000 AXNT20 KNHC 261137 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN MAY 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF SENEGAL NEAR 14N17W TO 6N21W 5N23W. THE ITCZ BEGINS FROM 5N23W AND CONTINUES ALONG 3N40W 3N53W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-8N BETWEEN 14W-29W. SIMILAR ACTIVITY IS FROM 9N-11N BETWEEN 43W- 49W...FROM 5N-10N BETWEEN 49W-57W...AND FROM 9N-13N BETWEEN 57W- 64W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGING SPREADS OVER THE GULF OF MEXICO WITH AXIS NEAR 90W SUPPORTING SURFACE RIDGING EXTENDING FROM A HIGH CENTER OVER THE WEST ATLC. DRY AIR ALOFT STILL COVERS A GOOD PORTION OF THE EASTERN HALF OF THE BASIN PROVIDING FAIR CONDITIONS AND CLEAR SKIES EXCEPT FOR A SMALL CLUSTER OF SHOWERS FROM 25N-26N BETWEEN 83W-85W. DIFFLUENT FLOW ALOFT AROUND THE WEST SIDE OF THE UPPER RIDGE IS PROVIDING CLOUD COVER AND POSSIBLE ISOLATED SHOWERS OVER THE WESTERN GULF WEST OF 90W. SHOWERS AND THUNDERSTORMS ARE ALSO IN THE BAY OF CAMPECHE FROM 17N-20N BETWEEN 92W-96W NEAR A SURFACE TROUGH ALONG 20N93W TO 17N94W. MAINLY EAST TO SOUTHEAST WINDS ARE THROUGHOUT THE AREA RANGING FROM 10-15 KT. A FEW 20 KT WINDS ARE PRESENT IN THE BAY OF CAMPECHE AND ALSO NEAR THE COAST OF TEXAS AND NE MEXICO. SURFACE RIDGING WILL DOMINATE THE AREA THROUGHOUT THE WEEKEND. CARIBBEAN SEA... CLEAR SKIES SPREAD ACROSS A LARGE AREA OF THE CARIBBEAN INCLUDING THE NW AND SE CORNERS. HOWEVER...A COUPLE AREAS OF SHOWERS/THUNDERSTORMS ARE STILL PRESENT. THE FIRST AREA IS IN THE SW CARIBBEAN WHERE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 9N-17N BETWEEN 80W-87W INCLUDING COSTA RICA...NICARAGUA...AND HONDURAS. IT COINCIDES WITH AN AREA OF MAXIMUM MOISTURE IN TOTAL PRECIPITABLE WATER IMAGERY. THE MONSOON TROUGH IS ALSO PLAYING A ROLE AS IT EXTENDS THROUGH COSTA RICA AND PANAMA TO NORTHERN COLOMBIA. SATELLITE IMAGERY ALSO INDICATES WHAT APPEARS TO BE MID-LEVEL CYCLONIC FLOW OVER HONDURAS NEAR 13N83W. ISOLATED SHOWERS ARE ALSO OVER SOUTHERN HISPANIOLA FROM 17N-18N BETWEEN 69W-73W. THIS IS LIKELY ASSOCIATED WITH AN UPPER LEVEL TROUGH WHOSE AXIS IS ALONG 70W. MOIST SOUTHWESTERLY FLOW ALOFT COVERS THE EASTERN CARIBBEAN EAST OF 70W...BUT ONLY A FEW ISOLATED SHOWERS ARE NOTED WITHIN THE TRADEWIND FLOW OF 15-20 KT. LITTLE CHANGE IS EXPECTED ACROSS THE BASIN. MOISTURE IS EXPECTED TO REMAIN OVER THE SW CARIBBEAN AS WELL AS THE FAR EASTERN PORTION LIKELY ASSOCIATED WITH THE UPPER TROUGH CURRENTLY ALONG 70W. AN AREA OF CONVECTION IS JUST EAST OF THE WINDWARD ISLANDS AND MAY IMPACT THE ISLANDS IF IT DRIFTS WEST. HISPANIOLA... ISOLATED SHOWERS/THUNDERSTORMS ARE ONLY OVER THE FAR SOUTHERN PORTION OF THE ISLAND FROM 17N-18N BETWEEN 69W-73W. AN UPPER LEVEL TROUGH LIES OVER THE ISLAND ALONG 70W...WHICH MAY BE CONTRIBUTING TO THE LATE ACTIVITY. AN AREA OF SHOWERS AND THUNDERSTORMS IS ALSO JUST NORTH OF THE DOMINICAN REPUBLIC. THE UPPER TROUGH SHOULD MOVE EAST OVER THE NEXT 24 HOURS...WHICH WILL BRING IN DRIER AIR ALOFT. HOWEVER...MODEL GUIDANCE INDICATES LOW-LEVEL MOISTURE EAST OF THE LESSER ANTILLES WILL BEGIN MOVING WEST AND MAY REACH HISPANIOLA WITHIN 48 HOURS. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE IN THE GULF OF MEXICO SUPPORTS SURFACE RIDGING IN THE FAR WESTERN ATLC AROUND A 1023 MB HIGH NEAR 32N76W. AN UPPER LEVEL TROUGH TO THE EAST ALONG 67W SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N64W AND CONTINUES TO 24N72W. ISOLATED SHOWERS AND THUNDERSTORMS ARE UP TO 320 NM EAST OF THE AXIS NORTH OF 25N. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO FARTHER SOUTH FROM 19N-22N BETWEEN 66W-72W. AN UPPER LEVEL RIDGE DOMINATES THE CENTRAL ATLC ALONG 49W SUPPORTING BROAD SURFACE RIDGING ACROSS THIS AREA AROUND A 1036 MB HIGH NEAR 42N41W. AN UPPER LEVEL TROUGH EXTENDS INTO THE EASTERN ATLC FROM NEAR 36N20W TO 28N44W. IT SUPPORTS A WEAK SURFACE TROUGH ALONG 29N38W TO 25N39W. ISOLATED SHOWERS ARE WITHIN 120 NM EAST OF THE AXIS. THE REMAINDER OF THE BASIN IS ALSO INFLUENCED BY SURFACE RIDGING SUPPORTED BY BROAD UPPER RIDGING ACROSS WEST AFRICA. BROAD UPPER RIDGING ALSO COVERS THE TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON