[Tropical] Tropical Weather Discussion

[EMWIN Server]

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




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