[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180550
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI MAR 18 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ...

ITCZ AXIS IS ALONG 04N08W TO THE EQUATOR NEAR 18W THE ALONG 01S
TO 36W AND INTO NE BRAZIL NEAR 03S43W. SCATTERED MODERATE
CONVECTION IS FROM THE EQUATOR TO 06N BETWEEN 15W-24W...AND FROM
THE EQUATOR TO 03N BETWEEN 34W-44W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE IS OVER THE SE CONUS WITH AXIS FROM
LOUISIANA NORTHEASTWARD TO THE OHIO RIVER VALLEY. SOUTH OF THIS
UPPER LEVEL RIDGE MOSTLY ZONAL WESTERLY FLOW ALOFT IS NOTED ON
WATER VAPOR IMAGERY. DRY AIR AND SUBSIDENCE ACCOMPANY THE RIDGE
WHICH FILTERS DOWN TO THE LOW-LEVELS AS A 1026 MB HIGH CENTERED
OVER THE NE GULF NEAR 29N85W PROVIDING OVERALL FAIR WEATHER FOR
THE OVERNIGHT PERIOD. LIGHT EAST TO SOUTHEAST WINDS ARE ACROSS
THE GULF WITH VERY LITTLE SIGNIFICANT PRECIPITATION NOTED ON
SATELLITE AND RADAR IMAGERY. HOWEVER...SHORTWAVE INFRARED
SATELLITE IMAGERY AND A FEW COASTAL OBSERVATIONS ARE INDICATING
THE FORMATION OF LOW-LEVEL STRATUS AND POSSIBLE FOG WITHIN 75 NM
OF THE TEXAS AND LOUISIANA GULF COASTS. THE SURFACE RIDGE IS
FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT SEVERAL DAYS
AND CONTINUE TO PROVIDE AN OVERALL STABLE WEATHER PATTERN.

CARIBBEAN SEA...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED EAST OF THE
LESSER ANTILLES NEAR 10N53W AND CONTINUES TO PROVIDE
SOUTHWESTERLY WINDS ALOFT OVER MUCH OF THE CARIBBEAN SEA BASIN.
MODERATELY DRY AIR IS ASSOCIATED WITH THE UPPER LEVEL RIDGING
WHICH EXTENDS WESTWARD TO 80W. AT THE SURFACE...A STRONG SURFACE
HIGH LOCATED OVER THE NE GULF AND PORTIONS OF THE SW NORTH ATLC
CONTINUES TO PRODUCE A LARGE AREA OF FRESH TO STRONG E-NE TRADES
OVER MUCH OF THE CARIBBEAN. THE STRONGEST WINDS ARE LOCATED IN
THE VICINITY OF THE WINDWARD PASSAGE AND ALSO ALONG THE COAST OF
COLOMBIA...MAINLY S OF 15N BETWEEN 72W-80W. THE HIGH OVER THE SW
NORTH ATLC IS EXPECTED TO REMAIN NEARLY STATIONARY AND
RELATIVELY STRONG OVER THE NEXT FEW DAYS...SO AS A RESULT...THE
TRADES ARE FORECAST TO REMAIN QUITE BRISK THROUGH THE WEEKEND.
ALTHOUGH NO SIGNIFICANT DEEP CONVECTION IS NOTED ON SATELLITE
IMAGERY...ISOLATED SHOWERS CONTINUE OVER MUCH OF THE EASTERN
HALF OF THE BASIN...WHILE ISOLATED SHOWERS CONTINUE TO PUSH
ONSHORE ALONG THE NICARAGUA...COSTA RICA...AND WESTERN PANAMA
COASTS.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS PROGRESSING ACROSS THE W ATLC WATERS
WITH AXIS ALONG 36N64W TO 30N68W TO THE FLORIDA COAST NEAR
28N80W. THE UPPER LEVEL TROUGHING SUPPORTS A COLD FRONT THAT
ENTERS THE DISCUSSION AREA 32N68W AND EXTENDS SW TO 28N77W. A
PRE-FRONTAL TROUGH IS ALSO ANALYZED FROM 30N70W TO ANDROS
ISLANDS IN THE BAHAMAS NEAR 25N78W. MOISTURE IN THE VERTICAL IS
VERY LIMITED WITH THIS FRONT...HOWEVER...MARGINAL LOW-LEVEL
CONVERGENCE IS GENERATING ISOLATED SHOWERS WITHIN 60 NM EITHER
SIDE OF THE FRONT AS IT CONTINUES TO BECOME MORE DIFFUSE. A
RECENT ASCAT PASS FROM 18/0224 UTC INDICATES STRONGER NORTHERLY
WINDS ARE LOCATED NW OF THE FRONT. THE FRONT IS FORECAST TO
SHIFT NORTHEASTWARD OVER THE NEXT 24 HOURS AND LOCATE NORTH OF
THE DISCUSSION AREA BY EARLY SATURDAY. FARTHER EAST...ANOTHER
UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY ALONG 29W
THAT SUPPORTS A COLD FRONT ANALYZED FROM 32N30W TO 28N31W THEN
W-SW ALONG 24N40W TO 25N59W. SCATTERED SHOWERS ARE OCCURRING
WITHIN 150 NM EAST OF THE FRONT N OF 26N WHILE ISOLATED SHOWERS
LINGER WITHIN 60 NM EITHER SIDE OF THE FRONT W OF 33W.

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

$$
HUFFMAN




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