000 AXNT20 KNHC 110604 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST THU DEC 11 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 06N11W TO 04N19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 05N35W TO 04N51W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE WITHIN 90 NM EITHER SIDE OF THE LINES E OF 32W. A DIFFLUENT ZONE ALOFT IS ENHANCING SIMILAR CONVECTION FROM 09N TO 19N E OF 41W. ...DISCUSSION... GULF OF MEXICO... MIDDLE- TO UPPER-LEVEL RIDGING CONTINUES TO DOMINATE ACROSS THE BASIN...THUS SUPPORTING A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH PRESSURE CENTER OVER WISCONSIN AND A 1025 MB HIGH OVER ARKANSAS. THIS OVERALL STABLE ENVIRONMENT ALONG WITH MIDDLE- TO LOW-LEVEL DRY AIR CONTINUE TO SUPPORT FAIR WEATHER OVER THE REGION. ALOFT...MODERATE MOISTURE BEING ADVECTED ACROSS THE BASIN BY SW FLOW SUPPORT BROKEN TO OVERCAST SKIES S OF 27N. N-NE WIND FLOW IN THE RANGE OF 10-15 KT IS ACROSS THE REGION. SIMILAR CONDITIONS WILL PREVAIL FOR THE NEXT THREE DAYS. CARIBBEAN SEA... A LOW PRESSURE SYSTEM IS OVER THE NW ATLC BEING SUPPORTED BY A CYCLONE ALOFT WHICH EXTENDS A TROUGH SOUTHWARD TO A BASE OVER THE SW N ATLC. A COLD FRONT EXTENDS FROM THE SURFACE LOW SW TO NW HAITI WHERE IT TRANSITIONS TO A STATIONARY FRONT TO EASTERN JAMAICA TO NE NICARAGUA NEAR 14N84W. NO CONVECTION IS ASSOCIATED WITH THE FRONT AT THIS TIME. A PRE-FRONTAL TROUGH ACROSS THE SW N ATLC EXTENDS ACROSS CENTRAL HISPANIOLA...THUS ENHANCING ISOLATED SHOWERS ACROSS MOST OF THE ISLAND. A PATCH OF SHALLOW MOISTURE BEHIND THE STATIONARY FRONT CONTINUES TO ENHANCE SCATTERED SHOWERS S 17N W OF 83W. OVER THE SW BASIN...A 1009 MB LOW IS OFF THE COAST OF COLOMBIA WHICH IS ENHANCING SCATTERED SHOWERS S OF 13N BETWEEN 68W-84W. ELSEWHERE...AN OVERALL STABLE ENVIRONMENT...INCLUDING DRY AIR SUBSIDENCE FROM ALOFT SUPPORTS FAIR WEATHER. TRADES OF 10-15 KT DOMINATE ACROSS THE EASTERN AND CENTRAL CARIBBEAN INCREASING TO 20 KT ALONG THE COAST OF COLOMBIA. SURFACE RIDGING ACROSS THE GULF OF MEXICO SUPPORT NORTHERLY FLOW OF 15-20 KT OVER THE NW CARIBBEAN. THE STATIONARY FRONT AS WELL AS THE LOW IN THE SW BASIN ARE FORECAST TO DISSIPATE BY THU MORNING. HISPANIOLA... SHALLOW MOISTURE ASSOCIATED WITH A SURFACE PRE-FRONTAL TROUGH EXTENDING FROM THE SW N ATLC TO SOUTHERN HAITI ENHANCES ISOLATED SHOWERS ACROSS THE ISLAND TONIGHT. THESE SHOWERS ARE FORECAST TO CEASE THU MORNING AS BOTH...A STATIONARY FRONT ACROSS EASTERN CUBA AND THE TROUGH DISSIPATE. ATLANTIC OCEAN... A LOW PRESSURE SYSTEM IS OVER THE NW ATLC FROM WHICH A COLD FRONT EXTENDS INTO THE SW N ATLC ALONG 30N62W TO NW HAITI NEAR 19N73W WHERE IT TRANSITIONS INTO A STATIONARY FRONT TO NE NICARAGUA. A SURFACE PRE-FRONTAL TROUGH IS ALONG 30N61W TO SOUTHERN HAITI NEAR 18N72W. ISOLATED SHOWERS ARE WITHIN 20 NM EITHER SIDE OF BOTH THE FRONT AND THE TROUGH. ANOTHER SURFACE TROUGH IS ANALYZED FROM 27N54W TO 21N56W LACKING CONVECTION. OVER THE EASTERN BASIN...A MID- TO UPPER-LEVEL CYCLONE CONTINUES TO SUPPORT A 1012 MB LOW NEAR 28N37W WHICH AT THE TIME LACKS CONVECTION. FARTHER EAST...A DIFFLUENT ENVIRONMENT ALOFT SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS FROM 26N-34N BETWEEN 16W-32W. SURFACE RIDGING DOMINATES ELSEWHERE IN THE CENTRAL AND EASTERN ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR