000 AXNT20 KNHC 271744 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAR 27 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... A STRONG PRESSURE GRADIENT EXISTS ACROSS THE SW CARIBBEAN SEA BETWEEN STRONG HIGH PRESSURE CENTERED ACROSS THE SW NORTH ATLC AND LOWER PRESSURE ACROSS THE NORTHWESTERN SOUTH AMERICAN CONTINENT. GALE FORCE NE TO E WINDS ARE OCCURRING FROM 11N-13N BETWEEN 74W-77W. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/ WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO THE EQUATOR NEAR 30W. SCATTERED MODERATE CONVECTION IS S OF 07N BETWEEN 07W-14W. ...DISCUSSION... GULF OF MEXICO... OVERALL WEST-SOUTHWESTERLY...ALMOST ZONAL...FLOW IS NOTED ALOFT OVER THE GULF BASIN THIS AFTERNOON. WATER VAPOR IMAGERY INDICATES THE SUBTROPICAL JET STREAM ADVECTING MOISTURE AND CLOUDINESS FROM THE EASTERN PACIFIC OVER CENTRAL MEXICO TO THE FLORIDA PENINSULA. A 240 NM WIDE SWATH OF MOISTURE WITH EMBEDDED AREAS OF MID-LEVEL ENERGY ARE ALONG THIS STREAM GENERATING SCATTERED SHOWERS AND TSTMS FROM BROWNSVILLE TEXAS E-NE TO 27N90W TO 29N81W..AND INTO THE SW NORTH ATLC REGION. MUCH OF THIS PRECIPITATION IS OCCURRING WITHIN THE SOUTHWESTERN PERIPHERY OF A SURFACE RIDGE ANCHORED ACROSS THE MID-ATLC COAST THAT PLACES THE GULF WITHIN PRIMARILY SE WINDS IN THE RANGE OF 15 TO 20 KT. WINDS ARE EXPECTED TO INCREASE ACROSS EASTERN PORTIONS OF THE GULF THROUGH THE EVENING AND OVERNIGHT HOURS INTO FRIDAY AND GRADUALLY DIMINISH SLIGHTLY INTO THE EARLY PART OF THE WEEKEND. BY LATE FRIDAY...THE NEXT AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE ARKLATEX REGION AND MOVE NE WITH THE ASSOCIATED COLD FRONT FORECAST TO EMERGE OFF THE TEXAS AND LOUISIANA COAST EARLY SATURDAY. CARIBBEAN SEA... NORTHWESTERLY FLOW ALOFT INFLUENCES THE CARIBBEAN BASIN WITH WATER VAPOR IMAGERY INDICATING RELATIVELY DRY AIR AND A SUBSIDENT ENVIRONMENT IN PLACE THIS AFTERNOON. TWO FEATURES ARE NOTED ACROSS THE CARIBBEAN...THE FIRST BEING A SHEAR LINE ANALYZED FROM NORTHERN HISPANIOLA NEAR 20N71W EXTENDING W-SW TO 19N78W TO 18N85W. ISOLATED SHOWERS ARE MAINLY OCCURRING WITHIN 120 NM EITHER SIDE OF THE SHEAR LINE E OF 75W...WITH THE OTHER IMPACT REMAINING STRONGER WINDS OCCURRING TO THE NORTH OF THE LINE ACROSS THE SW NORTH ATLC AND AREAS BETWEEN CUBA AND THE CAYMAN ISLANDS. THESE WINDS...NE TO E IN DIRECTION...RANGE BETWEEN 20 AND 30 KT AS CAPTURED BY EARLY MORNING SCATTEROMETER PASSES AT 27/1346 UTC AND 27/1442 UTC. THE REMAINING FEATURE IS A GALE WARNING IN EFFECT FOR THE SW CARIBBEAN WATERS OFF THE COAST OF COLOMBIA. THE STRONG PRESSURE GRADIENT CREATED BETWEEN HIGH PRESSURE CENTERED ACROSS THE SW NORTH ATLC AND LOWER PRESSURE ACROSS THE NORTHWESTERN SOUTH AMERICAN CONTINENT IS EXPECTED TO RELAX SOMEWHAT BY SATURDAY AS THE HIGH PRESSURE MOVES EASTWARD. ...HISPANIOLA... CURRENTLY A SHEAR LINE IS ANALYZED FROM 20N69W TO 19N78W AND IS PROVIDING FOCUS FOR ISOLATED SHOWERS ACROSS NORTHERN AND WESTERN PORTIONS OF THE ISLAND...INCLUDING THE NORTHERN ADJACENT COASTAL WATERS AS WELL. THIS BOUNDARY IS EXPECTED TO REMAIN DRAPED ACROSS THE REGION THROUGH LATE FRIDAY...GRADUALLY BECOMING DIFFUSE DURING THE WEEKEND. HIGHER PROBABILITY OF ISOLATED SHOWER ACTIVITY IS ANTICIPATED FOR HISPANIOLA AS THE AREA OF MAXIMUM LOW-LEVEL CONVERGENCE ALONG THE SHEAR LINE MOVES VERY LITTLE DURING THE UPCOMING EVENING AND OVERNIGHT HOURS. ATLANTIC OCEAN... MOSTLY ZONAL WESTERLY FLOW IS NOTED ON WATER VAPOR IMAGERY OVER THE SW NORTH ATLC W OF 60W THIS AFTERNOON AS HIGH PRESSURE AT THE SURFACE CONTINUES TO MOVE OFF THE MID-ATLC COAST AND PROVIDE OVERALL NE TO E WINDS IN THE RANGE OF 15 TO 25 KT. HOWEVER...A WEAK MID-LEVEL SHORTWAVE TROUGH IS FOCUSED IN THE VICINITY OF 31N80W AND WHILE LARGELY OVERSHADOWED BY THE SURFACE RIDGING IN PLACE...IS PRODUCING SCATTERED SHOWERS ACROSS THE CENTRAL FLORIDA PENINSULA INTO THE SW NORTH ATLC FROM 28N- 31N W OF 79W. FARTHER EAST...AN UPPER LEVEL TROUGH AXIS EXTENDS ALONG 57W REMAINING N OF 28N THAT SUPPORTS A COLD FRONT ANALYZED FROM 32N53W S-SW TO 24N60W BECOMING STATIONARY TO 20N69W THEN AS A SHEAR LINE ACROSS HISPANIOLA AND INTO THE NW CARIBBEAN SEA. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT N OF 26N AND WITHIN 90 NM NORTH OF THE FRONT W OF 58N. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1037 MB HIGH CENTERED NORTH OF THE AZORES NEAR 45N32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN