[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161045
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN AUG 16 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
1030 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS IN THE E ATLC ASSOCIATED WITH A 1011 MB LOW
NEAR 10N25W THAT MOVES W AT 10-15 KT. CIRA LAYER PRECIPITABLE
WATER IMAGERY FROM THE SURFACE TO 850 MB SHOW THE WAVE IS
ASSOCIATED WITH A BROAD AREA OF MAINLY MODERATE MOISTURE THAT
ALONG WITH A DIFFLUENT WIND ENVIRONMENT ALOFT SUPPORT SCATTERED
MODERATE CONVECTION FROM 07N TO 12N BETWEEN 21W AND 29W. SAHARAN
DRY AIR AND DUST ARE N OF THE LOW...THUS SUPPRESSING CONVECTION.

A TROPICAL WAVE IS IN THE CENTRAL ATLC WITH AXIS NEAR 43W
...MOVING W AT 10 KT OVER THE PAST 24 HOURS. CIRA LAYER
PRECIPITABLE WATER IMAGERY FROM THE SURFACE TO 850 MB SHOW THE
WAVE IS WITHIN A MODERATE MOIST ENVIRONMENT THAT ALONG WITH
DIFFLUENCE ALOFT SUPPORT SCATTERED MODERATE CONVECTION AND
ISOLATED TSTMS FROM 05N TO 12N BETWEEN 40W AND 46W.

A TROPICAL WAVE IS IN THE CARIBBEAN WITH AXIS NEAR 69W...MOVING
W AT 15-20 KT OVER THE PAST 24 HOURS. THE WAVE IS ASSOCIATED
WITH A MODERATE MOIST ENVIRONMENT FROM THE SURFACE TO 850 MB
ACCORDING TO CIRA LAYER PRECIPITABLE WATER IMAGERY. A DIFFLUENT
WIND ENVIRONMENT AT THE MIDDLE TO UPPER LEVELS NEAR THE MONA
PASSAGE SUPPORT SCATTERED TO ISOLATED SHOWERS OVER PUERTO
RICO...ADJACENT WATERS AND EASTERN HISPANIOLA. STRONG DEEP LAYER
WIND SHEAR HINDER CONVECTION ACROSS THE REMAINDER
CENTRAL AND EASTERN CARIBBEAN BASIN.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO
A 1011 MB LOW NEAR 10N25W TO 08N37W. THE INTERTROPICAL
CONVERGENCE ZONE AXIS EXTENDS FROM 08N45W TO 07N55W. ASIDE FROM
CONVECTION ASSOCIATED WITH THE TROPICAL WAVE NEAR THE CAPE VERDE
ISLANDS...SCATTERED MODERATE CONVECTION IS FROM 07N-11N E OF 20W.

...DISCUSSION...

GULF OF MEXICO...

AN ELONGATED UPPER TROUGH EXTENDS FROM THE NE CONUS SW TO
TENNESSEE TO A BASE OVER THE NW GULF...THUS SUPPORTING A SURFACE
TROUGH FROM 25N95W NE TO 28N91W TO MISSISSIPPI COASTAL WATERS
NEAR 30N88W. SOUTHWESTERLY WIND FLOW AROUND THE NW PERIPHERY OF
AN UPPER RIDGE CENTERED OVER THE CARIBBEAN AND SOUTHERLY WIND
FLOW OVER THE CENTRAL GULF GENERATE A DIFFLUENT WIND ENVIRONMENT
E OF 90W. SHALLOW MOISTURE ADVECTING FROM THE CARIBBEAN SUPPORT
SCATTERED SHOWERS AND TSTMS N OF 23N BETWEEN 85W AND 97W.
SIMILAR CONVECTION IS OVER THE SE GULF S OF 25N E OF 90W. BROAD
SURFACE HIGH PRESSURE OVER THE ATLC EXTENDS A RIDGE AXIS SW
ACROSS THE FLORIDA PENINSULA TO E OF 87W AND PROVIDES MAINLY SE
TO E WIND FLOW OF LESS THAN 15 KT ACROSS THE GULF. A TROUGH OF
LOW PRESSURE WILL PREVAIL ALONG THE NW BASIN THROUGH TONIGHT.
RIDGING WILL BE THE DOMINANT FEATURE ELSEWHERE THE NEXT TWO DAYS.

CARIBBEAN SEA...

A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR
13N77W AND COVERS THE BASIN. EVEN THAT SHALLOW MOISTURE
DOMINATES ACROSS THE BASIN...DRY AIR SUBSIDENCE FROM ALOFT ALONG
WITH STRONG DEEP LAYER WIND SHEAR PROVIDE STABILITY...SUPPORTING
MAINLY FAIR WEATHER BASIN-WIDE. SCATTERED SHOWERS AND TSTMS ARE
OVER THE NE CARIBBEAN ASSOCIATED WITH A TROPICAL WAVE WITH AXIS
CURRENTLY MOVING OVER THE MONA PASSAGE TOWARDS HISPANIOLA.
SIMILAR CONVECTION IS OVER THE SW BASIN S OF 11N BETWEEN
NORTHERN COLOMBIA AND COSTA RICA BEING ENHANCED BY THE EPAC
MONSOON TROUGH. NE TO E WINDS OF 20 TO 25 KT ARE FROM 11N TO
13.5N BETWEEN 72W AND 77W WITH SEAS TO 9 FT. THESE CONDITIONS
ARE EXPECTED TO PREVAIL IN THIS REGION FOR THE NEXT TWO DAYS.
THE WAVE WILL MOVE ACROSS THE CENTRAL BASIN TODAY THROUGH MONDAY
ENHANCING SHOWERS ACROSS HISPANIOLA AND ADJACENT WATERS.

...HISPANIOLA...

CLOUDY SKIES WITH POSSIBLE ISOLATED SHOWERS COVER THE ISLAND.
HOWEVER...CONVECTIVE ACTIVITY IS EXPECTED TO INCREASE LATER
TODAY AS A TROPICAL WAVE MOVES ACROSS THE ISLAND. THE INCREASED
PROBABILITY OF PRECIPITATION...LOCALLY HEAVY AT TIMES ON
SUNDAY...WILL INCREASE THE RISK OF FLASH FLOODING AND MUDSLIDES
THROUGH THROUGH MONDAY.

ATLANTIC OCEAN...

AN UPPER LEVEL LOW IS NEAR 30N59W AND EXTENDS A TROUGH SW TO A
BASE E-NE OF THE SOUTHERN BAHAMAS. THIS IS SUPPORTING A SURFACE
TROUGH EXTENDING FROM 30N58W SW TO 26N63W. ISOLATED SHOWERS ARE
POSSIBLE IN THE VICINITY OF THE LOW. SCATTERED SHOWERS ARE S OF
23N BETWEEN 62W AND 69W ASSOCIATED WITH THE PASSAGE OF A
TROPICAL WAVE ACROSS THE EASTERN CARIBBEAN. A BROAD SURFACE
RIDGE COVERS THE REMAINDER BASIN AND SUPPORTS FAIR WEATHER. FOR
TROPICAL WAVES SEE SECTION ABOVE.

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

$$
NR
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