[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191120
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI FEB 19 2010

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0745 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED FROM LIBERIA NEAR 6N10W ALONG 4N20W
1N30W 1N40W TO THE NE BRAZIL COAST NEAR 2N53W. SCATTERED
MODERATE/ ISOLATED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE
OF THE AXIS BETWEEN 12W-14W...AND BETWEEN 16W-27W.

...DISCUSSION...

GULF OF MEXICO...
SURFACE RIDGING AROUND A NEARLY STATIONARY 1024 MB HIGH JUST
OFFSHORE OF MOBILE ALABAMA CONTINUES TO IMPACT THE GULF OF
MEXICO THIS MORNING KEEP THE LOW LEVELS OF THE ATMOSPHERE DRY
AND STABLE. HOWEVER...CONVERGENCE NEAR A SURFACE TROUGH LINING
THE S TEXAS AND MEXICO COASTLINE FROM 27N97W TO 21N97W IS
SUPPORTING SCATTERED SHOWERS...HEAVY IN SOME AREAS...S OF 29N W
OF 93W INDICATED BY RADAR IMAGERY. LIGHT ANTICYCLONIC FLOW IS
AROUND THE SURFACE RIDGE...WITH SELY RETURN FLOW INCREASING TO
20 KT ACROSS THE WRN GULF. IN THE UPPER LEVELS...SWLY FLOW ALOFT
AROUND AN UPPER LEVEL RIDGE ACROSS THE GULF AND CENTRAL CONUS
ALONG WITH A STRONG JET STREAM ACROSS THE NRN GULF IS CARRYING
UPPER LEVEL MOISTURE FROM THE E PACIFIC ACROSS MEXICO AND INTO
THE GULF SUPPORTING HIGH CLOUDS ACROSS THE BASIN. AN APPROACHING
SHORTWAVE UPPER LEVEL TROUGH CURRENTLY OVER CENTRAL TEXAS AND
MEXICO IS SUPPORTING THE SURFACE TROUGH ALONG THE MEXICO
COASTLINE. EXPECT THE SURFACE RIDGE TO SHIFT EWD ALLOWING RETURN
FLOW TO INCREASE ACROSS THE WRN GULF AHEAD OF THE NEXT COLD
FRONT FORECAST TO MOVE OVER THE NW WATERS LATE SUN.

CARIBBEAN SEA...
UPPER LEVEL MOISTURE BEING DRAWN OVER THE GULF OF MEXICO IS ALSO
MAKING ITS WAY ACROSS THE FAR NW CARIBBEAN SUPPORTING HIGH
CLOUDS. A COLD FRONT ACROSS THE CENTRAL ATLC HAS NOW PUSHED
ACROSS HISPANIOLA AND PUERTO RICO EXTENDING FROM THE VIRGIN
ISLANDS NEAR 18N65W ALONG 17N70W TO 17N74W WHERE IT BECOMES A
DYING STATIONARY FRONT TO THE COSTA RICA/PANAMA BORDER.
SCATTERED SHOWERS ARE ACROSS PUERTO RICO AND HISPANIOLA...WITH
ISOLATED SHOWERS WITHIN 150 NM NW OF THE STATIONARY BOUNDARY S
OF 16N. THE REMAINDER OF THE BASIN IS EXPERIENCING GENERALLY
FAIR WEATHER WITH MODERATE TO FRESH TRADEWINDS UNDER THE
INFLUENCE OF DRY AIR AND SUBSIDENCE AROUND AN UPPER LEVEL RIDGE
ALONG 65W. EXPECT THE STATIONARY BOUNDARY TO DISSIPATE BY
TONIGHT...WHILE THE COLD FRONT CONTINUES TO PUSH INTO THE NE
CARIBBEAN.

ATLANTIC OCEAN.
A COLD FRONT PROGRESSES ACROSS THE CENTRAL ATLC ENTERING THE
DISCUSSION AREA NEAR 32N42W ALONG 23N55W TO THE VIRGIN ISLANDS
NEAR 18N65W. A SECONDARY COLD FRONT TRAILS BEHIND ALONG 32N47W
TO 26N55W. SCATTERED SHOWERS ARE WITHIN 200 NM BEHIND...AND 60
NM AHEAD OF THE PRIMARY FRONT. GALE FORCE WINDS ARE NOTED N OF
28N BETWEEN 52W-65W. A LARGE AREA OF STRATOCUMULUS CLOUDS COVER
THE W ATLC IN THE WAKE OF THE FRONT. AN UPPER LEVEL LONGWAVE
TROUGH EXTENDING FROM AN UPPER LEVEL LOW N OF NOVA SCOTIA
SUPPORTS THE FRONTAL SYSTEM. UPPER LEVEL DIFFLUENCE BETWEEN THIS
UPPER LEVEL TROUGH AND AN UPPER LEVEL RIDGE TO THE E WITH AXIS
FROM THE LESSER ANTILLES TO THE AZORES IS ENHANCING THE LARGE
AREA OF SHOWER ACTIVITY NEAR THE FRONT...AS WELL AS SCATTERED
SHOWERS WELL E OF THE FRONT N OF 29N W OF 35W. THE UPPER LEVEL
RIDGE ACROSS THE CENTRAL ATLC ALSO SUPPORTS A SURFACE RIDGE
DOMINATING THE REMAINDER OF THE BASIN ANCHORED BY A 1018 MB
SURFACE HIGH CENTERED NEAR 23N30W. THE RIDGE IS PROVIDING
GENERALLY FAIR WEATHER ACROSS THE ERN ATLC. A SHORTWAVE UPPER
LEVEL TROUGH EXTENDING FROM THE CANARY ISLANDS TO THE CAPE VERDE
ISLANDS IS MOST LIKELY SUPPORTING THE AREA OF CONVECTION ALONG
THE ERN ITCZ.

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

$$
WALTON




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