Tropical Weather Discussion
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000
AXNT20 KNHC 022353
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN AUG 02 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
2345 UTC.

...SPECIAL FEATURES...

GALE FORCE WINDS ARE EXPECTED TO DEVELOP ONCE AGAIN BY 03/06Z
ALONG THE COAST OF COLOMBIA FROM 11N-13N BETWEEN 74W-77W UNTIL
1800 UTC MONDAY AFTERNOON. THESE WINDS ARE ASSOCIATED WITH THE
TIGHT PRESSURE GRADIENT BETWEEN THE W ATLANTIC SURFACE RIDGE AND
THE LOWER PRESSURE OVER SOUTH AMERICA. PLEASE SEE THE HIGH SEAS
FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE
DETAILS.

...TROPICAL WAVES...

A LOW-AMPLITUDE TROPICAL WAVE IS IN THE E TROPICAL ATLANTIC WITH
AXIS EXTENDING FROM 16N31W TO 10N31W...MOVING W 15-20 KT OVER
THE PAST 24 HOURS. THE GLOBAL MODEL SHOWS A 700 MB TROUGH ALONG
THIS AREA AND THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS A
HIGHER MOISTURE CONTENT PREVAILING ACROSS THE SOUTHERN PORTION
OF THE WAVE MAINLY S OF 13N SUPPORTING SCATTERED MODERATE
CONVECTION BETWEEN 30W-36W. THE NOAA/NESDIS AEROSOL PRODUCT AND
THE VISIBLE SATELLITE IMAGERY INDICATES THAT THE NORTHERN
PORTION OF THE WAVE IS BETWEEN PLUMBS SAHARAN DUST THEREFORE NO
ASSOCIATED DEEP CONVECTION IS OBSERVED OVER THIS AREA.

A TROPICAL WAVE IN OVER THE E CARIBBEAN WITH AXIS EXTENDING FROM
20N66W TO 12N65W...MOVING W NEAR 20 KT OVER THE PAST 24 HOURS.
THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED
WITHIN A SURGE OF MODERATE MOISTURE THAT EXTENDS FROM THE
ATLANTIC ACROSS THE LESSER ANTILLES AND E PUERTO RICO. THE
NOAA/NESDIS AEROSOL PRODUCT AND THE VISIBLE SATELLITE IMAGERY
INDICATES THAT THE WAVE IS ALONG THE LEADING EDGE OF A SAHARAN
DUST AIRMASS OVER THE E CARIBBEAN. NO SIGNIFICANT CONVECTION IS
RELATED TO THIS WAVE AT THIS TIME.

A TROPICAL WAVE IN THE GULF OF MEXICO WITH AXIS EXTENDING FROM
20N94W INTO THE EPAC NEAR 13N95W...MOVING W AT 20-25 KT OVER THE
PAST 24 HOURS. THE NORTHERN PORTION OF THE TROPICAL WAVE HAS NO
SIGNIFICANT CONVECTION DESPITE THAT TPW IMAGERY SHOWS A SURGE OF
MODERATE MOISTURE PREVAILING ACROSS THIS AREA.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E
TROPICAL ATLANTIC NEAR 14N18W TO 12N30W THEN RESUMES W OF A
TROPICAL WAVE NEAR 12N32W TO 11N42W. THE ITCZ BEGINS FROM THIS
POINT TO 11N62W. ASIDE FROM THE CONVECTION RELATED TO THE
TROPICAL WAVE ALONG 31W...ISOLATED MODERATE CONVECTION IS FROM
10N-13N BETWEEN 15W-24W.

...DISCUSSION...

GULF OF MEXICO...

