000 AXNT20 KNHC 161046 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU JUL 16 2010 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC... ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 38W FROM 7N TO 18N MOVING W NEAR 20 KT. AN EARLIER ASCAT PASS SHOWED VERY WELL THE WIND SHIFT ASSOCIATED WITH THE WAVE. SOME CYCLONIC TURNING IS ALSO NOTED ON SATELLITE IMAGERY ALON THE AXIS NEAR 12N. IN ADDITION...THE WAVE IS EMBEDDED IN A REGION OF ELEVATED VALUES IN DEEP LAYER MOISTURE SEEN IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS AND ISOLATED TSTMS ARE JUST AHEAD OF THE WAVE AXIS. A LOW AMPLITUDE TROPICAL WAVE IS ALONG 48W FROM 7N TO 15N MOVING W ABOUT 15 KT. A LARGE AREA OF DRY SAHARAN DUST ENCOMPASSES THIS SYSTEM LIMITING CONVECTION. SCATTERED SHOWERS AND ISOLATED TSTMS ARE NOTED NEAR THE NORTHERN END OF THE WAVE AXIS. A TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN ALONG 67W S OF 16N MOVING W 10-15 KT. THE WAVE IS PRODUCING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION OVER CENTRAL VENEZUELA. BUOY 42059 LOCATED IN THE EASTERN CARIBBEAN IS REPORTING E WINDS OF 10-15 KT. ...ITCZ... THE ITCZ AXIS IS ALONG 8N13W 10N26W 11N35 10N44W 10N62W. OUTSIDE OF THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES... SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 160 NM S OF AXIS E OF 18W TO THE COAST OF WEST AFRICA. SIMILAR CONVECTION IS ALSO NOTED NEAR 9N26W. ...DISCUSSION... GULF OF MEXICO... A MOSTLY DRY AND STABLE AIR MASS REMAINS OVER THE WESTERN HALF OF THE GULF OF MEXICO COURTESY OF A 1018 MB HIGH LOCATED NEAR 28N93W. HOWEVER...AN AREA OF DEEP LAYERED MOISTURE IS OVER MOST OF THE EASTERN HALF OF THE GULF INCLUDING ALSO THE FLORIDA PENINSULA...WESTERN CUBA...AND THE YUCATAN PENINSULA. THIS AREA OF MOISTURE ALONG WITH A SURFACE TROUGH EXTENDING ALONG 89W S OF 27N TO THE YUCATAN PENINSULA ARE ENHANCING SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE REGION. THE HIGH PRES WILL BE REPLACED BY A RIDGE ALONG 27N SAT NIGHT WHILE THE TROUGH WILL MOVE TO THE FAR WESTERN PORTION OF THE GULF BY SAT EVENING WHILE BECOMING DIFFUSE. NE UPPER-LEVEL WINDS ARE SEEN OVER MUCH OF THE AREA. CARIBBEAN SEA... A MOIST AND UNSTABLE AIR MASS DOMINATES MUCH OF THE CARIBBEAN SEA. CONVECTION CONTINUES TO DEVELOP NEAR THE COLOMBIAN/ PANAMANIAN LOW...ANALYZED 1011 MB NEAR 10N75W ON THE 06Z SURFACE MAP. SCATTERED TO NUMEROUS MODERATE TO ISOLATED STRONG CONVECTION IS NOTED FROM 8N-12N BETWEEN 71W-78W. THIS ACTIVITY IS AFFECTING NORTHERN COLOMBIA AND WESTERN VENEZUELA INCLUDING THE LAKE MARACAIBO. SHOWERS AND TSTMS ARE ALSO DEVELOPING OVER THE WESTERN CARIBBEAN IN ASSOCIATION WITH A SURFACE TROUGH WHICH EXTENDS ALONG 82W/83W FROM 12N TO 18N. A DIFFLUENT PATTERN ALOFT...BETWEEN AN UPPER-LEVEL HIGH OVER THE EASTERN CARIBBEAN AND AN UPPER-LEVEL LOW SPINNING OVER EASTERN CUBA...IS ENHANCING ALL THIS CONVECTIVE ACTIVITY. THE SHOWER ACTIVITY OVER THE NE CARIBBEAN IS ON INCREASE. THE SAN JUAN DOPPLER RADAR SHOWS SCATTERED TO NUMEROUS SHOWERS WITH EMBEDDED TSTMS OVER THE US/UK VIRGIN ISLANDS...PUERTO RICO AND COASTAL WATERS. EXPECT MORE SHOWER AND TSTM ACTIVITY ACROSS THE NE CARIBBEAN THIS WEEKEND AS AN UPPER-LEVEL LOW FROM THE CENTRAL ATLC MOVES SW TOWARD THAT REGION. ATLANTIC OCEAN... CURRENTLY...THE AFOREMENTIONED UPPER-LEVEL LOW IS HELPING TO INDUCE CONVECTION BETWEEN CUBA AND THE BAHAMAS AS WELL AS OVER THE FLORIDA KEYS AND THE STRAITS OF FLORIDA. THE UPPER-LOW WILL SLOWLY MOVE WWD TODAY AND SAT TOWARD THE SE PORTION OF THE GULF OF MEXICO INCREASING THE LIKELIHOOD OF SHOWERS AND TSTMS OVER SOUTH FLORIDA AS THE EASTERN SIDE OF THE UPPER LOW TRANSPORTS THE MOISTURE NORTHWARD. AN UPPER-LEVEL RIDGE EXTENDS FROM NEAR BERMUDAS TO HISPANIOLA. ANOTHER UPPER-LEVEL LOW IS OVER THE CENTRAL ATLC GENERATING A FEW SHOWERS N OF 25N BETWEEN 50W AND 60W. AN UPPER LEVEL TROUGH STRETCHES FROM THIS LOW TO NEAR 16N55W. THE UPPER TROUGH SUPPORTS A SURFACE TROUGH THAT EXTENDS FROM 22N58W TO THE N LEEWARD ISLANDS NEAR 17N62W. THIS SYSTEM IS PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS FROM 18N-22N BETWEEN 55W-65W...MORE CONCENTRATED NEAR THE NORTHERN END OF THE TROUGH AXIS. AN EARLIER ASCAT PASS INDICATED NE WINDS OF 20 TO 25 KT WITHIN AROUND 240 NM NW OF THE TROUGH AXIS. FARTHER EAST ACROSS THE ATLANTIC...SURFACE RIDGING DOMINATES THE BASIN ANCHORED BY A SERIES OF 1025 AND 1026 MB HIGHS CENTERED N OF THE DISCUSSION AREA. THE STRONGEST ONE IS LOCATED NEAR THE AZORES. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR