000
AXNT20 KNHC 200534
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SAT DEC 20 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 
0530 UTC.

...THE ITCZ/THE MONSOON TROUGH...                                

THE MONSOON TROUGH CROSSES THROUGH NORTHERN LIBERIA AND 
CONTINUES OVER THE EASTERN ATLANTIC TO NEAR 07N13W WHERE THE 
ITCZ BEGINS AND CONTINUES ALONG 06N28W TO 05N41W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 02N-07N E OF 33W. 
 
...DISCUSSION...

GULF OF MEXICO... 

UPPER-LEVEL SW TO W FLOW CONTINUES ACROSS THE BASIN ADVECTING 
MOISTURE FROM THE ITCZ IN THE EPAC TO THE GULF WATERS. A 1014 MB 
SURFACE LOW IS OVER THE NE PORTION OF THE BASIN NEAR 29N95W FROM 
WHICH A COLD FRONT EXTENDS SW TO NORTHERN MEXICO. A STATIONARY 
FRONT EXTENDS EASTWARD FROM THE SAME LOW ALONG 29N90W TO 30N87W. 
ISOLATED CONVECTION IS OBSERVED BEHIND THE FRONTS AFFECTING THE 
NORTHERN GULF WATERS WITH A MODERATE BREEZE. FAIR WEATHER AND A 
SLIGHT BREEZE PREVAILS OVER THE REMAINDER OF THE BASIN AS A 
BROAD SURFACE RIDGE COVERING THE EASTERN U.S. EXTENDS S TO THE 
GULF. A SURFACE TROUGH OVER THE W CARIBBEAN IS ENHANCING 
CONVECTION AFFECTING THE YUCATAN CHANNEL. OVER THE NEXT 24 HOURS 
EXPECT FOR THE LOW TO MOVE E-NE ALONG THE NORTHERN GULF WHILE 
WEAKENING WITH ITS ASSOCIATED COLD FRONT EXTENDING SW TO EASTERN-
CENTRAL MEXICO COASTAL WATERS. 

CARIBBEAN SEA...   

A SURFACE 1010 MB LOW IS E OF BELIZE NEAR 18N87W WITH ASSOCIATED 
TROUGH EXTENDING FROM 21N86W TO THE LOW TO 15N87W. DEEP LAYER 
MOISTURE IN THE FAR WESTERN BASIN ENHANCES MAINLY W OF 82W IS 
ENHANCING SCATTERED MODERATE CONVECTION N OF 20N W OF 83W. AN 
UPPER-LEVEL TROUGH EXTENDS ACROSS THE SE CARIBBEAN SUPPORTING 
ISOLATED CONVECTION TO DEVELOP AFFECTING THE ADJACENT WATERS OF 
THE LESSER ANTILLES AND PUERTO RICO.  FAIR WEATHER PREVAILS 
ELSEWHERE ACROSS THE BASIN SUPPORTED BY DRY AIR SUBSIDENCE FROM 
ALOFT. A SLIGHT TO GENTLE BREEZE PREVAILS ACROSS THE BASIN. OVER 
THE NEXT 24 HOURS EXPECT FOR THE LOW TO DISSIPATE. 
HOWEVER...LINGERING MOISTURE ASSOCIATED WITH IT MAY CONTINUE 
ENHANCING CONVECTION OVER THE NW BASIN THROUGH THE WEEKEND.
                             
HISPANIOLA...                   

FAIR WEATHER IS PREVAILING ACROSS THE ISLAND AS AN UPPER-LEVEL 
HIGH CONTINUES SUPPORTING SUBSIDENCE. SIMILAR CONDITIONS ARE 
EXPECTED OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...   

A BROAD MID-LEVEL TROUGH OVER THE W ATLANTIC CONTINUES TO 
SUPPORT A SURFACE PRE-FRONTAL TROUGH THAT EXTENDS FROM 31N59W TO 
27N75W. TO THE E...A 1011 MB SURFACE LOW IS CENTERED NEAR 
28N45W. ITS COLD FRONT EXTENDS FROM THE LOW TO 23N42W. A WARM 
FRONT EXTENDS N FROM THE LOW TO THE N ATLANTIC. SCATTERED 
MODERATE CONVECTION IS N OF 21N BETWEEN 38W-49W. NEAR GALE FORCE 
WINDS ARE OBSERVED E OF THE LOW CENTER FROM 26N-30N BETWEEN 41W-
45W. SURFACE RIDGING PREVAILS ACROSS THE EASTERN PORTION OF THE 
BASIN SUPPORTING FAIR WEATHER. OVER THE NEXT 24 HOURS...EXPECT 
FOR THE LOW OVER THE CENTRAL ATLANTIC TO MOVE NW N OF THE AREA 
OF DISCUSSION. CONVECTION WILL CONTINUE IN THE VICINITY OF THE 
LOW.

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

$$
ERA