000 AXNT20 KNHC 060602 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT JUL 06 2013 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 19N34W TO 9N34W MOVING WEST NEAR 15 KT. THE WAVE IS EMBEDDED WITHIN AN AREA OF SLIGHTLY INCREASED MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...A LARGE SAHARAN AIR LAYER SURROUNDS THE WAVE...WHICH IS INHIBITING ANY DEEP CONVECTION NEAR THE AXIS. AN AREA OF CONVECTION IS EMBEDDED WITHIN THE MONSOON TROUGH NEAR A SURFACE LOW TO THE EAST THAT MAY BE ASSOCIATED WITH THE WAVE. THE LOW WILL BE DISCUSSED WITHIN THE ITCZ/MONSOON TROUGH SECTION. TROPICAL WAVE IS ALONG 20N46W TO 12N56W. THE LOCATION OF THIS WAVE HAS ESSENTIALLY STAYED STATIONARY OVER THE PAST 24 HOURS. HOWEVER...FROM LOOKING AT MODEL POTENTIAL VORTICITY FIELDS THE WAVE IS LIKELY FARTHER WEST NEAR THE LESSER ANTILLES WHERE A SURFACE TROUGH IS ANALYZED. THIS WAVE WILL LIKELY BE RELOCATED ON THE NEXT ANALYSIS. IN ITS CURRENT LOCATION...A BROAD MOISTURE SIGNAL IS PRESENT NEAR THE WAVE. ISOLATED MODERATE CONVECTION IS FROM 13N-17N BETWEEN 46W-49W...AND FROM 16N-18N BETWEEN 53W-56W. TROPICAL WAVE IS ALONG 18N84W TO 9N81W MOVING WEST INTO CENTRAL AMERICA 15-20 KT. ONLY A WEAK MOISTURE SIGNAL IS EVIDENT NEAR THE WAVE WITH MUCH HIGHER MOISTURE CONTENT TO THE NORTH OVER THE NW CARIBBEAN. ONLY A SMALL AREA OF MODERATE CONVECTION IS NEAR THE WAVE FROM 10N-11N BETWEEN 82W-84W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF MAURITANIA NEAR 19N16W TO A 1012 MB SURFACE LOW NEAR 8N28W TO 7N35W. THE ITCZ BEGINS NEAR 7N35W AND CONTINUES ALONG 6N44W 3N51W. SCATTERED MODERATE/STRONG CONVECTION IS WEST OF THE SURFACE LOW CENTER FROM 5N-9N BETWEEN 29W-33W. SIMILAR ACTIVITY IS FROM 4N-7N BETWEEN 42W-47W...AND FROM 2N-6N BETWEEN 48W-53W. ...DISCUSSION... GULF OF MEXICO... MOIST CONDITIONS REMAIN ACROSS MUCH OF THE GULF OF MEXICO. THIS IS DUE TO A COMBINATION OF MOIST SOUTHERLY TO SOUTHEASTERLY FLOW AT THE SURFACE THROUGHOUT MUCH OF THE AREA...AND MOIST SOUTHWESTERLY AND DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE CENTRAL CONUS THAT IS PUSHING INTO THE NW GULF...AND AN UPPER LEVEL RIDGE OVER THE REMAINDER OF THE BASIN EXTENDING FROM THE BAY OF CAMPECHE NEAR 20N96W TO 31N84W. ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS ARE THROUGHOUT THE AREA EXCEPT FOR THE NW CORNER WHERE SKIES ARE CLEAR. MORE SCATTERED ACTIVITY IS FROM 22N-27N BETWEEN 89W-91W NEAR THE AREA OF STRONGEST DIFFLUENCE ALOFT. SCATTERED ACTIVITY IS ALSO THROUGHOUT THE STRAITS OF FLORIDA. A SURFACE TROUGH IS ANALYZED IN THE FAR WESTERN GULF ALONG 27N94W TO 20N96W CONTRIBUTING TO SOME OF THE ACTIVITY. THE SURFACE TROUGH IS EXPECTED TO DRIFT WEST AND NORTH OVER THE NEXT 24 HOURS WHILE MOIST CONDITIONS WILL CONTINUE TO IMPACT