[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 120556
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU MAR 12 2015

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURES...

...GALE WARNING FOR THE SW CARIBBEAN...
A GALE WARNING IS IN EFFECT FOR THE COASTAL WATERS OF COLOMBIA
FROM 10N TO 14N BETWEEN 74W AND 77W.  UNFORTUNATELY...NO
SCATTEROMETER DATA WERE AVAILABLE OVER THE AREA.  HOWEVER...SHIP
PBIG WAS JUST SOUTHWEST OF THE AREA AND RECORDED 30 KT NE WINDS
AT 00 UTC. THE HIGH WINDS ARE BEING CAUSED BY THE STRONG
PRESSURE GRADIENT BETWEEN A 1005 MB LOW OVER NORTHERN COLOMBIA
AND A SURFACE RIDGE EXTENDING ALONG 30N...IN COMBINATION WITH
THE TYPICAL TOPOGRAPHICAL WIND ENHANCEMENTS NORTH OF COLOMBIA.
NEAR GALE TO GALE CONDITIONS SHOULD CONTINUE THROUGH FRIDAY
EVENING. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER
AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL
ATLANTIC NEAR 6N10W TO 4N11W WHERE THE ITCZ BEGINS AND CONTINUES
ALONG THE EQUATOR NEAR 25W THEN TO SOUTH AMERICA NEAR 48W.
SCATTERED MODERATE CONVECTION EXISTS WITHIN 60 NM OF THE ITCZ
BETWEEN 20 AND 37W.

...DISCUSSION...

GULF OF MEXICO...
A 1012 MB LOW IS CENTERED AT 26N94W IN THE NORTHWESTERN GULF OF
MEXICO ACCOMPANIED BY A COLD FRONT EXTENDING SOUTHWARD TO THE
BAY OF CAMPECHE AND A STATIONARY FRONT EXTENDING EAST-
NORTHEASTWARD TO THE LOUISIANA COAST.  SCATTERED MODERATE AND
ISOLATED STRONG CONVECTION IS OBSERVED NORTH OF 24N TO THE
LOUISIANA-MISSISSIPPI-ALABAMA COAST BETWEEN 87W TO 91W BASED
UPON GEOSTATIONARY IMAGERY...LIGHTNING DATA...AND THE U.S. WSR-
88D RADAR NETWORK.  ISOLATED MODERATE CONVECTION IS ALSO
OCCURRING NORTH OF 27N TO THE TEXAS COAST BETWEEN 94 AND 96W.
THE CONVECTION IS LIKELY SUPPORTED BY FORCING FROM A HIGH
AMPLITUDE MID TO UPPER LEVEL LONGWAVE TROUGH CENTERED OVER
CENTRAL MEXICO ALONG WITH AN EMBEDDED SHORTWAVE TROUGH NEAR THE
SOUTH TEXAS COAST.  SURFACE WINDS PEAK WEST OF THE COLD FRONT AT
30 KT...AS SEEN IN THE 0316 UTC ASCAT SCATTEROMETER PASS.  WINDS
IN THE EASTERN HALF OF THE GULF ARE GENERALLY 5-15 KT SE. OVER
THE NEXT TWO DAYS...THE COLD FRONT MOVES SLOWLY EASTWARD TO
STALL IN THE CENTRAL GULF WHILE THE WEAK LOW MOVES NORTHWARD
ALONG THE FRONT AND REACHES THE TEXAS-LOUISIANA COAST LATE
THURSDAY.  THE ADVECTION OF ABUNDANT MOISTURE ALONG WITH FORCING
BY THE UPPER LEVEL TROUGH SHOULD CONTINUE TO PROVIDE THE
POTENTIAL FOR CONVECTION DURING THE NEXT COUPLE OF DAYS IN THE
WESTERN AND CENTRAL GULF OF MEXICO INCLUDING THE COAST OF MEXICO
FROM THE BAY OF CAMPECHE TO THE U.S. GULF COAST FROM TEXAS TO
THE FLORIDA PANHANDLE.

CARIBBEAN SEA...
OUTSIDE OF THE GALE CONDITION DESCRIBED ABOVE...THE CARIBBEAN
SEA HAS NO SURFACE FEATURES OF INTEREST NOR IS THERE ANY
ORGANIZED DEEP CONVECTION.  A BROAD HIGH AMPLITUDE UPPER RIDGE
COVERS THE CARIBBEAN WITH AN AXIS ALONG 73W...WHICH IS PROMOTING
SUBSIDENCE OVER THE CARIBBEAN.  THE AFOREMENTIONED STRONG
PRESSURE GRADIENT FORCING THE GALE CONDITIONS NEAR COLOMBIA ARE
ALSO FORCING E TO NE TRADEWINDS OF 20 TO 30 KT ACROSS ALL OF THE
CARIBBEAN EXCEPT THE NORTHWEST.  LITTLE CHANGE IS EXPECTED
DURING THE NEXT TWO DAYS.

...HISPANIOLA...
GENERALLY FAIR SKIES WITH POSSIBLE ISOLATED FAST-MOVING SHOWERS
DOMINATE THE ISLAND THIS EVENING. WINDS ALONG THE COASTS WILL BE
A BRISK 20-25 KT...EXCEPT ON THE WESTWARD LEE SIDES OF THE
ISLAND. THESE CONDITIONS WILL PERSIST THROUGH AT LEAST FRIDAY
NIGHT.

ATLANTIC OCEAN...
THE MAIN SURFACE FEATURE ACROSS THE ATLANTIC IS THE RIDGING
EXTENDING FROM A 1029 MB HIGH NEAR 32N19W TO A 1030 MB HIGH NEAR
35N42W TO THE GEORGIA COASTLINE.  TRADEWINDS ARE GENERALLY NE
10-20 KT ACROSS MOST OF THE REGION WITH 25 KT E WINDS OCCURRING
JUST NORTH OF PUERTO RICO AND HISPANIOLA.  A SURFACE TROUGH
EXTENDS FROM 31N36W TO 24N56W...THOUGH NO SIGNIFICANT WEATHER IS
CURRENTLY ASSOCIATED WITH THIS FEATURE.  IN THE UPPER LEVELS...A
CUT OFF LOW IS CENTERED NEAR 22N40W.  SCATTERED SHOWERS ARE
OCCURRING FROM 18-24N BETWEEN 36-42W IN ASSOCIATION WITH THE
LOW...THOUGH NO SURFACE COMPONENT TO THE FEATURE IS CURRENTLY
PRESENT.  DURING THE NEXT COUPLE OF DAYS...THE UPPER-LEVEL LOW
WILL DRIFT SLOWLY EASTWARD AND OCCASIONALLY PRODUCE SOME
CONVECTION...BUT NO SIGNIFICANT SURFACE FEATURES ARE ANTICIPATED
TO FORM.  BY THURSDAY NIGHT...A NEW COLD FRONT WILL REACH THE
NORTHERN BORDER OF 32N WEST OF 70W.  THIS WILL PROGRESS QUICKLY
EASTWARD AND APPROACH 25N...BUT IS UNLIKELY TO CAUSE GALE
CONDITIONS.

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

$$
LANDSEA

This weather bulletin was brought to you by:
www.nashvilleweather.net