000 AXNT20 KNHC 270517 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 27 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 ERIKA IS CENTERED NEAR 16.7N 60.2W AT 27/0300 UTC OR ABOUT 170 NM E OF ANTIGUA...MOVING W AT 15 KT. ESTIMATED CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. NUMEROUS MODERATE TO ISOLATED STRONG CONVECTION IS FROM 13N TO 17N BETWEEN 55W AND 59W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 12N TO 19N BETWEEN 54W AND 60W. PLEASE SEE THE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE CAME OFF THE WEST AFRICAN COAST EARLIER THIS AFTERNOON...WITH AXIS EXTENDING FROM 17N21W TO 08N21W. MODERATE MOISTURE IS ASSOCIATED WITH THIS WAVE AS INDICATED TPW IMAGERY. LOW-LEVEL MOISTURE CONVERGENCE SUPPORTS ISOLATED CONVECTION FROM 08N-14N BETWEEN 21W-25W. A TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC WITH AXIS EXTENDING FROM 21N39W TO 10N37W...MOVING W AT 15 KT DURING THE PAST 24 HOURS. A BROAD AREA OF MODERATE MOISTURE IS ASSOCIATED WITH THIS WAVE AS INDICATED BY TPW IMAGERY. THE PRESENCE OF A SAHARAN AIRMASS IS LIMITING SIGNIFICANT CONVECTION TO THE NORTHERN PORTION OF THE WAVE N OF 19N BETWEEN 38W-40W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W OF A TROPICAL WAVE FROM 09N23W TO A 1014 MB LOW NEAR 09N28W TO 08N39W. ASIDE THE CONVECTION ASSOCIATED WITH THE WAVE E OF THE CAPE VERDE ISLANDS...ISOLATED SHOWERS ARE WITHIN 100 NM N OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... A BROAD MID TO UPPER-LEVEL TROUGH EXTENDS FROM THE OHIO VALLEY S- SW ACROSS THE GULF WITH BASE OVER THE YUCATAN PENINSULA. THIS TROUGH SUPPORTS A STATIONARY FRONT THAT EXTENDS FROM A 1012 MB LOW CENTERED OVER SOUTH CAROLINA ACROSS NORTHERN FLORIDA TO 29N83W TO 24N88W TO 24N94W. SCATTERED MODERATE CONVECTION IS OBSERVED ALONG THE FRONT. TO THE W OF THE FRONT...A SURFACE TROUGH EXTENDS ACROSS THE BAY OF CAMPECHE FROM 25N97W TO 20N95W. SCATTERED MODERATE CONVECTION PREVAILS ACROSS THIS AREA MAINLY S OF 22N BETWEEN 91W-97W. THE PROXIMITY OF THE FRONT AND UPPER LEVEL DIFFLUENCE ARE SUPPORTING ISOLATED CONVECTION ACROSS THE SE GULF MAINLY E OF 90W. SCATTEROMETER DATA DEPICTS A LIGHT TO GENTLE NORTHERLY FLOW PREVAILING ACROSS THE BASIN. OVER THE NEXT 24 HOURS...EXPECT FOR THE STATIONARY FRONT TO WEAKEN AND BEGIN TO DISSIPATE. A LOW PRESSURE CENTER IS FORECAST TO DEVELOP OVER THE NE GULF. CARIBBEAN SEA... AN ELONGATED UPPER-LEVEL LOW EXTENDS FROM THE CENTRAL BAHAMAS S- SW ACROSS THE CENTRAL CARIBBEAN. THIS FEATURE COMBINED WITH SHALLOW MOISTURE ARE SUPPORTING ISOLATED CONVECTION ACROSS THE W AND CENTRAL CARIBBEAN MAINLY W OF 70W. A SURFACE TROUGH...REMNANT OF DANNY...PREVAILS ACROSS HAITI EXTENDING FROM 24N73W TO 17N74W. SCATTERED MODERATE CONVECTION IS OBSERVED ALONG THIS BOUNDARY MAINLY BETWEEN 19N-21N. THE PROXIMITY OF TROPICAL STORM ERIKA IS SUPPORTING ISOLATED CONVECTION ACROSS THE E CARIBBEAN AFFECTING THE LESSER ANTILLES AND PUERTO RICO. FOR MORE INFORMATION ABOUT ERIKA...PLEASE REFER TO THE SECTION ABOVE. SCATTEROMETER DATA DEPICTS LIGHT TO GENTLE TRADES ACROSS THE BASIN EXCEPT GENTLE TO MODERATE WINDS S OF 14N BETWEEN 72W- 77W. OVER THE NEXT 24 HOURS...EXPECT FOR ERIKA TO ENTER THE EASTERN PORTION OF THE BASIN WITH CONVECTION. ...HISPANIOLA... THE REMNANTS OF DANNY REMAIN ACROSS THE ISLAND IN THE FORM OF A SURFACE TROUGH SUPPORTING SCATTERED SHOWERS AND TSTMS ACROSS HAITI AND THE WINDWARD PASSAGE. OVER THE NEXT 24 HOURS...EXPECT FOR THE TROUGH TO MOVE W AWAY FROM THE ISLAND AS TROPICAL STORM ERIKA APPROACHES FROM THE E WITH CONVECTION. ATLANTIC OCEAN... THE MAIN FEATURE IN THE TROPICAL ATLANTIC IS TROPICAL STORM ERIKA. FOR MORE DETAILS PLEASE REFER TO THE SECTION ABOVE. TWO TROPICAL WAVES ARE MOVING ACROSS THE E AND CENTRAL ATLANTIC. REFER TO THE TROPICAL WAVES SECTION ABOVE FOR DETAILS. A BROAD MID TO UPPER-LEVEL TROUGH EXTENDS FROM THE OHIO VALLEY S-SW ACROSS THE GULF TO A BASE OVER THE YUCATAN PENINSULA SUPPORTING A STATIONARY FRONT THAT IS CURRENTLY EXTENDING FROM SOUTH CAROLINA...ACROSS NORTHERN FLORIDA THEN INTO THE GULF OF MEXICO. SCATTERED MODERATE CONVECTION PREVAILS S OF THE FRONT AFFECTING THE FLORIDA PENINSULA AND THE W ATLANTIC MAINLY W OF 77W. TO THE E...A SURFACE RIDGE EXTENDS ACROSS THE REMAINDER OF THE BASIN ANCHORED BY A 1020 MB HIGH PRESSURE CENTERED NEAR 27N53W AND A 1022 MB HIGH NEAR 30N27W. OVER THE NEXT 24 OURS...EXPECT FOR ERIKA TO ENTER THE E CARIBBEAN. CONVECTION WILL PREVAIL ACROSS THE W ATLANTIC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA