[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 092329
TWDAT

TROPICAL WEATHER DISCUSSION...CORRECTION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU DEC 09 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

ITCZ AXIS IS ALONG 11N15W 5N25W 1N37W EQ. ISOLATED MODERATE
CONVECTION IS WITHIN 120 NM NORTH OF THE AXIS BETWEEN 22W AND
31W. SCATTERED MODERATE CONVECTION IS MOVING OFF THE COAST OF
LIBERIA.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES THE STRONG UPPER LEVEL SHORTWAVE
AND ASSOCIATED LOW PRESSURE SYSTEM ARE NOW TRAVELING INTO THE NW
CARIBBEAN. HOWEVER...SCATTERED WEAK SHOWERS LINGER OVER THE FAR
SE GULF INCLUDING THE FLORIDA STRAITS E OF 84W S OF 25N. THIS
AREA OF WEAK CONVECTION IS EXPECTED TO DISSIPATE OVER THE NEXT
12 HOURS. 10 TO 20 KT ANTI-CYCLONIC FLOW IS ACROSS THE AREA OF
DISCUSSION WITH AN UPPER LEVEL RIDGE OF HIGH PRESSURE GRADUALLY
BUILDING OVER THE NW GULF. CONDITIONS ARE EXPECTED TO REMAIN
CONSTANT OVER THE NEXT FEW DAYS...BEFORE RETURN FLOW INCREASES
OVER THE NW GULF...AHEAD OF THE NEXT COLD FRONT FORECAST TO
ENTER THE THE REGION BY EARLY SUNDAY.

CARIBBEAN SEA...
A STRONG UPPER LEVEL SHORTWAVE IS OVER THE NW BASIN NOTED ON
WATER VAPOR IMAGERY. THIS UPPER FEATURE SUPPORTS A 1014 MB LOW
NEAR 21N82W. A COLD FRONT EXTENDS SW FROM THE LOW CENTER TO
SOUTHERN BELIZE  ALONG 19N82W 17N85W 16N89W. NW WINDS UP TO 25
KT ARE OBSERVED BEHIND THE FRONT. A PRE-FRONTAL TROUGH IS 60 NM
EAST OF THE COLD FRONT. A WARM FRONT EXTENDS NE FROM THE LOW
CENTER TO 22N80W. THIS COMPLEX SCENARIO DOES NOT SEEM TO
PRODUCE ANY SIGNIFICANT/DEEP CONVECTION TO THE NW BASIN. JUST
SCATTERED WEAK CONVECTION IS FOCUSED ALONG THE PRE-FRONTAL
TROUGH...WITHIN 30 NM ON EITHER SIDE OF THE AXIS. FARTHER EAST
INTO THE CENTRAL AND SW CARIBBEAN...A SURFACE TROUGH IS ANALYZED
THROUGH THE WINDWARD PASSAGE AND TRANSITIONS TO A SHEARLINE JUST
EAST OF JAMAICA CONTINUING SW INTO A 1009 MB LOW CENTERED NEAR
11N78W. N-NE WINDS AND EASTERLY TRADES CONVERGE ALONG THE AXIS
OF THE SHEAR LINE AND INTO THE LOW PRESSURE CENTER PROVIDING
FOCUS FOR SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 100 NM ON
EITHER SIDE OF THE BOUNDARY. THIS AREA OF CONVECTION BROADENS
OVER THE N CENTRAL AFFECTING HISPANIOLA AND THE MONA PASSAGE N
OF16N BETWEEN 67W AND 73W. LOW-LEVEL MOISTURE CONTINUES TO
STREAM FROM THE CENTRAL ATLANTIC OVER THE EASTERN CARIBBEAN
PROVIDING THE LESSER ANTILLES...PUERTO RICO...AND US/UK VIRGIN
ISLANDS WITH ISOLATED SHOWERS THROUGH THE REMAINDER OF THE
EVENING HOURS.

ATLANTIC OCEAN...
A SHARP UPPER LEVEL TROUGH MOVES OFF THE EASTERN U.S. SEABOARD
SUPPORTING A STATIONARY FRONT ALONG 32N64W 28N70W 27N78W
BECOMING A SURFACE TROUGH TO 23N81W. NUMEROUS SHOWERS ARE
OCCURRING WITHIN 150 NM EITHER SIDE OF THE BOUNDARIES. FARTHER
SE...A SURFACE TROUGH IS ANALYZED FROM 25N68W TO THE WINDWARD
PASSAGE NEAR 20N74W. THIS TROUGH FALLS WITHIN A WEAKNESS OF THE
SUBTROPICAL RIDGE THAT IS GENERALLY PROVIDING FAIR CONDITIONS
OVER MUCH OF THE CENTRAL ATLC. HOWEVER...LOW-LEVEL CONVERGENCE
IN THE VICINITY OF THE SURFACE TROUGH IS PROVIDING FOCUS FOR
SCATTERED SHOWERS AND ISOLATED TSTMS COVERING THE AREA S OF 26N
BETWEEN 62W-74W. THIS AREA OF CONVECTIVE ACTIVITY FALLS UNDER AN
UPPER LEVEL DIFFLUENT ENVIRONMENT DUE TO A BROAD UPPER LEVEL
RIDGE. OVER THE EASTERN ATLC...AN UPPER LEVEL LOW IS CENTERED
NORTH OF THE AREA SUPPORTING A 1000 MB LOW CENTERED NEARBY THE
MADEIRA ISLANDS NEAR 35N18W WITH A DISSIPATING COLD FRONT
ANALYZED ALONG 32N14W TO 19N23W. NO SIGNIFICANT CONVECTION IS
OBSERVED AT THE MOMENT.

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

$$

GARCIA




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