000 AXNT20 KNHC 111759 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUN 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A NEW TROPICAL WAVE WILL BE ADDED TO THE 1800 UTC SFC MAP ALONG 45W S OF 12N BASED ON SATELLITE PICTURES AND THE SSMI-DERIVED TPW THAT SHOWS A PEAK OF MOISTURE IN THIS AREA. IN ADDITION... 850 MB SATELLITE DERIVED VORTICITY ALSO SUPPORTS THE POSITION OF THE WAVE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM EITHER SIDE OF WAVE AXIS FROM 5N-10N. A TROPICAL WAVE IS ALONG 57W S OF 17N MOVING W 10-15 KT. A TINY 1012 MB SFC LOW HAS DEVELOPED ALONG THE WAVE AXIS NEAR 10N. SAT IMAGERY SHOWS A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION ON THE WEST SIDE OF THE LOW WITH LINES OF LOW LEVEL CLOUDS SPINNING AROUND. THIS SYSTEM SHOWS UP VERY WELL ON THE UW-CIMMS TPW PRODUCT WHERE A BULGE OF MOISTURE IS OBSERVED. THE WIND SHIFT ASSOCIATED WITH THIS FEATURE IS CLEARLY DEFINED ON SFC DATA. MOISTURE ASSOCIATED WITH THIS TROPICAL WAVE AND ITS SFC LOW WILL AFFECT THE WINDWARD ISLANDS THIS AFTERNOON THROUGH AT LEAST THU. DEVELOPMENT IS NOT EXPECTED BEFORE THE SYSTEM MOVES INTO VENEZUELA OVERNIGHT. A TROPICAL WAVE IS OVER THE YUCATAN PENINSULA AND GUATEMALA. IT AXIS IS ALONG 90W/91W S OF 24N MOVING W NEAR 15 KT. WAVE REMAINS EMBEDDED WITHIN AN AREA OF DEEP LAYERED MOISTURE AS DEPICTED ON THE MIMIC-TPW ANIMATION. SCATTERED SHOWERS AND TSTMS ARE JUST BEHIND OF THE WAVE AXIS. THIS ACTIVITY AFFECTED CANCUN AND COZUMEL A FEW HOURS AGO. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 5N30W 10N54W 10N59W 9N62W. THERE ARE SOME SIGNS THAT A NEW TROPICAL WAVE EMERGED FROM AFRICA EARLY THIS MORNING. SATELLITE IMAGERY SHOWS AN AREA OF MODERATE TO ISOLATED STRONG CONVECTION COVERING FROM 4N-10N BETWEEN 16W-22W. CURRENTLY...LOW LEVEL SATELLITE DERIVED WIND INDICATES SOME WIND SHIFT AROUND 20W. WILL WAIT FOR THE 1800 UTC DATA TO HAVE BETTER INDICATIONS. THE REMAINDER OF THE CONVECTION ALONG THE ITCZ IS MAINLY ASSOCIATED WITH THE TROPICAL WAVES AFOREMENTIONED. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...A 1020 MB SFC HIGH IS CENTERED OVER THE W ATLANTIC NEAR 29N71W EXTENDING A RIDGE OVER MOST OF THE GULF REGION. UNDER THIS PATTERN...LIGHT TO MODERATE SE WINDS DOMINATES THE AREA...BUT WINDS ARE EXPECTED TO INCREASE LATE TODAY THROUGH FRI ACROSS THE WESTERN GULF IN RESPONSE TO A DEVELOPING LOW PRES SYSTEM OVER CENTRAL PLAINS. SFC PRESSURES ARE LOWER OVER THE BAY OF CAMPECHE...AND A SFC TROUGH IS ANALYZED THERE. SCATTERED SHOWERS AND TSTMS ARE OVER THE YUCATAN