Tropical Weather Discussion
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000
AXNT20 KNHC 011036
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT AUG 01 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 IS IN THE E TROPICAL ATLC WITH AXIS ACROSS THE
CAPE VERDE ISLANDS NEAR 23W...MOVING W AT 10-15 KT. METEOSAT
ENHANCED IMAGERY SHOW SAHARAN DRY AIR AND DUST IN THE NORTHERN
WAVE ENVIRONMENT WHERE NO CONVECTION IS OBSERVED.
HOWEVER...SOUTH OF THE MONSOON TROUGH...ABUNDANT MOISTURE AND A
DIFFLUENT WIND ENVIRONMENT ALOFT SUPPORT A CLUSTER OF MODERATE
TO ISOLATED STRONG CONVECTION FROM 10N TO 14N BETWEEN 19W AND
26W.

A TROPICAL WAVE IS IN THE W TROPICAL ATLC WITH AXIS NEAR
53W...MOVING W AT 20 KT. THE TOTAL PRECIPITABLE WATER IMAGERY
SHOW SHALLOW MOISTURE BEHIND THE WAVE AXIS AND DRY AIR AHEAD OF
IT. THE WAVE IS DEVOID OF CONVECTION AS SAHARAN DRY AIR AND DUST
COVER THE ENTIRE WAVE ENVIRONMENT.

A TROPICAL WAVE IS IN THE SW CARIBBEAN WITH AXIS NEAR 82W...
MOVING W AT 15 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE
WATER IMAGERY SHOWS THE WAVE IS ASSOCIATED WITH A SURGE OF DEEP
MOISTURE. A DIFFLUENT WIND ENVIRONMENT ALOFT SUPPORTS SCATTERED
MODERATE CONVECTION AND TSTMS AHEAD OF THE WAVE AXIS S OF 16N.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS INTO THE E TROPICAL ATLC NEAR
14N16W TO 13N30W TO A 1009 MB LOW NEAR 12N35W SW TO 08N48W. THE
ITCZ BEGINS NEAR 08N48W AND CONTINUES TO COASTAL GUYANA NEAR
06N58W. ASIDE FROM THE CONVECTION ASSOCIATED WITH THE TROPICAL
WAVE NEAR THE CAPE VERDE ISLANDS...SCATTERED MODERATE CONVECTION
IS FROM 09N-11N BETWEEN 33W-39W AND FROM 06N-10N BETWEEN 40W-54W.

...DISCUSSION...

GULF OF MEXICO...

DEEP MOISTURE ASSOCIATED WITH A LOW PRESSURE SYSTEM OVER THE SE
CONUS EXTENDS ACROSS THE NORTHERN GULF WHERE A 1011 MB LOW IS
ANALYZED NEAR 29N86W ALONG WITH A STATIONARY FRONT EXTENDING
FROM 30N85W TO THE LOW TO 28N90W TO 29N95W. A DIFFLUENT WIND
ENVIRONMENT ALOFT OVER THE NORTH-CENTRAL AND NE BASIN BEING
GENERATED BY THE SE PERIPHERY OF AN UPPER RIDGE SUPPORT
SCATTERED MODERATE CONVECTION AND TSTMS N OF 26N E OF 95W. OVER
THE W BASIN...TWO 1013 MB HIGH PRESSURE CENTERS PREVAILS...ONE
NEAR 26N95W...THE SECOND NEAR 23N94W. OTHERWISE...SURFACE
RIDGING DOMINATES THE SE GULF WHERE ISOLATED SHOWERS ARE
OBSERVED. WINDS ARE VARIABLE AND LIGHT OVER THE ENTIRE
BASIN...EXCEPT THE NE GULF WHERE WINDS ARE FROM THE SW RANGING
FROM 15 KT TO 20 KT. FRONT WILL MEANDER OVER THE N GULF THROUGH
THE WEEKEND. THE SURFACE RIDGE WILL CONTINUE TO BUILD BACK
ACROSS THE GULF THROUGH MON.

CARIBBEAN SEA...

AN UPPER-LOW IS OVER THE NW CARIBBEAN...WHICH ALONG WITH SHALLOW
MOISTURE SUPPORT ISOLATED SHOWERS AND TSTMS OVER SOUTHERN
WESTERN CUBA COASTAL WATERS. AN UPPER RIDGE DOMINATES ACROSS THE
REMAINDER BASIN. A TROPICAL WAVE IS BEING ANALYZED OVER THE SW
CARIBBEAN WITH AXIS NEAR 82W...WHICH IS ENHANCING SCATTERED
MODERATE CONVECTION AND TSTMS AHEAD OF ITS AXIS. SEE TROPICAL
WAVES SECTION FOR FURTHER DETAILS. EVEN THAT MODERATE MOISTURE
IS OBSERVED IN SSMI TPW IMAGERY ACROSS THE CENTRAL AND SE
CARIBBEAN...STRONG DEEP LAYER WIND SHEAR ACROSS THE REGION
SUPPORT STABLE CONDITIONS. NE TO E WINDS OF 25 TO 30 KT ARE FROM
11N TO 13N BETWEEN 73W AND 76W WITH SEAS TO 10 FT. TRADES OF 15
KT ARE W OF 76W. THE TROPICAL WAVE WILL MOVE INLAND CENTRAL
AMERICA LATER TODAY. THE NEXT TROPICAL WAVE WILL ENTER THE
CARIBBEAN SUN.

...HISPANIOLA...

SHALLOW MOISTURE ASSOCIATED WITH THE PASSAGE OF A TROPICAL WAVE IS
ACROSS THE ISLAND SUPPORTING CLOUDINESS. HOWEVER...NO CONVECTION
IS OBSERVED AT THIS TIME. MOISTURE IS EXPECTED TO DECREASE LATER
TODAY AS SAHARAN DRY AIR AND DUST START TO MOVE ACROSS THE
ISLAND AHEAD OF THE NEXT TROPICAL WAVE TO ENTER THE CARIBBEAN
SUNDAY NIGHT.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL LOW IS OVER THE SW N ATLC ALONG WITH
SHALLOW MOISTURE AHEAD OF A FRONTAL SYSTEM OVER THE SE CONUS.
LOW LEVEL MOISTURE CONVERGENCE IN THIS REGION AND A DIFFLUENT
WIND ENVIRONMENT ALOFT BEING GENERATED BY UPPER RIDGING ACROSS
THE GULF OF MEXICO SUPPORT SCATTERED MODERATE CONVECTION AND
TSTMS N OF 20N W OF 71W. SURFACE RIDGING DOMINATES ACROSS THE
REMAINDER BASIN...THUS FAVORING FAIR WEATHER. FOR TROPICAL WAVES
INFORMATION SEE SECTION ABOVE.

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

$$
NR



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