[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 160008
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI JUL 15 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N36W 16N36W 12N34W.
THIS WAVE SHOWS UP WELL IN THE VISIBLE SATELLITE IMAGERY METSAT
HIGH DENSITY WINDS FOR THE LOWER ATMOSPHERE. ASCAT DATA SHOW E
TO SE WINDS TO 20 KT ON THE NORTH SIDE OF THE WAVE. ISOLATED
MODERATE RAINSHOWERS ARE NOTED FROM 07N TO 13N BETWEEN 30W AND
40W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 13N48W 10N49W 07N49W.
IT HAS A DISTINCT MOSTLY MID LEVEL ROTATION NOTED ON VISIBLE
IMAGERY. SCATTERED MODERATE TO STRONG RAINSHOWERS AND
THUNDERSTORMS ARE FROM 13N TO 14N BETWEEN 46W AND 49W.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 84 SOUTH OF 22
EXTENDING FROM WESTERN CUBA TO EASTERN HONDURAS. THE WAVE IS
STARTING TO INTERACT WITH THE MONSOON TROUGH EXTENDING OVER
CENTRAL AMERICA...AND IS IN PHASE WITH AN AREA OF LOW TOPPED
CONVECTIVE CLOUDINESS MOVING INTO NICARAGUA AND EASTERN HONDURAS
AT THE NORTH END OF A BROAD CIRCULATION CENTERED OVER COSTA RICA
AND SE NICARAGUA. MODERATE RAINSHOWERS AND THUNDERSTORMS ARE
EMBEDDED IN THIS AREA ALONG THE NICARAGUAN COAST. THE WAVE WILL
BECOME MORE DIFFUSE OVER THE NEXT DAY OR TWO AS IT BECOMES
ABSORBED WITH THE MONSOON TROUGH.

1008 MB LOW PRESSURE IS CENTERED ALONG THE MONSOON TROUGH
NEAR 11N83W ALONG THE COAST OF SOUTHEASTERN NICARAGUA AND
NORTHEASTERN COSTA RICA. SATELLITE IMAGERY CONTINUES TO SHOW
THIS FEATURE AS A VERY BROAD SYSTEM WITH WELL DEFINED BANDING TO
THE NORTH AND SOUTH. CONVECTION REMAINS LIMITED TO THE LOW
TOPPED CONVECTION ASSOCIATED WITH THE TROPICAL WAVE TO THE NORTH
AS NOTED ABOVE. WINDS REMAIN LIGHT TO MODERATE OVER SOUTHERN
CENTRAL AMERICA AND ADJACENT WATERS OF THE WESTERN CARIBBEAN.
THE MAIN ISSUE WITH THIS SYSTEM WILL BE RAINFALL. UPPER
DIFFLUENCE...ABUNDANT UPPER MOISTURE...AND CONVERGENT MONSOONAL
LOW LEVEL FLOW WILL SUPPORT AREAS OF WIDESPREAD RAINFALL WITH
LOCALIZED TRAINING DEEP CONVECTION ACROSS CENTRAL AMERICA DURING
THE NEXT FEW DAYS. THIS MAY RESULT IN FLASH FLOODS AND MUDSLIDES
THROUGH THE WEEKEND.

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

THE MONSOON TROUGH PASSES THROUGH THE PRIME MERIDIAN ALONG 22N
TO 24N05W TO 08N21W. THE ITCZ CONTINUES TO 09N50W TO
06N59W...AND BECOMING INDISTINCT OVER NORTHERN SOUTH AMERICA.
DISORGANIZED ISOLATED MODERATE RAINSHOWERS AND THUNDERSTORMS ARE
TO THE SOUTH OF 10N WITHIN 120 S OF THE MONSOON TROUGH AXIS
BETWEEN 18W AND 26N.

...DISCUSSION...

THE GULF OF MEXICO...

LIGHT TO MODERATE WINDS ARE NOTED ON THE PERIPHERY OF A RIDGE
AXIS EXTENDING ACROSS THE GULF OF MEXICO FROM S FLORIDA TO
TEXAS. THIS RIDGE IS EXPECTED TO REMAIN MOSTLY STATIONARY
THROUGH SAT. WEAK SHOWERS ARE NOTED OVER THE NE GULF OF MEXICO
ASSOCIATED WITH A STATIONARY FRONT OVER THE FLORIDA PANHANDLE
ARE STARTING TO DIMINISH.

THE CARIBBEAN SEA...

AN UPPER TROUGH EXTENDS FROM AN UPPER CYCLONE NEAR 12N65W TO
OVER JAMAICA. A LINE OF SHOWERS AND THUNDERSTORMS PERSISTS ALONG
THIS UPPER TROUGH AXIS...PRODUCING AN ELONGATED OUTFLOW BOUNDARY
THAT IS MOVING NORTH TOWARD COASTS OF HISPANIOLA AND EASTERN
JAMAICA. CLUSTERS OF SHOWERS ARE ALSO ACTIVE OVER THE EASTERN
CARIBBEAN ASSOCIATED WITH THE UPPER CYCLONE. AN AREA OF SHOWERS
AND THUNDERSTORMS IS MOVING INTO THE COAST OF
NICARAGUA...ASSOCIATED WITH THE TROPICAL WAVE ALONG 84W AND THE
1008 MB LOW PRES OVER COSTA RICA AND SE NICARAGUA.

THE ATLANTIC OCEAN...

A COLD FRONT EXTENDS FROM 31N60W TO 27N70W THEN BECOMES
STATIONARY TO NE FLORIDA. A LARGE AREA OF SHOWERS AND LIGHT RAIN
IS ACTIVE TO THE NORTH OF THE FRONTAL BOUNDARY. RIDGING EXTENDS
FROM A 1036 MB HIGH OVER THE N CENTRAL ATLANTIC NEAR 40N32W...SW
TO THE LEEWARD ISLANDS. FRESH NE TO E WINDS ARE NOTED BETWEEN
THE HIGH PRES AND THE TROPICAL WAVE ALONG 35W. FURTHER
EAST...ASCAT DATA SHOW FRESH TO STRONG NE FLOW BETWEEN THE HIGH
PRES AND THE AFRICAN COAST. ANOTHER TROPICAL WAVE IS EXPECTED TO
EMERGE OFF THE COAST OF WEST AFRICA OVER THE NEXT DAY OR TWO.

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

$$
CHRISTENSEN





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