000
AXNT20 KNHC 302339
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON JUN 30 2008

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 38W S OF 13N MOVING W 10-15 KT. 
POSITION BASED ON EXTRAPOLATION AND ALL SIGNIFICANT CONVECTION 
REMAINS EMBEDDED WITHIN THE ITCZ.

A TROPICAL WAVE IS ALONG 49W S OF 14N MOVING W 10-15 KT. A 
LOW-AMPLITUDE INVERTED-V CURVATURE IS OBSERVED ON SATELLITE 
IMAGERY. A SMALL CLUSTER OF MODERATE CONVECTION IS WITHIN 60 NM 
W OF THE AXIS FROM 10N-11N.

A TROPICAL WAVE IS OVER VENEZUELA ALONG 65W S OF 14N MOVING W 
NEAR 15 KT. NEARBY SFC OBSERVATIONS INDICATE FALLING PRESSURE  
IN ADVANCE OF THE WAVE. NO SIGNIFICANT CONVECTION IS ASSOCIATED 
WITH THIS WAVE. 

A TROPICAL WAVE IS IN THE WESTERN CARIBBEAN ALONG 81W S OF 20N 
MOVING W 15-20 KT. SFC OBSERVATIONS DISPLAY THE EXPECTED E-SE 
WIND SHIFT BEHIND THE WAVE. NO SIGNIFICANT CONVECTION IS 
ASSOCIATED WITH THIS WAVE.

...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N10W 7N20W 7N30W 8N40W 10N50W 
AND INTO S AMERICA NEAR 10N60W. SCATTERED MODERATE CONVECTION IS 
WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 13W AND 23W. 
CLUSTERS OF MODERATE CONVECTION ARE FROM 5N-10N BETWEEN 33W-41W. 
SCATTERED MODERATE CONVECTION IS WITHIN 150 NM N OF THE AXIS W 
OF 52W. 

...DISCUSSION...

GULF OF MEXICO...
A DEEP-LAYERED TROUGH OVER THE EASTERN CONUS EXTENDS A COLD 
FRONT ALONG THE SOUTHERN GULF STATES...JUST NORTH OF THE 
DISCUSSION AREA. A PRE-FRONTAL TROUGH LIES ACROSS THE NE GULF 
FROM NEAR PANAMA CITY FLORIDA TO NEAR 8N89W. SCATTERED SHOWERS 
AND THUNDERSTORMS FILL THE GULF N OF 25N IN ADVANCE OF THE 
FRONTAL BOUNDARY. ALOFT...INSTABILITY AND DIVERGENCE ALONG A 
SHORTWAVE TROUGH IS GENERATING AN AREA OF SCATTERED SHOWERS AND 
THUNDERSTORMS IN THE WESTERN BAY OF CAMPECHE. THE REMAINDER OF 
THE GULF IS FREE OF SIGNIFICANT CONVECTION DUE TO AN UPPER RIDGE 
THAT STRETCHES ACROSS THE YUCATAN PENINSULA...FLORIDA 
STRAIGHTS...AND INTO THE W ATLC. EXPECT THE FRONTAL BOUNDARY TO 
MOVE INTO THE NE GULF LATE TONIGHT BEFORE DISSIPATING LATE TUE. 
THE ATLC SFC RIDGE WILL REBUILD OVER THE GULF THROUGH FRI.

CARIBBEAN...
ANTICYCLONIC FLOW FROM AN UPPER RIDGE OVER THE YUCATAN PENINSULA 
COVERS THE CARIBBEAN W OF 80W. THE FLOW CROSSES 80W AND FEEDS 
INTO THE UPPER LEVEL TROUGH THAT EXTENDS FROM THE ATLANTIC OCEAN 
OVER HISPANIOLA TO NEAR 14N76W. DIVERGENCE BETWEEN THESE 
FEATURES IS FUELING CONVECTION FROM 15N-19N BETWEEN 77W-85W. 
THIS DIVERGENCE HAS ALSO PROVIDED NEEDED LIFT TO SUPPORT 
CONVECTION INITIATED BY ONSHORE FLOW ALONG COASTAL 
HONDURAS/NICARAGUA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS 
HAVE FLARED UP IN THE SW CARIBBEAN ALONG THE COAST OF PANAMA IN 
RESPONSE TO LOW-LEVEL WIND SPEED CONVERGENCE. DAYTIME HEATING 
HAS ONCE AGAIN INDUCED ISOLATED THUNDERSTORMS OVER THE NRN 
CARIBBEAN ISLANDS. THE CENTRAL CARIBBEAN REMAINS RELATIVELY 
CLEAR UNDER A DRY AND STABLE AIR MASS ALONG THE BASE OF THE 
UPPER TROUGH. SWLY UPPER FLOW ALONG THE LEADING EDGE OF THE 
TROUGH IS ADVECTING A DEEP MOISTURE LAYER ACROSS THE EASTERN 
CARIBBEAN AND MAY BE GENERATING ISOLATED SHOWERS OVER THE 
LEEWARD ISLANDS. AT THE SFC...A STRONG RIDGE OVER THE ATLC 
CONTINUES TO PROVIDE A TIGHT PRESSURE GRADIENT ACROSS THE 
BASIN...PRODUCING STRONG EASTERLY TRADES THROUGHOUT.

ATLANTIC...
A STRONG HIGH PRESSURE RIDGE...ANCHORED BY A 1027 MB HIGH SW OF 
THE AZORES...CONTINUES TO DOMINATE THE ATLANTIC PRODUCING 
MODERATE EASTERLY FLOW THROUGHOUT THE REGION. THE ONLY AREA OF 
ACTIVE CONVECTION LIES IN THE W ATLC WHERE A SQUALL LINE HAS 
MOVED OUT AHEAD OF AN APPROACHING COLD FRONT AND...AS OF 
21Z...IS AFFECTING CENTRAL FLORIDA AND THE COASTAL WATERS W OF 
79W N OF 28N. ADDITIONAL CLUSTERS OF SCATTERED SHOWERS AND 
THUNDERSTORMS ARE W OF 72W EXTENDING FROM THE BAHAMAS TO NORTH 
OF THE DISCUSSION AREA. THIS ACTIVITY IS BEING GENERATED BY THE 
APPROACHING FRONTAL BOUNDARY AND IS ENHANCED BY UPPER LEVEL 
DIVERGENCE AHEAD OF THE DEEP-LAYERED TROUGH OVER THE EASTERN 
CONUS. ALOFT...DIVERGENCE ALONG THE SRN EXTENT OF AN UPPER-HIGH 
NEAR 16N46W IS ENHANCING CONVECTION ALONG THE ITCZ.

$$
WADDINGTON