000
AXNT20 KNHC 211138
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST MON JAN 21 2013

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.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM SOUTH LIBERIA NEAR 4N8W TO 
3N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
3N15W TO 3N20W 3N30W 1S41W. WIDESPREAD MODERATE TO ISOLATED 
STRONG CONVECTION IS FROM 3N-5N BETWEEN 12W-21W. ISOLATED 
MODERATE CONVECTION IS WITHIN 150 NM NORTH OF THE ITCZ AXIS 
BETWEEN 22W-32W. SCATTERED SHOWERS ARE WITHIN 200 NM EITHER 
SIDE OF THE ITCZ AXIS WEST OF 32W.  

...DISCUSSION...

GULF OF MEXICO...
SURFACE RIDGING IS OVER THE N GULF OF MEXICO DUE TO A 1021 MB 
HIGH NEAR GALVESTON TEXAS. COLD AIR ADVECTION REMAINS OVER THE 
NORTHERN GULF N OF 26N AND ANTICYCLONIC WINDS OF 5-10 KT ARE 
WEST OF 85W N OF THE SAME LATITUDE. A SURFACE TROUGH IS OVER THE 
EASTERN GULF EXTENDING FROM 28N84W TO 24N84W. SCATTERED SHOWERS 
ARE POSSIBLE IN THE VICINITY OF THE TROUGH. BROKEN TO OVERCAST 
LOW CLOUDS COVER THE GULF AND SCATTERED SHOWERS ARE POSSIBLE 
BEING SUPPORTED BY SIGNIFICANT UPPER LEVEL MOISTURE ADVECTED 
FROM THE EAST PACIFIC. NORTHERLIES OF 5-10 KT SPREAD OVER THE 
REST OF THE GULF. WITHIN 24 HOURS...ANTICYCLONIC WIND WILL 
DOMINATE THE ENTIRE GULF AND WINDS ARE EXPECTED TO INCREMENT UP 
TO 20 KT OVER THE NORTHERN GULF. 

CARIBBEAN SEA...
WEAK PRESSURE GRADIENT AND EASTERLY TRADE WINDS OF 10-20 KT 
DOMINATE THE CENTRAL AND EASTERN CARIBBEAN. IN THE SOUTHERN 
CARIBBEAN BETWEEN NICARAGUA AND THE NORTHERN COAST OF 
COLOMBIA...NORTHEASTERLIES WINDS OF UP TO 25 KT COVER THE REGION 
DUE TO TIGHTER PRESSURE GRADIENT WITH A LOW OVER NORTHERN 
COLOMBIA. FROM WEST OF JAMAICA TO THE YUCATAN 
PENINSULA...LIGHTER NORTHERLY TO NORTHEASTERLY WINDS OF 5-15 KT 
COVER THE WESTERN CARIBBEAN. SCATTERED SHOWERS ARE POSSIBLE OVER 
THE WESTERN CARIBBEAN AND ALONG THE COAST OF NICARAGUA BEING 
SUPPORTED BY AN UPPER LEVEL NARROW TROUGH WITH AXIS EXTENDING 
OVER JAMAICA. UPPER LEVEL RIDGING AND DRY AIR SUBSIDENCE IS OVER 
THE REMAINDER OF THE CARIBBEAN SUPPRESSING CONVECTIVE ACTIVITY. 
FRESH TO STRONG TRADE WINDS WILL CONTINUE TO BLOW OVER THE 
CENTRAL AND SOUTHERN CARIBBEAN WITHIN THE NEXT 24 HOURS.


ATLANTIC OCEAN...
OVER THE WESTERN ATLC...A DISSIPATING 1017 MB LOW WITH EMBEDDED 
STATIONARY FRONT IS LOCATED NEAR 28N75W. THE STATIONARY FRONT 
EXTENDS FROM 30N71W TO THE LOW TO THE FLORIDA SE COAST NEAR 
25N80W. SCATTERED OR ISOLATED SHOWERS ARE POSSIBLE IN THE 
VICINITY OF THE FRONTAL BOUNDARY SUGGESTED BY BROKEN LOW CLOUDS. 
OVER THE CENTRAL ATLC...SURFACE AND UPPER LEVEL RIDGING COVER 
THE REGION THAT ALONG DRY AIR SUBSIDENCE SUPPORT FAIR WEATHER. 
SURFACE RIDGING IS FOUND ALSO OVER THE EAST ATLC DUE TO A 1030 
MB HIGH NEAR 37N36W. HOWEVER AN UPPER LEVEL TROUGH FROM 16N-27N 
BETWEEN 22W-36W IS ENHANCING SCATTERED SHOWERS FROM 21N-27N 
BETWEEN 17W-28W.    

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

$$
NR