[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 210556
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST THU FEB 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA AND ENTERS THE TROPICAL
E ATLC ALONG THE NORTHERN LIBERIA COAST TO 4N12W 3N14W. THE ITCZ
CONTINUES FROM 3N14W TO 2N25W EQ36W EQ45W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM THE EQUATOR TO 4N BETWEEN 15W-35W.
SIMILAR CONVECTION IS FROM 2S TO 5N BETWEEN 37W AND 50W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 0300 UTC...A STATIONARY FRONT EXTENDS FROM S FLORIDA NEAR
25N81W THEN NW TO 26N87W 29N93W. IN THE NW GULF N OF 24N WEST OF
89W BROKEN TO OVERCAST SKIES ARE GENERATING SCATTERED MODERATE
CONVECTION. MOISTURE ADVECTION BY SOUTHEASTERLY FLOW AS WELL AS
MOISTURE ADVECTION FROM THE EAST PACIFIC IS SUPPORTING THE
RAINSHOWERS IN THE AFOREMENTIONED REGION. THE STRONGEST WINDS IN
THE BASIN ARE FOUND IN THE NW GULF RANGING FROM 20-30 KT WHILE
ELSEWHERE WINDS OF 15 KT DOMINATE. ISOLATED SHOWERS ARE ALONG
THE FRONTAL BOUNDARY AND OVER THE NE GULF. IN THE UPPER
LEVELS...STRONG ZONAL FLOW PREVAILS ASSOCIATED TO A 70-110 KT
JET N OF 25N. WITHIN 24 HOURS...SOUTHERLY FLOW WILL BUILD OVER
THE ENTIRE GULF GENERATING A WARM FRONT FOR THE SOUTHERN STATES
WHILE A COLD FRONT ENTERS THE NW GULF. RAINSHOWERS ARE EXPECTED
TO CONTINUE OVER THE NW AND N-CENTRAL GULF.

CARIBBEAN SEA...
TRADEWINDS OF 15-20 KT SPREAD OVER THE CENTRAL AND EASTERN
CARIBBEAN REGIONS WHILE LIGHTER WINDS IN THE RANGE OF 10-15 KT
DOMINATE OVER THE WESTERN REGION. NORTHEASTERLY WINDS IN THE
RANGE OF 20-30 KT ARE OVER THE SOUTHERN CARIBBEAN TRIGGERING
SHOWERS ALONG THE COAST OF COSTA RICA AND PANAMA. NEARLY
WESTERLY FLOW AND VERY DRY AIR IS DEPICTED IN THE UPPER LEVELS.
THESE CONDITIONS IN THE UPPER LEVELS ARE SUPPRESSING DEEP
CONVECTION IN THE ENTIRE BASIN. LOW LEVEL CLOUDS DOT THE WATERS
SE OF PUERTO RICO AND ISOLATED SHOWERS ARE POSSIBLE. EXPECT
LITTLE CHANGE OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
AS OF 0300 UTC AND IN THE WEST ATLC...A COLD FRONT EXTENDS FROM
30N68W TO 27N74W WHERE IT TRANSITIONS TO A STATIONARY FRONT THAT
STRETCH TO S FLORIDA AND THEN OVER THE GULF WATERS. SCATTERED
SHOWERS ARE WITHIN 40 NM EITHER SIDE OF THE COLD FRONT N OF 28N.
ISOLATED SHOWERS ARE POSSIBLE ALONG THE REMAINDER FRONTAL
BOUNDARY. A PREFRONTAL TROUGH EXTENDS ALONG 29N66W 27N67W TO
25N68W. NO CONVECTIVE PRECIPITATION IS NOTED AT THIS TIME
ASSOCIATED TO THIS FEATURE. SURFACE RIDGING DOMINATES THE
CENTRAL...EASTERN AND THE W ATLC E OF 67W ANCHORED BY A 1025 MB
HIGH LOCATED NEAR 29N45W. WEST OF THE HIGH WIDELY SCATTERED
SHOWERS ARE FROM 25N-30N BETWEEN 50W AND 60W. E OF THE
HIGH...THE TAIL END OF A COLD FRONT EXTENDS OVER THE E ATLANTIC
FROM 30N25W TO 27N35W. THERE IS NO CONVECTIVE PRECIPITATION
ASSOCIATED TO THIS FRONTAL BOUNDARY BUT ISOLATED SHOWERS ARE
POSSIBLE ALONG THE FRONT. WATER VAPOR IMAGERY SHOWS VERY DRY AIR
COVERING ALMOST THE ENTIRE REGION WHICH IS FAVORING FAIR WEATHER
CONDITIONS ELSEWHERE IN THE ATLC. IN 24 HOURS...THE COLD FRONT
IN THE W ATLC MOVES N OF THE DISCUSSION AREA WHILE THE FRONT IN
THE E ATLC GRADUALLY VANISHES.

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

$$
NR





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