[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 291043
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN MAY 29 2011

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1030 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS MOVING ACROSS THE BORDER BETWEEN VENEZUELA AND
GUYANA ANALYZED FROM 13N59W TO INLAND NEAR 5N60NW MOVING W AT
10-15 KT. VISIBLE SATELLITE IMAGERY SHOWS AN INVERTED-V
STRUCTURE WITH CYCLONIC FLOW ABOUT THE AXIS IN THE LOW-LEVEL
CLOUD PATTERN. TOTAL PRECIPITABLE WATER IMAGERY ALSO INDICATES
MODERATE LOW LEVEL MOISTURE VALUES IN THE VICINITY OF THE WAVE
AXIS. HOWEVER...DRY NW FLOW IN THE MIDDLE TO UPPER LEVELS ABOVE
IS INHIBITING ANY SIGNIFICANT CONVECTION WITH THE WAVE...
ALLOWING FOR ONLY ISOLATED SHOWERS WITHIN 80 NM ON EITHER SIDE
OF THE AXIS N OF 8N.

TROPICAL WAVE MOVES ACROSS THE COASTAL WATERS OF WESTERN
VENEZUELA ALONG 70W S OF 14N W AT 5-10 KT. THE ACTIVITY
ASSOCIATED TO THIS WAVE REMAINS INLAND OVER PORTIONS OF
NORTHWESTERN VENEZUELA AND NORTHERN COLOMBIA.

...ITCZ...

THE ITCZ AXIS IS ANALYZED FROM THE COAST OF SIERRA LEONE NEAR
8N13W SW ALONG 6N20W 4N30W 4N40W 3N50W 4N58W. WIDELY SCATTERED
MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM EITHER
SIDE OF THE AXIS BETWEEN 18W AND 21W...AND W OF 45W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE MOVES ACROSS THE GULF THIS MORNING.
CONSEQUENTLY...WATER VAPOR IMAGERY COMBINED WITH UPPER LEVEL
SATELLITE DERIVED WINDS INDICATE NORTHERLY FLOW ALOFT MOVING A
VERY DRY AIRMASS ACROSS THE AREA. AT SURFACE...RIDGING REFLECTS
ACROSS THE AREA...CENTERED OVER THE NE CORNER OF THE BASIN BY A
WEAK 1015 MB HIGH NEAR 29N85W. THE OUTPUT OF THESE CONDITIONS
BRINGS FAIR WEATHER ACROSS THE DISCUSSION AREA THIS MORNING
...WITH A FEW ISOLATED SHOWERS DEVELOPING OFF THE SW FLORIDA
COAST S OF 26N E OF 83W...INCLUDING THE FLORIDA STRAITS. HAZY
SKIES CONTINUE ACROSS THE WESTERN HALF OF THE BASIN DUE TO THE
ADVECTION OF SMOKE FROM THE SOUTHERN MEXICO WILDFIRES. MARINE
OBSERVATIONS OVER THE NW BASIN INDICATED VISIBILITIES BELOW 10
SM WITH A FEW STATIONS DOWN TO 5 SM. OTHERWISE...THE SURFACE
RIDGE IS EXPECTED TO SLOWLY STRENGTHEN AND LIFT N OF THE BASIN
THROUGH MON NIGHT.

CARIBBEAN SEA...
AN UPPER LEVEL ANTI-CYCLONIC CIRCULATION SITS OVER THE CARIBBEAN
SEA AND NORTHERN SOUTH AMERICA THIS MORNING. THIS FLOW IS
KEEPING FAIR WEATHER CONDITIONS OVER MUCH OF THE CARIBBEAN...
EXCEPT FOR THE SW BASIN...WHERE BROAD SURFACE CYCLONIC TURNING
IS NOTED IN THIS REGION. LOW LEVEL MOISTURE REMAINS QUITE HIGH
IN THIS REGION...NOTICED ON TPW PRODUCT. SCATTERED SHOWERS AND
TSTMS ARE S OF 18N W OF 73W. WITHIN THIS AREA OF CONVECTION...A
SURFACE TROUGH IS ANALYZED FROM THE COAST OF COSTA RICA NEAR
10N83W NE TO 14N76W. MODEL GUIDANCE IS IN BETTER AGREEMENT
SUGGESTING THE ACTIVITY IN THE SW BASIN WILL INCREASE OVER THE
NEXT 24 HOURS...AS CYCLOGENESIS IN THE FORM OF A WEAK LOW
PRESSURE CENTER DEVELOPS IN THE 36 TO 72 HOUR WINDOW ACROSS THE
SW CARIBBEAN SEA WATERS.

ATLANTIC OCEAN...
A SURFACE RIDGE AXIS EXTENDS ACROSS THE WEST ATLC W OF 61W
KEEPING CONDITIONS MOSTLY FAIR THIS MORNING. FARTHER EAST...A
BROAD ELONGATED UPPER LEVEL LOW CONTINUES TO ROTATE AROUND
32N55W. THIS UPPER LEVEL FEATURE IS SUPPORTING A SERIES OF
SURFACE LOWS MOVING ACROSS THE S CENTRAL ATLC...ANALYZED AS A
1014 MB LOW NEAR 28N60W...A 1013 MB LOW NEAR 24N57W...AND A 1013
MB LOW NEAR 25N50W. A SURFACE TROUGH EXTENDS ACROSS THE
EASTERNMOST LOW ALONG 30N50W TO THE LOW CENTER...CONTINUING SSW
ALONG 22N48W TO 20N52W. SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION IS N OF 18N BETWEEN 40W-50W...ENHANCED BY LOW LEVEL
CONVERGENCE AND STRONG DIFFLUENCE FLOW ALOFT...COINCIDING IN THE
VICINITY OF THE LEFT-FRONT QUADRANT OF AN UPPER LEVEL JET STREAK
ON MODEL DATA. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE
INFLUENCE OF A SURFACE RIDGE KEEPING FAIR WEATHER CONDITIONS E
OF 40W. THE RIDGE IS ANCHORED BY A 1033 MB HIGH CENTERED NW OF
THE AZORES NEAR 40N40W.

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

$$

GARCIA




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