[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202353
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI AUG 20 2010

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...

A 1009 MB LOW IS CENTERED OVER THE TROPICAL EASTERN ATLC NEAR
11N27W THAT REMAINS THE FOCAL POINT OF A BROAD MONSOONAL TROUGH
S OF 14N BETWEEN 18W-36W. WHILE CONVECTION REMAINS GENERALLY
UNORGANIZED...THE UPPER LEVEL ENVIRONMENT FOR TROPICAL CYCLONE
DEVELOPMENT IS FAVORABLE GIVEN BETTER UPPER LEVEL DIFFLUENCE AND
MINIMAL WIND SHEAR LOCATED TO THE WEST OF THE LOW. SCATTERED
MODERATE TO ISOLATED STRONG CONVECTION COVERS A BROAD AREA FROM
06N-14N BETWEEN 23W-35W.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 11N41W TO 26N44W MOVING W AT 15-20
KT. SATELLITE PRESENTATION INDICATES LOW-LEVEL CYCLONIC FLOW
ALONG THE WAVE AXIS AND THIS WAS ALSO NOTED ON AN EARLIER
MORNING ASCAT PASS AROUND 20/1214 UTC OVER THE NORTHERN PORTION
OF THE WAVE. AN AREA OF MAXIMUM DEEP LAYER MOISTURE IS OBSERVED
ON THE TPW IMAGERY FROM 12N-24N BETWEEN 39W-46W...HOWEVER MUCH
OF THIS MOISTURE IS POSITIONED BENEATH A STABLE SAHARAN AIR
LAYER THAT COVERS MUCH OF THE ATLC EAST OF THE WAVE AXIS TO 25W.
NO SIGNIFICANT DEEP ORGANIZED CONVECTION ACCOMPANIES THE WAVE...
HOWEVER ISOLATED SHOWERS ARE FROM 20N-23N BETWEEN 40W-44W.

A TROPICAL WAVE EXTENDS FROM 12N64W TO 24N66W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH A MID-LEVEL...700 MB...LOW CENTERED
ALONG THE WAVE AXIS NEAR 18N65W. MAXIMUM TOTAL PRECIPITABLE
WATER VALUES ARE HIGHEST N OF 17N BETWEEN 62W-69W AS THIS
MOISTURE CONTINUES TO ADVECT NORTHWARD DUE TO A WEAKNESS IN THE
SUBTROPICAL RIDGE BETWEEN 60W-70W. ISOLATED MODERATE CONVECTION
AND WIDELY SCATTERED SHOWERS ARE OCCURRING FROM 17N-24N BETWEEN
62W-70W.

TROPICAL WAVE EXTENDS FROM 13N92W TO 22N94W MOVING W AT 10-15
KT. LOW-LEVEL CYCLONIC FLOW IS NOTED ON SATELLITE IMAGERY ACROSS
THE SW GULF OF MEXICO AND CENTRAL AMERICA THIS EVENING. LOW-
LEVEL SURFACE CONVERGENCE ALONG WITH PEAK DAYTIME HEATING...AND
PLENTY OF LOW-LEVEL MOISTURE IS GENERATING A LARGE AREA OF
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION OVER MUCH OF
THE WESTERN CARIBBEAN AND CENTRAL AMERICA. THIS ACTIVITY IS
LOCATED W OF A LINE FROM 11N75W OVER NORTHERN COLOMBIA TO 22N86W
IN THE YUCATAN CHANNEL TO 24N98W NEAR LA PESCA MEXICO.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 11N30W 11N41W 12N63W. EMBEDDED
WITHIN THE MONSOONAL TROUGH MENTIONED IN THE SPECIAL FEATURES
SECTION...A 1010 MB LOW IS CENTERED NEAR 13N20W. SCATTERED
MODERATE AND ISOLATED STRONG CONVECTION IS FROM 10N-16N BETWEEN
17W-23W. ELSEWHERE...ISOLATED MODERATE CONVECTION AND WIDELY
SCATTERED SHOWERS ARE FROM 05N-12N BETWEEN 35W-58W.

...DISCUSSION...

