Tropical Weather Discussion
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000
AXNT20 KNHC 312357
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI JUL 31 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IN THE E TROPICAL ATLC EXTENDS ALONG 21W/22W FROM
10N-19N MOVING W 15-20 KT OVER THE PAST 12 HOURS. THE TOTAL
PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A
SURGE OF DEEP MOISTURE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE
LAST VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE REMAINS
WITHIN A PLUMB OF AEROSOLS OR SAHARAN DUST LIMITING ANY
ASSOCIATED CONVECTION.

TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 50W/51W FROM
12N-21N MOVING W-NW NEAR 25 KT OVER THE PAST 24 HOURS. THE TOTAL
PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS ALONG THE LEADING
EDGE OF A SURGE OF MODERATE MOISTURE. THE NOAA/NESDIS AEROSOL
PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT
THE WAVE IS ALSO ALONG THE LEADING EDGE OF A PLUMB OF AEROSOLS
OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION.

TROPICAL WAVE IN THE CARIBBEAN EXTENDS FROM 19N78W TO 10N80W
MOVING W 15-20 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE
WATER IMAGERY SHOWS THE WAVE IS ALONG THE LEADING EDGE OF A
SURGE OF MODERATE TO DEEP MOISTURE. THE WAVE IS ENHANCING THE
ACTIVITY OVER JAMAICA.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E
TROPICAL ATLC NEAR 20N16W TO E OF THE EASTERN MOST TROPICAL WAVE
NEAR 15N20W THEN RESUMES W OF THE WAVE NEAR 14N23W THEN THROUGH
A 1009 MB LOW NEAR 12N34W ALONG 9N42W TO 8N52W WHERE THE ITCZ
BEGINS AND CONTINUES TO SOUTH AMERICA NEAR 8N60W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-14N E OF 24W TO
THE COAST OF W AFRICA AND FROM 11N-13N BETWEEN 35W-38W
ASSOCIATED WITH THE 1009 MB LOW. CLUSTERS OF SCATTERED MODERATE
CONVECTION ARE FROM 6N-10N BETWEEN 35W-50W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER RIDGE REMAINS OVER THE GULF OF MEXICO AND THE FAR
SE CONUS ANCHORED OVER THE TEXAS PANHANDLE. A BROAD UPPER TROUGH
IS OVER THE NE CONUS SUPPORTING A QUASI-STATIONARY FRONT THAT
EXTENDS FROM A 1012 LOW OVER W GEORGIA ACROSS FLORIDA NEAR
PENSACOLA INTO THE GULF WATERS THEN ACROSS THE MISSISSIPPI DELTA
OF LOUISIANA ALONG 29N92W TO INLAND OVER TEXAS NEAR GALVESTON. A
SURFACE TROUGH EXTENDS FROM THE FLORIDA PANHANDLE NEAR FORT
WALTON BEACH ALONG 28N90W TO 26N94W. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE WITHIN 60 NM OF LINE FROM 29N88W TO 27N95W
WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS
DOTTING THE REMAINDER OF THE GULF N OF 23N EXCEPT N OF THE FRONT
WHERE CLEAR SKIES PREVAIL. A SURFACE TROUGH IS MOVING ACROSS THE
BAY OF CAMPECHE FROM 21N92W TO 18N94W. A WEAK SURFACE RIDGE
EXTENDS FROM THE W ATLC OVER S FLORIDA/STRAITS OF FLORIDA TO A
1017 MB HIGH IN THE YUCATAN CHANNEL. FRONT WILL MEANDER OVER THE
N GULF THROUGH THE WEEKEND. THE SURFACE RIDGE WILL BUILD BACK
ACROSS THE GULF THROUGH SUN.

CARIBBEAN SEA...
A CUTOFF UPPER LOW IS OVER THE NW CARIBBEAN CENTERED NEAR 17N85W
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 18N-20N
BETWEEN 82W-85W. AN UPPER TROUGH EXTENDS FROM AN UPPER LOW E OF
THE BAHAMAS TO OVER HISPANIOLA GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS OVER HAITI AND THE FAR W DOMINICAN
REPUBLIC MOVING TOWARD THE GULF OF GONAVE. AN UPPER RIDGE
ANCHORED OVER SOUTH AMERICA COVERS THE REMAINDER OF THE
CARIBBEAN. AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND
OVER PORTIONS OF CUBA MOVING S INTO THE CARIBBEAN WATERS.
ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER
THE SW CARIBBEAN FROM 10N-15N W OF 77W TO OVER NICARAGUA. W ATLC
SURFACE RIDGE WILL MAINTAIN FRESH TO STRONG TRADE WINDS OVER THE
S/CENTRAL CARIBBEAN TONIGHT. CARIBBEAN TROPICAL WAVE WILL MOVE
ACROSS THE CARIBBEAN THROUGH SUN NIGHT. THE NEXT TROPICAL WAVE
WILL ENTER THE CARIBBEAN SUN.

...HISPANIOLA...
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS HAITI AND
THE FAR W DOMINICAN REPUBLIC MOVING TOWARD THE GULF OF GONAVE
THIS EVENING BEING ENHANCED BY THE UPPER TROUGH. THE UPPER
TROUGH OVER THE ISLAND WILL PERSIST THROUGH FRI NIGHT THEN WILL
MEANDER WESTWARD. MOISTURE WILL DECREASE AGAIN SAT NIGHT
LESSENING THE CHANCES OF AFTERNOON/EVENINGS SHOWERS AND
THUNDERSTORMS SUN.

ATLANTIC OCEAN...
AN UPPER LOW IS CENTERED E OF THE BAHAMAS NEAR 25N74W EXTENDING
AN UPPER TROUGH AXIS SW OVER HISPANIOLA AND N TO BEYOND 32N74W
AND IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM
24N-29N W OF 78W TO OVER FLORIDA WITH SCATTERED SHOWERS WITHIN
90 NM OF LINE FROM 24N76W TO 32N79W. A SURFACE RIDGE COVERS THE
REMAINDER OF THE ATLC ANCHORED BY A 1023 MB HIGH OVER THE E ATLC
NEAR 32N35W AND A 1022 MB HIGH NEAR 28N60W WITH A RIDGE AXIS
EXTENDING ACROSS WESTWARD ACROSS S FLORIDA/STRAITS OF FLORIDA
INTO THE GULF OF MEXICO. THE SURFACE RIDGE AXIS WILL PERSIST
THROUGH SAT THEN BEGIN TO SHIFT N REACHING TO S FLORIDA ON SUN.

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

$$
PAW



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