[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 050533
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST WED NOV 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURE...
A BROAD AREA OF LOW PRESSURE OVER THE SW CARIBBEAN SEA IS
DRIFTING NORTH-NORTHWESTWARD. A SURFACE TROUGH EXTENDS FROM N OF
PANAMA NEAR 9N81W TO A 1008 MB SURFACE LOW E OF THE COAST OF
NICARAGUA NEAR 14N82W TO E CUBA NEAR 21N78W. LOW LEVEL
CONVERGENCE NEAR THE LOW AND TROUGH...COMBINED WITH DEEP
MOISTURE AND UPPER LEVEL DIVERGENCE OVER THE W CARIBBEAN...IS
SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS FROM 11N-21N
BETWEEN 74W-84W. THIS SYSTEM CONTINUES TO SHOW SOME SIGNS OF
ORGANIZATION...AND COULD BECOME A TROPICAL DEPRESSION DURING THE
NEXT DAY OR TWO AS IT CONTINUES MOVING SLOWLY TO THE
NORTH-NORTHWEST OR NORTH.

...THE ITCZ...
ITCZ AXIS IS ANALYZED ALONG 8N13W 6N20W 5N32W 6N38W 1N51W.
SCATTERED MODERATE CONVECTION IS WITHIN 150 NM EITHER SIDE OF
THE ITCZ AXIS BETWEEN 20W-29W...WHICH IS BEING ENHANCED BY WEAK
UPPER LEVEL DIVERGENCE. SCATTERED MODERATE CONVECTION IS FROM
2N-9N BETWEEN 30W-39W...WHICH IS BEING ENHANCED BY STRONG UPPER
LEVEL DIVERGENCE.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH OVER THE E CONUS EXTENDS INTO THE GULF.
DEEP LAYER SUBSIDENCE COVERS THE NW GULF...WHERE NORTHWESTERLY
FLOW ALOFT IS IN PLACE. ADDITIONALLY...SUBSIDENCE IS OCCURRING
IN ASSOCIATION WITH A SURFACE RIDGE OF HIGH PRESSURE OVER THE SE
CONUS THAT EXTENDS INTO THE GULF. ALSO...DEEP LAYER DRY AIR IS
CIRCULATING CYCLONICALLY AROUND THE BASE OF THE UPPER TROUGH
ACROSS MUCH OF THE GULF. THE COMBINATION OF THE SUBSIDENCE AND
DEEP LAYER DRY AIR IS MAINTAINING GENERALLY FAIR WEATHER
CONDITIONS ACROSS THE GULF REGION.

CARIBBEAN SEA...
AN UPPER LEVEL HIGH IS OVER THE E CARIBBEAN NEAR 17N72W...WITH
THE ANTICYCLONIC FLOW AROUND THE HIGH COVERING MUCH OF THE
CARIBBEAN. DEEP MOISTURE AND UPPER LEVEL DIVERGENCE W OF THE
HIGH...AS WELL AS LOW LEVEL CONVERGENCE AROUND A SURFACE LOW AND
SURFACE TROUGH IN THE W CARIBBEAN...ARE SUPPORTING SHOWERS AND
THUNDERSTORMS OVER THE W CARIBBEAN. PLEASE SEE THE SPECIAL
FEATURE SECTION ABOVE FOR MORE INFORMATION ON THIS SYSTEM. DEEP
LAYER DRY AIR E OF THE UPPER HIGH IS RESULTING IN GENERALLY FAIR
WEATHER CONDITIONS ACROSS THE E CARIBBEAN. ALSO...DEEP LAYER DRY
AIR OVER THE GULF OF MEXICO IS MOVING INTO THE FAR NW CARIBBEAN.

ATLANTIC OCEAN...
STRONG WEST-SOUTHWESTERLY FLOW ALOFT E OF AN UPPER TROUGH AXIS
OVER THE E CONUS IS ENHANCING UPPER LEVEL DIVERGENCE AND DEEP
ATMOSPHERIC LIFT OVER PORTIONS OF THE W ATLC. ALSO...A 1008 MB
SURFACE LOW IS CENTERED E OF FLORIDA NEAR 31N75W. TO THE S OF
THE LOW...A COLD FRONT EXTENDS FROM 31N75W TO 26N73W TO 22N73W.
TO THE E OF THE LOW...A WARM FRONT EXTENDS FROM 31N75W TO 31N70W
TO 31N66W. TO THE N OF THE LOW...A SURFACE TROUGH EXTENDS FROM
31N74W TO 32N75W TO NW OF THE DISCUSSION AREA. LOW LEVEL
CONVERGENCE IS FURTHER ENHANCING THE DEEP ATMOSPHERIC LIFT NEAR
THE SURFACE FRONTS...TROUGH...AND LOW...WHERE DEEP MOISTURE IS
MOVING NORTHEASTWARD FROM THE W CARIBBEAN. AS A RESULT...
ISOLATED MODERATE CONVECTION IS N OF 23N BETWEEN 58W-74W.
FARTHER TO THE E...AN UPPER LEVEL TROUGH IS PRESENT WITH AN AXIS
THAT EXTENDS FROM 3N44W TO 15N40W TO 32N44W TO NW OF THE
DISCUSSION AREA. THIS UPPER TROUGH IS ACCOMPANIED BY TWO SURFACE
TROUGHS. ONE SURFACE TROUGH EXTENDS FROM 10N48W TO 15N48W TO
21N46W...WITH ISOLATED MODERATE CONVECTION FROM 13N-21N BETWEEN
39W-48W. THE SECOND SURFACE TROUGH EXTENDS FROM 26N44W TO 29N41W
TO 32N38W...WITH ISOLATED MODERATE CONVECTION N OF 27N BETWEEN
34W-42W...WHICH IS BEING ENHANCED BY A COLD FRONT THAT EXTENDS
FROM 31N45W TO 32N42W TO NE OF THE DISCUSSION AREA. ALSO...AN
UPPER RIDGE IS PRESENT WITH AN AXIS THAT EXTENDS FROM 16N16W TO
19N21W TO 27N25W...WITH ASSOCIATED UPPER LEVEL DIVERGENCE S OF
THE RIDGE AXIS ENHANCING THE CONVECTION IN THE VICINITY OF THE
ITCZ AXIS.

$$
COHEN



This weather bulletin was brought to you by:
www.nashvilleweather.net