000 AXNT20 KNHC 180552 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE JUL 18 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 29W/30W S OF 15N MOVING W 15-20 KT. A CLUSTER OF SCATTERED MODERATE CONVECTION IS E OF THE WAVE AXIS FROM 11N-14N BETWEEN 20W-23W. HIGH AMPLITUDE TROPICAL WAVE IS ALONG 64W S OF 21N MOVING W 15-20 KT. THE WAVE IS STILL INTERACTING WITH AN UPPER LOW CENTERED NEAR 25N63W. ISOLATED MODERATE CONVECTION IS VERY CLOSE TO GUADELOUPE AND WITHIN 180 NM SOUTH OF PUERTO RICO. THE WAVE WILL CROSS THE VIRGIN ISLANDS AND PUERTO RICO TODAY...ENHANCING THE SHOWER ACTIVITY OVER THESE ISLANDS. TROPICAL WAVE IN THE W CARIBBEAN SEA IS ALONG 85W S OF 21N MOVING W 15-20 KT. A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OVER THE W CARIBBEAN SEA FROM 13N-17N BETWEEN 80W-84W. A DIFLUENT PATTERN ALOFT IS ENHANCING THIS CONVECTIVE ACTIVITY. THE WAVE IS ALSO ENHANCING CONVECTION OVER COSTA RICA AND WESTERN PANAMA. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 14N17W 9N30W 7N40W 8N50W 10N60W. OUTSIDE OF TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS FROM 5N-9N EAST OF 40W...AND FROM 5N-7N BETWEEN 48W-52W. ...DISCUSSION... GULF OF MEXICO... A 1011 MB LOW IS OVER CENTRAL MISSISSIPPI NEAR 32N89W. A SURFACE TROUGH EXTENDS E TO S GEORGIA NEAR 31N82W. A 1018 MB HIGH IS OVER NORTH FLORIDA NEAR 29N82W. PRES GRADIENT REMAINS VERY WEAK ACROSS THE ENTIRE GULF WITH LIGHT WINDS THROUGHOUT. THE AREA IS RELATIVELY FREE OF CONVECTION THANKS TO A MODERATE TO STRONG SUBSIDENCE ALOFT. AN UPPER LOW IS CENTERED OVER THE ISTHMUS OF TEHUANTEPEC IN MEXICO. AN UPPER HIGH IS CENTERED OVER THE TEXAS COAST WITH A RIDGE EXTENDING MOSTLY E ACROSS FLORIDA AND THE W ATLC. ELY UPPER LEVEL FLOW DOMINATES THE GULF. SHOWER AND TSTM ACTIVITY WILL INCREASE TODAY OVER THE YUCATAN PENINSULA...NORTHERN CENTRAL AMERICA AND THE BAY OF CAMPECHE WITH THE PASSAGE OF A TROPICAL WAVE AND THE PRESENCE OF THE UPPER LOW MENTIONED ABOVE. CARIBBEAN SEA... A TINY UPPER LEVEL LOW IS OVER THE YUCATAN CHANNEL/WESTERN CUBA. AN UPPER RIDGE COVERS THE W-CENTRAL CARIBBEAN WHILE AN UPPER TROUGH CROSSES THE E CARIBBEAN FROM THE LOW LOCATED NEAR 25N63W. ABUNDANT UPPER LEVEL MOISTURE IS OVER THE BASIN. TYPICAL SURFACE TRADEWINDS OF 15-20 KT DOMINATES THE AREA WITH THE STRONGEST WINDS NEAR THE COAST OF COLOMBIA AND VENEZUELA. PATCHES OF SCATTERED MODERATE TO STRONG CONVECTION ARE INLAND OVER NORTH-CENTRAL VENEZUELA AND NORTHERN COLOMBIA. SIMILAR CONVECTION IS OVER THE SW CARIBBEAN AND VERY CLOSE TO CABO GRACIAS A DIOS IN NICARAGUA ASSOCIATED WITH A WESTWARD MOVING TROPICAL WAVE. THE TRADE WINDS ARE EXPECTED TO INCREASE ACROSS THE CENTRAL CARIBBEAN ON WEDNESDAY. ATLANTIC OCEAN... CLOUDINESS WITH EMBEDDED MODERATE CONVECTION BETWEEN THE NORTHERN LEEWARD ISLANDS AND BERMUDA ARE ASSOCIATED WITH A TROPICAL WAVE MOVING ACROSS THE EASTERN CARIBBEAN WHICH IS INTERACTING WITH AN UPPER LOW CENTERED NEAR 25N63W. SURFACE PRESSURES REMAIN HIGH IN THE AREA AND TROPICAL CYCLONE FORMATION IS NOT EXPECTED. A BAND OF SHOWERS AND THUNDERSTORMS PRIMARILY ASSOCIATED WITH A LOW PRESSURE AREA ALONG A FRONTAL ZONE EXTENDS FROM THE NORTHERN BAHAMAS NORTHEASTWARD OVER THE ATLANTIC. THE LOW IS LOCATED NEAR 31N74W. THERE ARE NO SIGNS OF TROPICAL DEVELOPMENT AT THIS TIME...HOWEVER...THERE IS A POTENTIAL FOR A TROPICAL DEPRESSION TO FORM DURING THE NEXT DAY OR TWO. A 1031 MB HIGH OVER THE ATLANTIC NEAR 35N45W CONTINUES TO PRODUCE MAINLY ELY SURFACE FLOW WITH FAIR WEATHER FROM 15N-30N BETWEEN 20W-50W. IN THE UPPER LEVELS...A RIDGE IS OVER THE W ATLANTIC N OF 24N AND W OF 70W. A LOW IS FURTHER E NEAR 25N63W. A LARGE HIGH IS OVER THE E ATLANTIC NEAR 20N27W. $$ GR