000 AXNT20 KNHC 172349 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE AUG 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 23N22W TO 09N29W MOVING W AT 10-15 KT. GLOBAL MODEL GUIDANCE AND POTENTIAL VORTICITY FIELDS INDICATE THAT THE SOUTHERN EXTENT OF THE WAVE IS EMBEDDED WITHIN A BROAD MONSOONAL TROUGH ACROSS THE TROPICAL ATLC S OF 16N BETWEEN 21W-36W. THE WAVE ALSO COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY E OF 31W. AFRICAN DUST IS NOTED BEHIND THE WAVE AXIS FROM 17N-28N. DUE TO THIS AREA OF DRIER AIR...NO SIGNIFICANT AREAS OF DEEP CONVECTION ARE CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE EXTENDS FROM 23N34W TO 10N40W MOVING W AT 10-15 KT. BROAD LOW-LEVEL CYCLONIC FLOW IS NOTED IN THE VICINITY OF THE WAVE WITH A LARGE SURGE OF DEEP LAYER MOISTURE LOCATED TO THE EAST AND REMAINING LARGELY ASSOCIATED WITH THE PREVIOUS TROPICAL WAVE. THE SIGNIFICANT DRY AIR TO THE EAST IS SUPPRESSING CONVECTION NEAR THE WAVE AND LIMITING IT TO THE ITCZ REGION S OF 11N. TROPICAL WAVE IS FROM 11N-23N ALONG 71W MOVING W AT 15-20 KT. BROAD LOW-LEVEL CYCLONIC FLOW IS IN THE VICINITY OF THE WAVE AXIS AS IT MOVES ACROSS THE CENTRAL CARIBBEAN. TOTAL PRECIPITABLE WATER VALUES ARE MAXIMIZED S OF 23N BETWEEN 62W-72W...WITH SCATTERED MODERATE AND ISOLATED STRONG CONVECTION OCCURRING FROM 13N-23N BETWEEN 64W-75W...INCLUDING PUERTO RICO AND HISPANIOLA. TROPICAL WAVE IS FROM 09N-21N ALONG 88W MOVING W AT 10-15 KT. THE WAVE LIES EMBEDDED WITH AN AREA OF MODERATE DEEP LAYER MOISTURE AS INDICATED ON TOTAL PRECIPITABLE WATER IMAGERY COVERING THE WESTERN CARIBBEAN SEA AND PORTIONS OF THE SOUTHERN GULF OF MEXICO. THE WAVE IS ALSO COLLOCATED WITH AN UPPER LEVEL TROUGH OVER THE NW CARIBBEAN PROVIDING DIFFLUENCE WEST OF THE WAVE AXIS WHERE SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS OCCURRING FROM 18N-22N BETWEEN 86W-92W. SCATTERED MODERATE CONVECTION IS ALSO LOCATED EAST OF THE WAVE AXIS OCCURRING S OF 19N BETWEEN 84W-88W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 18N16W 12N39W 06N56W 08N63W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-12N BETWEEN 13W-46W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION COVERS MUCH OF THE SE CONUS CENTERED OVER NORTHERN LOUISIANA AND IS PROVIDING THE GULF WITH E-NE UPPER LEVEL FLOW. EMBEDDED BENEATH THIS UPPER LEVEL RIDGE IS A 1010 MB SURFACE LOW...THE REMNANT OF T.D. FIVE...CENTERED INLAND OVER EASTERN LOUISIANA NEAR 31N90W. A SURFACE TROUGH EXTENDS SW FROM THE LOW ALONG 29N91W TO THE TEXAS COAST NEAR 27N97W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE GENERALLY REMAINING INLAND THIS EVENING OVER TEXAS AND LOUISIANA...HOWEVER...ISOLATED SHOWERS ARE OCCURRING NW OF A LINE FROM MOBILE BAY TO 26N92W TO THE MEXICO COAST NEAR 25N98W. ANOTHER WEAKER SURFACE TROUGH IS LOCATED IN THE SW GULF AND IS ANALYZED FROM 20N96W TO 23N97W. ISOLATED SHOWERS ARE S OF 23N W OF 96W. WITH