000 AXNT20 KNHC 072351 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI AUG 07 2009 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS ALONG 9N18W TO 17N21W MOVING W NEAR 15 KT. EXAMINING THE UPPER-AIR TIME SECTION ANALYSIS FROM DAKAR SENEGAL INDICATES THAT THE WAVE PASSED DAKAR SLIGHTLY BEFORE 07/1200 UTC. OTHER INDICATIONS ARE EVIDENT ON THE 5-DAY HOVMOLLER DIAGRAM THAT VALIDATE THE POSITION ALONG WITH ADDING THIS WAVE TO THE 07/1800 UTC ANALYSIS. ALTHOUGH MOST OF THE DEEP CONVECTION HAS DISSIPATED IN THE VICINITY OF THE WAVE AXIS... SCATTERED SHOWERS ARE PRIMARILY 350 NM W OF THE WAVE AXIS. A TROPICAL WAVE IS ALONG 38W S OF 17N MOVING W NEAR 13 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. ALTHOUGH REMAINING MOSTLY EMBEDDED WITHIN THE ITCZ AXIS...DRY SAHARAN AIR AND DUST IS OBSERVED TO THE EAST AND WEST OF THE WAVE AXIS DENOTING ITS POSITION ACROSS THE CENTRAL TROPICAL ATLC. THIS SAHARAN AIR LAYER IS INHIBITING ANY DEEP CONVECTION IN THE VICINITY OF THE WAVE AXIS. HOWEVER...SCATTERED SHOWERS ARE FROM 8N-12N BETWEEN 36W-40W. A TROPICAL WAVE IS ALONG 55W S OF 15N MOVING W NEAR 15 KT. THIS WAVE IS LOW AMPLITUDE AND CONTINUES TO BE INFLUENCED BY A LOW- LEVEL SAHARAN AIR LAYER SURROUNDING THE WAVE. SCATTERED MODERATE CONVECTION IS CONFINED TO AN AREA IN CLOSE PROXIMITY TO THE ITCZ...FROM 8N-13N BETWEEN 53W-57W. A TROPICAL WAVE IS ALONG 72W S OF 20N MOVING W NEAR 13 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY ACROSS THE CENTRAL CARIBBEAN. DEEP CONVECTION IS BEING SUPPRESSED BY NORTHERLY WINDS ALOFT AND DRY AIR. HOWEVER...SCATTERED SHOWERS ARE FROM 13N-17N BETWEEN 69W-74W...AND ACROSS PORTIONS OF WRN VENEZUELA. A TROPICAL WAVE IS ALONG 91W S OF 21N MOVING W NEAR 20 KT. THIS WAVE LIES IN A BROAD AREA OF DEEP LAYER MOISTURE AS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY THAT STRETCHES FROM THE E PACIFIC REGION ACROSS NRN PORTIONS OF CENTRAL AMERICA AND SRN MEXICO INTO THE GULF OF MEXICO. TRACKING BENEATH AN AREA OF UPPER LEVEL DIFFLUENCE... SCATTERED MODERATE TO STRONG CONVECTION IS FROM 16N-22N BETWEEN 87W-92W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 12N20W 10N25W 12N36W 12N39W 12N46W 12N49W 10N54W AND INTO ERN VENEZUELA NEAR 9N61W. A CLUSTER OF SCATTERED STRONG CONVECTION IS ACROSS W AFRICA FROM 9N-15N BETWEEN 10W-15W. SCATTERED MODERATE CONVECTION IS FROM 7N-13N BETWEEN 24W-32W. A SURFACE TROUGH IS EMBEDDED IN THE ITCZ EXTENDING FROM 8N49W TO 14N45W. EAST OF THE SURFACE TROUGH AND WITHIN 150 NM EITHER SIDE OF THE AXIS...SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS OCCURRING BETWEEN 47W-64W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL TROUGHING SLICES THE GULF OF MEXICO WITH A TROUGH AXIS EXTENDING FROM THE FLORIDA BIG BEND REGION THROUGH 26N90W TO AN UPPER LEVEL LOW CENTERED NEAR 20N98W OVER E/CENTRAL MEXICO. