000 AXNT20 KNHC 120001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAR 11 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE SW CARIBBEAN... A GALE WARNING REMAINS IN EFFECT FOR THE COASTAL WATERS OF COLOMBIA FROM 11N TO 13.5N BETWEEN 74W AND 77W. SCATTEROMETER DATA CONFIRM THE PRESENCE OF THESE WINDS WHILE ALTIMETER DATA INDICATE SEA HEIGHTS FROM 11 TO 16 FT IN THE WARNING AREA. THESE HIGH WINDS ARE THE RESULT OF A STRONG PRESSURE GRADIENT BETWEEN A 1006 MB LOW ON NW COLOMBIA/E PANAMA COASTAL WATERS AND A 1029 MB HIGH PRES LOCATED EAST OF BERMUDA NEAR 36N44W. GALE CONDITIONS ARE FORECAST THROUGH THU MORNING...RESUMING AGAIN THU NIGHT AND CONTINUING THROUGH FRIDAY AFTERNOON. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLANTIC NEAR 05N09W TO 03N12W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 01N25W TO THE EQUATOR NEAR 35W TO THE COAST OF NORTHERN BRAZIL NEAR 01S44W. SCATTERED MODERATE CONVECTION IS FROM 04S TO 04N W OF 27W. ...DISCUSSION... GULF OF MEXICO... A TROUGH ALOFT STRETCHES FROM THE GREAT LAKES SW TO AN UPPER LOW OVER CENTRAL MEXICO TO A BASE OVER E PACIFIC WATERS AND PROVIDES SOUTHWESTERLY FLOW ACROSS THE GULF OF MEXICO. TROUGHING ALOFT CONTINUES TO SUPPORT A FRONTAL SYSTEM ANALYZED AS A STATIONARY FRONT FROM A 1019 MB LOW OVER NE ALABAMA SW TO SOUTHERN ALABAMA NEAR 30N88W TO A 1012 MB LOW OVER THE NW GULF NEAR 25N93W. FROM THE LOW...A COLD FRONT EXTENDS S-SW ALONG 22N92W TO THE BAY OF CAMPECHE NEAR 18N94W. LOW LEVEL MOISTURE CONVERGENCE ASSOCIATED WITH THE LOW PRESSURE ALONG WITH MOISTURE INFLOW FROM THE CARIBBEAN SUPPORT SCATTERED MODERATE CONVECTION WITHIN 75 NM OFF THE COAST FROM SOUTHERN TEXAS TO SOUTHERN-CENTRAL LOUISIANA. IN ADDITION...A LINE OF SHOWERS AND TSTMS IS OBSERVED WITHIN 120 NM AHEAD OF THE STATIONARY FRONT AND THE LOW PRESSURE. SEA FOG IS BEING REPORTED N AND NW OF THE LOW PRESSURE CENTER...COINCIDING WITH MODERATE TO HIGH GOES-13 IFR FOG PROBABILITIES. NORTH- NORTHWESTERLY FLOW OF 20 TO 25 KT CONTINUES TO DOMINATE BEHIND THE FRONT WHILE THE INFLUENCE OF ATLC SURFACE RIDGING PROVIDES SOUTHEASTERLY FLOW OF 10 TO 15 KT EAST OF THE FRONT. THE LOW WILL DRIFT N-NW TO INLAND SE TEXAS BY THU MORNING...RESULTING IN THE SLOW PROGRESSION OF THE COLD FRONT TOWARDS THE CENTRAL BASIN DURING THE NIGHT HOURS THAT DAY. ON FRIDAY MORNING THE LOW ALREADY INLAND WILL TAKE A TURN TO THE N-NE AND THE FRONT IS FORECAST TO DISSIPATE OVER THE GULF FRIDAY NIGHT...WHILE A SURFACE TROUGH DEVELOPS NW OF THE YUCATAN PENINSULA. CARIBBEAN SEA... TRADES OF 20 TO 25 KT ARE ACROSS THE CENTRAL AND EASTERN BASIN INCREASING TO GALE FORCE WINDS NEAR THE COAST OF COLOMBIA. PLEASE SEE SPECIAL FEATURES SECTION FOR DETAILS. TRADES RANGE BETWEEN 10 TO 15 KT ON THE NW CARIBBEAN SEA. ALOFT...RIDGING AND DRY AIR CONTINUE TO DOMINATE ACROSS THE ENTIRE REGION...THUS FAVORING A STABLE ENVIRONMENT THAT HINDERS THE DEVELOPMENT OF CONVECTION. HOWEVER...AT THE LOWER LEVELS...SSMI TPW IMAGERY CONTINUE TO SHOW PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE TRADES...SOME OF THEM NOW CROSSING THE UK/US VIRGIN ISLANDS... PUERTO RICO...HISPANIOLA AND JAMAICA. A HIGHER MOISTURE CONCENTRATION IS OVER THE SW BASIN ASSOCIATED WITH A LOW PRESSURE CENTERED OFF THE E PANAMA AND NW COLOMBIA COASTS. THIS MOISTURE IS ENHANCING PASSING TO SCATTERED SHOWERS LIKELY TO PERSIST DURING THE NIGHT HOURS. LITTLE CHANGE IN THE WEATHER PATTERN IS EXPECTED DURING THE NEXT TWO DAYS. ...HISPANIOLA... PATCHES OF SHALLOW MOISTURE CONTINUE TO MOVE ACROSS THE ISLAND EMBEDDED IN THE TRADE WIND FLOW. THIS MOISTURE IS SUPPORTING CLOUDINESS WITH POSSIBLE ISOLATED SHOWERS LIKELY TO CONTINUE DURING THE NIGHT HOURS. ALOFT...THE INFLUENCE OF A RIDGE AND DRY AIR FAVOR A STABLE ENVIRONMENT THAT HINDERS THE DEVELOPMENT OF CONVECTION. SIMILAR WEATHER CONDITIONS ARE FORECAST TO PERSIST THROUGH AT LEAST FRIDAY MORNING. ATLANTIC OCEAN... THE DOMINANT SURFACE FEATURE ACROSS THE ATLANTIC CONTINUES TO BE RIDGING BEING ANCHORED BY A 1029 MB HIGH PRES CENTER LOCATED NE OF BERMUDA NEAR 36N44W. VARIABLE WINDS OF 20 TO 25 KT ARE N OF 20N W OF A LINE FROM 30N48W SW TO 20N70W AND OVER THE E ATLC FROM 17N TO 27N E OF 25W. VARIABLE WINDS OF 5 TO 15 KT DOMINATE ELSEWHERE. A SURFACE TROUGH EXTENDS FROM 30N41W TO 26N51W...THOUGH NO SIGNIFICANT WEATHER IS CURRENTLY ASSOCIATED WITH THIS FEATURE. IN THE UPPER LEVELS...A CUT OFF LOW IS CENTERED NEAR 21N41W. SCATTERED TO ISOLATED SHOWERS ARE ASSOCIATED WITH THIS FEATURE MAINLY FROM 18N TO 25N BETWEEN 34W AND 46W. DURING THE NEXT COUPLE OF DAYS...THE UPPER-LEVEL LOW WILL DRIFT SLOWLY EASTWARD AND OCCASIONALLY PRODUCE SOME SHOWERS...BUT NO SIGNIFICANT SURFACE FEATURES ARE ANTICIPATED TO FORM. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS