000
AXNT20 KNHC 191725
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST TUE JAN 19 2010

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...METEOROLOGICAL ANALYSIS...WEATHER 
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1645 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED FROM S IVORY COAST IN AFRICA NEAR 6N4W 
ALONG 4N16W 2N28W 1N41W TO NE BRAZIL COAST NEAR EQ50W. ISOLATED 
MODERATE CONVECTION IS WITHIN 90 NM OF THE AXIS BETWEEN 33W-42W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH S OF ALABAMA NEAR 
28N87W DOMINATES THE GULF OF MEXICO TODAY PROVIDING GENERALLY 
FAIR WEATHER ACROSS THE BASIN. LIGHT ANTI-CYCLONIC SURFACE FLOW 
IS AROUND THE RIDGE REACHING 15 KT ACROSS THE WRN GULF. IN THE 
UPPER LEVELS...AN UPPER LEVEL SHORTWAVE TROUGH EXTENDS ALONG 
91W. WHILE MAINLY DRY AIR ALOFT COVERS THE BASIN SWLY FLOW 
AROUND THE E SIDE OF THE UPPER TROUGH IS DRAWING A SWATH OF 
MODERATE MOISTURE FROM THE YUCATAN PENINSULA ACROSS S FLORIDA 
SUPPORTING HIGH CLOUDS IN THIS AREA. ALSO...A FEW ISOLATED 
SHOWERS ARE NOTED ACROSS THE FLORIDA KEYS EVIDENT IN RADAR 
IMAGERY. EXPECT THE SURFACE RIDGE TO SHIFT E ALLOWING SLY RETURN 
FLOW TO INCREASE ACROSS THE NW GULF AHEAD OF THE NEXT COLD FRONT 
FORECAST TO MOVE OFF THE TEXAS COAST EARLY THU. 

THE CARIBBEAN SEA...
A COLD FRONT THAT DRAPES ACROSS THE W ATLC TO NW HAITI BECOMES A 
SURFACE TROUGH ACROSS THE NW CARIBBEAN FROM NEAR 19N75W TO N OF 
JAMAICA NEAR 18N79W CONTINUING SWD TO NEAR 11N81W. ISOLATED 
SHOWERS ARE WITHIN 90 NM W OF THE TROUGH AXIS S OF 18N. A 
PRE-FRONTAL SURFACE TROUGH IS AHEAD OF THE COLD FRONT IN THE W 
ATLC EXTENDING ACROSS E DOMINICAN REPUBLIC SUPPORTING ISOLATED 
SHOWERS N OF 17N BETWEEN 68W-74W. THE REMAINDER OF THE CARIBBEAN 
IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF 
DRY AIR AND SUBSIDENCE AROUND AN UPPER LEVEL RIDGE COVERING THE 
BASIN WITH AXIS ALONG 70W. FRESH TO STRONG TRADEWINDS ARE ACROSS 
MUCH OF THE BASIN WITH THE STRONGEST WINDS OFF THE COAST OF 
COLOMBIA WHERE THEY REACH GALE FORCE UP TO 35 KT. THE GALE FORCE 
WINDS ARE FORECAST TO PERSIST FOR ANOTHER 48 HOURS. 

THE ATLANTIC OCEAN...
A COLD FRONT EXTENDS ACROSS THE W ATLC FROM A 987 MB LOW NEAR 
41N54W ENTERING THE DISCUSSION AREA NEAR 32N55W CONTINUING SW TO 
THE NW TIP OF HAITI NEAR 19N74W. SCATTERED SHOWERS ARE WITHIN 60 
NM OF THE FRONT N OF 25N WITH POSSIBLE ISOLATED SHOWERS 
ELSEWHERE ALONG THE FRONT. A PRE-FRONTAL SURFACE TROUGH IS E OF 
THE FRONT ALONG 23N65W TO WRN DOMINICAN REPUBLIC NEAR 18N70W. 
SCATTERED SHOWERS ARE WITHIN 60 NM OF THE TROUGH AXIS. A 
SECONDARY COLD FRONT TRAILS BEHIND THE PRIMARY ONE ALONG 31N61W 
27N68W 27N75W. ISOLATED SHOWERS ARE POSSIBLE ALONG THE FRONT 
WITH A LARGE AREA OF STRATOCUMULUS CLOUDS FOLLOWING BEHIND. AN 
UPPER LEVEL SHORTWAVE TROUGH ALONG 45N55W TO 32N50W SUPPORTS THE 
FRONTAL SYSTEM. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE 
W AND CENTRAL ATLC EXTENDING FROM THE CARIBBEAN. TO THE SE...A 
SURFACE TROUGH IS E OF THE LESSER ANTILLES ALONG 17N56W TO 
11N59W. ISOLATED SHOWERS ARE WITHIN 90 NM W OF THE AXIS. AN AREA 
OF SCATTERED SHOWERS IS ALSO NOTED N OF THE LEEWARD ISLANDS FROM 
18N-20N BETWEEN 57W-62W. ACROSS THE E ATLC...A BROAD SURFACE 
RIDGE ANCHORED BY A 1027 MB HIGH NEAR 31N28W DOMINATES BRINGING 
GENERALLY FAIR WEATHER ACROSS THE AREA. HOWEVER...AN UPPER LEVEL 
TROUGH COVERING THE ERN ATLC EXTENDING FROM THE AZORES ISLANDS 
IS SUPPORTING SOME HIGH CLOUDS ACROSS THE AREA. 

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

$$
WALTON