000 AXNT20 KNHC 111055 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT OCT 11 2014 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 1030 UTC. ...SPECIAL FEATURES... SUBTROPICAL STORM FAY IS CENTERED NEAR 26.7N 64.7W AT 11/0900 UTC OR ABOUT 335 NM S OF BERMUDA MOVING N AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WINDS SPEED IS 50 KT WITH GUSTS TO 60 KT. THE CENTER OF FAY IS EXPECTED TO PASS EAST OF BERMUDA LATER TODAY OR EARLY SUNDAY. NUMEROUS MODERATE CONVECTION IS FROM 26N-31N BETWEEN 63W-69W. SCATTERED MODERATE CONVECTION E OF FAY N OF 26N BETWEEN 56W-63W IS BEING SUPPORTED BY A DIFFLUENT ENVIRONMENT GENERATED BY AN UPPER-LEVEL RIDGE. SEE THE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS ON THE CENTRAL ATLC WITH AXIS EXTENDING FROM 18N33W TO 6N37W...MOVING W AT 10-15 KT. THE WAVE IS ASSOCIATED WITH A BROAD AIRMASS OF LOW TO MIDDLE LEVELS HIGH MOISTURE AND COINCIDES WITH AN UPPER-LEVEL TROUGH THAT SUPPORTS NUMEROUS MODERATE/ISOLATED STRONG CONVECTION FROM 12N-17N BETWEEN 27W-35W AND SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 5N-11N BETWEEN 28W-37W. A TROPICAL WAVE FORMERLY ANALYZED ACROSS THE LESSER ANTILLES HAS BEEN RELOCATED ACCORDING TO ASCAT WIND DATA...SATELLITE IMAGERY AND MODEL GUIDANCE. THE WAVE IS ALONG 54W AND ASSOCIATED WITH A 1009 MB LOW NEAR 16N54W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 13N-16N BETWEEN 52W-55W. A TROPICAL WAVE IS OVER THE W CARIBBEAN WITH AXIS ALONG 86W... MOVING W AT 15 KT. A MIDDLE-LEVEL INVERTED TROUGH SUPPORT THE WAVE THAT IS EMBEDDED IN A DEEP LAYER MODERATE MOIST ENVIRONMENT. ISOLATED SHOWERS AND TSTMS ARE WITHIN 120 NM EITHER SIDE OF THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 9N13W AND CONTINUES TO 9N10W. THE ITCZ BEGINS NEAR 9N22W AND CONTINUES TO 9N31W. ASIDE THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS FROM 6N-9N E OF 16W AND FROM 3N-12N BETWEEN 21W-30W. WEST OF THE TROPICAL WAVE...A 1010 MB LOW IS NEAR 7N42W...WHICH IS ENHANCING SCATTERED MODERATE CONVECTION FROM 4N-9N BETWEEN 40W-46W. ...DISCUSSION... GULF OF MEXICO... A BROAD MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS ANCHORED OVER THE NORTHERN GULF...THUS SUPPORTING SURFACE RIDGING ACROSS THE BASIN BEING ANCHORED BY A 1017 MB HIGH NEAR 30N82W. EXCEPT FOR A PORTION OF THE BAY OF CAMPECHE...DEEP LAYER DRY AIR IS ACROSS THE REMAINDER BASIN...WHICH SUPPORTS CLEAR SKIES AND FAIR WEATHER. A MIDDLE TO UPPER LEVEL DIFFLUENT ENVIRONMENT IN THE SW GULF ALONG WITH A PATCH OF MODERATE MOISTURE SUPPORT ISOLATED SHOWERS AND TSTMS S OF 20N. SURFACE RIDGING WILL PERSIST THROUGH THE WEEKEND. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE W CARIBBEAN SEA WITH AXIS ALONG 86W. SEE TROPICAL WAVES SECTION ABOVE. TRAILING MOISTURE ASSOCIATED WITH THE WAVE AS WELL AS A DIFFLUENT ENVIRONMENT ALOFT ENHANCE ISOLATED SHOWERS AND TSTMS W OF 72W...INCLUDING OFFSHORE WATERS OF SOUTHERN CUBA AND THE WINDWARD PASSAGE. IN THE SW BASIN...THE MONSOON TROUGH ENHANCES SCATTERED MODERATE CONVECTION AND TSTMS S OF 12N. SIMILAR CONVECTION IS OCCURRING IN THE MONA PASSAGE. STRONG DEEP LAYER ENVIRONMENTAL SHEAR ALONG WITH DRY AIR SUPPORT CLEAR SKIES AND FAIR WEATHER ELSEWHERE. A TROPICAL WAVE ASSOCIATED WITH A SURFACE LOW PRESSURE CENTER IS EXPECTED TO ENTER THE NE CARIBBEAN BY MONDAY MORNING. ...HISPANIOLA... CURRENTLY...SHALLOW MOISTURE ALONG WITH A DIFFLUENT ENVIRONMENT IN THE MIDDLE TO UPPER LEVELS SUPPORT CLOUDINESS ACROSS THE ISLAND AS WELL AS SCATTERED SHOWERS AND TSTMS ACROSS ITS COASTAL WATERS. SIMILAR SHOWER ACTIVITY IS FORECAST FOR THE WEEKEND. ATLANTIC OCEAN... THE PRIMARY CONCERN IN THE BASIN IS SUBTROPICAL STORM FAY DISCUSSED IN THE SPECIAL FEATURES SECTION ABOVE. A WEAK SURFACE RIDGE COVERS THE W ATLC W OF 73W ANCHORED BY A 1017 MB HIGH OVER SE GEORGIA. A 1009 MB LOW IS IN THE W TROPICAL ATLC NEAR 16N53W. THIS LOW IS ASSOCIATED WITH A TROPICAL WAVE. SEE DISCUSSION ON WAVES ABOVE. SURFACE RIDGING AND FAIR WEATHER DOMINATES ELSEWHERE IN THE CENTRAL AND EASTERN ATLC N OF 20N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR