Tropical Weather Discussion
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000
AXNT20 KNHC 050950
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED AUG 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0915 UTC.

...SPECIAL FEATURES...

A TIGHT PRESSURE GRADIENT BETWEEN W ATLC HIGH PRESSURE AND LOW
PRESSURE OVER N COLOMBIA SUPPORTS GALE FORCE WINDS FROM 11N TO
14N BETWEEN 72W AND 76W. THE GALE-FORCE WINDS ARE FORECAST TO
PERSIST UNTIL 1800 UTC TODAY. SEE THE LATEST NWS HIGH SEAS
FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE
DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE E ATLANTIC WITH AN AXIS EXTENDING
FROM 19N30W TO 10N28W...MOVING W AT 15 TO 20 KT. THE WAVE
COINCIDES WITH AN INVERTED 700 MB TROUGH BETWEEN 27W AND 33W.
SSMI TPW IMAGERY INDICATES MODERATE MOISTURE OVER THE WAVE
ENVIRONMENT. NO DEEP CONVECTION IS NOTED.

A LOW AMPLITUDE TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC WITH
AN AXIS EXTENDING FROM 16N40W TO 10N40W...MOVING W AT AROUND 10
KT OVER THE PAST 24 HOURS. THE WAVE COINCIDES WITH A SUBTLE 700
MB TROUGH BETWEEN 38W AND 42W. HIGH MOISTURE IS LOCATED S OF 13N
AND DRY AIR IS N OF 13N IN THE WAVE ENVIRONMENT. NO DEEP
CONVECTION IS NOTED WITH THIS WAVE.

A TROPICAL WAVE IS APPROACHING THE LESSER ANTILLES WITH AN AXIS
EXTENDING FROM 19N58W TO 11N59W...MOVING W AT 15 TO 20 KT OVER
THE PAST 24 HOURS. THE WAVE COINCIDES WITH BROAD 700 MB
TROUGHING BETWEEN 51W AND 65W. ISOLATED MODERATE CONVECTION IS
FROM 11N TO 13N BETWEEN 57W AND 60W.

A TROPICAL WAVE IS EXITING THE W CARIBBEAN AND MOVING ACROSS
ENTERING CENTRAL AMERICA WITH AN AXIS EXTENDING FROM 20N88W TO
09N88W...MOVING W AT 20 TO 25 KT OVER THE PAST 24 HOURS. THE
INTERACTION OF THIS WAVE WITH AN UPPER LOW IS SUPPORTING
SCATTERED MODERATE CONVECTION FROM 15N TO 21N BETWEEN 82W AND
89W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 13N17W THROUGH A 1010 MB LOW
NEAR 11N20W TO 11N27W...THEN RESUMES W OF A TROPICAL WAVE NEAR
11N29W TO 09N39W. THE ITCZ BEGINS W OF A TROPICAL WAVE NEAR
11N41W AND CONTINUES THROUGH A 1012 MB LOW NEAR 12N48W TO
10N57W. A SURFACE TROUGH EXTENDS NORTH OF THIS LOW TO 17N47W.
CLUSTERS OF MODERATE CONVECTION ARE WITHIN 175 NM OF THE 1010 MB
LOW OVER THE EASTERN ATLC. WIDELY SCATTERED MODERATE CONVECTION
IS FROM 05N TO 11N BETWEEN 23W AND 36W...AND FROM 09N TO 13N
BETWEEN 41W AND 57W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER LEVEL TROUGH EXTENDS FROM THE NW CARIBBEAN TO THE SE
GULF. THIS IS SUPPORTING SCATTERED THUNDERSTORMS OVER THE GULF
FROM 22N TO 26N BETWEEN 81W AND 85W. AN UPPER RIDGE AXIS EXTENDS
FROM TX E TO THE FL PANHANDLE. UPPER LEVEL DIFFLUENCE ASSOCIATED
WITH THIS RIDGE SUPPORTS ISOLATED MODERATE CONVECTION FROM 29N
TO 31N BETWEEN 88W AND 90W. A 1018 MB HIGH CENTERED NEAR 28N83W
IS PART OF A BROAD SURFACE RIDGE THAT EXTENDS FROM THE W ATLC TO
CENTRAL FL TO THE TX COAST. MODERATE E TO SE WINDS COVER MOST OF
THE GULF S OF 28N...WITH MODERATE S TO SW WINDS N OF 28. LIGHTER
WINDS ARE NEAR THE RIDGE AXIS OVER THE EAST CENTRAL GULF.
CONVECTION IS FORECAST TO CONTINUE OVER THE SE GULF TODAY...AND
SPREAD WESTWARD TOWARD THE SW GULF THIS AFTERNOON.

