[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111052
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUL 11 2015

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.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 11N25W TO 18N23W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH A 700 MB TROUGH BETWEEN 19W-27W AND A
MAXIMUM IN 850 MB RELATIVE VORTICITY ALONG THE WAVE AXIS. NO
SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY DUE TO
SAHARAN DUST THAT COVERS A LARGE PORTION OF THE TROPICAL NORTH
ATLC.

TROPICAL WAVE EXTENDS FROM 07N41W TO 17N40W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH A RELATIVELY BROAD 700 MB GLOBAL MODEL
INDICATED TROUGH BETWEEN 35W-45W. IN ADDITION...A MAXIMUM IN 850
MB RELATIVE VORTICITY IS NOTED IN GUIDANCE ALONG THE WAVE AXIS
NEAR 11N. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE
IMAGERY DUE LARGELY TO SAHARAN DUST THAT COVERS A LARGE AREA OF
THE TROPICAL NORTH ATLC.

TROPICAL WAVE EXTENDS FROM 10N63W TO 18N63W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH A SUBTLE 700 MB SHORTWAVE TROUGH AND A
MAXIMUM OF 850 MB RELATIVE VORTICITY CENTERED IN THE VICINITY OF
15N66W. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY
AT THIS TIME.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO
11N25W TO 09N31W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 09N31W TO 07N41W TO 06N57W. SCATTERED MODERATE
CONVECTION IS FROM 05N-09N BETWEEN 19W-25W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE SW
GULF WATERS AND SOUTHERN MEXICO S OF 24N W OF 90W. MIDDLE TO
UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGING IS GENERATING
AN AREA OF ISOLATED SHOWERS AND TSTMS ACROSS THE SW GULF AND
SOUTHERN MEXICO S OF 21N BETWEEN 92W-98W. OTHERWISE...THE
REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A PAIR OF 1021 MB HIGHS ONE CENTERED IN THE NE GULF
WATERS NEAR 29N86W AND THE OTHER CENTERED ACROSS LOUISIANA NEAR
31N91W. GENERALLY LIGHT TO MODERATE EAST-SOUTHEAST WINDS PREVAIL
AND ARE EXPECTED TO PERSIST THROUGH SATURDAY AS THE HIGH DRIFTS
SLOWLY WESTWARD TO THE NW GULF BY SUNDAY.

CARIBBEAN SEA...
NORTHWESTERLY FLOW ALOFT BECOMES MORE WESTERLY E OF 80W AS AN
OVERALL STABLE ENVIRONMENT EXISTS OVER MUCH OF THE BASIN THIS
MORNING WITH THIS SYNOPTIC SETUP. THE WESTERLY FLOW LIES ON THE
SOUTHERN PERIPHERY OF A BROAD AND ELONGATED UPPER LEVEL LOW
CENTERED OVER THE WINDWARD PASSAGE NEAR 20N73W. WHILE MOSTLY
CLEAR SKIES PREVAILED EARLIER...THE UPPER LEVEL LOW IN TANDEM
WITH A DEVELOPING MID-LEVEL TROUGH IS GENERATING MORE EXTENSIVE
CLOUDINESS BETWEEN 65W-79W WITH A FEW ISOLATED SHOWERS AND TSTMS
ACROSS PORTIONS OF PUERTO RICO...HISPANIOLA...AND A LARGE
PORTION OF THE CENTRAL CARIBBEAN. SCATTERED SHOWERS AND TSTMS
ARE ALSO OCCURRING WITHIN S OF 13N W OF 78W...INCLUDING
PANAMA...COSTA RICA...AND NICARAGUA DUE TO CLOSE PROXIMITY OF
THE MONSOON TROUGH AXIS ALONG 08N/09N. A TROPICAL WAVE IS ALONG
65W AND IS INCREASING LOW-LEVEL CONVERGENCE EAST OF THE WAVE
AXIS PRODUCING ISOLATED SHOWERS AND TSTMS ACROSS THE LESSER
ANTILLES. FINALLY...THE PRIMARY IMPACT FOR THE CARIBBEAN REMAINS
THE FRESH TO STRONG TRADES OCCURRING S OF 16N BETWEEN 68W-80W.
THE PRESSURE GRADIENT IS EXPECTED TO RELAX SOMEWHAT BY LATE
MONDAY.

...HISPANIOLA...
AN ELONGATED UPPER LEVEL LOW IS CENTERED N OF THE WINDWARD
PASSAGE NEAR 20N73W PROVIDING AMPLE LIFTING DYNAMICS TO GENERATE
A FEW ISOLATED SHOWERS AND TSTMS OCCURRING ACROSS THE ISLAND
THIS MORNING...INCLUDING MUCH OF THE ADJACENT COASTAL ATLC AND
CARIBBEAN WATERS. WITH THE UPPER LEVEL LOW SLOW TO MOVE ON
SATURDAY...WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE
FORECAST DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.

ATLANTIC OCEAN...
AN UPPER LEVEL LOW IS CENTERED NORTH OF THE WINDWARD PASSAGE
NEAR 20N73W SUPPORTING WIDELY SCATTERED SHOWERS AND ISOLATED
TSTMS ACROSS PORTIONS OF THE SW NORTH ATLC FROM 19N-27N BETWEEN
66W-78W. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER
THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH
CENTERED NEAR 29N71W. FARTHER EAST...THE CENTRAL AND EASTERN
ATLC ARE DOMINATED BY AN INFLUENCE OF ANOTHER SURFACE RIDGE
ANCHORED BY A NEARLY STATIONARY 1028 MB HIGH CENTERED SE OF THE
AZORES NEAR 37N27W.

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

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