000 AXNT20 KNHC 100552 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU SEP 10 2015 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 0515 UTC. ...SPECIAL FEATURES... TROPICAL STORM HENRI IS CENTERED NEAR 31.1N 60.7W AT 10/0300 UTC OR ABOUT 215 NM E-SE OF BERMUDA MOVING N AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE CONVECTION IS FROM 30N-33N BETWEEN 56W-60W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 09N30W TO 18N28W MOVING W AT 15 KT. THE WAVE COINCIDES WITH A RELATIVELY SHARP 700 MB TROUGH AND A MAXIMUM IN 850 MB RELATIVE VORTICITY STRETCHED WITHIN 120 NM EITHER SIDE OF THE WAVE AXIS. NO SIGNIFICANT DEEP CONVECTION IS OCCURRING WITH THE WAVE AT THIS TIME. SURFACE TROUGHING EXTENDS FROM 13N53W TO 18N51W MOVING W AT 15- 20 KT. THE TROUGH...REMNANTS OF GRACE...CONTINUES TO SHOW A WEAK 1011 MB LOW CENTERED NEAR 14.5N52W PER A RECENT ASCAT PASS AROUND 10/0024 UTC WITH THE STRONGEST WINDS...RANGING FROM 20-25 KT...WITHIN 150 NM OF CENTER IN THE NE QUADRANT. SCATTERED MODERATE CONVECTION IS FROM 14N-16N BETWEEN 51W-55W. TROPICAL WAVE EXTENDS FROM 09N62W TO 15N61W MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH RELATIVELY WEAK 700 MB TROUGHING BETWEEN 60W-66W WITH 850 MB RELATIVE VORTICITY MAXIMIZED FROM 10N-12N BETWEEN 60W-68W IN THE VICINITY OF THE SOUTHERN PORTION OF THE AXIS. ISOLATED MODERATE CONVECTION IS FROM 11N-14N BETWEEN 58W-67W. TROPICAL WAVE EXTENDS FROM 06N80W TO 17N76W MOVING W AT 25 KT. THE WAVE COINCIDES WITH SUBTLE 700 MB TROUGHING STRETCHING FROM OVER THE WINDWARD PASSAGE REGION ALONG THE WAVE AXIS TO OVER THE GULF OF PANAMA. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS FROM 05N-11N BETWEEN 80W-87W. SCATTERED MODERATE IS ALSO FROM 05N-09N BETWEEN 75W-78W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO 10N30W TO 10N40W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N40W TO 13N52W TO 12N61W. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS FROM 11N-16N BETWEEN 11W-17W... WITH WIDELY SCATTERED MODERATE CONVECTION ELSEWHERE FROM 05N-11N BETWEEN 08W-17W. THIS CONVECTION IS LIKELY THE NEXT TROPICAL WAVE TO EMERGE OFF THE WEST AFRICAN COAST LATER THIS MORNING. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH CONTINUES TO MOVE OVER THE OHIO AND SOUTHERN MISSISSIPPI RIVER VALLEYS THIS EVENING DIPPING SOUTHWARD TO A BASE OVER THE NW GULF WATERS NEAR 28N93W. A NARROW SHEAR AXIS ALOFT EXTENDS SOUTH-SOUTHWESTWARD TO AN UPPER LEVEL LOW CENTERED NEAR 19N95W. THE UPPER LEVEL LOW REMAINS RELATIVELY WEAK AS TWO BROAD ANTICYCLONES INFLUENCE MUCH OF THE GULF...ONE CENTERED OVER THE FLORIDA STRAITS NEAR 24N81W AND THE OTHER CENTERED OVER THE SOUTHERN BAJA CALIFORNIA PENINSULA NEAR 24N109W. GENERALLY THE ANTICYCLONIC CIRCULATIONS ARE PROVIDING THE BASIN WITH MIDDLE TO UPPER LEVEL CLOUDINESS... AND POSSIBLE ISOLATED SHOWERS STRETCHING FROM THE EASTERN BAY OF CAMPECHE N-NE TO NEAR 26N86W. OTHERWISE...SURFACE RIDGING INFLUENCES THE GULF WITH GENTLE TO MODERATE BREEZE CONDITIONS AROUND A 1015 MB HIGH CENTERED WEST OF THE TAMPA BAY REGION NEAR 27N84W. THE RIDGING IS FORECAST TO HOLD IN PLACE UNTIL LATE FRIDAY INTO SATURDAY WHEN WEAK SURFACE TROUGHING IS EXPECTED TO EXTEND ALONG THE GULF COAST FROM THE FLORIDA BIG BEND TO NEAR GALVESTON BAY. CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 23N82W AND INFLUENCES MUCH OF THE WESTERN CARIBBEAN WITH RELATIVELY DRY NORTHERLY FLOW W OF 72W. MOST ACTIVE CONVECTION REMAINS ACROSS PORTIONS OF CENTRAL AMERICA THIS EVENING IN ASSOCIATION WITH TROPICAL WAVES...ONE ALONG 79W AND THE OTHER ALONG 91W. THE TROPICAL WAVE ALONG 79W AND THE CLOSE PROXIMITY OF THE MONSOON TROUGH AXIS IS GENERATING NUMEROUS SHOWERS AND SCATTERED TSTMS S OF 11N BETWEEN 76W-87W. OTHERWISE...FARTHER EAST...ANOTHER TROPICAL WAVE ALONG 62W IS PROVIDING INCREASED MOISTURE AND CLOUDINESS FOR THE SE CARIBBEAN WITH ISOLATED SHOWERS AND TSTMS S OF 14N E OF 69W...INCLUDING THE ABC ISLANDS...AND PORTIONS OF THE WINDWARD ISLANDS. OTHERWISE... MODERATE TO FRESH TRADE PREVAIL WITH SLIGHTLY STRONGER WINDS NOTED S OF 13N BETWEEN 72W-77W OFF THE COAST OF COLOMBIA. ...HISPANIOLA... CURRENTLY MOSTLY CLEAR SKIES PREVAIL WITH DRY NORTHERLY FLOW ALOFT PROVIDING OVERALL STABLE CONDITIONS FOR THE OVERNIGHT PERIOD INTO THURSDAY MORNING. ATLANTIC OCEAN... MOST OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED NEAR 23N82W OVER THE FLORIDA STRAITS. THE RIDGING ALOFT SUPPORTS A 1016 MB HIGH CENTERED NEAR 29N75W PROVIDING MOSTLY FAIR CONDITIONS WITH ISOLATED SHOWERS OCCURRING WITHIN THE NW PERIPHERY FROM 27N-32N BETWEEN 67W-74W. THIS IS LIKELY ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH NOTED ON WATER VAPOR IMAGERY NEAR 30N72W AND THE PARENT UPPER LEVEL LOW CENTERED NEAR 35N67W. FARTHER EAST...TROPICAL STORM HENRI IS TRACKING GENERALLY NORTHWARD ON THE EASTERN PERIPHERY OF THE UPPER LEVEL LOW AND WITHIN THE INFLUENCE OF AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 28N55W. OTHERWISE...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF SURFACE RIDGING ANCHORED BY A 1019 MB HIGH CENTERED NEAR 30N23W AND A 1018 MB HIGH CENTERED NEAR 26N41W. ON THE NORTHERN PERIPHERY OF THIS RIDGING...A WEAKENING FRONTAL BOUNDARY EXTENDS FROM 33N20W TO 24N27W TO 30N35W TO 29N47W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN