000 AXNT20 KNHC 201802 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI FEB 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE SW CARIBBEAN... A GALE WARNING WILL GO INTO EFFECT ALONG THE COAST OF COLOMBIA SATURDAY MORNING FROM 10N TO 13N BETWEEN 73.5W AND 76W. SEAS WILL RANGE FROM 9 TO 12 FT. WINDS AND SEAS ARE EXPECTED TO DIMINISH BY 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 ATLC NEAR 05N10W TO 01N20W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 01S30W TO THE NE COAST OF BRAZIL NEAR 05S37W. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM EITHER SIDE OF BOTH THE MONSOON TROUGH AND THE ITCZ. ...DISCUSSION... GULF OF MEXICO... A PAIR OF HIGH PRESSURE CENTERS OVER THE MIDDLE ATLC STATES ANCHORS A BROAD SURFACE RIDGE THAT EXTENDS FROM THE GREAT LAKES...ACROSS THE EASTERN CONUS...THE SW N ATLC AND THE GULF OF MEXICO. THIS RIDGE IS ADVECTING COLD AIR ACROSS THE FLORIDA PENINSULA AS WELL AS THE EASTERN AND CENTRAL GULF. IN TERMS OF WINDS...NORTHEASTERLY TO EASTERLY WIND FLOW IN THE RANGE OF 10 TO 20 KT COVERS THE BASIN E OF 90W...SOUTHEASTERLY TO SOUTHERLY FLOW OF 20 TO 25 KT IS ELSEWHERE W OF 90W. MOISTURE CONVERGENCE ALONG THE NW GULF COAST AND W OF 96W SUPPORT BROKEN TO OVERCAST SKIES WITH POSSIBLE ISOLATED SHOWERS...FAIR WEATHER PREVAILS ELSEWHERE. A STATIONARY FRONT ASSOCIATED WITH A CENTER OF LOW PRESSURE OVER THE CENTRAL AND SOUTHERN PLAINS EXTENDS SE ACROSS TEXAS WITH TAIL REACHING FROM 29N94W TO 28N90W. ALOFT...A RIDGE STARTING TO MOVE ACROSS THE BASIN PROVIDES NORTHWESTERLY FLOW. SURFACE RIDGING WILL CONTINUE TO DOMINATE ACROSS THE BASIN THROUGH SATURDAY NIGHT. A NEW COLD FRONT WILL ENTER THE NW TO N GULF SUNDAY MORNING. CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE FAR WESTERN ATLC WITH BASE EXTENDING ACROSS THE CENTRAL CARIBBEAN SEA. THIS TROUGH ALOFT SUPPORTS A COLD FRONT EXTENDING TO THE SW N ATLC TO NE DOMINICAN REPUBLIC WHERE IT TRANSITIONS TO A STATIONARY FRONT SW ACROSS HISPANIOLA TO 18N74W TO EASTERN JAMAICA TO COSTA RICA ADJACENT WATERS NEAR 10N82W. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE FRONT AND TROUGHING ALOFT SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS OVER HISPANIOLA AND WITHIN 100 NM EITHER SIDE OF THE FRONTAL BOUNDARY. RAINSHOWERS ARE OVER THE CENTRAL BASIN S OF 16N BETWEEN 68W AND 73W AND THE LESSER ANTILLES ASSOCIATED WITH TWO MOIST AIR MASSES MOVING ACROSS THOSE REGIONS. SHOWERS AND TSTMS ARE FORECAST FOR WESTERN PUERTO RICO THIS AFTERNOON AS THE COLD FRONT OVER THE SW N ATLC CONTINUES TO DRIFT EASTWARD. THE SURFACE RIDGE COVERING THE SW N ATLC AND THE GULF OF MEXICO IS PROVIDING NORTHEASTERLY FLOW OF 20 TO 25 KT WEST OF THE STATIONARY FRONT. TRADES OF 15 TO 20 KT DOMINATES ELSEWHERE. THE RIDGE ACROSS THE GULF OF MEXICO IS FORECAST TO DRIFT E-NE RESULTING IN AN INCREASE ON THE SURFACE PRESSURE GRADIENT IN THE SW CARIBBEAN AND THE DEVELOPMENT OF GALE FORCE WINDS. SEE SPECIAL FEATURES SECTION. ...HISPANIOLA... A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE FAR WESTERN ATLC WITH BASE EXTENDING ACROSS THE CENTRAL CARIBBEAN SEA. THIS TROUGH ALOFT SUPPORTS A COLD FRONT EXTENDING TO THE SW N ATLC TO NE DOMINICAN REPUBLIC WHERE IT TRANSITIONS TO A STATIONARY FRONT SW ACROSS HISPANIOLA TO 18N74W TO EASTERN JAMAICA TO COSTA RICA ADJACENT WATERS NEAR 10N82W. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE FRONT AND TROUGHING ALOFT SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS OVER HISPANIOLA. SHOWERS ARE FORECAST TO CONTINUE THROUGH SATURDAY MORNING. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE FAR WESTERN ATLC WITH BASE EXTENDING ACROSS THE CENTRAL CARIBBEAN SEA. A COLD FRONT IS BEING SUPPORTED BY THE TROUGH ALOFT ENTERING THE SW N ATLC ALONG 30N60W SW TO NE DOMINICAN REPUBLIC NEAR 19N70W WHERE IT TRANSITIONS TO A STATIONARY FRONT SW TO COSTA RICA ADJACENT WATERS NEAR 10N82W. SCATTERED MODERATE CONVECTION IS WITHIN 130 NM E OF THE COLD FRONT N OF 24N. SCATTERED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE COLD FRONT S OF 24N. A 1040 MB HIGH NEAR 36N34W ANCHORS A BROAD SURFACE RIDGE THAT COVERS THE REMAINDER CENTRAL AND EASTERN ATLC N OF 16N. THE FRONT WILL BECOME STATIONARY AND STARTS TO DISSIPATE SATURDAY TO SATURDAY NIGHT. A NEW COLD FRONT ENTERS THE SW N ATLC SUNDAY NIGHT TO MONDAY MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR