Tropical Weather Discussion
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000
AXNT20 KNHC 050541
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 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 AXIS EXTENDING FROM
19N28W TO 10N25W...MOVING W AT 15 TO 20 KT. THE WAVE COINCIDES
WITH 700 MB TROUGHING BETWEEN 24W AND 32W. SSMI TPW IMAGERY
INDICATES A BROAD POLEWARD SURGE OF MOISTURE ASSOCIATED WITH THE
WAVE. NO DEEP CONVECTION IS CURRENTLY NOTED.

A LOW AMPLITUDE TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC WITH
AXIS EXTENDING FROM 16N39W TO 09N39W...MOVING W AT AROUND 10 KT
OVER THE PAST 24 HOURS. THE WAVE COINCIDES WITH 700 MB TROUGHING
BETWEEN 38W AND 41W. 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 AXIS
EXTENDING FROM 19N58W TO 11N58W...MOVING W AT 15 TO 20 KT OVER
THE PAST 24 HOURS. THE WAVE COINCIDES WITH BROAD 700 MB
TROUGHING BETWEEN 52W AND 65W. NO SIGNIFICANT CONVECTION IS
OBSERVED AT THIS TIME AS SAHARAN DUST IS ALSO IN THE ENVIRONMENT
OF THE WAVE.

A TROPICAL WAVE IS OVER THE W CARIBBEAN AND ENTERING CENTRAL
AMERICA WITH AXIS EXTENDING FROM 20N86W TO 10N87W...MOVING W AT
20 TO 25 KT OVER THE PAST 24 HOURS. THIS WAVE COINCIDES WITH
700 MB TROUGHING BETWEEN 82W AND 90W. THE INTERACTION OF THIS
WAVE WITH AN UPPER LOW IS SUPPORTING SCATTERED MODERATE
CONVECTION FROM 15N TO 23N BETWEEN 80W AND 88W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 11N17W THROUGH A 1010 MB LOW
NEAR 10N20W TO 11N25W...THEN RESUMES W OF A TROPICAL WAVE NEAR
11N27W TO 11N38W. THE ITCZ BEGINS W OF A TROPICAL WAVE NEAR
11N40W AND CONTINUES THROUGH A 1012 MB LOW NEAR 11N47W TO
11N58W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE WITHIN
200NM OF THE LOW OVER THE EASTERN ATLC. WIDELY SCATTERED
MODERATE CONVECTION IS WITHIN 100NM OF THE ITCZ AXIS BETWEEN 41W
AND 55W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER LEVEL LOW OVER CENTRAL AMERICA HAS A TROUGH AXIS THAT
EXTENDS OVER THE SW GULF. THIS IS SUPPORTING SCATTERED
THUNDERSTORMS OVER THE GULF FROM 22N TO 25N BETWEEN 81W AND 87W.
A 1018 MB HIGH CENTERED NEAR 27N84W IS PART OF A BROAD SURFACE
RIDGE THAT EXTENDS FROM THE W ATLC TO CENTRAL FL TO THE TX
COAST. A SURFACE TROUGH IS OVER THE SW GULF FROM 21N90W TO
18N91W. SHOWERS ARE WITHIN 50 NM OF THE TROUGH AXIS. 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 ELONGATED UPPER-LEVEL LOW CENTERED OVER NICARAGUA AND
EXTENDING ACROSS THE NW CARIBBEAN IS INTERACTING WITH A TROPICAL
WAVE...SUPPORTING SCATTERED MODERATE CONVECTION FROM 15N TO 23N
BETWEEN 80W AND 88W. 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 24N78W SUPPORTING
ISOLATED MODERATE CONVECTION FROM 22N TO 25N BETWEEN 78W AND
80W...INCLUDING OFFSHORE WATERS BETWEEN THE CENTRAL BAHAMAS AND
THE FL KEYS. A SURFACE TROUGH IS OVER THE CENTRAL ATLC EXTENDING
FROM 26N55W TO 21N57W. THIS TROUGH IS A SURFACE REFLECTION OF A
BROAD MID LEVEL TROUGH EXTENDING N FROM A TROPICAL WAVE TO 31N.
AN UPPER LOW IS ALSO IN THE AREA...CENTERED NEAR 28N56W.
SCATTERED THUNDERSTORMS ARE WITHIN 150 NM OF THE UPPER LOW.
SURFACE RIDGING ANCHORED BY A 1028 MB HIGH CENTERED NEAR 35N48W
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. CONVECTION WILL
CONTINUE WITH THE W ATLC SURFACE TROUGH OVER THE BAHAMAS TODAY.

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

$$

LATTO



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