CARIBBEAN SEA...

AN UPPER LEVEL TROUGH EXTENDS FROM NICARAGUA ACROSS THE NW
CARIBBEAN. THIS UPPER TROUGH IS INTERACTING WITH A TROPICAL
WAVE...SUPPORTING SCATTERED MODERATE CONVECTION FROM 15N TO 21N
BETWEEN 82W AND 89W. PLEASE REFER TO THE TROPICAL WAVES SECTION
FOR MORE DETAILS. A TIGHT PRESSURE GRADIENT BETWEEN THE W ATLC
SURFACE RIDGE AND LOW PRESSURE OVER N COLOMBIA SUPPORTS GALE
FORCE WINDS OVER A PORTION OF THE S CENTRAL CARIBBEAN. PLEASE
SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. FRESH TO
STRONG TRADE WINDS EXTEND ACROSS MUCH OF THE REMAINDER OF THE
CENTRAL CARIBBEAN WITH MODERATE TO FRESH TRADE WINDS ELSEWHERE.
CONVECTION WILL CONTINUE UNDER THE UPPER TROUGH OVER THE NW
CARIBBEAN TODAY. A TROPICAL WAVE WILL BRING SHOWERS TO THE
LESSER ANTILLES TODAY AS IT ENTERS THE EASTERN CARIBBEAN FROM
THE ATLC.

...HISPANIOLA...

ISOLATED SHOWERS IN LOW LEVEL MOISTURE IN TRADE WIND FLOW ARE
MOVING ACROSS PORTIONS OF THE DOMINICAN REPUBLIC THIS MORNING.
OTHERWISE...FAIR WEATHER EXTENDS ACROSS THE ISLAND. THIS
MOISTURE MAY RESULT IN ISOLATED THUNDERSTORMS THIS AFTERNOON.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE BY
THURSDAY AS A TROPICAL WAVE PASSES BY THE ISLAND.

ATLANTIC OCEAN...

A SURFACE TROUGH EXTENDS FROM 28N77W TO 24N80W SUPPORTING
ISOLATED MODERATE CONVECTION WITHIN 30 NM OF THE TROUGH
AXIS...INCLUDING THE N BAHAMAS. FARTHER EAST...AN UPPER LOW
CENTERED NEAR 28N57W SUPPORTS A PAIR OF SURFACE TROUGHS OVER THE
CENTRAL ATLC FROM 26N61W TO 21N63W...AND FROM 28N51W TO 21N51W.
SCATTERED SHOWERS ARE WITHIN 100 NM OF BOTH OF THE SURFACE
TROUGH AXIS. SCATTERED THUNDERSTORMS ARE WITHIN 150 NM OF THE
UPPER LOW. SURFACE RIDGING ANCHORED BY A 1026 MB HIGH CENTERED
NEAR 35N50W EXTENDS ACROSS THE REMAINDER OF THE SUBTROPICAL
ATLC. THREE TROPICAL WAVES ARE OVER THE TROPICAL ATLC. PLEASE
REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. TWO LOW
PRESSURE SYSTEMS AND A SURFACE TROUGH ARE OVER THE TROPICAL
ATLC. PLEASE REFER TO THE ITCZ/MONSOON TROUGH SECTION FOR MORE
DETAILS. CONVECTION WILL CONTINUE WITH THE W ATLC SURFACE TROUGH
OVER THE BAHAMAS TODAY...AS WELL AS WITH THE UPPER LOW OVER THE
CENTRAL ATLC.

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

$$

LATTO


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