[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 011127
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SUN JAN 01 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1100 UTC.

...ITCZ/MONSOON TROUGH...

THE ITCZ BEGINS FROM THE COAST OF LIBERIA NEAR 5N8W CONTINUING
ALONG 3N20W 2N30W 1N37W 2N42W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS FROM 3N-5N BETWEEN 17W-24W...AND FROM 1N-3N
BETWEEN 25W-30W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY SHOWS SOME MODERATE UPPER LEVEL MOISTURE
MOVING IN SW FLOW ACROSS THE GULF OF MEXICO BETWEEN AN UPPER
LEVEL RIDGE OVER THE CARIBBEAN AND FAR ERN CONUS AND AN UPPER
LEVEL TROUGH MOVING OVER THE CENTRAL CONUS. BESIDES A FEW UPPER
LEVEL CLOUDS...THE BASIN REMAINS UNDER MOSTLY FAIR CONDITIONS
AROUND A WEAK SURFACE RIDGE ANCHORED BY A PAIR OF 1024 MB HIGHS
ON EITHER SIDE OF THE FLORIDA PENINSULA. LIGHT ANTI-CYCLONIC
FLOW IS AROUND THE RIDGE. SATELLITE IMAGERY INDICATES AN AREA OF
FOG ALONG THE GULF COASTLINE BETWEEN THE FLORIDA PANHANDLE AT
84W ALL THE WAY TO THE SRN COAST OF TEXAS. THE AFOREMENTIONED
UPPER TROUGH OVER THE CENTRAL CONUS WILL MOVE EWD PUSHING A COLD
FRONT INTO THE NW GULF LATER TODAY. STRONG NE WINDS ARE EXPECTED
BEHIND THE FRONT WHICH WILL REACH GALE FORCE IN THE SW CARIBBEAN
ON MONDAY.

CARIBBEAN SEA...
A BROAD UPPER RIDGE CONTINUES TO SIT ACROSS THE BASIN WITH AXIS
ALONG 70W. WATER VAPOR IMAGERY ALSO INDICATES DRY AIR
ACCOMPANYING THE RIDGE WHICH IS LIMITING CONVECTION. A FEW
ISOLATED SHOWERS/THUNDERSTORMS ARE NOTED IN THE NW CARIBBEAN
FROM HONDURAS TO CUBA INFLUENCED BY A SURFACE TROUGH EXTENDING
FROM THE CENTRAL BAHAMAS TO ERN CUBA NEAR 22N77W TO 19N79W. A
FEW ISOLATED SHOWERS ARE ALSO ALONG THE CENTRAL AMERICAN
COASTLINE LIKELY DUE TO WIND SPEED CONVERGENCE. THE REMAINDER OF
THE BASIN HAS MOSTLY CLEAR SKIES. NE-E TRADEWIND FLOW OF 20-25
KTS IS ACROSS THE AREA REACHING 30 KTS IN THE FAR ERN CARIBBEAN
AND THE SW CARIBBEAN NEAR THE COAST OF COLOMBIA. THE STRONG
PRESSURE GRADIENT BETWEEN HIGH PRESSURE ACROSS THE GULF AND W
ATLC AND LOWER PRESSURES OVER S AMERICA IS HELPING MAINTAIN THE
STRONG WINDS. THIS WILL PERSIST THROUGH THE DAY UNTIL A FRONT
MOVES THROUGH THE GULF OF MEXICO LATER TODAY AND INTO THE W ATLC
MONDAY ALLOWING THE PRESSURE GRADIENT TO RELAX.

ATLANTIC OCEAN...
UPPER LEVEL RIDGING COVERS THE FAR WRN ATLC WITH AXIS ALONG 74W
WHICH IS HELPING SUPPORT A 1024 MB HIGH OFF THE COAST OF FLORIDA
NEAR 28N79W. AN UPPER LEVEL TROUGH TO THE NE ALONG 58W IS
SUPPORTING A COLD FRONT THAT DIPS INTO THE DISCUSSION AREA ALONG
32N68W 29N74W. A SURFACE TROUGH IS TO THE S FROM 27N70W TO
23N75W ACROSS THE CENTRAL BAHAMAS TO ERN CUBA AT 22N77W
SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS NEAR THE AXIS. THE
REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A
1034 MB HIGH NEAR 33N31W PROVIDING MOSTLY FAIR WEATHER.
HOWEVER...A SHARP UPPER LEVEL TROUGH ALONG 28N26W TO 15N41W IS
PLACING A LARGE AREA OF DIFFLUENCE ALOFT OVER THE SE ATLC AND
SUPPORTING SCATTERED SHOWERS FROM 5N-9N BETWEEN 38W-52W...AS
WELL AS A LARGE AREA OF UPPER LEVEL CLOUDS. DUE TO THE STRONG
PRESSURE GRADIENT BETWEEN THE SURFACE HIGH TO THE N AND LOWER
PRESSURES NEAR THE ITCZ...ENE TRADEWIND FLOW OF 20 KTS IS ACROSS
MUCH OF THE E ATLC REACHING 25 KTS NEAR THE CAPE VERDE ISLANDS.
EXPECT SURFACE RIDGING TO REMAIN ACROSS THE MAJORITY OF THE
BASIN WITH A STRONG COLD FRONT ENTERING THE W ATLC WITHIN THE
NEXT 24 HOURS.

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

$$
WALTON






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