PENINSULA AND COASTAL WATERS ASSOCIATED WITH THE N END OF A TROPICAL WAVE MOVING WWD ACROSS THE AREA. SIMILAR CONVECTIVE ACTIVITY IS NEAR 26N86W WITH LIGHTNING DATA INDICATING SCATTERED TSTMS. ALL THIS ACTIVITY IS BEING ENHANCED BY A SHORT WAVE TROUGH ALOFT LOCATED OVER THE SE GULF AND THE YUCATAN PENINSULA. CARIBBEAN... HIGH PRES N OF THE AREA IS PRODUCING LIGHT TO MODERATE TRADE WINDS ACROSS THE BASIN. A QSCAT PASS FROM THIS MORNING INDICATED E WINDS OF 15-20 KT...OCCASIONALLY 25 KT JUST OFF THE COLOMBIAN COAST. SIMILAR WIND SPEEDS ARE ALSO FOUND W OF 85W BEHIND THE TROPICAL WAVE LOCATED OVER THE YUCATAN PENINSULA. A SFC TROUGH IS ANALYZED JUST OFF THE ATLANTIC COAST OF NICARAGUA WHERE THERE IS SOME SHOWER/TSTM ACTIVITY...LIKELY RELATED TO THE LOW LEVEL WIND/SPEED CONVERGENCE. THE TROPICAL WAVE ALONG 57W IS FORECAST TO REACH THE E CARIBBEAN EARLY THU. SEE ABOVE FOR DETAILS. IN THE UPPER LEVELS...MOSTLY WLY ZONAL FLOW PREVAILS WITH A FAIR AMOUNT OF UPPER LEVEL MOISTURE. A NARROW BAND OF TRANSVERSE HIGH CLOUDS EXTENDS FROM WEST TO EAST ALONG 14N/15N FROM CABO GRACIAS A DIOS ALL THE WAY TO BEYOND THE LESSER ANTILLES. ATLANTIC... TWO UPPER-LEVEL LOWS ARE OVER THE W ATLC. ONE IS MEANDERING JUST E OF THE NE COAST OF FLORIDA NEAR 30N80W...AND CONTINUES TO ENHANCE TSTM ACTIVITY OVER THE STATE OF FLORIDA AND THE NW BAHAMAS. MOSAIC DOPPLER RADAR FROM THE SE...INDICATES THAT THE STRONGEST TSTMS ARE OVER SE AND NORTHERN PORTIONS OF FLORIDA. THESE SLOW MOVING STORMS WILL BE CAPABLE PRIMARILY OF HEAVY RAINFALL AND FREQUENT LIGHTNING. THE SECOND UPPER-LEVEL LOW IS N OF THE VIRGIN ISLANDS NEAR 21N65W. CYCLONIC FLOW AROUND THIS LOW IS HELPING TO INDUCE SOME SHOWER/TSTM ACTIVITY OVER PUERTO RICO...THE UK/US VIRGIN ISLANDS AND THE SURROUNDING COASTAL WATERS. AT THE SFC...THE 1020 MB HIGH PREVIOUSLY MENTIONED DOMINATES THE AREA. A COLD FRONT EXTENDING E-W ALONG 31N CLIPS THE CENTRAL ATLC. A BROKEN BAND OF LOW/MID CLOUDS IS AHEAD OF THE FRONT N OF 28N BETWEEN 40W AND 60W. A BROAD UPPER-LEVEL TROUGH OVER THE CENTRAL ATLANTIC SUPPORTS THIS FRONT. A SFC RIDGE ANCHORED ON A HIGH SITUATED WELL N OF THE AREA IS IN CONTROL OF THE WEATHER PATTERN OVER THE E ATLC. ZONAL FLOW IS OVER THE E ATLANTIC N OF 20N AND E OF 30W. IN THE TROPICS... AN UPPER LEVEL HIGH IS CENTERED NEAR 11N40W WITH THE ANTICYCLONIC FLOW REACHING THE WINDWARD ISLANDS. THIS UPPER FEATURE IS ASSISTING IN THE DEVELOPMENT OF SHOWERS AND TSTMS RELATED TO THE ABOVE MENTIONED TROPICAL WAVES. AN INVERTED TROUGH LIES JUST SOUTH OF THE CAPE VERDE ISLANDS. $$ GR