000 AXNT20 KNHC 130556 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI MAR 13 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... ...GALE WARNING FOR THE SW CARIBBEAN... GALE CONDITIONS ARE CURRENTLY AFFECTING THE COASTAL WATERS OF COLOMBIA FROM 11N TO 13N BETWEEN 73W AND 75W. A 0158 AND 0250 UTC ASCAT SCATTEROMETER PASSES INDICATED 35 KT ENE WINDS RIGHT ALONG AND WITHIN 60 NM OF THE COLOMBIA COAST. THE HIGH WINDS ARE BEING CAUSED BY THE STRONG PRESSURE GRADIENT BETWEEN A 1003 MB LOW OVER NORTHERN COLOMBIA AND A 1039 MB HIGH CENTERED OVER NEW ENGLAND...IN COMBINATION WITH THE TYPICAL TOPOGRAPHICAL WIND ENHANCEMENTS NORTH OF COLOMBIA. NEAR GALE TO GALE CONDITIONS SHOULD CONTINUE THROUGH SATURDAY NIGHT. PLEASE SEE THE LATEST 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 6N11W TO 3N16W WHERE THE ITCZ BEGINS AND CONTINUES ALONG THE EQUATOR NEAR 25W THEN TO SOUTH AMERICA NEAR 48W. SCATTERED MODERATE ISOLATED STRONG CONVECTION EXISTS WITHIN 60 NM OF THE AXIS BETWEEN 15 AND 35W. SCATTERED MODERATE CONVECTION IS ALSO OCCURRING NORTH OF 03N TO THE COAST OF AFRICA BETWEEN 0W TO 05W. ...DISCUSSION... GULF OF MEXICO... A 1013 MB LOW IS CENTERED AT 29N94W IN THE NORTHWESTERN GULF OF MEXICO ACCOMPANIED BY A COLD FRONT EXTENDING SOUTHEASTWARD TO THE COAST OF YUCATAN AT 21N90W. NUMEROUS MODERATE AND ISOLATED STRONG CONVECTION IS OBSERVED FROM YUCATAN TO THE U.S. GULF COAST WITHIN 120 NM EAST OF THE FRONT BASED UPON GEOSTATIONARY IMAGERY...LIGHTNING DATA...AND THE U.S. WSR-88D RADAR NETWORK. SCATTERED MODERATE CONVECTION IS ALSO OCCURRING NORTH OF 22N TO THE TEXAS COAST BETWEEN 91W AND 95W. THE CONVECTION IS SUPPORTED BY FORCING FROM A HIGH AMPLITUDE MID- TO UPPER-LEVEL LONGWAVE TROUGH CENTERED OVER MEXICO ALONG WITH AN EMBEDDED SHORTWAVE TROUGH OVER SOUTHERN TEXAS. SURFACE NORTHERLY WINDS PEAK WEST OF THE COLD FRONT ARE 25-30 KT...AS SEEN IN THE 0254 UTC ASCAT SCATTEROMETER PASS. WINDS IN THE EASTERN HALF OF THE GULF ARE GENERALLY 10-20 KT SE. OVER THE NEXT TWO DAYS...THE FRONTAL BOUNDARY SHOULD STALL IN THE CENTRAL GULF AND WEAKEN...WHILE THE WEAK LOW MOVES NORTHWARD ALONG THE FRONT AND CROSS THE U.S. GULF COAST. THE ADVECTION OF ABUNDANT MOISTURE ALONG WITH FORCING BY THE UPPER-LEVEL TROUGH SHOULD CONTINUE TO PROVIDE THE POTENTIAL FOR CONVECTION DURING THE NEXT COUPLE OF DAYS IN THE WESTERN AND CENTRAL GULF OF MEXICO INCLUDING THE COAST OF MEXICO FROM THE BAY OF CAMPECHE TO THE U.S. GULF COAST FROM TEXAS TO THE FLORIDA PANHANDLE. CARIBBEAN SEA... OUTSIDE OF THE GALE CONDITION DESCRIBED ABOVE...THE CARIBBEAN SEA HAS NO SURFACE FEATURES OF INTEREST NOR IS THERE ANY ORGANIZED DEEP CONVECTION. A BROAD HIGH AMPLITUDE UPPER RIDGE COVERS THE CARIBBEAN WITH AN AXIS ALONG 75W...WHICH IS PROMOTING SUBSIDENCE OVER THE CARIBBEAN. THE AFOREMENTIONED STRONG PRESSURE GRADIENT FORCING THE GALE CONDITIONS NEAR COLOMBIA ARE ALSO FORCING E TO NE TRADEWINDS OF 15 TO 25 KT ACROSS ALL OF THE CARIBBEAN. LITTLE CHANGE IS EXPECTED DURING THE NEXT TWO DAYS. ...HISPANIOLA... GENERALLY FAIR SKIES WITH POSSIBLE ISOLATED FAST-MOVING SHOWERS DOMINATE THE ISLAND THIS EVENING. WINDS ALONG THE COASTS WILL BE A BRISK 20-25 KT OUT OF THE EAST-NORTHEAST. THESE CONDITIONS WILL PERSIST THROUGH AT LEAST SATURDAY NIGHT. ATLANTIC OCEAN... THE MAIN SURFACE FEATURE ACROSS THE ATLANTIC IS THE RIDGING EXTENDING FROM A 1030 MB HIGH NEAR 35N24W SOUTHWESTWARD TO A RIDGELINE ALONG 27N TO A 1039 MB HIGH OVER NEW ENGLAND. TRADEWINDS ARE GENERALLY NE 10-20 KT ACROSS MOST OF THE REGION. A COLD FRONT HAS REACHED OUR NORTHERN BORDER...EXTENDING FROM 32N58W TO 30N81W AT THE NORTHEAST FLORIDA COAST. WINDS BEHIND THE FRONT WEST OF 75W ARE NE 25-30 KT...AS OBSERVED BY SCATTEROMETER AND THE 41002 BUOY. THE FRONT IS NOT ASSOCIATED WITH ANY DEEP CONVECTION...THOUGH SCATTERED SHOWERS ARE PRESENT WITHIN 60 NM OF THE FRONT. THE FRONT WILL QUICKLY MOVE EASTWARD DURING THE NEXT COUPLE OF DAYS AND REACH DOWN TO ABOUT 25N. WINDS BEHIND THE FRONT SHOULD GENERALLY BE 20-25 KT AND CONTINUE TO PRODUCE SCATTERED SHOWERS. IN THE UPPER LEVELS...A CUT OFF LOW IS CENTERED NEAR 21N38W...THOUGH NO SURFACE COMPONENT TO THE FEATURE NOR ANY SIGNIFICANT WEATHER IS CURRENTLY PRESENT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LANDSEA