000
AXNT20 KNHC 071059
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUL 06 2009

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 37W TO THE SOUTH
OF 15N MOVING WEST 15 TO 20 KT. THE WAVE IS MOVING THROUGH
AN AREA OF UPPER LEVEL ANTICYCLONIC FLOW. WARMING CLOUD TOP
TEMPERATURES AND DISSIPATING BUT LINGERING PRECIPITATION
FROM 9N TO 12N BETWEEN 32W AND 36W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 78W/79W...PASSING OVER
THE WESTERN END OF JAMAICA...TO THE SOUTH OF 20N MOVING WEST
20 TO 25 KT. THIS WAVE IS MOVING THROUGH THE AREA OF
A PRE-EXISTING EAST-TO-WEST ORIENTED UPPER LEVEL TROUGH IN
THE NORTHERN CARIBBEAN SEA WITH AN UPPER LEVEL RIDGE TO THE 
SOUTHEAST AND SOUTH OF THE TROUGH. SHOWERS AND THUNDERSTORMS
HAVE MOVED AWAY FROM THE AREA OF THE WINDWARD PASSAGE AND THE 
JAMAICA CHANNEL...TO THE WEST OF 80W.

...THE ITCZ...

FROM AFRICA NEAR 9N13W TO 8N25W TO 11N39W...INTO NORTHEASTERN
VENEZUELA NEAR 8N64W. STRONG SHOWERS AND THUNDERSTORMS FROM
7N TO 9N BETWEEN AFRICA AND 17W. SCATTERED STRONG SHOWERS AND
THUNDERSTORMS ARE FROM 5N TO 7N BETWEEN 28W AND 32W. ISOLATED
MODERATE SHOWERS ARE FROM 8N TO 12N BETWEEN 40W AND 50W...AND
FROM 7N TO 10N BETWEEN 50W AND 60W.

...DISCUSSION...

THE GULF OF MEXICO AND INTERIOR MEXICO...
AN UPPER LEVEL RIDGE PASSES ACROSS NORTHERN FLORIDA NEAR 29N83W
TOWARD THE LOWER TEXAS COAST. AN UPPER LEVEL CYCLONIC 
CIRCULATION CENTER IS MOVING ACROSS THE EASTERN PACIFIC OCEAN 
COAST OF SOUTHERN MEXICO NEAR 18N102W. ISOLATED MODERATE SHOWERS 
AND POSSIBLE THUNDERSTORMS ARE FROM 25N TO 27N BETWEEN 103W AND 
107W IN INTERIOR NORTHERN MEXICO...AND IN THE GULF OF 
TEHUANTEPEC.

THE CARIBBEAN SEA...
AN UPPER LEVEL TROUGH PASSES THROUGH THE THE ATLANTIC OCEAN TO
THE SOUTHEAST OF THE BAHAMAS...THROUGH THE WINDWARD PASSAGE...
ON TOP OF THE CAYMAN ISLANDS INTO THE YUCATAN PENINSULA. UPPER 
LEVEL RIDGE IS WITHIN 210 NM ON EITHER SIDE OF THE LINE 21N64W 
IN THE ATLANTIC OCEAN...17N73W 16N80W 13N90W. SCATTERED MODERATE 
TO STRONG SHOWERS AND THUNDERSTORMS ARE FROM THE WATERS TO THE 
EAST OF NICARAGUA FROM 15N TO 19N BETWEEN 80W AND 85W...IN AN 
AREA ALONG THE SOUTHERN EDGE OF THE CYCLONIC FLOW OF THE TROUGH 
AND UPPER LEVEL DIFFLUENT FLOW AS THE RIDGE PULLS AWAY THE FLOW 
IN THE OPPOSITE DIRECTION. STRONG SHOWERS AND THUNDERSTORMS ARE
IN THE GULF OF PANAMA...ALONG THE SOUTHERN END OF THE 78W/79W 
TROPICAL WAVE AND ALONG THE ITCZ.

THE ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE PASSES THROUGH 32N72W TO NORTHWESTERN 
FLORIDA NEAR 29N83W AND CONTINUES INTO THE GULF OF MEXICO. 
WARMING CLOUD TOP TEMPERATURES AND DISSIPATING PRECIPITATION
ARE TO THE NORTH OF THE BAHAMAS ISLANDS TO THE WEST OF 73W.
STRONG SHOWERS AND THUNDERSTORMS ARE FROM 30N TO 32N BETWEEN
74W AND 77W. AN UPPER LEVEL TROUGH PASSES THROUGH 31N57W TO 
23N65W TO 20N70W THROUGH THE WINDWARD PASSAGE INTO THE NORTHERN 
CARIBBEAN SEA. AN UPPER LEVEL SHORTWAVE TROUGH EXTENDS FROM
A 29N30W CYCLONIC CIRCULATION CENTER TO 24N38. BROAD MIDDLE
LEVEL TO UPPER LEVEL CYCLONIC FLOW COVERS THE ATLANTIC OCEAN 
FROM 10N TO 28N BETWEEN 40W AND 62W IN THE EASTERN CARIBBEAN
SEA. SHOWERS ARE POSSIBLE WITHIN 60 TO 90 NM ON EITHER SIDE OF
26N40W 20N49W 18N58W. A SURFACE TROUGH PASSES THROUGH 31N24W
TO 27N30W TO A 1016 MB LOW PRESSURE CENTER NEAR 25N42W TO
20N48W TO 17N56W.

$$
MT