000
AXNT20 KNHC 190004
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT OCT 18 2008

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...
NONE.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 36W S OF 16N MOVING W 10-15 KT. VERY
BROAD INVERTED-V CURVATURE IS OBSERVED ON SATELLITE IMAGERY.
WIDELY SCATTERED MODERATE CONVECTION IS FROM 14N-19N BETWEEN
32W-38W.

TROPICAL WAVE IS ALONG 56W S OF 16N MOVING W NEAR 10 KT. WEAK
INVERTED-V CURVATURE IS OBSERVED ON SATELLITE IMAGERY. NO
SIGNIFICANT CONVECTION IS NOTED.

...THE ITCZ...
ITCZ AXIS IS ANALYZED ALONG 8N11W 7N20W 11N36W 9N45W 11N56W
9N61W. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE
ALONG THE COAST OF WEST AFRICA FROM 3N-12N BETWEEN 10W-20W
MOVING W. ISOLATED MODERATE CONVECTION IS FROM 13N-15N BETWEEN
28W-32W. SCATTERED MODERATE CONVECTION IS OVER THE WINDWARD
ISLANDS FROM 9N-13N BETWEEN 58W-62W.

...DISCUSSION...

GULF OF MEXICO...
COLD FRONT EXTENDS FROM CENTRAL FLORIDA TO THE CENTRAL GULF OF
MEXICO ALONG 29N81W 25N90W. A STATIONARY FRONT CONTINUES TO THE
BAY OF CAMPECHE ALONG 21N92W 18N92W. N OF FRONT WINDS ARE FROM
THE N AT 15-20 KT. S OF FRONT WINDS ARE FROM THE S AT 5-10 KT.
NORTHERLY SURFACE WINDS ARE ENTERING THE ISTHMUS OF TEHUANTEPEC
PRODUCING GALE FORCE GAP WINDS THAT ARE EXITING TO THE E
PACIFIC. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS
ARE OVER THE YUCATAN...S MEXICO...AND THE BAY OF CAMPECHE...
WITHIN 60 NM ALONG THE COAST. ISOLATED SHOWERS ARE ALSO OVER THE
STRAITS OF FLORIDA BETWEEN 80W-84W. A SURFACE RIDGE IS BUILDING
S OVER THE NW GULF OF MEXICO WITH DRY/STABLE AIR PRODUCING CLEAR
SKIES OVER THE N GULF BEHIND THE FRONT. IN THE UPPER
LEVELS...THE BASE OF A TROUGH IS PRODUCING ZONAL FLOW OVER THE
ENTIRE GULF OF MEXICO. STRONG SUBSIDENCE COVERS THE GULF EXCEPT
WITHIN 60 NM OF A LINE FROM COCOA BEACH FLORIDA TO TAMPICO
MEXICO. EXPECT THE FRONT TO EXTEND FROM S FLORIDA TO THE BAY OF
CAMPECHE IN 24 HOURS WITH PRECIPITATION CONFINED TO THE BAY OF
CAMPECHE.

CARIBBEAN SEA...
FRESH TRADEWINDS ARE OVER THE CARIBBEAN SEA. A 1011 MB LOW IS
CENTERED OVER THE NW CARIBBEAN NEAR 18N87W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 15N-21N BETWEEN 83W-88W. ANOTHER
1011 MB LOW IS CENTERED OVER THE CENTRAL CARIBBEAN S OF JAMAICA
NEAR 17N77W. NO SIGNIFICANT CONVECTION IS NOTED WITH THIS LOW.
ELSEWHERE...WIDELY SCATTERED MODERATE CONVECTION IS INLAND OVER
CENTRAL AMERICA FROM PANAMA TO HONDURAS...AND IS OVER THE SW
CARIBBEAN FROM 10N-12N BETWEEN 81W-83W. SCATTERED MODERATE
CONVECTION IS ALSO OVER THE COAST OF N COLOMBIA FROM 10N-12N
BETWEEN 72W-76W. IN THE UPPER LEVELS...A SMALL UPPER LEVEL HIGH
IS CENTERED OVER THE NW CARIBBEAN NEAR 19N86W. THE BASE OF A
LARGE RIDGE IS OVER THE E CARIBBEAN E OF 70W PRODUCING MOSTLY
EASTERLY FLOW. SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE W
CARIBBEAN AND CENTRAL AMERICA W OF 80W...AND IS OVER NORTHERN
SOUTH AMERICA S OF 13N. EXPECT CONTINUED CONVECTION OVER THE W
CARIBBEAN W OF 80W OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
A COLD FRONT IS OVER THE W ATLANTIC FROM 32N76W AND EXTENDS SW
TO CENTRAL FLORIDA NEAR 29N80W. NO SIGNIFICANT PRECIPITATION IS
NOTED. A 1018 MB HIGH IS FURTHER E OVER THE W ATLANTIC NEAR
28N65W. THE REMNANTS OF OMAR ARE OVER THE CENTRAL ATLANTIC NEAR
34N51W WITH 1005 MB MOVING NE FURTHER OUT OF THE AREA. A 1026 MB
HIGH IS OVER THE E ATLANTIC NEAR 32N31W. A RIDGE AXIS EXTENDS SW
FROM THE HIGH TO 26N43W. IN THE UPPER LEVELS...AN UPPER LEVEL
LOW IS CENTERED OVER THE W ATLANTIC NEAR 28N63W. AN UPPER LEVEL
HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 21N55W. AN UPPER
LEVEL LOW IS OVER THE E ATLANTIC NEAR 16N43W. AN UPPER LEVEL
HIGH IS CENTERED OVER THE CAPE VERDE ISLANDS NEAR 14N26W. THE
BASE OF A TROUGH IS OVER THE CANARY ISLAND E OF 30W N OF 20N.

$$
FORMOSA