A BROAD UPPER-LEVEL RIDGE EXTENDS OVER THE GULF OF MEXICO
ANCHORED OVER NORTHERN TEXAS EXTENDING A RIDGE AXIS FROM NE
TEXAS...THEN ACROSS THE NE GULF WATERS TO NEAR THE FLORIDA KEYS.
AT THE SURFACE...A 1009 MB SURFACE LOW IS CENTERED OVER THE
FLORIDA PANHANDLE NEAR 30N84W. A STATIONARY FRONT EXTENDS FROM
THE LOW TO 29N91W TO 26N97W. SCATTERED MODERATE CONVECTION IS
OBSERVED IN THE VICINITY OF THE LOW AND FRONT FROM 23N-29N AND E
OF 89W WHILE ISOLATED CONVECTION IS OBSERVED ALONG THE
STATIONARY FRONT W OF 90W. FAIR WEATHER PREVAILS ACROSS THE
REMAINDER OF THE GULF. SCATTEROMETER DATA DEPICTS A LIGHT AND
VARIABLE WIND FLOW ACROSS THE BASIN EXCEPT OVER THE E PORTION OF
THE BAY OF CAMPECHE FROM 18N-24N BETWEEN 90W-94W WHERE LIGHT TO
GENTLE WINDS PREVAIL. OVER THE NEXT 24 HOURS...THE SURFACE LOW
WILL MOVE NE AND GRADUALLY CARRYING THE FRONTAL BOUNDARY OVER
THE NORTHERN GULF WATERS. A SURFACE RIDGE WILL THEN BUILD W
ACROSS THE BASIN.

CARIBBEAN SEA...

THE UPPER-LEVEL RIDGE OVER THE GULF OF MEXICO COVERS THE FAR W
CARIBBEAN. A BROAD UPPER-LEVEL TROUGH COVERS THE REMAINDER OF
THE CARIBBEAN WITH AN UPPER LOW CENTERED N OF CUBA AND A SECOND
UPPER LOW SW OF PUERTO RICO NEAR 17N66W. SCATTERED MODERATE
CONVECTION PREVAILS ACROSS THE NW PORTION OF THE BASIN MAINLY W
OF 71W AFFECTING HAITI...CUBA AND THEIR ADJACENT CARIBBEAN
WATERS. THE REMAINDER OF THE BASIN CONTINUES CONVECTION FREE AS
A SURGE OF SAHARAN DUST IS ENTERING THE E CARIBBEAN BEHIND A
TROPICAL WAVE CURRENTLY ALONG 66W. SCATTEROMETER DATA SHOWS
GENTLE TO MODERATE TRADES PREVAILING ACROSS THE BASIN. OVER THE
NEXT 24 HOURS...EXPECT FOR GALE FORCE WINDS TO DEVELOP ACROSS
THE SOUTHERN CARIBBEAN. THE TROPICAL WAVE WILL CONTINUE MOVING W
SUPPORTING ISOLATED CONVECTION.

...HISPANIOLA...

ISOLATED CONVECTION IS CURRENTLY MOVING ACROSS HAITI SUPPORTED
BY AN UPPER-LEVEL LOW CENTERED N OF CUBA. OVER THE NEXT 24
HOURS...A TROPICAL WAVE CURRENTLY OVER E PUERTO RICO WILL MOVE
ACROSS THE ISLAND INCREASING THE CHANCES OF SHOWERS.

ATLANTIC OCEAN...

A BROAD UPPER-LEVEL TROUGH COVERS THE W ATLANTIC WITH AN UPPER
LOW CENTERED BETWEEN CUBA AND THE BAHAMA ISLANDS NEAR 22N76W AND
A SECOND UPPER LOW SW OF PUERTO RICO. THIS IS GENERATING
ISOLATED CONVECTION MAINLY S OF 26N AND W OF 75W. TO THE E...A
SURFACE TROUGH EXTENDS FROM 25N63W TO 21N66W WITH ISOLATED
CONVECTION. THE REMAINDER OF THE BASIN IS DOMINATED BY A BROAD
SURFACE RIDGE ANCHORED BY A 1023 SURFACE HIGH LOCATED NEAR
30N57W. FAIR WEATHER PREVAILS ACROSS THE BASIN AS A SAHARAN
AIRMASS EXTENDS ACROSS THE MAJORITY OF THE TROPICAL ATLANTIC.
OVER THE NEXT 24 HOURS...EXPECT FOR THE SURFACE RIDGE TO PERSIST
WITH FAIR WEATHER.

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

$$

ERA



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