000
AXNT20 KNHC 230522
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST WED DEC 23 2009

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 6N11W 5N20W 4N45W 3N51W. 
SCATTERED MODERATE CONVECTION IS FROM 3N-5N BETWEEN 16W-20W. 
WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-5N BETWEEN 
26W-30W. ISOLATED MODERATE CONVECTION IS FROM 3N-5N BETWEEN 
41W-44W.

...DISCUSSION...

GULF OF MEXICO...
SURFACE RETURN FLOW IS PRODUCING 15-20 KT E-SE FLOW OVER THE 
ENTIRE GULF OF MEXICO. BROKEN TO OVERCAST MULTILAYERED CLOUDS 
ARE OVER E TEXAS...LOUISIANA...AND THE NW GULF N OF 24N W OF 
87W. SIMILAR CLOUDS ARE OVER CUBA AND THE STRAITS OF FLORIDA S 
OF 25N E OF 82W. THE REMAINDER OF THE GULF HAS MOSTLY FAIR 
SKIES. IN THE UPPER LEVELS...A VERY SHARP TROUGH IS OVER THE 
GULF WITH AXIS ALONG 84W. UPPER LEVEL MOISTURE AND CLOUDS ARE AS 
NOTED ABOVE WHILE STRONG SUBSIDENCE IS OVER THE REMAINDER OF THE 
GULF. EXPECT OVER THE NEXT 24 HOURS...A COLD FRONT TO BE ALONG 
THE TEXAS COAST WITH PREFRONTAL CONVECTION EXTENDING OVER THE NW 
GULF. ALSO EXPECT THE UPPER LEVEL WINDS TO BECOME ZONAL.  

CARIBBEAN SEA...
A WEAK STATIONARY FRONT IS OVER THE CARIBBEAN FROM HISPANIOLA TO 
JAMAICA TO THE SW CARIBBEAN ALONG 19N70W 18N78W 14N81W 10N80W. A 
SURFACE TROUGH EXTENDS FROM HISPANIOLA TO N COLOMBIA ALONG 
17N73W 12N75W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
IS OVER THE NORTH CENTRAL CARIBBEAN FROM 15N-20N BETWEEN 
71W-76W. WIDELY SCATTERED MODERATE CONVECTION IS OVER JAMAICA 
AND E CUBA FROM 17N-21N BETWEEN 76W-79W. SIMILAR CONVECTION IS 
ALONG THE COAST OF N COLOMBIA FROM 10N-12N BETWEEN 75W-76W. 
MOSTLY FAIR WEATHER IS OVER THE E CARIBBEAN E OF 70W. 15-20 KT 
N-NE WINDS ARE OVER THE NW CARIBBEAN N OF THE STATIONARY FRONT. 
STRONG TRADEWINDS ARE S OF THE FRONT OVER THE CENTRAL CARIBBEAN 
WHILE MODERATE TRADEWINDS ARE OVER THE E CARIBBEAN E OF 70W. IN 
THE UPPER LEVELS...A SHARP TROUGH IS OVER THE W CARIBBEAN W OF 
80W. AN UPPER LEVEL RIDGE IS OVER THE REMAINDER OF THE CARIBBEAN 
PRODUCING WSW UPPER LEVEL WINDS. SIGNIFICANT UPPER LEVEL 
MOISTURE IS OVER THE CENTRAL CARIBBEAN BETWEEN 68W-78W WHILE 
STRONG SUBSIDENCE IS OVER THE REMAINDER OF THE CARIBBEAN. 
EXPECT OVER THE NEXT 24 HOURS FOR THE STATIONARY FRONT TO 
DISSIPATE AND A SURFACE LOW TO FORM S OF HISPANIOLA WITH A 
TROUGH EXTENDING S TO N COLOMBIA. ALSO EXPECT CONVECTION NEAR 
THIS LOW AND TROUGH.  

ATLANTIC OCEAN...
A COLD FRONT EXTENDS FROM THE EASTERN ATLANTIC NEAR 32N19W TO 
HISPANIOLA ALONG 27N30W 22N50W 19N70W. WIDELY SCATTERED MODERATE 
CONVECTION IS OVER THE E ATLANTIC NEAR THE CANARY ISLANDS FROM 
26N-31N BETWEEN 12W-27W. SCATTERED SHOWERS ARE WITHIN 60 NM OF 
THE REMAINDER OF THE FRONT. A 1018 MB HIGH IS OVER THE CENTRAL 
ATLANTIC NEAR 16N37W. IN THE UPPER LEVELS... AN UPPER LEVEL HIGH 
IS CENTERED E OF THE LESSER ANTILLES NEAR 13N57W. UPPER LEVEL 
ANTICYCLONIC FLOW IS BETWEEN 35W-80W. AN UPPER LEVEL TROUGH IS 
OVER THE E ATLANTIC E OF 35W. EXPECT OVER THE NEXT 24 HOURS FOR 
THE COLD FRONT TO MOVE E WITH CONVECTION. ALSO EXPECT A NEW AREA 
OF CONVECTION N OF HISPANIOLA FROM 20N-27N BETWEEN 58W-74W DUE 
TO A NEW SURFACE LOW. 

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

$$
FORMOSA