000
AXNT20 KNHC 190511
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI JUN 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0430 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 43W S OF 8N MOVING W 5-10 KT. THIS WAVE 
REMAINS RELATIVELY LOW AMPLITUDE AND EMBEDDED WITHIN THE ITCZ. 
POSITION IS BASED ON CONTINUITY. CURRENTLY LITTLE CONVECTION IS 
ASSOCIATED WITH THIS WAVE.

A TROPICAL WAVE IS IN THE BAY OF CAMPECHE ALONG 96W/97W S OF 20N 
INTO THE E PACIFIC MOVING W NEAR 15 KT. THIS WAVE COINCIDES WITH A 
DEEP MOISTURE MAXIMUM PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. 
SURFACE CONVERGENCE ALONG WITH AN UPPER DIFFLUENT PATTERN OVER THE 
REGION IS SUPPORTING SCATTERED MODERATE CONVECTION S OF 20N W OF 93W 
OVER THE BAY OF CAMPECHE WITH STRONGER CONVECTION OVER PORTIONS OF 
SRN MEXICO AND THE E PACIFIC...SEE TWDEP FOR DETAILS.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 12N11W 7N20W 5N30W 4N42W AND INTO NE 
BRAZIL NEAR 3N51W. SCATTERED MODERATE CONVECTION/ISOLATED STRONG 
CONVECTION IS FROM 11N-15N BETWEEN 12W-27W INLAND OVER W AFRICA. 
SCATTERED MODERATE CONVECTION IS FROM 4N-6N BETWEEN 9W-13W AND FROM 
7N-9N BETWEEN 19W-21W. ISOLATED MODERATE CONVECTION IS WITHIN 200 NM 
N OF THE AXIS BETWEEN 20W-40W.

...DISCUSSION...

GULF OF MEXICO...
AN AMPLIFIED UPPER RIDGE EXTENDS ACROSS THE WRN GULF WITH AXIS ALONG 
THE E COAST OF MEXICO CONTINUING  ALONG THE COAST OF TEXAS. SURFACE 
CONVERGENCE NEAR A TROUGH N OF THE DISCUSSION AREA OVER THE SE 
UNITED STATES COAST IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS 
OVER N FLORIDA AND THE ADJACENT COASTAL WATERS IN THE FAR NE GULF OF 
MEXICO N OF 28N BETWEEN 81W-86W. A TROPICAL WAVE OVER THE FAR W BAY 
OF CAMPECHE IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS S OF 20N W 
OF 93W...SEE ABOVE. UPPER LEVEL DIFFLUENCE NEAR AN UPPER LEVEL LOW 
NEAR 23N85W IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS OVER THE 
FLORIDA KEYS. ELSEWHERE...A STATIONARY 1015 MB SURFACE HIGH NEAR 
28N88W IS BRINGING TRANQUIL WEATHER ACROSS THE REMAINDER OF THE GULF 
OF MEXICO. ANTICYCLONIC FLOW DOMINATES THE REGION EXCEPT FOR A 
PORTION IN THE FAR NW GULF WHERE SE TO S 15-20 KT WINDS ARE PRESENT 
W OF 95W. EXPECT THE TROPICAL WAVE IN THE S BAY OF CAMPECHE TO EXIT 
THE REGION OVER THE NEXT SEVERAL HOURS 

CARIBBEAN SEA...
UPPER LEVEL DIFFLUENCE NEAR AN UPPER LEVEL LOW W OF CUBA NEAR 23N85W 
IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS N OF 18N W OF 73W 
INCLUDING PORTIONS OF JAMAICA...W HAITI...AND CUBA. UPPER LEVEL 
TROUGHING DOMINATES THE REMAINDER OF THE NW AND CENTRAL CARIBBEAN W 
OF 66W AS MODERATELY DRY NWLY FLOW ALOFT IS IN PLACE. 
HOWEVER...LOW-LEVEL INSTABILITY AND MIDDLE TO UPPER LEVEL LIFT DUE 
TO THE UPPER LEVEL TROUGH IS GENERATING SCATTERED 
SHOWERS/THUNDERSTORMS S OF 13N W OF 72W INCLUDING INLAND OVER 
COLUMBIA. E OF 66W...MOIST SWLY FLOW ALOFT IS GENERATING SCATTERED 
HIGH CLOUDS AND SUPPORTING ISOLATED SHOWERS ACROSS THE E CARIBBEAN. 

ATLANTIC OCEAN...
A DEEP LAYER CENTRAL ATLC TROUGH IS SUPPORTING A COLD FRONT THAT 
ENTERS THE DISCUSSION AREA NEAR 32N51W AND EXTENDS W-SW TO 30N57W 
CONTINUING AS A STATIONARY FRONT TO 32N68W. SCATTERED SHOWERS ARE 
SUPPORTED BY THE STATIONARY FRONT N OF 29N BETWEEN 60W-69W. A 
SURFACE TROUGH EXTENDS S-SW ALONG 31N74W 28N76W TO 27N79W ACROSS THE 
FAR NW BAHAMAS. UPPER LEVEL DIFFLUENCE AROUND THE UPPER LEVEL LOW W 
OF CUBA THAT IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE 
N CARIBBEAN IS ALSO SUPPORTING SIMILAR ACTIVITY ACROSS THE BAHAMAS S 
OF 26S W OF 75W. ACROSS THE MAJORITY OF THE CENTRAL AND E ATLC A 
BROAD SURFACE RIDGE DOMINATES ANCHORED BY A 1030 MB SURFACE HIGH N 
OF THE DISCUSSION AREA NEAR 42N23W. HOWEVER...A DEEP LAYER LOW OVER 
THE NE ATLC IS ASSOCIATED WITH A 1016 MB SURFACE LOW NW OF THE 
CANARY ISLANDS NEAR 31N19W. LOW LEVEL CONVERGENCE NEAR THIS SURFACE 
LOW IS SUPPORTING ISOLATED SHOWERS N OF 31N BETWEEN 18W-20W.

$$
WALTON