[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191121
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SUN JAN 19 2014

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
1115 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE ITCZ PASSES BEGINS AT COASTAL LIBERIA NEAR 5N9W TO 0N39W.
CONVECTIVE PRECIPITATION...ISOLATED MODERATE WITHIN 60 NM OF
AXIS EAST OF 25W.

...DISCUSSION...

...THE GULF OF MEXICO...

A 1024 MB HIGH IS CENTERED NEAR 27N85W.  SCATTERED SHOWERS EXIST
IN A LOW TO MID LEVEL CLOUD BAND WHICH IS SOUTH A COUPLE HUNDRED
NM OF TEXAS TO THE FLORIDA PANHANDLE.  WHILE THERE IS NO OBVIOUS
SURFACE FEATURE CONNECTED TO THESE CLOUDS/SHOWERS...A STRONG MID-
 TO UPPER-LEVEL TROUGH PLUNGING SOUTHWARD OVER THE SOUTHEASTERN
U.S. MAY BE SUPPORTING IT.  ADDITIONALLY...TWO LINES OF
CONVECTION HAVE DEVELOPED ALONG THE COAST FROM LOUISIANA TO THE
FLORIDA PANHANDLE...BOTH MOVING TOWARD THE EAST-SOUTHEAST.  THE
LEADING LINE...MORE RAGGED...MAY BE ASSOCIATED WITH A PRE-
FRONTAL TROUGH.  THE SECOND LINE...A BIT MORE INLAND...IS
ASSOCIATED WITH A COLD FRONT ITSELF.  THE SURFACE WINDS IN THE
GULF ARE QUITE WEAK...20 KT OR LESS...AS THE PRESSURE GRADIENT
ACROSS THE GULF IS SLIGHT. THE FORECAST CALLS FOR THE JUST-
INLAND COLD FRONT TO MOVE ACROSS THE EASTERN GULF/FLORIDA
PENINSULA BY TONIGHT.  HOWEVER...BECAUSE THERE IS NO OPPORTUNITY
FOR THE RETURN FLOW TO SET UP SIGNIFICANTLY...THE CHANCE FOR
DEEP CONVECTION ASSOCIATED WITH THE NEW FRONTAL BOUNDARY IS LOW.

...THE WESTERN ATLANTIC OCEAN...

TWO FRONTAL BOUNDARIES ARE ACTIVE THIS EVENING...A LEADING COLD
FRONT EXTENDING FROM 32N60W SOUTHWESTWARD BECOMING A STATIONARY
FRONT AT 24N70W TO EASTERN CUBA AND A COLD FRONT EXTENDING FROM
32N67W SOUTHWESTWARD TO CENTRAL CUBA.  NO DEEP CONVECTION IS
ASSOCIATED WITH EITHER FEATURE...THOUGH SCATTERED SHOWERS ARE
LOCATED WITHIN 180 NM WEST OF THE LEADING FRONT.  SCATTEROMETERS
AND BUOYS INDICATES THAT THE SURFACE WINDS ASSOCIATED WITH THE
FRONTAL BOUNDARIES HAVE DROPPED TO 20 KT OR WEAKER.  THE
FORECAST CALLS FOR THE TWO FRONTS TO MERGE AND BE STATIONARY BY
SUNDAY NIGHT EXTENDING FROM 32N61W SOUTHWESTWARD TO HISPANIOLA.
MOIST CONVERGENT SOUTHERLY FLOW REACHING THE MERGED FRONTS
SHOULD CONTINUE THE LIKELIHOOD OF RAINFALL...SOME OF WHICH COULD
BE DEEP CONVECTION NORTH OF 25N...OVER THE NEXT DAY OR SO.  SOME
OF THESE RAINS COULD AFFECT THE CENTRAL AND SOUTHERN BAHAMAS.

...THE CENTRAL AND EASTERN ATLANTIC OCEAN...

