Tropical Weather Discussion
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000
AXNT20 KNHC 071047
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUL 07 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
1030 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE CAME OFF THE WEST AFRICAN COAST EARLIER THIS
MORNING. THE APPROXIMATE LOCATION OF ITS AXIS IS ALONG 17W AND
IS BEING ENGULFED BY SAHARAN DRY AIR ACCORDING TO METEOSAT
SAHARAN AIR LAYER TRACKING IMAGERY. DUST IS ALSO EVIDENT IN THE
WAVE ENVIRONMENT IN METEOSAT IMAGERY. ISOLATED SHOWERS ARE IN
THE SOUTHERN REGION OF THE WAVE S OF THE MONSOON TROUGH.

A TROPICAL WAVE IS EAST OF THE LESSER ANTILLES WITH AXIS
APPROXIMATELY NEAR 58W...MOVING W AT 15 KT. SSMI TOTAL
PRECIPITABLE WATER AND METEOSAT SATELLITE IMAGERY SHOW SAHARAN
DRY AIR AND DUST IN THE NORTHERN WAVE ENVIRONMENT WHICH IS
HINDERING CONVECTION IN THAT REGION. SCATTERED MODERATE
CONVECTION IS SE OF THE WAVE AXIS FROM 06N TO 09N BETWEEN 50W
AND 57W.

A TROPICAL WAVE IS IN THE EASTERN CARIBBEAN BASIN WITH AXIS
APPROXIMATELY NEAR 69W...MOVING W AT 15 KT. SSMI TOTAL
PRECIPITABLE WATER IMAGERY DEPICT DRY AIR IN THE NORTHERN WAVE
ENVIRONMENT. BOTH THE DRY AIR AND STRONG DEEP LAYER WIND SHEAR
HINDER CONVECTION IN THE VICINITY OF THE WAVE AT THIS TIME.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO
09N30W TO 07N38W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 07N38W TO 07N48W TO THE COAST OF FRENCH GUIANA NEAR
04N52W. ASIDE THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...
SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 07N-
12N BETWEEN 14W AND 36W.

...DISCUSSION...

GULF OF MEXICO...

THE GULF BASIN CONTINUES UNDER THE INFLUENCE OF A VERY BROAD
UPPER LEVEL LOW CENTERED NEAR 24N86W. SSMI TOTAL PRECIPITABLE
WATER IMAGERY SHOW MOISTURE INFLOW FROM THE SE CONUS TO THE
FLORIDA PENINSULA AND THE EASTERN GULF AND FROM THE NW CARIBBEAN
TO THE WESTERN BASIN. MOISTURE ON THE EASTERN BASIN ALONG WITH
LIFTING PROVIDED BY THE LOW ALOFT SUPPORT ISOLATED SHOWERS AND
TSTMS FROM 27N TO 29N E OF 84W. STRONG DEEP LATER WIND SHEAR
HINDER CONVECTION DEVELOPMENT ELSEWHERE. OTHERWISE...SURFACE
HIGH PRESSURE AND RIDGING HOLD ANCHORED BY A 1021 MB CENTER NEAR
27N85W. N TO NE WINDS OF 20 TO 25 KT ARE FROM 20N TO 22N BETWEEN
89W AND 92W WITH SEAS LESS THAN 8 FT. SURFACE HIGH PRESSURE AND
RIDGING WILL PERSIST THE NEXT THREE DAYS.

CARIBBEAN SEA...

SSMI TOTAL PRECIPITABLE WATER IMAGERY SHOW DRY AIR ACROSS GREAT
PORTIONS OF THE BASIN...INCLUDING THE LEEWARD ISLANDS...PUERTO
RICO AND HISPANIOLA WHERE DUST AND HAZY CONDITIONS ARE BEING
REPORTED. THE IMAGERY SHOW A MOIST AIRMASS MOVING ACROSS THE
WINDWARD PASSAGE THAT IS ENHANCING SCATTERED SHOWERS AND TSTMS
OVER HAITI SW ADJACENT WATERS AND JAMAICA. ISOLATED SHOWERS ARE
BEING REPORTED ACROSS THE WINDWARD ISLANDS BEING ENHANCED BY
MOISTURE ASSOCIATED WITH A TROPICAL WAVE WITH AXIS CURRENTLY
NEAR 69W AND ANOTHER WAVE NEAR 58W. WATER VAPOR IMAGERY
INDICATES RELATIVELY DRY CONDITIONS ALOFT...SUPPORTING FAIR
WEATHER ELSEWHERE. DEEP CONVECTION IS ONLY OCCURRING ACROSS N-NW
COLOMBIA...PANAMA...SOUTHERN NICARAGUA AND COSTA
RICA...INCLUDING THE ADJACENT COASTAL WATERS S OF 11N.
OTHERWISE...NE TO E WINDS OF 20 TO 30 KT ARE FROM 10.5N TO 15N
BETWEEN 72W AND 80W WITH SEAS FROM 8 TO 13 FT. E WINDS OF 20 TO
25 KT ARE FROM 10.5N TO 13N W OF 80W WITH SEAS FROM 8 TO 11 FT.
E TO SE WINDS OF 20 TO 25 KT ARE FROM 17N TO 18N BETWEEN 70W AND
73W WITH SEAS TO 8 FT. WINDS OF 20 KT OR LESS ARE ELSEWHERE S OF
17N BETWEEN 72W AND 83W WITH SEAS FROM 8 TO 11 FT IN NE TO E
SWELL. THE AREA OF STRONGEST TRADES IS EXPECTED TO REMAIN
BETWEEN 68W-82W THROUGHOUT THE WEEK AHEAD.

...HISPANIOLA...

A PATCH OF MOIST AIR MOVED FROM INLAND HISPANIOLA TO THE
WINDWARD PASSAGE WHERE IT IS ENHANCING SCATTERED SHOWERS AND
TSTMS OVER HAITI SW ADJACENT WATERS AND JAMAICA. SAHARAN DRY AIR
AND DUST HAS MOVED INTO THE ISLAND AND WILL CONTINUE TO MOVE
ACROSS THROUGH WED...THUS SUPPORTING FAIR WEATHER BUT HAZY
CONDITIONS.

ATLANTIC OCEAN...

AN UPPER LEVEL LOW OVER THE SW N ATLC CENTERED NEAR 25N71W ALONG
WITH A MODERATE MOIST ENVIRONMENT SUPPORT ISOLATED SHOWERS AND
TSTMS FROM 21N TO 30N BETWEEN 66W AND 74W. SIMILAR WEATHER IS
BETWEEN THE E FLORIDA PENINSULA OFFSHORE WATERS AND THE NORTHERN
BAHAMAS...BEING ENHANCED BY UPPER LEVEL DIFFLUENCE. THE
REMAINDER OF THE ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A 1025 MB HIGH CENTERED NEAR 33N37W AND A 1023 MB
HIGH NEAR 31N65W. HIGH PRESSURE AND RIDGING WILL BE THE DOMINANT
FEATURE THE NEXT THREE DAYS. FOR TROPICAL WAVES
INFORMATION...SEE SECTION ABOVE.

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

$$
NR



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