[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180008
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU JAN 17 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 2345 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH SOUTHERN COASTAL LIBERIA NEAR
4N8W TO 4N13N 4N17W. THE ITCZ CONTINUES FROM 4N17W TO 3N23W
2N30W 1N43W. MODERATE ISOLATED SHOWERS ARE BETWEEN THE ITCZ AND
MONSOON TROUGH FROM 2N TO 6N.

...DISCUSSION...

THE GULF OF MEXICO...
SURFACE RIDGING BUILDS OVER THE GULF OF MEXICO WEST OF THE COLD
FRONT AS A 1031 MB HIGH STARTS TO COME OFF THE MEXICO EAST COAST
NEAR TAMPICO. AS 2100 UTC...THE COLD FRONT EXTENDS FROM
JACKSONVILLE AND ENTERS THE GULF WATERS NEAR FORT MYERS...FROM THERE
THE COLD FRONT CONTINUES SOUTHWESTWARD TO 25N83W 20N85W AND
ENTERS THE YUCATAN PENINSULA NEAR 17N88W. A GALE WARNING IS JUST
WEST OF THE COLD FRONT N OF 27N E OF 87W. BESIDES THE AREA OF
GALE WARNING WHERE WINDS ARE FROM THE NW...NORTHERLY WINDS OF
15-25 KT SPREAD WEST OF THE COLD FRONT. BROKEN TO OVERCAST LOW
CLOUDS AND LIGHT RAIN AS INDICATED BY THE RADAR IS WITHIN 110 NM
EAST OF THE FRONT. FOG OR LOW VISIBILITY IS INDICATED FROM
NAPLES FLORIDA SOUTHWESTWARD ALONG THE FRONT TO OVER THE YUCATAN
PENINSULA. IN THE MIDDLE TO UPPER LEVELS A BROAD TROUGH WITH
AXIS CROSSING THE EASTERN CONUS TO THE WEST ATLC SUPPORTS THE
COLD FRONT AND ASSOCIATED SHOWERS ACTIVITY. WITHIN THE NEXT 24
HOURS...THE FRONT WILL BE OUT OF THE GULF. WINDS WILL BECOME
NORTHEASTERLY COMING FROM A BROAD SURFACE HIGH THAT WILL BUILD
OVER THE SOUTHEAST STATES AS WELL AS THE LOWEST MISSISSIPPI AND
TENNESSEE VALLEY.

THE CARIBBEAN SEA...
WEAK PRESSURE GRADIENT IS OVER THE REGION. LIGHT TRADE WINDS OF
MAINLY 10-15 KT COVER THE EASTERN AND CENTRAL CARIBBEAN. WINDS
OF 20 KT CAN BE FOUND SOUTH OF THE HISPANIOLA AND OFF THE
COLOMBIA COAST WHERE THE WINDS TURN NORTHEASTERLY. IN THE
WESTERN CARIBBEAN...THE COLD FRONT FROM THE GULF STARTS TO ENTER
THE AREA AND EXTENDS FROM THE WEST COAST OF CUBA NEAR 21N84W TO
THE EAST COAST OF THE YUCATAN PENINSULA NEAR 17N88W. NORTHERLY
AND NORTHEASTERLY WINDS OF 5-15 KT SPREAD OVER THE WESTERN
CARIBBEAN. BESIDES LIGHT SHOWERS IN THE WESTERN CARIBBEAN ALONG
THE FRONTAL BOUNDARY...THE REST OF THE REGION ENJOYS FROM FAIR
WEATHER CONDITIONS BEING SUPPORTED BY UPPER LEVEL RIDGING AND
DRY AIR SUBSIDENCE. EXPECT SIMILAR WIND CONDITIONS WITHIN 24
HOURS AND FOR THE COLD FRONT TO MOVE NORTH OF THE REGION.

THE ATLANTIC OCEAN...
IN THE WESTERN ATLC...A COLD FRONT STARTS TO MOVE OFF THE
NORTHERN COAST OF FLORIDA AND ENTERS THE REGION NEAR 30N81W.
AHEAD OF THE FRONT A SURFACE TROUGH IS ALONG 30N79W 28N79W THEN
ENTERS THE FLORIDA PENINSULA SOUTH OF FORT PIERCE ALL THE WAY
SOUTH TO NORTH OF THE FLORIDA KEYS. A GALE IS EXPECTED TO
DEVELOP N OF 29N WITHIN 150 NM E OF THE FRONT. THE COLD FRONT
AND SURFACE TROUGH ARE BEING SUPPORTED BY A BROAD TROUGH WITH
AXIS CROSSING THE EASTERN CONUS TO THE WEST ATLC. LIGHT SHOWERS
ACTIVITY ARE WEST OF 68W NORTH OF 24N. THE REMAINDER OF THE WEST
ATLC IS BEING INFLUENCED BY SURFACE RIDGING FROM A 1024 MB HIGH
NORTH OF THE REGION AND FAIR CONDITIONS PREVAILS SUPPORTED BY
UPPER LEVEL RIDGING AND DRY AIR SUBSIDENCE. IN THE CENTRAL
ATLC...A SURFACE LOW  WITH EMBEDDED TROUGH IS NEAR 21N41W. THE
TROUGH EXTENDS FROM THE LOW TO 17N40W 13N45W. SCATTERED SHOWERS
ARE EAST OF THE LOW FROM 17N TO 24N BETWEEN 31W AND 41W. THIS
LOW SYSTEM IS BEING SUPPORTED BY A CUT-OFF LOW IN THE UPPER
LEVELS. IN THE EASTERN ATLC RIDGING FROM A 1027 MB HIGH LOCATED
NEAR 32N16W DOMINATES. WIDESPREAD MODERATE TO ISOLATED STRONG
SHOWERS ARE FROM 3N TO 16N BETWEEN 21W AND 41W. THIS CONVECTIVE
ACTIVITY IS ASSOCIATED TO MOISTURE BEING ADVECTED FROM SOUTH OF
THE EQUATOR.

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

$$
RAMOS




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