROUGH MON...AND INTERACTS WITH A QUASI-STATIONARY UPPER TROUGH
EXTENDING OVER THE NW CARIBBEAN. THE WAVE WILL LOSE ITS DISTINCT
IDENTITY THROUGH SUN AS IT INTERACTS WITH THE UPPER TROUGH...AND
STALLS OVER THE FAR SW CARIBBEAN.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EMERGES OFF THE SENEGAL/GAMBIA COAST NEAR
13N17W TO 09N20W. THE ITCZ CONTINUES FROM 09N20W TO 04N40W TO
02N47W. SCATTERED MODERATE CONVECTION IS NOTED FROM 02N TO 07N E
OF 40W.

...DISCUSSION...

GULF OF MEXICO...
DRY NORTHERLY MID TO UPPER LEVEL FLOW PERSISTS BETWEEN THE UPPER
OUTFLOW OF SUBTROPICAL STORM BERYL AND DEEP LAYER RIDGING OVER
THE WESTERN GULF. THIS IS KEEPING THE SKIES GENERALLY CLOUD FREE
ACROSS THE GULF. CLUSTERS OF CONVECTION ACTIVE OVER THE SOUTHERN
BAY OF CAMPECHE EARLIER THIS MORNING HAVE DISSIPATED. AT THE
SURFACE...BUOY AND SHIP OBSERVATIONS INDICATE A WEAK TROUGH FROM
NORTHERN YUCATAN TO THE SOUTHEAST GULF NEAR 25N85W. BUOY AND
SCATTEROMETER DATA SHOW 15 TO 20 KT SE FLOW OVER THE FAR WESTERN
GULF...SOUTH OF HIGH PRES OVER THE LOWER MISSISSIPPI VALLEY.
THIS WILL DIMINISH TONIGHT AS THE HIGH PRES SHIFTS SOUTH.

THE CARIBBEAN SEA...
AN UPPER LEVEL TROUGH EXTENDS FROM SUBTROPICAL STORM BERYL NEAR
32N76W ACROSS WESTERN CUBA TO THE GULF OF HONDURAS. SCATTERED
MODERATE CONVECTION IS NOTED ON SATELLITE IMAGERY CLOSE TO THE
ISLE OF YOUTH AT THE BASE OF THE UPPER TROUGH. SCATTERED
MODERATE TO ISOLATED STRONG CONVECTION IS NOTED OVER THE FAR SW
CARIBBEAN FROM WESTERN PANAMA TO SE NICARAGUA...LIKELY DUE TO
WEAK SPEED CONVERGENCE IN THE LOWER LEVELS...AIDED BY DIVERGENCE
ALOFT ON THE SE PORTION OF THE UPPER TROUGH. FRESH TRADES COVER
THE CENTRAL CARIBBEAN WHERE A BROAD TROPICAL WAVE IS MIGRATING
THROUGH 71W...BUT WILL SHIFT W AND INTERACT WITH THE UPPER
TROUGH OVERNIGHT. THE FRESH TRADE WIND FLOW WILL PERSIST ACROSS
THE EASTERN AND CENTRAL CARIBBEAN INTO EARLY NEXT WEEK AS HIGH
PRES BUILDS N OF THE AREA. PLEASE REFER TO THE HIGH SEAS
FORECAST... MIAHSFAT2...AND THE OFFSHORE FORECAST...
MIAOFFNT3...FOR MORE DETAILS ON WINDS AND SEAS.

THE ATLANTIC OCEAN...
DEEP LAYER MOISTURE IS TAPERING OFF FROM CENTRAL CUBA THROUGH
THE CENTRAL BAHAMAS TOWARD BERMUDA...IN THE SW FLOW TO THE EAST
OF SUBTROPICAL STORM BERYL. THIS MOIST FLOW HAD BEEN RESPONSIBLE
FOR CONTINUOUS HEAVY RAINFALL OVER CENTRAL CUBA AND THE BAHAMAS
IN THE PREVIOUS 2 TO 3 DAYS...BUT THIS IS STARTING TO DIMINISH.
LIGHT TO MODERATE E TO SE FLOW SURFACE IS NOTE W OF 65W OUTSIDE
THE VICINITY OF BERYL...EXCEPT FOR 20 KT FLOW N OF HISPANIOLA
THROUGH THE SOUTHERN BAHAMAS AND TURKS/CAICOS. FURTHER EAST...A
LARGE SCALE UPPER LEVEL TROUGH EXTENDS ACROSS THE CENTRAL ATLC
FROM 35N37W TO 20N50W. DRY...SUBSIDENT NORTHERLY FLOW IN THE MID
AND UPPER LEVELS OF THE ATMOSPHERE ON THE WEST SIDE OF THE
TROUGH ARE INHIBITING CONVECTIVE GROWTH OVER MUCH OF THE AREA
BETWEEN 40W AND 60W. EAST OF 40W...SAHARAN DUST IS EVIDENT
ACROSS THE EASTERN ATLC...N OF 11N. FRESH N TO NE FLOW IS NOTED
ALONG THE COAST OF NW AFRICA...TO THE SE OF 1025 MB SURFACE HIGH
CENTERED NEAR 32N25W.

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

$$
CHRISTENSEN





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