A LARGE 1029 MB SURFACE HIGH CENTERED AT 32N37W DOMINATES THE
CENTRAL AND EASTERN ATLANTIC OCEAN WITH RIDGING EXTENDING WEST-
SOUTHWESTWARD TO 25N62W AND SOUTHEASTWARD TO THE WEST AFRICAN
COAST AT 22N17W.  NO DEEP CONVECTION IS OCCURRING UNDER THE
PRIMARILY SUBSIDENT CONDITIONS.  A VIGOROUS UPPER- TO MID-LEVEL
LOW IS CENTERED AT 20N45W WITH A TROUGH EXTENDING SOUTHWARD TO
7N50W.  THE LOW/TROUGH IS PROMOTING MID- TO UPPER-LEVEL
CLOUDINESS AND SCATTERED SHOWERS TO THE EAST OF THE TROUGH AXIS.
HOWEVER...DESPITE PROMINENT TURNING OBSERVED IN THE SATELLITE
IMAGERY...THE FEATURE IS NOT AT THE SURFACE AS SEEN FROM
NUMEROUS SCATTEROMETER PASSES TODAY AS WELL AS SHIP BATFR19...
WHICH ALL HAVE SHOWN UNIDIRECTIONAL NORTHEASTERLY FLOW ACROSS
THE AREA.

...THE CARIBBEAN SEA...

A STATIONARY FRONT EXTENDS FROM EASTERN CUBA TO THE COAST OF
NICARAGUA.  ADDITIONALLY...A COLD FRONT EXTENDS FROM CENTRAL
CUBA SOUTHWESTWARD TO 20N82W.  NO DEEP CONVECTION IS OCCURRING
IN ASSOCIATION WITH EITHER FRONT.  SCATTERED SHOWERS ARE
OCCURRING WITHIN 180 NM WEST OF THE FRONT INCLUDING OVER EASTERN
CUBA...JAMAICA...NICARAGUA...HONDURAS...AND BELIZE.  THE
RAINFALL OVER PORTIONS OF CENTRAL AMERICA IS ENHANCED BY UPSLOPE
FLOW INDUCED BY THE 15-20 KT NORTHEASTERLY WINDS IMPACTING THE
COAST.  THE TYPICAL ACCELERATED EASTERLY TRADES NORTH OF
COLOMBIA ARE ALSO IN PLACE...REACHING 25-30 KT.  THE FORECAST
CALLS FOR THE TWO FRONTS TO MERGE AND BECOME STATIONARY FROM
HISPANIOLA SOUTHWESTWARD TO 16N77W TONIGHT.  CONTINUED SCATTERED
SHOWERS ARE EXPECTED WITHIN 180 NM WEST OF THE FRONTAL
BOUNDARY...AS WELL AS EAST-FACING SLOPES OF NICARAGUA...
HONDURAS...AND BELIZE DURING THE NEXT DAY OR SO.  THE EASTERN
CARIBBEAN SHOULD REMAIN RELATIVELY DRY.

THE MONSOON TROUGH FROM THE NORTHEAST PACIFIC DOES NOT EXTEND
INTO THE CARIBBEAN THIS MORNING.

...HISPANIOLA...

A STATIONARY FRONT EXTENDS FROM EASTERN CUBA TO THE COAST OF
NICARAGUA.  NO SHOWER ACTIVITY IS CURRENTLY AFFECTING
HISPANIOLA. THE FORECAST CALLS FOR THE FRONT TO MERGE WITH COLD
FRONT THAT IS CURRENTLY OVER CENTRAL CUBA AND BECOME STATIONARY
FROM HISPANIOLA SOUTHWESTWARD TO 16N77W TONIGHT. SCATTERED
SHOWERS ARE EXPECTED WITHIN 180 NM WEST OF THE FRONTAL BOUNDARY
INCLUDING HISPANIOLA FOR THE NEXT DAY OR SO.

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

$$
LANDSEA

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