Tropical Weather Discussion
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000
AXNT20 KNHC 051746
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN JUL 05 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...

...GALE IN THE CARIBBEAN...
A GALE WARNING IS IN EFFECT FOR THE SW CARIBBEAN FROM 11N TO
13.5N BETWEEN 73W AND 78W THROUGH MONDAY MORNING. THESE WINDS
ARE GENERATED BY A TIGHT PRESSURE GRADIENT BETWEEN THE STRONG
SURFACE RIDGE OVER THE ATLC AND LOW PRESSURE OVER COLOMBIA. SEE
LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS
MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE OVER THE CENTRAL TROPICAL ATLC EXTENDS ALONG 45W
FROM 5N TO 15N MOVING W NEAR 25 KT OVER THE PAST 24 HOURS. THE
TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED
WITHIN AN SURGE OF MODERATE MOISTURE S OF 12N. ENHANCED METEOSAT
IMAGERY SHOWS SAHARAN DUST ACROSS THE NORTHERN PORTION OF THE
WAVE. ISOLATED MODERATE CONVECTION IS FROM 06N TO 09N BETWEEN
43W AND 48W. THIS CONVECTION IS PARTIALLY ASSOCIATED WITH THE
SURROUNDING ITCZ.

TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 54W FROM 6N
TO 15N MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THE TOTAL
PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN
DEEP HIGH MOISTURE S OF 12N. DRY SAHARAN AIR IS NORTH OF 12N.
SCATTERED MODERATE CONVECTION IS FROM 06N TO 11N BETWEEN 52W AND
56W. THIS CONVECTION IS PARTIALLY ASSOCIATED WITH THE
SURROUNDING ITCZ.

TROPICAL WAVE IN THE WESTERN CARIBBEAN EXTENDS ALONG 82W/83W
FROM 10N TO 19N MOVING W AT AROUND 20 KT OVER THE PAST 24 HOURS.
THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED
WITHIN A SURGE OF MODERATE TO DEEP MOISTURE. ISOLATED MODERATE
CONVECTION IS FROM 15N TO 19N BETWEEN 82W AND 86W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC
NEAR 19N16W ALONG 14N20W TO 8N24W WHERE THE ITCZ BEGINS AND
CONTINUES TO 07N44W...THEN RESUMES W OF THE CENTRAL ATLC
TROPICAL WAVE NEAR 8N47W TO 08N53W...THEN RESUMES AGAIN W OF THE
WESTERN ATLC WAVE NEAR 8N56W TO THE S AMERICA COAST NEAR 09N62W.
ISOLATED MODERATE CONVECTION IS WITHIN 50 NM OF THE ITCZ AXIS
BETWEEN 28N AND 48W. SCATTERED MODERATE CONVECTION IS WITHIN 125
NM OF THE ITCZ AXIS W OF 48W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LOW IS CENTERED OVER THE SOUTHERN GULF NEAR 23N87W WITH
THE BASE OF AN UPPER TROUGH EXTENDING FROM THE TENNESSEE VALLEY
TO THE NE GULF. UPPER LEVEL DIFFLUENCE BETWEEN THESE TWO UPPER
LEVEL FEATURES AND LIFT ASSOCIATED WITH THE TROUGH SUPPORTS
CLUSTERS OF MODERATE TO STRONG CONVECTION FROM 28N TO THE N GULF
COAST BETWEEN 84W AND 90W. AT THE SURFACE...A RIDGE AXIS EXTENDS
ACROSS CENTRAL FL AND OVER THE NORTHERN GULF TO THE TX GULF
COAST. S TO SE WINDS OF 10 TO 15 KT COVER THE GULF S OF 27N. S
TO SW WINDS OF 5 TO 15 KT COVER THE GULF N OF 27N...WITH THE
LIGHTEST WINDS OVER THE NE GULF AWAY FROM THE CONVECTION. EXPECT
CONVECTION TO DECREASE OVER THE NE GULF TONIGHT WITH MAINLY
ISOLATED TO SCATTERED WEAK CONVECTION OVER THE EASTERN GULF ON
MONDAY.

CARIBBEAN SEA...
THE UPPER LOW OVER THE SOUTHERN GULF OF MEXICO IS SUPPORTING
SCATTERED THUNDERSTORMS N OF 16N AND W OF 85W OVER THE NW
CARIBBEAN. A TROPICAL WAVE IS OVER THE SW CARIBBEAN. PLEASE SEE
THE TROPICAL WAVES SECTION FOR MORE DETAILS. ENHANCED
METEOSAT IMAGERY INDICATES THE THE CENTRAL AND EASTERN CARIBBEAN
IS COVERED IN A SAHARAN AIR LAYER WITH DUST. THIS...COMBINED
WITH DRY AIR AND SHEAR IS INHIBITING CONVECTION ACROSS THIS
PORTION OF THE BASIN. A STRONG PRESSURE GRADIENT BETWEEN HIGH
PRESSURE OVER THE SUBTROPICAL NORTHERN ATLC AND LOWER PRESSURES
OVER S AMERICA SUPPORTS WINDS OF 20 TO 30 KT FROM 10N TO 18N
BETWEEN 63W AND 82W WITH GALE FORCE WINDS OVER A PORTION OF THE
SW CARIBBEAN. PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE
DETAILS. THE PRESSURE GRADIENT WILL WEAKEN SLIGHTLY ON MONDAY AS
THE HIGH OVER THE ATLC ERODES FROM THE WEST WITH THE APPROACH OF
AN UPPER TROUGH. THIS WILL BE SUFFICIENT TO BRING WINDS BELOW
GALE FORCE OVER THE SW CARIBBEAN BY LATE MONDAY MORNING. A
TROPICAL WAVE WILL MOVE OVER THE LEEWARD ISLANDS ON MONDAY.
EXPECT CONVECTION ACROSS THE SOUTHERN LEEWARD ISLANDS LATE TODAY
THROUGH MONDAY.

...HISPANIOLA...
DRY AIR AND SAHARAN DUST ARE OVER THE ISLAND TODAY. CANNOT RULE
OUT AN ISOLATED THUNDERSTORM OVER THE INLAND MOUNTAINS THIS
AFTERNOON AND EARLY EVENING. OTHERWISE...FAIR CONDITIONS ARE
EXPECTED. A TROPICAL WAVE APPROACHING FROM THE EAST MAY BRING AN
INCREASE IN SHOWER AND THUNDERSTORM COVERAGE BY LATE MONDAY.

ATLANTIC OCEAN...

AN UPPER RIDGE AXIS EXTENDS FROM THE CARIBBEAN AND OVER THE
NORTHERN BAHAMAS TO THE CAROLINA COASTS. DIFFLUENCE ASSOCIATED
WITH THIS RIDGE SUPPORTS ISOLATED MODERATE CONVECTION AND
THUNDERSTORMS FROM 27N TO 31N BETWEEN 78W AND 80W. AN UPPER LOW
CENTERED NEAR 27N69W SUPPORTS ISOLATED MODERATE CONVECTION AND
THUNDERSTORMS FROM 27N TO 31N BETWEEN 63W AND 69W. A SURFACE
TROUGH EXTENDS FROM 29N57W TO 25N58W. ISOLATED MODERATE
CONVECTION IS FROM 27N TO 31N BETWEEN 55W AND 58W. A 1029 MB
HIGH CENTERED NEAR 34N41W ANCHORS SURFACE RIDGING THAT COVERS
THE MAJORITY OF THE SUBTROPICAL NORTHERN ATLC. TWO TROPICAL
WAVES ARE OVER THE TROPICAL NORTHERN ATLC. PLEASE SEE THE
TROPICAL WAVES SECTION FOR MORE DETAILS.

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

$$
LATTO



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