[Tropical] Tropical Weather Discussion

EMWIN Server emwin at nashvilleweather.net
Wed Oct 8 19:06:40 CDT 2014


AXNT20 KNHC 090006
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED OCT 08 2014

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE EASTERN ATLANTIC ASSOCIATED WITH A
1011 MB LOW NEAR 10N21W EMBEDDED IN THE MONSOON TROUGH. THE AXIS
OF THE WAVE EXTENDS FROM 14N21W TO THE LOW TO 8N21W...MOVING W
AT 5-10 KT. A MIDDLE-LEVEL INVERTED TROUGH SUPPORTS THIS WAVE
THAT IS ASSOCIATED WITH DEEP LAYER MOISTURE. A DIFFLUENT
ENVIRONMENT ALOFT HAS BEEN SUPPORTING THE CONVECTION OF THIS WAVE
THAT HAS DECREASED IN THE LAST COUPLE OF HOURS PARTLY DUE TO A
STRONG DEEP LAYER ENVIRONMENTAL SHEAR. ISOLATED MODERATE
CONVECTION IS FROM 6N-16N BETWEEN 20W-25W.

A TROPICAL WAVE IS WITHIN 700 NM EAST OF THE LESSER ANTILLES
WITH AXIS EXTENDING FROM 18N48W TO 6N49W...MOVING W AT 10-15 KT.
MIDDLE TO UPPER LEVEL DRY AIR IS OBSERVED IN THE GOES-R AIRMASS
PRODUCT W OF THE WAVE AXIS...AREA CURRENTLY DEVOID OF
CONVECTION. HOWEVER...MIDDLE TO HIGH LEVEL CLOUDS ARE EAST OF
THE AXIS WHERE DEEP LAYER MOISTURE AND A DIFFLUENT ENVIRONMENT
ALOFT SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS
FROM 8N-20N BETWEEN 40W-49W.

A TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN WITH AXIS
EXTENDING FROM 18N66W TO 11N69W...MOVING W AT 15 KT. SSMI TPW
IMAGERY SHOW THE WAVE IS IN A MODERATE MOIST ENVIRONMENT IN THE
LOWER TO MIDDLE LEVELS...HOWEVER STRONG DEEP LAYER ENVIRONMENTAL
SHEAR IN THIS REGION OF THE BASIN INHIBITS THE DEVELOPMENT OF
DEEP CONVECTION. ISOLATED SHOWERS AND TSTMS ARE SW OF PUERTO
RICO FROM 17N-18N WITHIN 60 NM W OF THE AXIS.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE COAST OF AFRICA NEAR 14N17W
SW TO A 1011 MB SURFACE LOW NEAR 10N21W AND THEN CONTINUES ALONG
8N30W TO 11N38W. THE ITCZ EXTENDS FROM 10N39W TO 10N48W. BESIDES
THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES AND SURFACE
LOW...SCATTERED MODERATE CONVECTION IS FROM 5N-14N BETWEEN 26W-
40W.

...DISCUSSION...

GULF OF MEXICO...

SURFACE RIDGING DOMINATES ACROSS THE BASIN BEING ANCHORED BY A
1018 MB HIGH IN THE NE GULF NEAR 29N84W AND SUPPORTED BY A
MIDDLE LEVEL ANTICYCLONE CENTERED NEAR 28N94W. THE RIDGE IS
PROVIDING E-SE WINDS OF 5-15 KT N OF 22N AS WELL AS SUPPORTING
STABLE WEATHER CONDITIONS. IN THE SW GULF...A MIDDLE-LEVEL
INVERTED TROUGH SUPPORTS A SURFACE TROUGH ALONG 23N92W TO
16N94W...WHICH IS ENHANCING ISOLATED SHOWERS AND TSTMS WITHIN
160 NM W OF THE TROUGH. FAIR WEATHER IS ELSEWHERE BEING
SUPPORTED BY DRY AIR SUBSIDENCE. SURFACE RIDGING AND FAIR
WEATHER WILL DOMINATE ACROSS THE BASIN THE NEXT THREE DAYS.

CARIBBEAN SEA...

ABUNDANT DEEP LAYER MOISTURE IS IN A PORTION OF THE NW AND SW
CARIBBEAN COLOCATED WITH A BROAD AREA OF DIVERGENT FLOW IN THE
UPPER LEVELS. THESE TWO FACTORS ALONG WITH INSTABILITY PROVIDED
BY THE PASSAGE OF A TROPICAL WAVE CURRENTLY ALONG 92W SUPPORT
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION S OF 20N W OF
80W. A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL-EASTERN CARIBBEAN
WITH AXIS ALONG 68W. SEE THE TROPICAL WAVE SECTION ABOVE FOR
DETAILS. AN ELONGATED MIDDLE TO UPPER LEVEL TROUGH NE OF PUERTO
RICO SUPPORT A SURFACE TROUGH THAT EXTENDS FROM THE ATLC ALONG
THE LESSER ANTILLES FROM 16N61W TO 13N61W...THUS ENHANCING
SHOWERS THIS REGION OF THE ANTILLES. OTHERWISE...ISOLATED
SHOWERS AND TSTMS ARE WITHIN 40 NM OF EASTERN CUBA. THE
REMAINDER BASIN IS BEING INFLUENCED BY STRONG DEEP LAYER
ENVIRONMENTAL SHEAR AND DRY AIR SUBSIDENCE...THUS SUPPORTING
FAIR WEATHER. TRADES OF 10 TO 15 KT DOMINATE ACROSS THE REGION
DUE TO A RELAXED PRESSURE GRADIENT. THE NEXT TROPICAL WAVE WILL
ENTER THE EASTERN BASIN SATURDAY MORNING WHILE THE FORMER WAVE
MOVES ACROSS THE CENTRAL-WESTERN BASIN.

...HISPANIOLA...

CLOUDINESS AS WELL AS ISOLATED SHOWERS AND TSTMS ARE ACROSS THE
CENTRAL AND WESTERN ISLAND BEING SUPPORTED BY SHALLOW MOISTURE
AND A ZONE OF MIDDLE LEVEL DIFFLUENCE. SIMILAR CONDITIONS ARE
EXPECTED TO PREVAIL THROUGH FRIDAY NIGHT AS A BROAD REGION OF
MOISTURE CURRENTLY E OF THE LESSER ANTILLES CONTINUES TO MOVE
WESTWARD.

ATLANTIC OCEAN...

MIDDLE TO UPPER LEVEL RIDGING DOMINATES IN THE SW N ATLC...THUS
SUPPORTING A SURFACE RIDGE IN THAT REGION OF THE BASIN. FARTHER
EAST...AN ELONGATED MIDDLE TO UPPER LEVEL LOW CONTINUE TO
SUPPORT A SURFACE TROUGH ALONG 22N61W S TO THE CENTRAL-SOUTHERN
LESSER ANTILLES NEAR 13N61W. A DIFFLUENT ENVIRONMENT GENERATED
BY A MIDDLE TO UPPER LEVEL TROUGH E OF THE ELONGATED LOW SUPPORT
A REGION OF SCATTERED HEAVY SHOWERS AND TSTMS FROM 15N-25N
BETWEEN 50W-60W. OTHERWISE...TWO TROPICAL WAVES ARE IN THE CENTRAL
AND EASTERN ATLC. SEE WAVES SECTION ABOVE.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR

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




More information about the Tropical mailing list