000
AXNT20 KNHC 172343
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU DEC 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURE...

GALE-FORCE WINDS ARE FORECAST FOR THE GULF OF MEXICO ON 18/1200
UTC. EXPECT THE COLD FRONT TO EXTEND FROM 30N81W TO 23N90W TO
18N94W. THE FORECAST CONSISTS OF NORTHERLY GALE-FORCE WINDS AND
SEA HEIGHTS RANGING FROM 8 FEET TO 11 FEET TO THE SOUTH OF 24N
WEST OF FRONT TO 96W.

...ITCZ/MONSOON TROUGH...
                                   
A TROUGH EXTENDS FROM 02N AND THE PRIME MERIDIAN TO 03N03W TO
02N09W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
04N13W TO 03N29W THEN RESUMES FROM 03N32W TO 01N45W. A SURFACE
TROUGH IS EMBEDDED IN THE ITCZ FROM 08N30W TO 01N30W. ISOLATED
MODERATE CONVECTION IS FROM 03N-13N BETWEEN 23W-37W. 

...DISCUSSION...

GULF OF MEXICO...                             

AS OF 2100 UTC...A COLD FRONT IS OVER THE GULF OF MEXICO FROM
NEAR THE FLORIDA PANHANDLE AT 30N85W TO THE SW GULF AT 22N94W TO
THE BAY OF CAMPECHE AT 19N95W. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE WITHIN 60 NM OF THE FRONT. 15-25 KT N WINDS
ARE W OF FRONT. A PREFRONTAL TROUGH IS OVER THE BAY OF CAMPECHE
FROM 22N92W TO 19N93W. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE WITHIN 60 NM OF THE TROUGH. THE REMAINDER OF
THE GULF HAS 10-15 KT SE TO E WINDS AND MOSTLY FAIR WEATHER. IN
THE UPPER LEVELS...A BROAD UPPER LEVEL TROUGH IS OVER THE GULF
WITH AXIS ALONG 97W SUPPORTING THE COLD FRONT. UPPER LEVEL
MOISTURE IS OVER THE GULF EXCEPT OVER THE SE GULF WHERE STRONG
SUBSIDENCE REMAINS. EXPECT IN 18 HOURS FOR THE COLD FRONT TO
EXTEND FROM JACKSONVILLE FLORIDA TO THE BAY OF CAMPECHE WITH
SHOWERS AND THUNDERSTORMS. ALSO EXPECT GALE FORCE WINDS W OF
FRONT. SEE ABOVE. 

CARIBBEAN SEA...                                              

10-25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST
WINDS N OF VENEZUELA. IN THE UPPER LEVELS...AN UPPER LEVEL LOW
IS CENTERED N OF PUERTO RICO NEAR 21N67W. A TROUGH AXIS EXTENDS
S TO VENEZUELA NEAR 10N66W. SCATTERED SHOWERS WITH ISOLATED
THUNDERSTORMS ARE S OF 20N BETWEEN 60W-75W. EXPECT THE UPPER
LEVEL LOW TO BE OVER HISPANIOLA IN 24 HOURS. ALSO EXPECT
CONTINUED SHOWERS OVER THE EASTERN AND CENTRAL CARIBBEAN. 

...HISPANIOLA...  

SCATTERED SHOWERS ARE PRESENTLY OVER E HISPANIOLA DUE TO THE
UPPER LEVEL SYSTEM. EXPECT OVER THE NEXT 24 HOURS FOR CONTINUED
SHOWERS MOSTLY S OF THE ISLAND.   

ATLANTIC OCEAN...                                          

A COLD FRONT IS OVER THE CENTRAL ATLANTIC FROM 31N36W TO 25N50W
TO 25N64W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT. A
PREFRONTAL TROUGH EXTENDS FROM 28N36W TO 23N44W. SCATTERED
SHOWERS ARE WITHIN 60 NM OF THE TROUGH. A 1019 MB HIGH IS
CENTERED OVER THE CENTRAL ATLANTIC NEAR 22N49W. ANOTHER 1022 MB
HIGH IS CENTERED OVER THE EASTERN ATLANTIC NEAR 23N31W PRODUCING
FAIR WEATHER. A SURFACE TROUGH IS ALSO OVER THE E ATLANTIC FROM
24N20W TO 16N19W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE
TROUGH. OF NOTE IN THE UPPER LEVELS...A VERY LARGE UPPER LEVEL
TROUGH IS OVER THE ATLANTIC N OF 25N BETWEEN25W-60W SUPPORTING
THE SURFACE FRONT. EXPECT OVER THE NEXT 24 HOURS FOR THE COLD
FRONT TO MOVE E. ALSO EXPECT IN 24 HOURS FOR ANOTHER COLD FRONT
TO BE OVER THE WESTERN ATLANTIC FROM 30N78W TO SOUTH FLORIDA
WITH CONVECTION. 

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

$$
FORMOSA