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ACROSS MUCH OF THE ERN GULF CLUSTERED NEAR AND S OF SURFACE CONVERGENCE NEAR A SURFACE TROUGH EXTENDING FROM JACKSONVILLE FLORIDA INTO THE N/CENTRAL GULF NEAR 27N91W. MOST OF THIS ACTIVITY IS N OF 24N AND E OF 90W...INCLUDING THE SRN AND CENTRAL FLORIDA PENINSULA. THE UPPER LEVEL LOW OVER E/CENTRAL MEXICO IS GENERATING SCATTERED SHOWERS COVERING THE AREA FROM 22N-26N BETWEEN 91W-97W. UPPER LEVEL DIFFLUENCE LOCATED E OF THE TROUGH AXIS OVER THE SE GULF...ALONG WITH ATMOSPHERIC INSTABILITY IS GENERATING SCATTERED SHOWERS AND TSTMS OVER PORTIONS OF WRN CUBA AND THE YUCATAN PENINSULA...INCLUDING THE NEARBY COASTAL GULF WATERS. CARIBBEAN SEA... AN UPPER LEVEL DIFFLUENT PATTERN IS OVER THE NW CARIBBEAN AND CENTRAL AMERICA DUE TO AN UPPER LEVEL LOW CENTERED OVER E/CENTRAL MEXICO AND AN ANTICYCLONIC CIRCULATION CENTERED OVER HONDURAS. SCATTERED SHOWERS AND TSTMS CONTINUE TO BE ENHANCED OVER CENTRAL AMERICA AND THE WRN CARIBBEAN WATERS FROM 10N-22N W OF A LINE FROM THE YUCATAN CHANNEL TO CENTRAL PANAMA. THE MOST INTENSE ACTIVITY ACCORDING TO SATELLITE IMAGERY IS AN AREA COVERING FROM 11N-16N BETWEEN 82W-87W...OVER NICARAGUA AND ERN HONDURAS. THIS DIFFLUENT PATTERN AND UPPER LEVEL RIDGING IS ALSO ENHANCING SCATTERED SHOWERS AND TSTMS OVER CUBA THIS EVENING. A TROPICAL WAVE ALONG 72W IS SUPPORTING SCATTERED SHOWERS FROM 13N-17N BETWEEN 69W-74W...AND OVER PORTIONS OF WRN VENEZUELA. AS THE ITCZ AXIS EXTENDS ALONG 10N BETWEEN 57W AND 70W...SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER THE SE CARIBBEAN S OF 12N E OF 65W. FRESH TO STRONG TRADE WINDS CONTINUE ACROSS MUCH OF THE ERN AND CENTRAL CARIBBEAN. ATLANTIC OCEAN... SCATTERED SHOWERS AND TSTMS ARE FOCUSED ON THE OUTER PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE NW BAHAMAS NEAR 26N77W ACROSS THE SW NORTH ATLC. UPPER LEVEL DIFFLUENCE PROVIDED BY THE UPPER LEVEL RIDGE AND ENHANCEMENT BY SURFACE CONVERGENCE S OF A COLD FRONT N OF THE DISCUSSION AREA ALONG 32N AND TWO SURFACE TROUGHS...ONE EXTENDING FROM JACKSONVILLE FLORIDA INTO THE NE GULF OF MEXICO AND THE OTHER EXTENDING FROM 25N74W TO 30N72W ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 24N W OF 70W. ISOLATED SHOWERS ARE ALSO IN THE CENTRAL ATLC IN THE VICINITY OF A SURFACE TROUGH THAT EXTENDS FROM 25N43W TO 30N45W. THIS ACTIVITY IS LOCATED FROM 27N-31N BETWEEN 44W-50W AND CONTINUES TO BE ENHANCED BY AN UPPER LEVEL LOW CENTERED NEAR 28N44W. THE REMAINDER OF THE ATLC IS CONTROLLED BY A BROAD SURFACE RIDGE ANCHORED BY A 1028 MB SURFACE HIGH NEAR 36N45W. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL HIGH IS CENTERED E OF THE LESSER ANTILLES NEAR 17N58W ENHANCING CONVECTION ALONG THE WRN PORTION OF THE ITCZ. A SECOND UPPER LEVEL RIDGE CENTERED NEAR 22N28W IS ENHANCING CONVECTION ALONG THE ERN PORTION OF THE ITCZ. $$ HUFFMAN