GULF OF MEXICO...
ONE UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER WEST
TEXAS NEAR 31N105W AND ANOTHER IS CENTERED OVER GEORGIA NEAR
33N84W THAT IS PROVIDING MUCH OF THE GULF WITH E-NE UPPER LEVEL
FLOW FROM THE FLORIDA PENINSULA TO THE COAST OF MEXICO. THIS
UPPER LEVEL RIDGE SUPPORTS A 1016 MB HIGH CENTERED OVER THE W
ATLC NEAR 26N77W THAT EXTENDS A SURFACE RIDGE AXIS ALONG 25N TO
98W. NORTH OF THE RIDGE AXIS...LOW-LEVEL WARM AIR ADVECTION...
AND PEAK DAYTIME INSTABILITY ARE SUPPORTING SCATTERED SHOWERS
AND ISOLATED TSTMS OVER THE NE GULF N OF 28N E OF 87W...
INCLUDING MUCH OF THE INTERIOR GULF COAST AND NORTHERN FLORIDA
BETWEEN 81W-96W. THE SW GULF IS UNDER THE INFLUENCE OF A
TROPICAL WAVE ALONG 94W IMPACTING THE YUCATAN PENINSULA AND
AREAS SW OF A LINE FROM 21N88W TO 24N98W WITH SCATTERED SHOWERS
AND TSTMS. A FEW ISOLATED SHOWERS AND TSTMS ARE ALSO OCCURRING
FROM 24N-26N BETWEEN 94W-97W. ELSEWHERE...SCATTERED SHOWERS AND
TSTMS ARE OCCURRING OVER THE SOUTHERN FLORIDA PENINSULA THIS
EVENING FROM 25N-28N BETWEEN 80W-82W. THE REMAINDER OF THE GULF
IS UNDER GENERALLY CLEAR SKIES AND FAIR CONDITIONS THIS EVENING.

CARIBBEAN SEA...
WITH THE PASSAGE OF A TROPICAL WAVE ALONG 94W...CONVERGENT
LOW-LEVEL SOUTHEASTERLY FLOW DOMINATES ACROSS THE WESTERN
CARIBBEAN W OF 80W AND CENTRAL AMERICA. ABUNDANT MOISTURE AND
INSTABILITY ASSOCIATED WITH THE TROPICAL WAVE ARE GENERATING
SCATTERED SHOWERS AND ISOLATED TSTMS W OF A LINE FROM 11N75W
OVER NORTHERN COLOMBIA TO 22N86W IN THE YUCATAN CHANNEL.
SATELLITE IMAGERY DENOTES THE STRONGEST ACTIVITY LIES WITHIN 90
NM OF A LINE FROM WESTERN PANAMA NEAR 09N83W TO THE SW YUCATAN
PENINSULA NEAR 19N91W...MOSTLY OVER INTERIOR CENTRAL AMERICA
THIS EVENING. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED OVER
EASTERN CUBA NEAR 20N76W AND ALONG WITH A TROPICAL WAVE ALONG
66W IN THE EASTERN CARIBBEAN IS PROVIDING SCATTERED SHOWERS AND
ISOLATED TSTMS OVER THE NORTH-CENTRAL CARIBBEAN FROM 17N-20N
BETWEEN 66W-73W. A LACK OF LOW-LEVEL MOISTURE ACCOMPANIES THE
REMAINDER OF THE TROPICAL WAVE OVER THE EASTERN CARIBBEAN AS DRY
AIR IS NOTED ON WATER VAPOR IMAGERY S OF 17N E OF 73W.

ATLANTIC OCEAN...
A WEAK 1016 MB HIGH IS CENTERED OVER THE NW BAHAMAS NEAR 26N77W
THAT RESIDES ON THE SE PERIPHERY OF AN ANTICYCLONIC CIRCULATION
CENTERED OVER THE SE CONUS NEAR 33N84W. MOSTLY NE UPPER LEVEL
FLOW COVERS THE W ATLC N OF 23N W OF 70W. WITH A FRONTAL
BOUNDARY DRAPED TO THE NORTH OF THE DISCUSSION AREA ALONG 33N...
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING OVER
THE W ATLC W OF 68W. SE OF THE UPPER LEVEL ANTICYCLONE...AN
UPPER LEVEL LOW IS CENTERED NEAR 24N66W AND EXTENDS UPPER LEVEL
TROUGHING TO 30N BETWEEN 60W-70W AND SOUTHWARD INTO THE NE
CARIBBEAN SEA. THIS TROUGHING EXTENDS W-SW INTO AN UPPER LEVEL
LOW CENTERED OVER EASTERN CUBA NEAR 20N76W. A SURFACE TROUGH IS
ANALYZED FROM 25N66W TO 30N63W WITH POSSIBLE ISOLATED SHOWERS
WITHIN 180 NM EAST OF THE TROUGH AXIS. SOUTH OF THE SURFACE
TROUGH...A TROPICAL WAVE IS ALONG 66W AND IS PROVIDING FOR
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 17N-24N BETWEEN
62W-70W. ELSEWHERE ACROSS THE REMAINDER OF THE CENTRAL AND
EASTERN ATLC...SURFACE RIDGING DOMINATES N OF 26N ANCHORED BY A
1021 MB HIGH CENTERED NEAR 32N26W MAINTAINING GENERALLY FAIR
WEATHER. THE RIDGE AXIS EXTENDS FROM THE HIGH CENTER ALONG 30N
TO 48W THEN SW TO 24N58W. ALOFT...AN UPPER LEVEL ANTICYCLONE
COVERS THE CENTRAL ATLC CENTERED NEAR 31N47W.

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

$$
HUFFMAN



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