THE BASIN FOR AT LEAST THE NEXT DAY OR SO. CARIBBEAN SEA... MOISTURE FROM THE GULF OF MEXICO IS DRAWN OVER THE NW CARIBBEAN IN NORTHERLY FLOW ALOFT AROUND AN UPPER LEVEL RIDGE OVER THE GULF. ONLY A SMALL AREA OF SCATTERED SHOWERS/THUNDERSTORMS IS NEAR CENTRAL CUBA FROM 20N-23N BETWEEN 78W-81W. A FEW POSSIBLE ISOLATED SHOWERS ARE OVER THE REMAINDER OF WESTERN CUBA AND THE WATERS TO THE SOUTH. A TROPICAL WAVE IS MOVING INTO CENTRAL AMERICA...BUT DRY AIR IS LIMITING ANY ACTIVITY NEAR THE AXIS. THE REMAINDER OF THE BASIN IS FAIRLY DRY AS WELL WITH A FEW ISOLATED SHOWERS OVER THE NE CARIBBEAN NEAR A SURFACE TROUGH ANALYZED ALONG 22N58W TO 12N66W. THIS SURFACE TROUGH IS MORE LIKELY A TROPICAL WAVE THAT IS CURRENTLY ANALYZED FARTHER EAST. FROM THE CURRENT ANALYSIS THE TROPICAL WAVE APPEARS TO NOT HAVE MOVED MUCH IN THE LAST 24 HOURS...BUT IT LIKELY HAS MOVED AND WILL BE RELOCATED NEAR THE EASTERN CARIBBEAN ON THE NEXT ANALYSIS. ALOFT...A NARROW UPPER TROUGH EXTENDS FROM HAITI TO PANAMA...BUT IS ACCOMPANIED BY DRY AIR ALOFT. UPPER LEVEL RIDGING COVERS THE REMAINDER OF THE BASIN ALSO ACCOMPANIED BY DRY AIR ALOFT. THE WAVE MOVING INTO CENTRAL AMERICA IS EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS...WHILE THE WAVE THAT WILL BE ANALYZED NEAR THE EASTERN CARIBBEAN WILL CONTINUE WESTWARD TO WEST-NORTHWESTWARD. HISPANIOLA... SHOWERS THAT WERE IMPACTING WESTERN HAITI ARE NOW MOSTLY DISSIPATED LEAVING THE ISLAND MOSTLY DRY AT THIS TIME. DRY AIR WILL CONTINUE TO KEEP CONDITIONS FAIR EXCEPT DURING PEAK DAYTIME HEATING WHERE CONVECTION IS POSSIBLE. AN AREA OF MOISTURE OVER THE FAR EASTERN CARIBBEAN IS EXPECTED TO REACH HISPANIOLA BY SUNDAY MORNING...WHICH WILL INCREASE THE CHANCE OF PRECIPITATION FOR SEVERAL DAYS AFTER. ATLANTIC OCEAN... BROAD SURFACE RIDGING DOMINATES THE WEST ATLC AROUND A 1028 MB HIGH NEAR 34N71W. THE RIDGE IS SUPPORTED BY BROAD UPPER RIDGING CENTERED NEAR 36N68W. HOWEVER...A NARROW UPPER TROUGH ALONG 80W IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS NEAR THE STRAITS OF FLORIDA FROM 23N-26N WEST OF 79W. AN UPPER LEVEL LOW IS CENTERED NEAR 23N64W SUPPORTING A FEW ISOLATED SHOWERS FROM 22N-24N BETWEEN 62W-66W. A SURFACE TROUGH IS TO THE EAST ALSO SUPPORTING ISOLATED SHOWERS FROM 17N-23N BETWEEN 57W-63W. A DISSIPATING COLD FRONT TO THE NORTH EXTENDS INTO THE AREA ALONG 31N45W TO 30N52W SUPPORTING SCATTERED SHOWERS WITHIN 45 NM EITHER SIDE. THE REMAINDER OF THE BASIN IS DOMINATED BY BROAD SURFACE RIDGING. BROAD UPPER RIDGING COVERS THE TROPICAL ATLC CENTERED NEAR 12N56W. AN UPPER TROUGH IS TO THE NORTH SUPPORTING THE FRONTAL BOUNDARY. VERY DRY AIR IS THROUGHOUT THE EAST ATLC DUE TO THE PRESENCE OF A BROAD SAHARAN AIR LAYER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON