[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261051
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT SEP 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...

TROPICAL DEPRESSION EIGHT IS CENTERED NEAR 17.6N 33.8W AT
26/0900 UTC OR ABOUT 575 NM W OF THE CAPE VERDE ISLANDS MOVING
WNW AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB.
MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE
THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. SCATTERED MODERATE WITH
EMBEDDED CLUSTERS OF ISOLATED STRONG CONVECTION COVERS THE AREA
FROM 16N-20N BETWEEN 31W-34W.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 65W/66W S OF 18N MOVING W NEAR 15 KT.
WAVE REMAINS IN AN AREA OF RATHER DRY STABLE AIR. HOWEVER
DIFFLUENCE ALOFT IS ENSUING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS FROM 12N-15N BETWEEN THE WAVE AXIS AND THE
WINDWARD ISLANDS.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 12N13W 8N23W 13N36W 8N60W. A
SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ EXTENDING FROM 12N20W
TO 6N21W WITH CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN
90 NM EITHER SIDE OF THE TROUGH AXIS. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION IS WITHIN 75 NM OF LINE FROM 8N48W TO
11N53W. CLUSTERS OF SIMILAR CONVECTION ARE FROM 6N-9N BETWEEN
22W-26W.

...DISCUSSION...

GULF OF MEXICO...
A STATIONARY FRONT REMAINS OVER THE W GULF ENTERING FROM
LOUISIANA OVER VERMILION BAY CONTINUING ALONG 27N96W INTO THE
BAY OF CAMPECHE AND S MEXICO TO NEAR 18N94W. SCATTERED SHOWERS/
THUNDERSTORMS ARE W OF THE FRONT TO THE COAST OF TEXAS AND S OF
26N W OF 93W TO INLAND OVER MEXICO. BROAD UPPER RIDGE ANCHORED
OVER THE NE GULF JUST S OF THE BIG BEND AREA OF FLORIDA
EXTENDING AN AXIS SW TO JUST S OF BROWNSVILLE TEXAS FORCING
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE GULF WATERS
FROM 24N-29N BETWEEN THE W COAST OF FLORIDA AND 84W. POSSIBLE
ISOLATED SHOWERS DOT THE REMAINDER OF THE GULF.

CARIBBEAN SEA...
A SHARP UPPER TROUGH EXTENDS FROM THE W/CENTRAL ATLC OVER HAITI
TO THE YUCATAN PENINSULA OVER N BELIZE GIVING THE ENTIRE
CARIBBEAN W TO SW UPPER WINDS AND GENERATING SCATTERED SHOWERS
AND POSSIBLE ISOLATED THUNDERSTORMS FROM 17N-20N BETWEEN 71W-83W
INCLUDING JAMAICA. AN UPPER RIDGE STILL EXTENDS OVER THE SW
CARIBBEAN FROM CENTRAL PANAMA TO CENTRAL AMERICA OVER NICARAGUA
PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS OVER THE SW CARIBBEAN S OF A LINE FROM
COLOMBIA NEAR 10N75W TO NICARAGUA NEAR 14N84W. FRESH TO STRONG
EASTERLY TRADE WINDS CONTINUE ACROSS THE AREA WITH THE CENTRAL
CARIBBEAN REMAINING RATHER CLEAR AGAIN THIS MORNING WITH THE
EXCEPTION OF ISOLATED SHOWERS OVER THE ABC ISLANDS TO INLAND
OVER VENZUELA.

ATLANTIC OCEAN...
BROAD UPPER RIDGE ANCHORED IN THE NE GULF OF MEXICO COVERS THE W
ATLC AND COMBINED WITH A SHARP UPPER TROUGH IN THE W/CENTRAL
ATLC THAT EXTENDS THROUGH 32N58W 24N66W OVER HAITI INTO THE
CARIBBEAN ARE PRODUCING STRONG NE UPPER WINDS OVER THE W ATLC W
OF THE UPPER TROUGH. THE UPPER TROUGH IS SUPPORTING A SURFACE
TROUGH THAT EXTENDS FROM 31N63W 27N67W TO 22N71W. THE UPPER
TROUGH IS ALSO PRODUCING A LARGE AREA WITH CLUSTERS OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS N OF 23N BETWEEN 48W-64W AND
SIMILAR ACTIVITY WITHIN 90 NM ALONG THE COAST OF HISPANIOLA. THE
E ATLC IS DOMINATED BY A SURFACE RIDGE N OF 23N E OF 50W. THE
FIRST VISIBLE SATELLITE IMAGES SHOW YET ANOTHER SURGE OF SAHARAN
DUST COVERING THE FAR E TROPICAL ATLC FROM 14N-26 ACROSS THE
CAPE VERDE ISLANDS TO 30W...WHICH IS JUST TO THE E OF T.D.
EIGHT.

$$
WALLACE






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