000 AXNT20 KNHC 061155 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT AUG 06 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURE... THE REMNANTS OF EMILY CONTINUE TO IMPACT THE CENTRAL BAHAMAS. CURRENTLY A 1012 MB LOW IS ANALYZED N OF CENTRAL CUBA NEAR 23N79W MOVING NW-N NEAR 10-12 KT. A SURFACE TROUGH EXTENDS THROUGH THE LOW CENTER FROM NEAR 27N76W TO THE LOW CENTER. A LARGE CLUSTER OF MODERATE/STRONG CONVECTION HAS FLARED UP NEAR THE CENTER AND TO THE NE FROM 23N-25N BETWEEN 76W-79W. UPPER LEVEL WINDS ARE FAVORABLE FOR SOME DEVELOPMENT AND A TROPICAL DEPRESSION COULD FORM LATER TODAY. AN AIR FORCE PLANE IS SCHEDULED TO INVESTIGATE THE LOW THIS AFTERNOON. EVEN IF THE SYSTEM BECOMES A TROPICAL DEPRESSION...ENVIRONMENTAL CONDITIONS ARE ONLY MARGINAL...AND DO NOT FAVOR SIGNIFICANT INTENSIFICATION. REGARDLESS OF DEVELOPMENT...THIS DISTURBANCE WILL BRING SQUALLS AND LOCALLY HEAVY RAINFALL TO PORTIONS OF THE NORTHWESTERN BAHAMAS TODAY AS IT MOVES NORTHWARD OVER THE NORTHERN BAHAMAS AND INTO THE OPEN ATLANTIC DURING THE NEXT DAY OR TWO. ...TROPICAL WAVES... TROPICAL WAVE IS ACROSS THE CENTRAL TRPCL ATLC WITH A NEGATIVE TILT ALONG 14N36W TO 11N33W MOVING W AT 15-20 KT. SLIGHT CURVATURE IN THE LOW LEVEL WINDS IS AROUND THE WAVE AXIS ALSO INDICATED BY SATELLITE DERIVED WINDS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE IS E OF THE LESSER ANTILLES ALONG 15N51W TO 10N54W MOVING W 15-20 KT. THE WAVE IS EMBEDDED WITHIN AN AREA OF DEEP LAYER MOISTURE AND AHEAD OF A BROAD NWD SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. BROAD CYCLONIC FLOW IS ALSO AROUND THE WAVE AXIS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 12N-15N BETWEEN 50W-54W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 12N-14N BETWEEN 56W-59W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM W AFRICAN COAST NEAR 19N16W ALONG 11N20W 12N27W 11N32W. THE ITCZ CONTINUES ON THE OTHER SIDE OF A TROPICAL WAVE ALONG 11N34W 14N43W 13N51W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS OFF THE W AFRICAN COAST FROM 8N-14N BETWEEN 15W-19W MOST LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE THAT WILL MOVE OFF THE COAST DURING THE NEXT DAY. SCATTERED MODERATE CONVECTION IS FROM 6N-8N BETWEEN 22W-30W. ...DISCUSSION... GULF OF MEXICO... THE GULF OF MEXICO REMAINS MOSTLY DRY THIS MORNING INFLUENCED BY DRY AIR ALOFT BEING DRAWN FROM THE NW CARIBBEAN AROUND AN UPPER LEVEL LOW CENTERED OVER SRN MEXICO NEAR 18N96W WITH TROUGH AXIS EXTENDING TO CENTRAL FLORIDA NEAR 28N81W. AN UPPER LEVEL RIDGE CENTERED OVER TEXAS IS PROVIDING NELY FLOW OVER THE NW GULF. A WEAK PRESSURE GRADIENT IS ACROSS THE BASIN SUPPORTING WEAK E-SE FLOW. A CLUSTER OF SHOWERS/THUNDERSTORMS ARE CURRENTLY