000 AXNT20 KNHC 071046 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI MAY 07 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 1015 UTC... ...TROPICAL WAVES... A SERIES OF TROPICAL WAVES ARE EMBEDDED IN THE ITCZ. ONE JUST OFF THE WEST COAST OF AFRICA ALONG 15W...A SECOND ONE ALONG 36W...AND A THIRD ONE ALONG 45W. TOTAL PRECIPITABLE WATER VALUES ARE ELEVATED NEAR THESE WAVES. SCATTERED MODERATE TO HEAVY SHOWERS ARE WITHIN 80 NM OF EACH WAVE AXIS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 5N20W 4N30W 6N40W TO 5N51W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM THE EQUATOR TO 8N BETWEEN 12W AND 25W. WIDELY SCATTERED WEAK CONVECTION WITHIN 50 NM ON EITHER SIDE OF THE ITCZ BETWEEN 33W AND 44W. ...DISCUSSION... GULF OF MEXICO... A DRY AND STABLE AIRMASS CONTINUES TO DOMINATE MOST OF THE REGION NOTED BY STRONG SUBSIDENCE ON THE WATER VAPOR IMAGERY MOSTLY CLEAR SKIES ON THE VISIBLE IMAGERY...EXCEPT FOR SOME LOW LEVEL MOISTURE BANKING UP OVER THE WESTERN GULF COAST WEST OF 95W. HOWEVER...THIS DRY AIRMASS IS KEEPING STRONG CONVECTION FROM DEVELOPING. ONLY THE REMNANTS OF A SURFACE TROUGH CONTINUE TO BRING SOME INSTABILITY TO THE NORTHEAST GULF INCLUDING THE NORTHERN FLORIDA PENINSULA. THIS TROUGH IS ANALYZED CROSSING THE CENTRAL FLORIDA PENINSULA FROM EAST TO WEST...ENTERING THE GULF NEAR 29N83W TO 26N87W. BRIEF ISOLATED WEAK SHOWERS ARE POSSIBLE WITHIN 30 NM ON EITHER SIDE OF THE REMNANT CLOUD LINE. COMPUTER MODELS INDICATE SOME WEAK CONVECTION MAY LINGER OVER THE NORTHEAST BASIN AND NORTHERN FLORIDA THROUGH LATE FRIDAY. ALSO...THE COMBINATION OF DIURNAL HEATING...AVAILABLE LOW LEVEL MOISTURE...AND INSTABILITY OVER THE SOUTHERN FLORIDA PENINSULA MAY RESULT IN AFTERNOON SHOWERS AND POSSIBLE THUNDERSTORMS SOUTH OF 27N. MARINE OBSERVATIONS SHOW A VERY WEAK SURFACE PRESSURE GRADIENT ACROSS THE GULF. CARIBBEAN SEA... AN UPPER LEVEL LOW IS OVER THE FAR SOUTHWESTERN CORNER OF THE BASIN NOTED BY EVIDENT CYCLONIC ROTATION JUST OFF THE CENTRAL COAST OF NICARAGUA. THIS FEATURE IS PRODUCING AN AREA OF SURFACE CONVERGENCE THAT IS BRINGING SCATTERED MODERATE TO STRONG CONVECTION WITHIN 200 NM OFF THE COAST OF NICARAGUA...COSTA RICA...AND PANAMA. FURTHERMORE...THIS FEATURE HAS BEEN MOVING MID/UPPER LEVEL MOISTURE ACROSS JAMAICA AND EASTERN CUBA. THUS...THIS AVAILABLE MOISTURE COMBINED WITH DIURNAL HEATING AND OROGRAPHIC EFFECT WILL PRODUCE SOME AFTERNOON SHOWERS AND POSSIBLE THUNDERSTORMS OVER THIS AREAS. SOME LOCALIZED FLOODING MAY BE POSSIBLE IN AREAS WHERE THE TERRAIN HAS BECOME SATURATED. A SURFACE TROUGH IS RIGHT OVER THE US/UK VIRGIN ISLANDS. THIS TROUGH IS ANALYZED FROM 20W62N SOUTHWEST ALONG 18N64W 16N65W. SCATTERED MODERATE TO HEAVY CONVECTION IS WITHIN 50 NM ON EITHER SIDE OF THE TROUGH. THIS TROUGH IS EXPECTED TO MOVE OVER THE ISLAND OF PUERTO RICO TODAY...PRODUCING HEAVY SHOWERS AND LOCALIZED FLOODING TO THE CENTRAL AND EASTERN PART OF THE ISLAND. ELSEWHERE OUTSIDE THESE AREAS OF ACTIVE WEATHER...DRY AND STABLE AIR ALOFT IS NOTED ON WATER VAPOR IMAGERY SUPPORTING FAIR WEATHER. MARINE OBSERVATIONS SHOW EASTERLY WINDS 10 TO 20 KT ACROSS THE BASIN WITH STRONGEST WINDS OVER THE NORTH COAST OF COLOMBIA. ATLANTIC OCEAN... A SURFACE TROUGH IS ANALYZED FROM 23W57N SOUTHWEST ALONG 21N59W 18N59W. SCATTERED MODERATE TO HEAVY CONVECTION IS WITHIN 50 NM ON EITHER SIDE OF THE TROUGH. THE REMNANTS OF A SURFACE TROUGH CONTINUE TO PRODUCE WEAK CONVECTION OVER THE FAR WESTERN BASIN NORTH OF 28N WEST OF 70W. THE TAIL END OF A COLD FRONT IS OVER THE NORTH CENTRAL ATLANTIC FROM 32N30W TO 29N40W. WEAK SCATTERED SHOWERS ARE WITHIN 60 NM ON EITHER SIDE OF THE FRONT. NO SIGNIFICANT ACTIVITY IS DEVELOPING ELSEWHERE OUTSIDE THESE AREAS OF ACTIVE WEATHER...DUE TO AN UPPER LEVEL RIDGE OVER THE WEST AND CENTRAL BASIN SUPPORTING A NEARLY STATIONARY 1020 MB HIGH CENTERED NEAR 32N50W. OVER THE NEXT 24 HOURS EXPECT THE FRONT TO MOVE SOUTHEAST WITH SHOWERS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA