000
AXNT20 KNHC 201725
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
105 PM EST TUE JAN 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 
1715 UTC.

...ITCZ/MONSOON TROUGH...                                     

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLC NEAR 9N13W TO 4N20W WHERE THE ITCZ BEGINS AND CONTINUES 
ALONG 2N30W TO SOUTH AMERICA NEAR 2N51W. ISOLATED MODERATE 
CONVECTION IS FROM 1N TO 5N BETWEEN 27W AND 45W. 
 
...DISCUSSION...

GULF OF MEXICO...       

A SURFACE TROUGH EXTENDS FROM 29N88W TO 23N87W WHILE AN UPPER 
LEVEL SHORTWAVE TROUGH MOVES EASTWARD ACROSS THE E GULF. THE 
COMBINATION OF THESE FEATURES IS SUPPORTING ISOLATED MODERATE 
CONVECTION AND SHOWERS FROM 23N TO 30N BETWEEN THE FL PENINSULA 
AND 88W. A WEAK SURFACE RIDGE OF 1016 MB HAS DEVELOPED OVER THE 
SW BASIN WITH VARIABLE WINDS OF 5 TO 10 KT ACROSS THE WESTERN 
HALF OF THE GULF. EASTERLY WINDS OF 10 TO 15 KT ARE OVER THE 
EASTERN GULF. OVER THE NEXT 24 HOURS THE UPPER TROUGH WILL MOVE 
INTO THE ATLANTIC WHILE THE SURFACE TROUGH WEAKENS. 

CARIBBEAN SEA... 
                                            
BROAD UPPER RIDGE COVERS THE CARIBBEAN W OF 80W ANCHORED OVER 
SOUTH AMERICA. NO DEEP CONVECTION IS OVER THE CARIBBEAN. TRADE 
WINDS OF 10 TO 20 KT COVER THE BASIN. SCATTERED SHOWERS ARE 
OCCURRING IN THE TRADE WIND FLOW MAINLY NORTH OF 14N ACROSS THE 
CARIBBEAN AND ARE AFFECTING THE LEEWARD ISLANDS AND PUERTO 
RICO. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS. 

...HISPANIOLA...                                                 
ISOLATED SHOWERS ARE OCCURRING IN NE TRADE WIND FLOW DURING 
DAYTIME HEATING OVER THE ISLAND TODAY. CLEARING IS EXPECTED 
TONIGHT. ISOLATED SHOWERS WILL BE POSSIBLE AGAIN DURING THE DAY 
ON WEDNESDAY. 

ATLANTIC OCEAN...  

THE UPPER TROUGH OVER GULF IS PRODUCING CLOUDINESS AND LIGHT 
SHOWERS OVER THE BAHAMAS AND FL. A 1020 MB SURFACE HIGH IS 
CENTERED NEAR 29N72W. AN UPPER TROUGH ALONG 63W SUPPORTS A 
WEAKENING COLD FRONT FROM 31N57W TO 22N69W WHERE IT TRANSITIONS 
TO A DISSIPATING STATIONARY FRONT TO 21N75W. ISOLATED SHOWERS 
ARE WITHIN 100 NM OF EITHER SIDE OF THE FRONTAL BOUNDARIES. THE 
UPPER TROUGH IS ALSO SUPPORTING A 1016 MB SURFACE LOW NEAR 
26N59W. A STATIONARY FRONT EXTENDS FROM THE SURFACE LOW TO 
32N50W AND OVER THE N CENTRAL ATLANTIC. A SURFACE TROUGH EXTENDS 
FROM THE SURFACE LOW TO 20N64W. WIDELY SCATTERED MODERATE 
CONVECTION IS FROM 24N TO 32N BETWEEN 46W AND 56W. SCATTERED 
SHOWERS ARE WITHIN 50 NM OF EITHER SIDE OF THE SURFACE TROUGH. A 
1037 MB SURFACE HIGH CENTERED NEAR 43N31W IS SUPPORTING FAIR 
WEATHER ACROSS THE EASTERN ATLANTIC. OVER THE NEXT 36 HOURS THE 
CURRENT FRONTS IN THE ATLANTIC WILL DISSIPATE WITH A SURFACE 
TROUGH EXPECTED NEAR 30N50W. A NEW COLD FRONT WILL DEVELOP AND 
MOVE FROM THE SE US INTO THE WESTERN ATLANTIC.                   

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

$$
LATTO