000
AXNT20 KNHC 111048
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...THE ITCZ/THE MONSOON TROUGH...                                
 
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLC NEAR 06N11W TO 05N23W WHERE THE ITCZ BEGINS AND CONTINUES 
ALONG 04N37W TO 02N50W. SCATTERED MODERATE CONVECTION AND 
ISOLATED TSTMS ARE FROM 03N-06N E OF 33W. A DIFFLUENT 
ENVIRONMENT ALOFT IS ENHANCING SIMILAR CONVECTION FROM 07N TO 
15N BETWEEN 30W-41W.

...DISCUSSION...

GULF OF MEXICO...                                         

MIDDLE- TO UPPER-LEVEL RIDGING CONTINUES TO DOMINATE ACROSS THE 
BASIN...THUS SUPPORTING A SURFACE RIDGE ANCHORED BY A 1028 MB 
HIGH PRESSURE CENTER OVER WISCONSIN. 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 EPAC SW FLOW SUPPORT BROKEN 
TO OVERCAST. N-NE WIND FLOW IN THE RANGE OF 5-10 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 DOMINICAN REPUBLIC WHERE IT TRANSITIONS TO A DISSIPATING 
STATIONARY FRONT TO COASTAL WATERS OF NICARAGUA NEAR 12N82W. 
ISOLATED SHOWERS ARE WITHIN 100 NM EITHER SIDE OF THE 
DISSIPATING STATIONARY FRONT. OVER THE SW BASIN...A 1009 MB LOW 
IS OFF THE COAST OF COLOMBIA WHICH IS ENHANCING SCATTERED 
SHOWERS S OF 13N BETWEEN 75W-84W. ELSEWHERE...AN OVERALL STABLE 
ENVIRONMENT...INCLUDING DRY AIR SUBSIDENCE FROM ALOFT SUPPORTS 
FAIR WEATHER. TRADES OF 15 KT DOMINATE ACROSS THE EASTERN AND 
CENTRAL CARIBBEAN INCREASING TO 20 KT ALONG THE COAST OF 
COLOMBIA AND VENEZUELA. SURFACE RIDGING ACROSS THE GULF OF 
MEXICO SUPPORT NORTHERLY FLOW OF 15 KT OVER THE NW CARIBBEAN. 
THE FRONT AND THE LOW IN THE SW BASIN ARE FORECAST TO VANISH 
LATER TODAY.
                             
HISPANIOLA...                                                   

SHALLOW MOISTURE ASSOCIATED WITH A FRONTAL BOUNDARY EXTENDING 
FROM THE SW N ATLC...ACROSS THE NW ISLAND TO COASTAL WATERS OF 
NICARAGUA ENHANCES ISOLATED SHOWERS ACROSS HAITI...THE WINDWARD 
PASSAGE AND NORTHERN COASTAL WATERS. THESE SHOWERS ARE FORECAST 
TO CEASE LATER THIS MORNING AS THE PORTION OF THE FRONT OVER THE 
ISLAND AND THE CARIBBEAN SEA VANISHES.
 
ATLANTIC OCEAN...    

A LOW PRESSURE SYSTEM IS OVER THE NW ATLC FROM WHICH A COLD 
FRONT EXTENDS INTO THE SW N ATLC ALONG 30N60W TO NW HISPANIOLA 
WHERE IT TRANSITIONS INTO A DISSIPATING STATIONARY FRONT TO 
COASTAL WATERS OF NICARAGUA. SCATTERED SHOWERS AND ISOLATED 
TSTMS ARE WITHIN 100 NM E OF THE FRONT N OF 24N. FARTHER 
EAST...SURFACE RIDGING DOMINATES THE CENTRAL ATLC. HOWEVER...A 
WEAKNESS IN THE RIDGE IS BEING ANALYZED AS A SURFACE TROUGH 
ALONG 28N52W TO 18N58W LACKING CONVECTION. OVER THE EASTERN 
BASIN...A MID- TO UPPER-LEVEL CYCLONE CONTINUES TO SUPPORT A 
1012 MB LOW NEAR 27N38W WHICH AT THE TIME LACKS CONVECTION. A 
DIFFLUENT ENVIRONMENT ALOFT E-NE OF THE LOW SUPPORT SCATTERED 
MODERATE CONVECTION AND ISOLATED TSTMS FROM 26N-35N E OF 32W. BY 
FRIDAY NIGHT...THE FRONT OVER THE SW N ATLC DISSIPATES WHILE A 
REINFORCING COLD FRONT ENTERS THE REGION. THE LOW OVER THE 
EASTERN ATLC WILL WEAKEN INTO A SURFACE TROUGH FRIDAY.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR