000
AXNT20 KNHC 221718
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON JUN 22 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1645 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE EXTENDS FROM 13N54W TO 2N57W MOVING W AROUND 15 
KT. SATELLITE IMAGERY SHOWS GOOD CYCLONIC CURVATURE AROUND THIS 
WAVE. THE WAVE ALSO COINCIDES WITH A DEEP MOISTURE MAXIMUM SEEN 
IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE 
CONVECTION IS FROM 8N-14N BETWEEN 50W-58W. 

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 10N14W 6N24W 5N36W 5N46W AND 
INTO NE S AMERICA NEAR 5N53W. ISOLATED MODERATE CONVECTION IS 
WITHIN 150 NM S OF THE AXIS BETWEEN 14W-24W. SCATTERED MODERATE 
CONVECTION IS FROM 4N-7N BETWEEN 30W-40W. SIMILAR CONVECTION IS 
FROM 7N-10N BETWEEN 47W-49W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER LEVEL LOW 
CENTERED OVER MEXICO NEAR 25N101W IS SUPPORTING NUMEROUS 
SHOWERS/ THUNDERSTORMS OVER THE S GULF OF MEXICO S OF 23N W OF 
93W. ACROSS THE N AND CENTRAL GULF...A 1012 MB STATIONARY 
SURFACE HIGH NEAR 29N92W DOMINATES BRINGING FAIR WEATHER. THE 
SURFACE HIGH HAS UPPER LEVEL SUPPORT FROM AN UPPER LEVEL HIGH 
OVER S MISSISSIPPI NEAR 31N90W WHICH IS PROVIDING DEEP LAYER DRY 
AIR AND SUBSIDENCE. ANTICYCLONIC FLOW AROUND THE SURFACE HIGH IS 
AFFECTING MUCH OF THE GULF...WITH SE WINDS OF 10-15 KTS 
AFFECTING THE NW GULF W OF 93W. EXPECT THE SURFACE HIGH TO MOVE 
W ACROSS THE N GULF TOMORROW AND THEN MEANDER OVER THE WESTERN 
WATERS WED.

CARIBBEAN SEA...
WEAK UPPER LEVEL RIDGING IS OVER THE W CARIBBEAN W OF 79W. TO 
THE EAST OF 79W BROAD UPPER LEVEL TROUGHING COVERS THE REMAINDER 
OF THE CARIBBEAN. UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER RIDGE 
AND TROUGH IS SUPPORTING SCATTERED SHOWERS/ THUNDERSTORMS S OF 
12N BETWEEN 75W-84W INCLUDING THE COASTS OF COSTA 
RICA...PANAMA...AND COLUMBIA. SURFACE CONVERGENCE NEAR A 1009 MB 
SURFACE LOW OVER NW COLUMBIA NEAR 8N76W IS ALSO SUPPORTING THIS 
ACTIVITY AND SIMILAR ACTIVITY INLAND OVER COLUMBIA. ATMOSPHERIC 
INSTABILITY IS RESULTING IN ISOLATED SHOWERS OVER 
CUBA...HISPANIOLA...AND THE NEARBY COASTAL WATERS. THE REMAINDER 
OF THE CENTRAL AND E CARIBBEAN S OF 15N E OF 77W IS UNDER UPPER 
LEVEL EWD FLOW DRAWING MOISTURE AND HIGH CLOUDS. A TROPICAL WAVE 
OVER THE W TROPICAL ATLC IS FORECAST TO MOVE INTO THE E 
CARIBBEAN TOMORROW.

ATLANTIC OCEAN...
A DEEP UPPER LEVEL TROUGH OVER THE NW ATLC IS SUPPORTING...A 
COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N67W EXTENDING TO 
30N75W...A STATIONARY FRONT FROM 30N75W TO 32N81W...AND A 
PRE-FRONTAL SURFACE TROUGH EXTENDING FROM 30N69W TO 27N78W. 
SURFACE CONVERGENCE NEAR THE SURFACE TROUGH AND UPPER LEVEL 
DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL TROUGH ARE SUPPORTING 
NUMEROUS SHOWERS/ SCATTERED THUNDERSTORMS WITHIN 250 NM AHEAD OF 
THE SURFACE TROUGH...INCLUDING THE BAHAMAS. THE REMAINDER OF THE 
ATLC IS UNDER A BROAD SURFACE RIDGE ANCHORED BY A 1024 MB HIGH N 
OF THE DISCUSSION AREA NEAR 35N32W. IN THE UPPER LEVELS...A 
STEEP UPPER LEVEL RIDGE IS E OF THE UPPER LEVEL TROUGH IN THE NW 
ATLC EXTENDING FROM 25N51W TO 32N53W TO N OF THE DISCUSSION 
AREA. E OF THE RIDGE ANOTHER UPPER LEVEL TROUGH DIPS FROM N OF 
THE DISCUSSION AREA TO 16N28W. UPPER LEVEL DIFFLUENCE E OF THE 
UPPER LEVEL TROUGH OVER THE E ATLC IS SUPPORTING ISOLATED 
SHOWERS FROM 23N-26N BETWEEN 22W-27W...FROM 29N-31N BETWEEN 
27W-29W...AND FROM 28N-32N BETWEEN 20W-24W. 

$$
WALTON