[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280004
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN JAN 27 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH COMES OFF THE COASTLINE OF IVORY COAST NEAR
05N05W AND CONTINUES ALONG TO 04N18W. THE ITCZ CONTINUES FROM
THERE TO 01N44W. NO SIGNIFICANT DEEP CONVECTION EXISTS THIS
EVENING IN ASSOCIATION WITH THE MONSOON TROUGH AND ITCZ.

...DISCUSSION...

GULF OF MEXICO...
A 1036 MB HIGH CENTERED OVER VIRGINIA IS CONTRIBUTING TOWARD A
MODERATE NORTH-SOUTH PRESSURE GRADIENT OVER THE GULF OF MEXICO.
THE SURFACE WINDS VEER FROM WEAK ENE IN THE EASTERN GULF TO
FRESH BREEZE SE IN THE WESTERN GULF.  NO SIGNIFICANT DEEP
CONVECTION IS OCCURRING TODAY...THOUGH SCATTERED SHOWERS ARE
LOCATED IN THE SOUTHEASTERN GULF OF MEXICO AND FLORIDA STRAITS
AS WELL AS ALONG THE EASTERN TEXAS COAST.  A WEAK UPPER LEVEL
TROUGH OVER TEXAS IS SUPPORTING THE SHOWERS IN THAT VICINITY.
THE REMAINDER OF THE GULF IS OVERLAID BY SUBSIDENT SW UPPER
LEVEL FLOW.  LITTLE CHANGE IS EXPECTED FOR THE CONDITIONS OVER
THE GULF DURING THE NEXT DAY.

CARIBBEAN SEA...
THE AFOREMENTIONED HIGH IS ALSO FORCING A MODERATE NORTH-SOUTH
PRESSURE GRADIENT OVER THE CARIBBEAN SEA.  THIS IS FORCING
MODERATE TO FRESH NE TRADEWINDS ACROSS THE CARIBBEAN...WITH THE
EXCEPTION OF NEAR GALE CONDITIONS NORTH OF COLUMBIA DUE TO THE
INTERACTION OF THE PRESSURE GRADIENT WITH THE MOUNTAINOUS
TERRAIN OF COLUMBIA.  THESE NEAR GALE WINDS NEAR COLUMBIA WERE
OBSERVED THIS AFTERNOON WITH AN OSCAT SCATTEROMETER PASS AT
1628Z.  NO SIGNIFICANT DEEP CONVECTION IS OCCURRING THIS
EVENING...THOUGH SCATTERED SHOWERS ARE OCCURRING WITH
ENHANCEMENT OF THIS PRECIPITATION ALONG THE EASTWARD FACING
SLOPES OF THE GREATER ANTILLES AND CENTRAL AMERICA.  IN THE
UPPER LEVELS...STRONGLY SUBSIDENT SW UPPER LEVEL WINDS PREVAIL.
OVER THE NEXT DAY OR SO...AS THE VIRGINIA HIGH SHIFTS
SOUTHEASTWARD ...THE PRESSURE GRADIENT OVER THE CARIBBEAN WILL
BE ENHANCED BOOSTING THE TRADEWINDS SLIGHTLY.  CONDITIONS NEAR
COLUMBIA ARE ANTICIPATED TO REACH GALE FORCE AROUND TUESDAY
MORNING.

ATLANTIC OCEAN...
THE MOST IMPORTANT FEATURE OVER THE ATLANTIC TODAY IS A COLD
FRONT THAT EXTENDS FROM 32N57W WESTWARD TO 29N81W AT CENTRAL
FLORIDA.  SURFACE WINDS ARE LIGHT AHEAD OF THE FRONT...BUT ARE
UP TO STRONG BREEZE NORTH OF THE FRONT WITH NW WINDS E OF 70W
AND NE WINDS W OF 70W.  THE FRONT IS BEING SUPPORTED BY A
SHORTWAVE TROUGH ALONG 58W AS OBSERVED BY THE WATER VAPOR
IMAGERY.  A SECOND BOUNDARY...A DISSIPATING STATIONARY
FRONT...EXTENDS FROM 32N37W SOUTHWESTWARD TO 24N64W.  NEITHER
FRONTS CONTAIN ANY SIGNIFICANT DEEP CONVECTION...THOUGH
SCATTERED SHOWERS ARE OCCURRING WITHIN 120 NM N OF THE FRONTAL
BOUNDARIES.  FARTHER EAST...A 1029 MB HIGH IS CENTERED NEAR
32N23W IN THE EASTERN ATLANTIC.  THIS HIGH...AND A RIDGE
EXTENDING WEST-SOUTHWESTWARD FROM THE HIGH...ARE DRIVING FRESH
TO MODERATE BREEZE E-NE TRADEWINDS ACROSS THE MAJORITY OF THE
ATLANTIC OCEAN AREA OF RESPONSIBILITY.  IN THE REMAINDER OF THE
UPPER LEVELS...SUBSIDENT RIDGING FLOW PREVAILS.  IN THE NEXT DAY
OR SO...WHILE THE STATIONARY FRONT SHOULD DISSIPATED...THE COLD
FRONT SHOULD CONTINUE TO BE PROGRESSIVE ACROSS THE ATLANTIC AND
REACH DOWN TO 25N OVER THE BAHAMAS.  THIS SHOULD ALSO
DIMINISHING THE PRESSURE GRADIENT AND WEAKEN THE TRADEWINDS
SLIGHTLY SOUTH OF 25N.

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

$$
LANDSEA







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