[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 110556
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 07N38W TO 16N38W MOVING W AT 10-15
KT. THE WAVE COINCIDES WITH A RELATIVELY BROAD 700 MB GLOBAL
MODEL INDICATED TROUGH BETWEEN 33W-44W. IN ADDITION...A MAXIMUM
IN 850 MB RELATIVE VORTICITY IS NOTED IN GUIDANCE ALONG THE WAVE
AXIS NEAR 12N. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE
IMAGERY DUE LARGELY TO SAHARAN DUST THAT COVERS A LARGE AREA OF
THE TROPICAL 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
16N62W. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY
AT THIS TIME.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 21N17W TO
13N23W TO 11N31W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 11N31W TO 09N48W TO 11N61W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE SW
GULF WATERS AND SOUTHERN MEXICO S OF 25N W OF 88W. MIDDLE TO
UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGING IS GENERATING
AN AREA OF SCATTERED SHOWERS AND TSTMS ACROSS THE SW GULF AND
SOUTHERN MEXICO S OF 21N BETWEEN 90W-98W. OTHERWISE...THE
REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A 1020 MB HIGH CENTERED IN THE NE GULF WATERS NEAR
29N85W. 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
EVENING WITH THIS SYNOPTIC SETUP. THIS FLOW LIES ON THE SOUTHERN
PERIPHERY OF A BROAD AND ELONGATED UPPER LEVEL LOW CENTERED OVER
THE WINDWARD PASSAGE NEAR 21N74W. WHILE MOSTLY CLEAR SKIES
PREVAIL...THE UPPER LEVEL LOW IS GENERATING A FEW ISOLATED
SHOWERS AND TSTMS ACROSS PORTIONS OF HISPANIOLA AND THE
CARIBBEAN APPROACHES TO THE WINDWARD PASSAGE. SCATTERED SHOWERS
AND TSTMS ARE ALSO OCCURRING S OF 12N W OF 75W...INCLUDING
PANAMA...COSTA RICA...AND NICARAGUA DUE TO CLOSE PROXIMITY OF
THE MONSOON TROUGH AXIS ALONG 08N/09N. A TROPICAL WAVE IS ALONG
63W AND IS INTRODUCING A GRADUAL INCREASE IN CLOUDINESS AND
POSSIBLE ISOLATED SHOWERS ACROSS THE WINDWARD ISLAND S OF 15N.
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 21N74W PROVIDING AMPLE LIFTING DYNAMICS TO GENERATE
A FEW ISOLATED SHOWERS AND TSTMS OCCURRING ACROSS WESTERN
PORTIONS OF THE ISLAND THIS EVENING...INCLUDING THE SOUTHWESTERN
ADJACENT COASTAL WATERS. THIS ACTIVITY IS EXPECTED TO CONTINUE
ON A DIMINISHING TREND BY THE LATE MORNING HOURS. WITH THE UPPER
LEVEL LOW SLOW TO MOVE ON SATURDAY...WIDELY SCATTERED SHOWERS
AND ISOLATED TSTMS ARE POSSIBLE DURING THE LATE AFTERNOON AND
EARLY EVENING HOURS.

ATLANTIC OCEAN...
AN UPPER LEVEL LOW IS CENTERED NORTH OF THE WINDWARD PASSAGE
NEAR 21N74W SUPPORTING WIDELY SCATTERED SHOWERS AND ISOLATED
TSTMS ACROSS PORTIONS OF THE SW NORTH ATLC FROM 20N-27N BETWEEN
66W-76W. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER
THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH
CENTERED NEAR 29N75W. FARTHER EAST...THE CENTRAL AND EASTERN
ATLC IS DOMINATED BY A INFLUENCE OF ANOTHER SURFACE RIDGE
ANCHORED BY A NEARLY STATIONARY 1029 MB HIGH CENTERED SE OF THE
AZORES NEAR 36N25W.

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

$$
HUFFMAN
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