N OF THE FLORIDA KEYS FROM 24N-25N BETWEEN 81W-82W. A FEW ISOLATED SHOWERS ARE ALSO ALONG THE N CENTRAL GULF N OF 27N BETWEEN 92W-94W. EXPECT WEAK SURFACE RIDGING TO FORM OVER THE ERN PORTION OF THE BASIN OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A SURFACE TROUGH IS ACROSS THE NW CARIBBEAN FROM S OF CUBA NEAR 20N83W TO 16N84W. HOWEVER...NO STRONG SHOWER ACTIVITY IS ASSOCIATED WITH IT DUE TO STRONG DRY AIR ALOFT INDICATED BY WATER VAPOR IMAGERY. THE DRY AIR IS BEING WRAPPED AROUND AN UPPER LEVEL TROUGH ACROSS THE SRN GULF OF MEXICO. A SMALL CLUSTER OF SHOWERS/THUNDERSTORMS IS NEAR THE SRN EXTENT OF THE SURFACE TROUGH OVER HONDURAS. UPPER RIDGING COVERS THE WRN CARIBBEAN CENTERED OVER HONDURAS NEAR 15N86W. MOST OF THE SHOWER/THUNDERSTORM ACTIVITY ASSOCIATED WITH THE REMNANTS OF EMILY HAVE NOW MOVED N OF THE BASIN EXCEPT FOR A FEW SHOWERS FROM 19N-21N BETWEEN 77W-79W. SCATTERED SHOWERS/THUNDERSTORMS HAVE ALSO DEVELOPED OVER COSTA RICA AND PANAMA ASSOCIATED WITH THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS COSTA RICA TO NRN COLOMBIA. THE REMAINDER OF THE BASIN IS UNDER MOSTLY FAIR CONDITIONS WITH NE-E TRADEWIND FLOW NEAR 20 KT. A FEW ISOLATED SHOWERS ARE EMBEDDED IN THIS TRADEWIND FLOW FROM 15N-17N BETWEEN E OF 66W. ALOFT...WEAK UPPER TROUGHING COVERS THE ERN CARIBBEAN EXTENDING FROM THE ATLC. EXPECT THE SURFACE TROUGH IN THE NW CARIBBEAN TO DISSIPATE OVER THE NEXT 24 HOURS. A TROPICAL WAVE E OF THE LESSER ANTILLES WILL BEGIN TO IMPACT THE ERN CARIBBEAN DURING THE NEXT 24 HOURS. SOME SHOWER ACTIVITY IS WELL AHEAD OF THE WAVE ALMOST APPROACHING THE ISLANDS. ATLANTIC OCEAN... SHOWERS/THUNDERSTORMS ASSOCIATED WITH THE REMNANTS OF EMILY ARE IMPACTING MUCH OF THE CENTRAL BAHAMAS FROM 23N-26N BETWEEN 76W-80W. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. A CLUSTER OF ACTIVITY IS ALSO FROM 24N-27N BETWEEN 73W-75W. A LARGE AREA OF DUST IS TO THE E OF THIS AREA OF ACTIVE WEATHER BETWEEN 55W-65W. ALOFT...AN UPPER LEVEL RIDGE IS CENTERED TO THE N NEAR 32N75W WHILE UPPER LEVEL TROUGHING IN THE SRN GULF EXTENDS ACROSS CENTRAL FLORIDA. AN UPPER LEVEL TROUGH TO THE NE ALONG 55W THAT EXTENDS SWD TO 30N SUPPORTS A FRONTAL BOUNDARY N OF THE AREA THAT IS ENHANCING SCATTERED SHOWERS/THUNDERSTORMS N OF 29N BETWEEN 50W-56W. A DRY UPPER LEVEL TROUGH IS ACROSS THE CENTRAL ATLC ALONG 32N42W TO 20N60W. BROAD UPPER RIDING COVERS MUCH OF THE REMAINDER OF THE BASIN CENTERED NEAR 21N39W SUPPORTING A SURFACE RIDGE AROUND A 1026 MB HIGH NEAR 33N34W. A SECOND UPPER LEVEL RIDGE IS CENTERED N OF THE CANARY ISLANDS NEAR 36N12W. ANOTHER AREA OF AFRICAN DUST EXTENDS N OF THE TROPICAL WAVES FROM 15N-20N E OF 40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON