000 AXNT20 KNHC 131752 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUN 13 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 LOCATED ALONG 20W MOVING W NEAR 15 KT. THIS WAVE PASSED BAMAKO ABOUT 36 HOURS AGO CLEARLY SEEN ON THE UPPER AIR TIME SECTION AND SFC PRESSURE TENDENCIES IN W AFRICA. SATELLITE PICTURES AND DERIVED WINDS SHOW LOW TO MID-LEVEL TURNING AND A FAINT INVERTED V-SHAPE ASSOCIATED WITH THIS FEATURE. CONVECTION IS MINIMAL AND LINEAR IN STRUCTURE WITHIN 180 NM EITHER SIDE OF THE AXIS FROM 6N-10N. A TROPICAL WAVE IS ALONG 55W/56W FROM 6N TO 21N MOVING QUICKLY TO THE W NEAR 25 KT. THIS LARGE WAVE HAS BEEN VERY EASY TO TRACK SINCE IT EMERGED OFF THE AFRICAN COAST SEVERAL DAYS AGO. TODAY...THE WAVE HAS LOST SOME STRUCTURE AS IT NEARS THE WRN PERIPHERY OF THE SFC SUBTROPICAL RIDGE. THERE IS A SMALL AREA OF SHOWERS AND ISOLATED TSTMS NEAR THE NRN PORTION OF THE WAVE...OTHERWISE THE SYSTEM REMAINS ABSENT OF ANY DEEP CLOUDINESS OR SIGNIFICANT SHOWER ACTIVITY. A LOW AMPLITUDE TROPICAL WAVE IS ALONG 62W S OF 11N MOVING W NEAR 15 KT. SFC OBSERVATIONS FROM THE SRN WINDWARD ISLANDS HAVE BEEN THE BEST AID IN LOCATING THIS WAVE AXIS WITH WINDS JUST RECENTLY VEERING TO THE SE AND 24-HOUR PRES FALLS CLOSE TO 2 MB. THIS SLIGHTLY ADJUSTED PSN ALSO MATCHES UP WELL WITH A SURGE OF CLOUDS MOSTLY BEHIND THE ANALYZED WAVE AXIS. SHOWER AND TSTM ACTIVITY HAS BEEN ON THE INCREASE...BUT MOSTLY EMBEDDED IN THE ITCZ FROM 9N-11N BETWEEN 56W-59W. A TROPICAL WAVE IS MOVING ACROSS CENTRAL AMERICA ALONG 84W S OF 15N MOVING W 10-15 KT. SATELLITE PICTURES AND SFC OBSERVATIONS SHOW BROAD TURNING WHICH IS PARTIALLY ASSOCIATED WITH THIS WAVE. CLUSTERS OF SCATTERED MODERATE CONVECTION IS WITHIN 150 NM E OF THE AXIS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N17W 8N22W 4N34W 3N43W 6N53W. BESIDES FOR CONVECTION ASSOCIATED WITH THE TROPICAL WAVES ...SCATTERED MODERATE IS WITHIN 150 NM N OF THE AXIS BETWEEN 36W-42W. ...DISCUSSION... THE GULF OF MEXICO... A LARGE HIGHLY ELONGATED UPPER TROUGH EXTENDS FROM THE WRN ATLC TO AN UPPER LOW OVER THE FL/GA BORDER. TROUGHING CONTINUES SW INDUCED BY ANOTHER UPPER LOW WHICH IS SPINNING IN THE ERN BAY OF CAMPECHE NEAR 21N91W. THIS LARGE SCALE TROUGH IS SUPPORTING TWO SFC BOUNDARIES WHICH CONNECT TO A SFC LOW PRES SYSTEM NE OF THE NRN BAHAMAS. THE SRN BOUNDARY IS LOCATED ACROSS THE FL STRAITS TO NEAR 25N91W...PURELY DEFINED BY WIND OBSERVATIONS SHIFTING TO THE NW...THIS HAS BECOME INCREASINGLY DIFFUSE AND WILL LIKELY BE DROPPED AT 18Z. THE MAIN BOUNDARY IS LOCATED FURTHER N FROM S FLORIDA TO A 1010 MB NEAR SE LOUISIANA. THIS BOUNDARY...ALONG WITH ENERGY FROM AN UPPER JET...IS PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 60 NM EITHER SIDE OF THE AXIS. UPPER RIDGING COVERS THE WRN HALF OF THE REGION ANCHORED BY AN UPPER HIGH CENTER OVER NRN MEXICO NEAR 25N101W WITH AN ASSOCIATED 1014 MB SFC HIGH LOCATED NEAR 27N94W. THIS PATTERN IS MAINTAINING FAIR WEATHER AND LIGHT WINDS ACROSS MUCH OF THE W GULF. THE CARIBBEAN SEA... THE ACTIVE WEATHER IN THE REGION REMAINS ACROSS THE WRN PORTION WHERE PATCHES OF SCATTERED MODERATE AND ISOLATED STRONG CONVECTION ARE GENERALLY W OF 78W AND S OF 21N. THIS ACTIVITY APPEARS TO BE INDUCED BY SEVERAL FACTORS. THE MOST PERSISTENT HAS BEEN DIFFLUENCE ALOFT BETWEEN AN UPPER LOW SPINNING OVER THE BAY OF CAMPECHE NEAR 21N91W AND A SPRAWLING RIDGE/ANTICYCLONE CENTERED NEAR 14N81W. A TROPICAL WAVE ALONG 84W S OF 15N AND A SFC TROUGH ANALYZED FROM HONDURAS TO THE WRN TIP OF CUBA ALONG 16N85W 20N85W 22N83W ARE SUPPLYING LOW-LEVEL LIFT AIDING IN THE CONVECTIVE DEVELOPMENT. ELSEWHERE...A PLUME OF MID-HIGH LEVEL CLOUDINESS AND POSSIBLE SHOWERS ARE STREAMING ACROSS THE NRN CARIB...N OF 18N...AS DEBRIS MOISTURE IS PULLED AROUND THE NRN BRANCH OF THE ANTICYCLONE. THE REMAINDER OF THE CARIB WATERS IS FREE OF SIGNIFICANT MOISTURE...ALTHOUGH TYPICAL TRADE WIND SHOWERS ARE POSSIBLE AT ANY GIVEN LOCATION...ESPECIALLY ACROSS THE SE CARIB WHERE THE ENVIRONMENT IS MOISTENED FROM THE NEARBY TROPICAL WAVE. THE ATLANTIC OCEAN... EXTENSIVE STRONG SWLY FLOW ALOFT TO THE E/SE OF A LARGE HIGHLY ELONGATED UPPER TROUGH IS PROVIDING PLENTY OF MOISTURE FOR PRECIP. THIS UPPER SYSTEM IS SUPPORTING A 1009 MB LOW CENTERED ABOUT 120 NM NE OF THE NRN BAHAMAS NEAR 28N75W. A WARM FRONT EXTENDS EWD FROM THE LOW ALONG 29N73W 29N65W. IR IMAGERY AND LIGHTNING DATA DETECT CLUSTERS OF SCATTERED SHOWERS AND TSTMS ALONG THE BOUNDARY AND IN THE WARM SECTION FROM 22N-29N BETWEEN 68W-74W. SIMILAR ACTIVITY LIES FURTHER E N OF 28N BETWEEN 57W-60W IN A DIFFLUENT ZONE BETWEEN THE EXTENSIVE TROUGHING AND RIDGING TO THE E. FARTHER E...WV IMAGERY SHOWS A WEAK SHORTWAVE RIDGE EXTENDING NEWD ALONG 23N58W 32N44W. MUCH MORE EXTENSIVE RIDGING STRETCHES W FROM AFRICA ALONG 22N TO ABOUT 30W. A WEAK SHEARED UPPER TROUGH LIES BETWEEN THESE RIDGES EXTENDING FROM 32N24W TO AN UPPER LOW NEAR 23N41W CONTINUING TO 17N51W. THE ASSOCIATED COLD FRONT REMAINS WELL N OF THE REGION. THESE UPPER FEATURES ARE ONLY PRODUCING PATCHES OF CIRRUS. ELSEWHERE....HIGH PRES DOMINATES THE AREA ANCHORED BY A NEARLY STATIONARY 1025 MB CENTER NEAR 28N39W. THIS HIGH IS AIDING IN THE MOSTLY FAIR WEATHER AND PRODUCING A LARGE AREA OF MODERATE TRADES ACROSS THE TROPICAL ATLC...ESPECIALLY BETWEEN THE HIGH ITSELF AND THE LARGE TROPICAL WAVE NOTED ALONG 55W. $$ CANGIALOSI