[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI NOV 21 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 55W/56W S OF 13N MOVING W NEAR 10 KT.
SATELLITE IMAGERY INDICATES THAT THIS WAVE COINCIDES WITH A
WELL-DEFINED INVERTED-V PATTERN IN CLOUD COVERAGE...WHERE CIMSS
WAVETRAK PRODUCT INDICATES A MAXIMUM IN LOW LEVEL CYCLONIC
CIRCULATION. ADDITIONALLY...A MAXIMUM IN DEEP LAYER MOISTURE
COINCIDES WITH THIS WAVE BASED ON TOTAL PRECIPITABLE WATER
PRODUCT FROM CIMSS. SCATTERED SHOWERS ARE OCCURRING WITHIN 60
NM EITHER SIDE OF THE WAVE AXIS N OF 9N. TRENDS IN SATELLITE
IMAGERY INDICATE THAT THIS TROPICAL WAVE IS NOW DETACHED FROM A
NEARLY STATIONARY AREA OF LOW LEVEL CYCLONIC CIRCULATION FARTHER
NORTH...WHICH IS BEING ANALYZED AS A SURFACE TROUGH EXTENDING
FROM 20N52W TO 17N52W TO 15N51W.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 12N16W 6N30W 4N51W. SCATTERED
MODERATE CONVECTION IS FROM 3N-4N BETWEEN 32W-36W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 1500 UTC A COLD FRONT EXTENDS FROM CENTRAL FLORIDA TO THE
CENTRAL GULF OF MEXICO TO NE MEXICO NEAR TAMPICO ALONG 29N80W
27N84W 26N90W 26N96W 23N98W. OVERCAST LOW CLOUDS WITH SCATTERED
SHOWERS ARE OVER S TEXAS AND NE MEXICO FROM 20N-28N BETWEEN
95W-100W. 20-25 KT NORTHERLY WINDS ARE N OF THE FRONT. 10-15 KT
NORTHERLY WINDS ARE S OF THE FRONT. THIS MODIFIED CONTINENTAL
POLAR FRONT WILL REQUIRE FREEZE WARNINGS FOR N FLORIDA FOR
TONIGHT AND SATURDAY MORNING. ADDITIONALLY...STRONG N TO NE
SURFACE WINDS ARE FUNNELING THROUGH THE ISTHMUS OF TEHUANTEPEC
RESULTING IN GALE FORCE WINDS IN THE E PACIFIC. IN THE UPPER
LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS SUPPORTING THE
COLD FRONT. UPPER LEVEL WINDS ARE PREDOMINATELY FROM THE WNW AT
90-110 KT. STRONG SUBSIDENCE COVERS THE ENTIRE GULF OF MEXICO.
EXPECT...THE FRONT TO EXTEND FROM THE STRAITS OF FLORIDA TO THE
BAY OF CAMPECHE IN 24 HOURS WITH SHOWERS OVER THE W GULF W OF
90W.

CARIBBEAN SEA...
IN THE SW CARIBBEAN...A 1009 MB SURFACE LOW IS LOCATED N OF
PANAMA NEAR 10N81W. ADDITIONALLY...A SURFACE STATIONARY FRONT
EXTENDS NE FROM THIS SURFACE LOW TO 15N77W TO 20N64W. LOW LEVEL
CONVERGENCE NEAR THE SURFACE LOW AND SURFACE FRONT IS
INTERACTING WITH DEEP LAYER MOISTURE OVER THE S CARIBBEAN TO
GENERATE SCATTERED SHOWERS AND THUNDERSTORMS OVER THE S
CARIBBEAN S OF 15N W OF 77W. SCATTERED SHOWERS ARE ALSO OVER THE
E CARIBBEAN E OF 70W. ISOLATED MODERATE CONVECTION IS OVER THE
SE CARIBBEAN FROM 11N-14N BETWEEN 60W-68W. IN THE UPPER LEVELS
...A RIDGE COVERS THE ENTIRE CARIBBEAN SEA WITH AXIS FROM
TRINIDAD TO THE YUCATAN PENINSULA. SIGNIFICANT UPPER LEVEL
MOISTURE IS S OF 16N. EXPECT... LITTLE CHANGE WITH THE
STATIONARY FRONT FOR THE NEXT 24 HOURS.

ATLANTIC OCEAN...
A 1020 MB HIGH IS OVER THE W ATLANTIC NEAR 27N69W. A STATIONARY
FRONT EXTENDS FROM 32N49W TO N OF PUERTO RICO ALONG 32N49W
22N60W 20N65W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT.A
1015 MB LOW IS OVER THE CENTRAL ATLANTIC NEAR 27N45W. ANOTHER
1013 MB LOW IS OVER THE E ATLANTIC NEAR 24N30W. A TROUGH EXTENDS
S FROM THIS LOW TO 20N32W 18N35W. SCATTERED SHOWERS ARE WITHIN
60 NM OF THE TROUGH. IN THE UPPER LEVELS...ZONAL FLOW IS N OF
20N AND W OF 40W. AN UPPER LEVEL LOW IS CENTERED OVER THE E
ATLANTIC NEAR 33N22W. A TROUGH IS N OF 20N AND E OF 40W. ZONAL
FLOW IS OVER THE TROPICS S OF 20N AND E OF 50W.

$$
FORMOSA





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