000 AXNT20 KNHC 201753 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUN 20 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 37W/38W S OF 13N MOVING W NEAR 15 KT. THIS PSN HAS BEEN ADJUSTED A FEW DEGREES TO THE W BASED ON AN INVERTED-V SHAPE IN THE LOW TO MID LEVEL CLOUDS. LOW-LEVEL SATELLITE DERIVED WINDS CONFIRM A PRETTY CLEAR ASSOCIATED NE-SE WIND SHIFT. CONVECTION IS MINIMAL WITH ONLY SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 240 NM EITHER SIDE OF THE WAVE AXIS. A TROPICAL WAVE IS IN THE ERN CARIBBEAN TITLED ALONG 65W/66W S OF 19N MOVING W NEAR 15 KT. WHILE THE OVERALL STRUCTURE OF THE WAVE IS NOT PARTICULARLY IMPRESSIVE...THERE STILL IS A FAIR AMOUNT OF ASSOCIATED MOISTURE. DOPPLER RADAR FROM SAN JUAN DEPICTS SCATTERED SHOWERS AND TSTMS ACROSS THE COASTAL WATERS. SIMILAR ACTIVITY IS LIKELY OCCURRING N OF 15N BETWEEN 64W-70W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N14W 9N21W 7N29W 6N41W 5N52W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 20W-30W. THIS ACTIVITY COULD BE ASSOCIATED WITH THE LEADING EDGE OF A WEAK TROPICAL WAVE JUST OFF THE COAST OF W AFRICA. THIS AREA WILL BE MONITORED AND A TROPICAL WAVE MAY BE ADDED TO THE SFC MAP DURING THE NEXT DAY OR TWO. ...DISCUSSION... THE GULF OF MEXICO... MOST OF THE GULF LIES IN A NLY UPPER FLOW REGIME BETWEEN AN UPPER HIGH CENTERED OVER S MEXICO NEAR 21N100W...A DIGGING UPPER TROUGH ACROSS THE EASTERN CONUS AND A CUT OFF LOW JUST N OF THE CENTRAL BAHAMAS. THESE UPPER WINDS ARE ADVECTING DEBRIS HIGH LEVEL CLOUDINESS INTO THE REGION FROM MESOSCALE CONVECTIVE COMPLEXES OVER THE S CENTRAL U.S. AND NE MEXICO. AT THE SFC...A WEAK 1015 MB LOW IS LOCATED OVER THE FL PANHANDLE WITH ASSOCIATED SFC TROUGHING STRETCHING SW TO 27N86W. DOPPLER RADAR DEPICTS SCATTERED SHOWERS AND TSTMS OVER N FL WITH A NARROW LINE OF ACTIVITY EXTENDING INTO THE COASTAL WATERS ALONG THE SFC TROUGH. MODEST HIGH PRES RIDGING IS BUILDING SE W OF THE LOW. THIS OVERALL WEAK PRES PATTERN IS PROVIDING THE AREA WITH LIGHT WINDS AND LOW SEAS. LOOKING AHEAD...NWP MODELS SHOW THE WEAK LOW OR TROUGH MOVING VERY SLOWLY TO THE E. THIS WILL ALLOW THE SFC FLOW TO REMAIN LIGHT THRU THE END OF THE WORK WEEK. THEREAFTER...SFC WINDS AND MOISTURE MAY INCREASE ACROSS THE SRN WATERS AS THE CARIB TROPICAL WAVE APPROACHES. THE CARIBBEAN SEA... A SPRAWLING UPPER HIGH IS CENTERED JUST E OF THE LESSER ANTILLES NEAR 14N56W WITH RIDGING STRETCHING W TO 75W. ANOTHER UPPER HIGH...CENTERED OVER S MEXICO...HAS RIDGING THAT STRETCHES E ALONG 20N TO 84W. THE ACTIVE WEATHER LIES IN THE WEAKNESS BETWEEN THESE RIDGES...INDUCED BY TROUGHING N OF THE REGION. UPPER DIFFLUENCE...MID-LEVEL ENERGY AND CONVERGENCE ASSOCIATED WITH THE ITCZ ARE LIKELY ALL FACTORS THAT HAVE IGNITED AND MAINTAINED LARGE CLUSTERS OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IN THE SW CARIB S OF 12N BETWEEN 77W-82W. AN EXTENDED SATELLITE LOOP INDICATES THAT THIS CONVECTIVE ACTIVITY FORMED AROUND 00Z OVER NW COLOMBIA. SINCE THEN...THIS LARGE CLUSTER HAS EXPANDED AND BEEN TRACKING RATHER QUICKLY WWD. SHALLOWER SCATTERED SHOWERS AND TSTMS...ASSOCIATED WITH A TROPICAL WAVE ALONG 65W/66W...IS AFFECTING A GOOD PORTION OF THE NE CARIB N OF 16N BETWEEN 64W-70W. FOR MORE DETAILS REFER TO THE TROPICAL WAVES SECTION ABOVE. TRADE WINDS ARE ON THE STRONG SIDE...20 TO 30 KT...IN THE CENTRAL CARIB. THESE STRONG WINDS ARE EXPECTED TO PERSIST AND EXPAND OVER THE NEXT COUPLE DAYS. THE ATLANTIC OCEAN... AN UPPER LOW IS SPINNING N OF THE CENTRAL BAHAMAS NEAR 27N74W. THIS LOW HAS IS DEEPENING THE LARGE SCALE UPPER TROUGHING ASSOCIATED WITH AN OCCLUDED LOW PRES SYSTEM IN THE N ATLC. A SLOW MOVING DRY FRONTAL BOUNDARY CLIPS THE NRN PORTION OF THE AREA RUNNING E-W ALONG 31N/32N BETWEEN 50W AND BERMUDA. SCATTERED SHOWERS ARE AHEAD OF THIS FRONT TRIGGERED BY A PRE-FRONTAL TROUGH ANALYZED FROM 31N47W 26N64W. ANOTHER WEAK INACTIVE TROUGH LIES FURTHER E ALONG 37W FROM 23N-30N. OTHERWISE...A SFC HIGH PRES RIDGE IS IN CONTROL RUNNING FROM A 1024 MB HIGH S OF THE AZORES NEAR 35N26W TO A 1022 MB CENTER NEAR 25N46W TO A 1021 MB CENTER NEAR 28N69W. THIS NARROW RATHER LOW-LATITUDE RIDGE IS ALLOWING WINDS TO BE LIGHT TO MODERATE ACROSS MOST OF THE ATLC DISCUSSION AREA. THE COMBINATION OF THIS HIGH PRES ALONG WITH DRY STABLE AIR ALOFT ASSOCIATED WITH AN UPPER RIDGE CENTERED NEAR 17N23W IS PROVIDING TRANQUIL CONDITIONS ACROSS THE E AND MOST OF THE TROPICAL ATLC. $$ CANGIALOSI