THE APPROACH OF A TROPICAL WAVE ALONG 88W... INCREASED MID-LEVEL MOISTURE IS NOTED ON WATER VAPOR IMAGERY AND IS PROVIDING FOR SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE FLORIDA PENINSULA...EASTERN GULF...AND YUCATAN PENINSULA... STRETCHING INTO PORTIONS OF THE EASTERN BAY OF CAMPECHE THIS EVENING. THIS ACTIVITY LIES MAINLY EAST OF A LINE FROM THE FLORIDA BIG BEND REGION NEAR 30N83W TO 25N91W TO 18N93W. CARIBBEAN SEA... A TROPICAL WAVE IS IMPACTING THE WESTERN CARIBBEAN AND PORTIONS OF CENTRAL AMERICA EXTENDING ALONG 88W FROM NEAR CANCUN MEXICO TO EASTERN EL SALVADOR AND INTO THE EASTERN PACIFIC. THE TROPICAL WAVE ALONG WITH A SURFACE TROUGH ANALYZED TO THE SE FROM 10N82W TO 15N83W ARE GENERATING SCATTERED SHOWERS AND TSTMS SW OF A LINE FROM THE YUCATAN CHANNEL TO NORTHERN COLOMBIA NEAR 10N76W. THIS AREA...IN ADDITION TO MOST OF CENTRAL AMERICA... FALLS BENEATH AN UPPER LEVEL TROUGH WITH AXIS ALONG 87W...WHICH COLLOCATES WITH THE TROPICAL WAVE AXIS. THE STRONGEST CONVECTION IS LOCATED IN THE VICINITY OF THE SURFACE TROUGH FROM 11N-15N BETWEEN 78W-85W. FARTHER EAST...A SECOND TROPICAL WAVE IS IMPACTING THE EASTERN AND CENTRAL CARIBBEAN EXTENDING FROM THE W ATLC ACROSS CENTRAL HISPANIOLA TO ARUBA ALONG 71W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER A LARGE AREA FROM 13N-23N BETWEEN 64W-75W...INCLUDING PUERTO RICO AND HISPANIOLA. AS THE TROPICAL WAVE ALONG 71W MOVES WESTWARD...CONDITIONS REMAIN FAIR ACROSS THE LESSER ANTILLES AND THE EASTERN CARIBBEAN E OF 64W THIS EVENING DUE TO DRY AIR ASSOCIATED WITH AN UPPER LEVEL LOW CENTERED OVER THE TROPICAL N ATLC NEAR 18N52W. ATLANTIC OCEAN... A WEAK SURFACE TROUGH...REMNANTS OF A FRONTAL BOUNDARY...REMAIN IN THE W ATLC ALONG 32N65W 30N70W 30N75W 29N78W. ISOLATED SHOWERS AND TSTMS ARE WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS. ALOFT...AN UPPER LEVEL RIDGE AXIS ALONG 33N TO 60W CONTINUES TO PROVIDE NE TO E FLOW OVER THE W ATLC. A SLIGHT WEAKNESS IN THIS UPPER LEVEL RIDGE OVER THE NW BAHAMAS AND SOUTHERN FLORIDA PENINSULA IS SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS THIS EVENING FROM 23N-28N BETWEEN 75W-81W. A TROPICAL WAVE S OF 23N ALONG 71W IS SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS OVER HISPANIOLA AND PUERTO RICO AND AREAS NORTH OF THOSE ISLANDS FROM 18N-23N BETWEEN 66W-74W. FARTHER EAST...A SURFACE RIDGE DOMINATES ANCHORED BY A 1029 MB HIGH CENTERED OVER THE AZORES NEAR 40N27W. THE SURFACE RIDGE AXIS EXTENDS SW TO A 1024 MB HIGH CENTERED NEAR 29N56W THEN WSW TO 26N74W. THE RIDGE IS MAINTAINING FAIR WEATHER OVER MUCH OF THE CENTRAL AND EASTERN ATLC WITH THE SAHARAN AIR LAYER PROVIDING OVERALL STABLE CONDITIONS N OF 12N BETWEEN 32W-60W. ALOFT...AN UPPER LEVEL CYCLONE IS CENTERED E OF LESSER ANTILLES NEAR 18N52W. AN UPPER LEVEL ANTICYCLONE IS COVERING THE FAR E ATLC CENTERED NEAR 26N29W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN