Tropical Weather Discussion
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000
AXNT20 KNHC 040556
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE AUG 04 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.

...SPECIAL FEATURES...

GALE FORCE WINDS ARE FORECAST STARTING AT 0600 UTC THIS MORNING
AND CONTINUING UNTIL 1800 UTC FROM 11N TO 13N BETWEEN 74W AND
77W. THESE WINDS ARE ASSOCIATED WITH THE TIGHT PRESSURE GRADIENT
BETWEEN THE W ATLANTIC SURFACE RIDGE AND THE 1004 MB LOW
CENTERED OVER N COLOMBIA. PLEASE SEE THE HIGH SEAS FORECAST
UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE EASTERN ATLANTIC WITH AN AXIS
EXTENDING FROM 19N34W TO 10N35W MOVING W AT AROUND 10 KT OVER
THE PAST 24 HOURS. MODEL GUIDANCE SHOWS BROAD 700 MB TROUGHING
FROM 31W TO 38W. SSMI TPW SHOWS THE WAVE A THE LEADING EDGE OF A
POLEWARD SURGE IN TROPICAL MOISTURE. NO DEEP CONVECTION IS
ASSOCIATED WITH THIS WAVE.

A TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC WITH AXIS EXTENDING
FROM 20N46W TO 10N45W...MOVING W AT 10 TO 15 KT. THIS WAVE
COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 40W AND 48W. SSMI
TPW IMAGERY SHOWS A DRY ENVIRONMENT SURROUNDING THIS WAVE N OF
13N ALONG WITH SAHARAN DUST. A MOIST ENVIRONMENT IS INDICATED S
OF 13N. ISOLATED MODERATE CONVECTION IS FROM 07N TO 12N BETWEEN
44W AND 48W.

A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AN AXIS
EXTENDING FROM THE WINDWARD PASSAGE AT 20N75W TO N COLOMBIA AT
10N76W MOVING W AT 15 KT OVER THE PAST 24 HOURS. THIS WAVE
COINCIDES WITH 700 MB TROUGHING BETWEEN 74W AND 80W. NO DEEP
CONVECTION IS ASSOCIATED WITH THIS WAVE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA TO THE E TROPICAL
ATLANTIC NEAR 12N16W TO 11N34W AND RESUMES W OF A TROPICAL WAVE
NEAR 12N38W TO 10N44W. THE ITCZ EXTENDS W OF A TROPICAL WAVE
NEAR 10N48W TO S AMERICA NEAR 10N62W. CLUSTERS OF MODERATE TO
STRONG CONVECTION ARE FROM 06N TO 14N BETWEEN 13W AND
20W...WHICH MAY ALSO BE ASSOCIATED WITH A TROPICAL WAVE ABOUT TO
EMERGE OFF THE AFRICAN COAST. ISOLATED MODERATE CONVECTION IS
ELSEWHERE WITHIN 200 NM OF THE MONSOON TROUGH E OF 44W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER RIDGE EXTENDS FROM TX TO THE NW GULF WITH AN AXIS THAT
EXTENDS E ACROSS N FL. THE UPPER LEVEL DIFFLUENCE ASSOCIATED
WITH THE UPPER RIDGE AXIS AND MODERATE MOISTURE SUPPORTS ISOLATED
MODERATE CONVECTION FROM 26N TO 29N BETWEEN 82W AND 92W. AN
UPPER TROUGH EXTENDS NE FROM THE NW CARIBBEAN TO CENTRAL CUBA
AND SUPPORTS ISOLATED THUNDERSTORMS OVER THE FL STRAITS. AT THE
SURFACE...A SURFACE RIDGE OVER THE W ATLC EXTENDS AN AXIS ACROSS
S FL AND THE CENTRAL GULF. SE WINDS AROUND 10 KT COVER THE S
GULF. S TO SW WINDS AROUND 10 KT COVER THE N GULF. A SURFACE
TROUGH OVER THE SOUTHERN US WILL MOVE OVER THE NORTHERN GULF
COAST TODAY...ENHANCING CONVECTION OVER THAT PORTION OF THE GULF
BASIN.

CARIBBEAN SEA...

A DEVELOPING GALE IS OVER THE COAST OF N COLOMBIA. PLEASE SEE
THE SPECIAL FEATURES SECTION FOR MORE DETAILS. STRONG TRADE
WINDS ARE OVER THE REMAINDER OF THE S CENTRAL CARIBBEAN.
MODERATE TO FRESH TRADE WINDS ARE ELSEWHERE OVER THE CARIBBEAN.
A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN. PLEASE SEE THE
TROPICAL WAVES SECTION FOR MORE DETAILS. AN UPPER TROUGH THAT
EXTENDS ACROSS THE NW CARIBBEAN IS INTERACTING WITH A MODERATELY
MOIST AIRMASS TO SUPPORTS ISOLATED MODERATE CONVECTION FROM 18N
TO 23N BETWEEN 77W AND 87W. THE REMAINDER OF THE CARIBBEAN IS
FREE OF DEEP CONVECTION THIS MORNING. CONVECTION WILL CONTINUE
OVER THE NW CARIBBEAN TODAY.

...HISPANIOLA...

DRY AIR AT THE MID TO UPPER LEVELS IS SPREADING ACROSS THE
ISLAND THIS MORNING AS A TROPICAL WAVE AND UPPER TROUGH W OF THE
AREA CONTINUES TO MOVE FARTHER FROM HISPANIOLA. PRECIPITATION
TODAY WILL BE FROM WEAK SHOWERS IN THE TRADE WIND FLOW OVER THE
EASTERN DOMINICAN REPUBLIC...AND ISOLATED THUNDERSTORMS OVER THE
ISLAND DUE TO TERRAIN IN THE AFTERNOON.

ATLANTIC OCEAN...

AN UPPER RIDGE AXIS EXTENDS ACROSS N FL AND OVER THE W ATLC TO
77W. UPPER LEVEL DIFFLUENCE UNDER THE RIDGE AXIS COMBINED WITH
CONVERGENCE FROM A LOW OVER THE ATLC COAST OF GA SUPPORTS
ISOLATED MODERATE CONVECTION FROM 29 TO 31N BETWEEN 79W AND 81.
AN UPPER TROUGH EXTENDS FROM THE NW CARIBBEAN TO THE CENTRAL
BAHAMAS. MODEL GUIDANCE AND SATELLITE IMAGERY ALSO CONFIRM THE
PRESENCE OF AN INVERTED MID LEVEL TROUGH FROM 73W TO 80W. THESE
FEATURES ARE SUPPORTING SCATTERED THUNDERSTORMS AND ISOLATED
MODERATE CONVECTION FROM CUBA TO 26N BETWEEN 72W AND
80W...INCLUDING THE CENTRAL BAHAMAS. A SURFACE TROUGH IS OVER
THE W ATLC FROM 30N69W TO 27N68W SUPPORTING ISOLATED MODERATE
CONVECTION WITHIN 100 NM OF THE TROUGH AXIS. SURFACE RIDGING
ANCHORED BY A 1028 MB HIGH CENTERED NEAR 34N55W DOMINATES THE
CENTRAL AND EASTERN SUBTROPICAL ATLC. TWO TROPICAL WAVES ARE
OVER THE TROPICAL ATLC. PLEASE REFER TO THE TROPICAL WAVES
SECTION FOR MORE DETAILS. CONVECTION IS EXPECTED TO CONTINUE
THROUGH TODAY FROM THE CENTRAL BAHAMAS NORTHWARD TO 31N W OF 75W.

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

$$
LATTO


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