[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 151018
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED JUL 15 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
1015 UTC.

...TROPICAL WAVES...

A LOW AMPLITUDE TROPICAL WAVE IS OVER THE E ATLANTIC WITH AXIS
EXTENDING FROM 17N34W TO 07N36W...MOVING W AT AROUND 15 KT OVER
THE PAST 24 HOURS. A SAHARAN AIRMASS PREVAILS IN THE ENVIRONMENT
OF THIS WAVE LIMITING THE CONVECTION TO ISOLATED ON EITHER SIDE
OF THE WAVE AXIS FROM 10N-12N BETWEEN 30W-33W.

A LARGE AMPLITUDE TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC
WITH AXIS EXTENDING FROM 21N55W TO 09N55W...MOVING W AT 15 TO 20
KT OVER THE PAST 24 HOURS. AN INVERTED-V LOW-LEVEL SIGNATURE IS
OBSERVED IN SATELLITE IMAGERY.  MODERATE MOISTURE IS DEPICTED IN
TPW IMAGERY TO THE E OF THE WAVE AXIS. A BROAD AREA OF SAHARAN
DUST ALSO SURROUNDS THIS WAVE WHICH CONTINUES INHIBITING
CONVECTION. EXPECT FOR THIS WAVE TO ENTER THE E CARIBBEAN WITHIN
THE NEXT 24 HOURS ENHANCING CONVECTION ACROSS THE LESSER
ANTILLES AND PUERTO RICO.

A TROPICAL WAVE EXTENDS FROM THE WINDWARD PASSAGE TO NORTHERN
COLOMBIA FROM 20N74W TO 11N76W AND IS MOVING W AT 15 KT OVER THE
PAST 24 HOURS. THE WAVE IS WELL DEFINED IN THE TPW PRODUCT AND
700 MB STREAMLINES. SCATTERED CONVECTION PREVAILS ACROSS THE
SOUTHERN PORTION OF THE WAVE AFFECTING NORTHERN COLOMBIA WHILE
ISOLATED CONVECTION IS OBSERVED BETWEEN 15N-20N AND ALONG 71W.
EXPECT FOR THIS WAVE TO CONTINUE MOVING W ACROSS THE W CARIBBEAN
WITH ISOLATED CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH ENTERS THE ATLANTIC OCEAN THROUGH GUINEA
BISSAU THEN CONTINUES TO NEAR 11N19W. THE ITCZ EXTENDS FROM THAT
POINT TO 09N34W THEN RESUMES W OF A TROPICAL WAVE NEAR 08N37W TO
06N57W. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 08N-12N
BETWEEN 24W-34W AND FROM 04N-08N BETWEEN 38W-56W.

...DISCUSSION...

GULF OF MEXICO...

A SURFACE RIDGE EXTENDS ACROSS THE NORTHERN GULF FROM THE
ATLANTIC. THIS PATTERN WILL PREVAIL THROUGH THE WEEK MAINTAINING
GENERALLY TRANQUIL CONDITIONS. SCATTEROMETER DATA DEPICTS A
LIGHT ANTICYCLONIC FLOW PREVAILING ACROSS THE WHOLE BASIN.
ALOFT...BROAD UPPER-LEVEL ANTICYCLONE ANCHORED OVER E TEXAS IS
PRODUCING MAINLY A NE FLOW ACROSS THE FLORIDA AND GULF OF
MEXICO. AN UPPER-LEVEL LOW IS SPINNING OVER THE NORTHERN COAST
OF THE YUCATAN PENINSULA. UPPER-LEVEL DIFFLUENCE BETWEEN THESE
TWO UPPER-LEVEL FEATURES WILL SUPPORT CONVECTION THIS AFTERNOON
OVER PARTS OF THE YUCATAN PENINSULA AND THE NORTHERN PORTION OF
CENTRAL AMERICA. UPPER-LEVEL DIFFLUENCE IS ALSO NOTED OVER
SOUTHERN GEORGIA AND NORTHERN FLORIDA  SUPPORTING ISOLATED
CONVECTION ACROSS THE AREA.

CARIBBEAN SEA...

A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN. PLEASE REFER TO
THE TROPICAL WAVES SECTION FOR MORE DETAILS. THE COMBINATION OF
THE SURFACE HIGH THAT PREVAILS ACROSS THE ATLANTIC AND LOWER
PRESSURES ACROSS SOUTH AMERICA IS PRODUCING FRESH TO STRONG
WINDS ACROSS THE S-CENTRAL CARIBBEAN MAINLY S OF 16N BETWEEN 66W-
75W. SCATTEROMETER DATA DEPICTS GENTLE TO MODERATE TRADES
PREVAILING ELSEWHERE. ALOFT...AN UPPER-LEVEL TROUGH EXTENDS FROM
THE W ATLANTIC ACROSS W CUBA INTO THE W CARIBBEAN. TO THE E OF
THIS FEATURE...AN UPPER-LEVEL RIDGE EXTENDS FROM SOUTH AMERICA
ACROSS THE CENTRAL AND E CARIBBEAN. THESE FEATURES ARE
GENERATING A DIFFLUENT FLOW ACROSS THE CENTRAL CARIBBEAN WHICH
SUPPORTS CLOUDINESS AND ISOLATED CONVECTION BETWEEN 73W-84W.
OVER THE NEXT 24 HOURS...EXPECT FOR THE WAVE OVER THE CENTRAL
CARIBBEAN TO CONTINUE MOVING W WHILE THE NEXT TROPICAL WAVE WILL
ENTER THE E CARIBBEAN ENHANCING CONVECTION ACROSS THE LESSER
ANTILLES AND PUERTO RICO.

...HISPANIOLA...

A TROPICAL WAVE IS CURRENTLY OVER THE WINDWARD PASSAGE WITH
ISOLATED CONVECTION E OF THE WAVE AXIS AFFECTING THE NORTHERN
COAST OF DOMINICAN REPUBLIC AND THE ADJACENT COASTAL WATERS.
EXPECT FOR THE WAVE TO CONTINUE MOVING W AWAY FROM THE ISLAND
WITHIN THE NEXT 24 HOURS. ISOLATED SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE IN THE AFTERNOON HOURS DUE TO LOCAL EFFECTS.

ATLANTIC OCEAN...

TWO TROPICAL WAVES ARE OVER THE TROPICAL ATLANTIC. PLEASE SEE
THE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. AS IT IS
NORMAL FOR THIS TIME OF THE YEAR...THE AZORES HIGH EXTENDS A
RIDGE ACROSS THE TROPICAL ATLANTIC WITH FAIR WEATHER AS ABUNDANT
AFRICAN DUST IS OBSERVED ON THE SAHARAN AIR LAYER TRACKING
PRODUCT FROM CIMSS BETWEEN THE COAST OF AFRICA AND THE LESSER
ANTILLES. AT UPPER-LEVELS...A TROUGH PREVAILS OVER THE W
ATLANTIC SUPPORTING CLOUDINESS AND ISOLATED CONVECTION BETWEEN
70W-75W. THIS TROUGH WILL CONTINUE TO ENHANCE CONVECTION OVER
THE SOUTHERN BAHAMAS...E CUBA AND NORTHERN HISPANIOLA OVER THE
NEXT 24 HOURS.

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

$$

ERA
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