000
AXNT20 KNHC 070548
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SAT JAN 07 2012

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0535 UTC.

...ITCZ/MONSOON TROUGH...

MOST OF THE MONSOON TROUGH REMAINS INLAND OVER AFRICA. ONLY A 
SMALL PORTION OF IT EXTENDS FROM THE COAST OF LIBERIA NEAR 6N11W 
TO ABOUT 5N16W. THE ITCZ EXTENDS W FROM THIS POINT ALONG 3N20W 
2N30W 1N40W TO THE COAST OF BRAZIL NEAR EQ50. SCATTERED WEAK TO 
ISOLATED MODERATE CONVECTION IS WITHIN 100 NM ON EITHER SIDE OF 
THE ITCZ AXIS BETWEEN 17W-32W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW MOVING ACROSS THE 
CENTRAL BASIN GENERATING A FEW ISOLATED THUNDERSTORMS DEPICTED 
ON NIGHT VISION SATELLITE IMAGERY N OF 25N W BETWEEN 87W-94W.  
WSW FLOW ALOFT IS OVER THE REMAINDER OF THE GULF PROVIDING DRY 
AIR AND MODERATE SUBSIDENCE ACROSS THE BASIN. THIS UPPER LEVEL 
ENVIRONMENT SUPPORTS A 1022 MB HIGH CENTERED OVER THE ERN BASIN 
NEAR 26N83W. WHILE LIGHT AND VARIABLE WINDS ARE IN THE VICINITY 
OF THE HIGH CENTER...GENTLE ANTICYCLONIC FLOW IS ELSEWHERE 
ACROSS THE AREA WITH MOSTLY FAIR WEATHER CONDITIONS. THE HIGH 
PRESSURE CENTER WILL CONTINUE TO SLOWLY DRIFT E OUT OF THE AREA 
OVER THE NEXT 24 HOURS. ANOTHER ROUND OF CONVECTIVE WEATHER IS 
EXPECTED STARTING LATE SUNDAY...AS THE NEXT COLD FRONT IS 
FORECAST TO ENTER THE NW BASIN BY MONDAY MORNING.

CARIBBEAN SEA...
THE SRN EXTENSION OF A NEARLY STATIONARY FRONTAL BOUNDARY 
ANALYZED ACROSS THE ATLC ENTERS THE CARIBBEAN THROUGH THE ISLAND 
OF PUERTO RICO AND CONTINUES WSW ALONG 16N69W TO NEAR 15N74W. 
SCATTERED WEAK SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE 
OVER PUERTO RICO AND WITHIN 70 NM W OF THE BOUNDARY. EASTERLY 
TRADES REMAIN GENTLE TO MODERATE ACROSS THE AREA WITH LOW-LEVEL 
MOISTURE CONVERGENCE MAXIMIZED OVER PORTIONS OF THE WESTERN 
CARIBBEAN GENERATING WIDELY SCATTERED SHOWERS WITHIN 70 NM OFF 
THE COAST OF ERN HONDURAS...NICARAGUA...COSTA RICA...AND WRN 
PANAMA. OTHERWISE...A BROAD UPPER LEVEL RIDGE DOMINATES THE 
CARIBBEAN WITH RELATIVELY DRY AND STABLE AIR ALOFT. THIS IS 
RESULTING IN A LACK OF SIGNIFICANT DEEP CONVECTION ELSEWHERE 
ACROSS THE BASIN. EXPECT FOR THE FRONTAL BOUNDARY TO CONTINUE TO 
WEAKEN OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
A BROAD UPPER LEVEL TROUGH COVERS THE WRN N ATLC W OF 40W. AN 
UPPER LEVEL LONGWAVE MOVES ALONG THE SRN EXTENSION OF THE UPPER 
TROUGH SUPPORTING A COLD FRONT THAT EXTENDS INTO OUR DISCUSSION 
AREA ALONG 32N53W TO NEAR 27N57W. AS THIS FRONT CONTINUES TO 
TRACK EASTWARD...IT IS EXPECTED TO CATCH UP AND MERGE WITH 
ANOTHER COLD FRONT CURRENTLY EXTENDING SW ACROSS THE N CENTRAL 
ATLC ENTERING THE REGION ALONG 32N47W CONTINUING WSW INTO THE 
CARIBBEAN BASIN ACROSS THE ISLAND OF PUERTO RICO. THIS FRONT IS 
GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 
140 NM E OF IT N OF 24N. ONCE THE TWO COLD FRONTS ARE MERGED...A 
SINGLE FRONTAL BOUNDARY WILL CONTINUE EASTWARD WITH INCREASING 
CONVECTION OVER THE NEXT 6-9 HOURS. A WEAK SURFACE TROUGH IS 
ANALYZED OVER THE SW TROPICAL WATERS OF THE ATLC FROM 13N52W TO 
6N55W GENERATING A FEW ISOLATED SHOWERS WITHIN 100 NM ON EITHER 
SIDE OF ITS AXIS. OTHERWISE...BROAD SURFACE RIDGING AROUND A 
STRONG 1037 MB HIGH CENTERED N OF THE DISCUSSION AREA NEAR 
43N18W IS KEEPING FAIR WEATHER CONDITIONS ACROSS THE REMAINDER 
OF THE DISCUSSION AREA THIS EVENING.  

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

$$

GARCIA