[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231137
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUL 23 2011

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...
NONE.

...TROPICAL WAVES...

TROPICAL WAVE IS ANALYZED FROM 10N31W TO 17N29W MOVING W AT 10
KT. SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE BROAD
CYCLONIC LOW-LEVEL FLOW IN THE VICINITY OF THE WAVE AXIS WHICH
REMAINS EMBEDDED WITHIN THE ITCZ AXIS. TOTAL PRECIPITABLE WATER
IMAGERY ALSO INDICATES A NORTHWARD EXTENSION OF LOW-LEVEL
MOISTURE TO 18N BETWEEN 27W-35W. WIDELY SCATTERED MODERATE
CONVECTION IS FROM 10N-14N BETWEEN 30W-35W.

TROPICAL WAVE IS ANALYZED FROM 13N59W TO 20N57W MOVING W-NW AT
15 KT. SHORTWAVE INFRARED SATELLITE IMAGERY INDICATES CYCLONIC
TURNING OF THE LOW-LEVEL CLOUD FIELD IN THE VICINITY OF THE WAVE
AXIS. TOTAL PRECIPITABLE WATER IMAGERY ALSO SHOWS A MAXIMUM OF
DEEP LAYER MOISTURE ASSOCIATED WITH THE WAVE ACROSS THE NE
CARIBBEAN SEA AND LESSER ANTILLES. AN AREA OF SCATTERED MODERATE
CONVECTION IS OCCURRING WITH THE WAVE FROM 14N-21N BETWEEN
56W-66W THAT IS EXPECTED TO IMPACT THE LESSER ANTILLES...NE
CARIBBEAN SEA...AND PUERTO RICO THROUGH LATE SATURDAY INTO
SUNDAY.

TROPICAL WAVE IS ANALYZED FROM 18N93W TO 23N92W MOVING W AT 15
KT. THE WAVE IS EMBEDDED WITHIN MARGINAL LOW-LEVEL MOISTURE
ACROSS THE YUCATAN PENINSULA AND SW GULF OF MEXICO AND LACKS ANY
SIGNIFICANT CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO
08N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
08N20W TO 12N31W TO 06N44W TO 07N54W. SCATTERED MODERATE
CONVECTION IS FROM 05N-09N BETWEEN 13W-26W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL ANTICYCLONE COVERS
MUCH OF THE EASTERN CONUS AND THE RIDGING EXTENDS SOUTHWARD
ACROSS MUCH OF THE GULF N OF 23N. THIS STRONG SUBSIDENCE REACHES
TO THE SURFACE IN THE FORM OF A RIDGE AXIS EXTENDING FROM THE W
ATLC NEAR 30N70W ACROSS THE CENTRAL FLORIDA PENINSULA TO THE
MEXICO COAST NEAR 25N97W. THIS MORNING A FEW ISOLATED SHOWERS
AND TSTMS ARE OCCURRING ACROSS THE NE GULF N OF 26N E OF 91W...
BUT OVER THE NEXT SEVERAL DAYS THE SURFACE RIDGE IS FORECAST TO
HOLD STRONG WITH THE AXIS SHIFTING SLIGHTLY NORTHWARD TO 29N BY
EARLY MONDAY. ELSEWHERE...THE TROPICAL WAVE WILL MOVE ACROSS THE
SW GULF SATURDAY AND MOVE INLAND AND DISSIPATE OVER CENTRAL
MEXICO SUNDAY.

CARIBBEAN SEA...
AN ELONGATED UPPER LEVEL LOW IS ACROSS THE WESTERN CARIBBEAN
CENTERED NEAR 17N79W. MIDDLE TO UPPER LEVEL LIFT ASSOCIATED WITH
THIS FEATURE IS GENERATING A FEW OVERNIGHT ISOLATED SHOWERS AND
TSTMS S OF EASTERN CUBA NEAR 20N76W. WESTWARD MOVING ISOLATED
SHOWERS LINGER ACROSS THE NW CARIBBEAN N OF 17N BETWEEN 80W-87W
AND ARE EXPECTED TO MOVE ONSHORE ACROSS BELIZE AND THE YUCATAN
PENINSULA THROUGH LATE SATURDAY. FARTHER EAST...AN UPPER LEVEL
ANTICYCLONIC CIRCULATION IS CENTERED IN THE TROPICAL N ATLC NEAR
18N44W THAT EXTENDS A RIDGE AXIS WESTWARD ALONG 18N TO OVER
PUERTO RICO NEAR 18N66W. THIS UPPER LEVEL DIFFLUENT ENVIRONMENT
IS LIKELY ENHANCING THE CONVECTION ASSOCIATED WITH THE
APPROACHING TROPICAL WAVE ALONG 59W. ELSEWHERE THE REMAINDER OF
THE CENTRAL CARIBBEAN IS UNDER MOSTLY CLEAR SKIES AND FAIR
CONDITIONS DUE TO MODERATE SUBSIDENCE ALOFT BETWEEN 66W-80W.
HOWEVER...A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING FROM
15N-18N BETWEEN 67W-73W. THE MONSOON TROUGH ALSO EXTENDS ALONG
09N OVER THE SW CARIBBEAN AND CONTINUES TO GENERATE SCATTERED
SHOWERS AND TSTMS S OF 12N AND OVER INTERIOR PORTIONS OF
PANAMA...COSTA RICA...AND NICARAGUA.

ATLANTIC OCEAN...
A BROAD SURFACE RIDGE COVERS THE MAJORITY OF THE ATLC ANCHORED
BY A 1028 MB AZORES HIGH NEAR 41N27W AND A 1025 MB HIGH NEAR
31N54W PROVIDING MOSTLY FAIR WEATHER BASIN-WIDE. WITH AN UPPER
LEVEL LOW CENTERED NEAR 17N79W IN THE WESTERN CARIBBEAN SEA...A
FEW ISOLATED SHOWERS AND TSTMS ARE NOTED ACROSS THE FLORIDA
STRAITS. A FEW ISOLATED SHOWERS ARE ALSO NOTED FROM 26N-29N
BETWEEN 71W-77W ASSOCIATED WITH AN UPPER LEVEL LOW NEAR 30N70W.
OTHERWISE THE AZORES HIGH PRESSURE IS LARGE IN AREAL COVERAGE
AND PROVIDING FAIR WEATHER N OF 20N...WITH THE EXCEPTION OF THE
TROPICAL WAVE ALONG 59W AND THE ASSOCIATED CONVECTION IN THE
VICINITY OF 19N58W.

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

$$
HUFFMAN




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