[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 150535
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SUN NOV 15 2009

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 8N13W 7N29W 6N32W 7N44W 7N48W
6N57W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-10N
BETWEEN 22W-34W NEAR A SURFACE TROUGH THAT IS ANALYZED ALONG 32W
FROM 6N-10N. SCATTERED SHOWERS ARE ALSO FOCUSED WITHIN 150 NM
EITHER SIDE OF A SURFACE TROUGH THAT IS ANALYZED FROM 13N41W TO
6N46W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NORTH OF
THE SURFACE TROUGH FROM 13N-17N BETWEEN 36W-43W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE INFLUENCES MOST OF THE GULF ANCHORED BY A 1016
MB HIGH CENTERED IN THE N/CENTRAL GULF NEAR 29N89W. THE RIDGE IS
PROVIDING GENERALLY FAIR WEATHER BASIN WIDE THIS EVENING WITH
LIGHT SURFACE WINDS E OF 93W. STRONGER SE RETURN FLOW...UP TO 20
KT IS OBSERVED IN SHIP AND BUOY DATA AS WELL AS A RECENT
SCATTEROMETER PASS ACROSS THE WRN GULF. ALOFT...AN UPPER LEVEL
RIDGE COVERS MUCH OF THE GULF WITH AXIS EXTENDING FROM SOUTHERN
MEXICO ACROSS ALONG 90W TO OVER THE SE CONUS AND MID-ATLC
STATES. STRONG SUBSIDENCE AND DRY AIR IS NOTED ON WATER VAPOR
IMAGERY WHICH EXTENDS FROM EASTERN MEXICO ACROSS THE GULF OF
MEXICO INTO THE W ATLC AND ACROSS THE NW CARIBBEAN. THE SURFACE
RIDGE IS FORECAST TO DRIFT E-NE AND WEAKEN THROUGH LATE SUNDAY
WITH THE SOUTHERLY RETURN FLOW GRADUALLY INCREASING OVER THE
WESTERN GULF AHEAD OF THE NEXT COLD FRONT TO MOVE OFF THE TEXAS
COAST MONDAY AFTERNOON.

CARIBBEAN SEA...
THE SURFACE RIDGE INFLUENCING THE GULF OF MEXICO EXTENDS ACROSS
CUBA AND THE NW CARIBBEAN SEA AND IS PROVIDING MOSTLY FAIR
WEATHER N OF 17N E OF 77W. IT IS SUPPORTED ALOFT BY AN UPPER
LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER EASTERN NICARAGUA
NEAR 12N84W AND AN UPPER RIDGE AXIS THAT EXTENDS NORTHWARD ALONG
86W TO THE YUCATAN CHANNEL. FARTHER SOUTH...UPPER LEVEL
DIFFLUENCE NEAR THE CORE OF THE UPPER LEVEL HIGH IS ENHANCING
SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE SW CARIBBEAN S OF
14N BETWEEN 77W-85W. THE REMAINDER OF THE CARIBBEAN IS
INFLUENCED BY UPPER LEVEL TROUGHING THAT EXTENDS FROM AN UPPER
LEVEL LOW CENTERED IN THE W ATLC NEAR 33N69W. THE UPPER TROUGH
AXIS EXTENDS ACROSS PUERTO RICO THEN W-SW TO NEAR 15N75W.
ISOLATED SHOWERS ARE OCCURRING ACROSS HISPANIOLA AND THE NE
CARIBBEAN N OF 16N E OF 73W.

ATLANTIC OCEAN...
A 1004 MB LOW IS CENTERED NEAR 33N71W IN THE W ATLC WITH A
SURFACE TROUGH ENTERING THE DISCUSSION AREA NEAR 32N70W AND
CONTINUING SOUTHWARD ALONG 26N68W TO 20N69W. MOST OF THE
CONVECTIVE ACTIVITY ASSOCIATED WITH THIS LOW IS LOCATED E OF THE
SURFACE TROUGH AND LARGELY ENHANCED BY UPPER LEVEL DIFFLUENCE E
OF THE SURFACE TROUGH WHICH COINCIDES WITH THE UPPER LEVEL
TROUGH AXIS ALONG 66W. SCATTERED SHOWERS AND TSTMS ARE LOCATED
IN THE UPPER DIFFLUENT AREA COVERING FROM 19N TO BEYOND 32N
BETWEEN 55W-66W. SCATTERED SHOWERS LINGER ACROSS THE TURKS AND
CAICOS ISLANDS...HISPANIOLA AND THE WINDWARD PASSAGE BEHIND THE
SURFACE TROUGH. FARTHER EAST...A 1012 MB LOW IS CENTERED NEAR
30N32W WITH A COLD FRONT EXTENDING W-SW ALONG 27N40W TO 28N50W
TO BEYOND 31N57W. SCATTERED SHOWERS ARE OCCURRING WITHIN 120 NM
EITHER SIDE OF THE COLD FRONT. SE OF THIS COLD FRONT...ANOTHER
COLD FRONT IS ANALYZED ENTERING THE DISCUSSION AREA NEAR 32N22W
AND EXTENDS SW TO 27N33W. SCATTERED SHOWERS AND TSTMS ARE WITHIN
75 NM EITHER SIDE OF THE FRONT. BOTH OF THESE COLD FRONTS ARE
SUPPORTED ALOFT BY AN UPPER LEVEL LONGWAVE TROUGH LOCATED ACROSS
THE EASTERN NORTH ATLC N OF 26N BETWEEN 20W-45W. FARTHER SOUTH
OVER THE TROPICAL ATLC...A SHORTWAVE UPPER LEVEL TROUGH EXTENDS
FROM 24N37W TO 10N50W. UPPER LEVEL DIFFLUENCE E OF THE TROUGH
AXIS IS SUPPORTING AN AREA OF SCATTERED SHOWERS AND TSTMS FROM
13N-17N BETWEEN 36W-43W.

$$
HUFFMAN



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