Tropical Weather Discussion
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000
AXNT20 KNHC 220003
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON JUL 21 2014

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...SPECIAL FEATURES...
FORMER LOW PRESSURE CENTER EMBEDDED IN THE MONSOON TROUGH AND
ASSOCIATED WITH A TROPICAL WAVE HAS INTENSIFIED TO A TROPICAL
DEPRESSION NEAR 2000 UTC. AS OF 2100 UTC...TROPICAL DEPRESSION
TWO IS LOCATED NEAR 11.6N 43.8W OR ABOUT 1045 NM E OF THE LESSER
ANTILLES. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1012 MB.
MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS TO 40 KT. A CLUSTER
OF MODERATE CONVECTION IS FROM 10N-12N BETWEEN 43W-46W.
RAINBANDS ASSOCIATED WITH THE SYSTEM EXTENDS FROM 9N-14N BETWEEN
42W-46W. SEE THE LATEST NHC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AXIS EXTENDING FROM
19N35W TO 12N35W MOVING W AT 20 KT. THE WAVE  IS SLIGHTLY N OF
THE MONSOON TROUGH AND EMBEDDED IN THE DRY SAHARAN AIR LAYER
WHICH IS HINDERING CONVECTION.

TROPICAL WAVE HAS DETACHED FROM THE CURRENT TROPICAL DEPRESSION
TWO. THE WAVE CONTINUES TO MOVE WESTWARD WITH AXIS EXTENDING
FROM 18N44W TO 12N45W AT A SPEED OF 20 KT DURING THE PAST 24
HOURS. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL
DEPRESSION SE OF THE AXIS...NO OTHER CONVECTIVE ACTIVITY IS
ASSOCIATED WITH THE WAVE AS IT IS EMBEDDED IN THE DRY SAHARAN
AIR LAYER.

TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AXIS EXTENDING
FROM 18N76W TO 10N76W MOVING W AT 20-25 KT DURING THE LAST 24
HOURS. DRY AIR SUBSIDENCE FROM ALOFT AS WELL AS A STRONG DEEP
LAYER ENVIRONMENTAL SHEAR OVER THE CENTRAL AND EASTERN CARIBBEAN
ARE FACTORS INHIBITING CONVECTION AT THE TIME.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N16W TO
9N21W 12N35W TO A 1013 MB LOW NEAR 11N43W TO 8N45W. THE
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 8N45W TO 8N52W
TO 7N58W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL
WAVES...WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-10N
BETWEEN W OF 36W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL LOW IS CENTERED JUST N OF FLORIDA AND
SUPPORTS A STATIONARY FRONT EXTENDING ACROSS THE SE CONUS AND
ALONG THE LOUISIANA GULF COAST. A PRE-FRONTAL SURFACE TROUGH IS
ANALYZED FROM THE WESTERN FLORIDA PANHANDLE NEAR 31N85W SW TO
29N87W TO 27N89W. LOW-LEVEL MOISTURE CONVERGENCE IN THE E-SE
GULF IS ENHANCING SCATTERED SHOWERS AND TSTMS N OF 23N E OF 89W
AS WELL AS THE FLORIDA STRAITS. OTHERWISE...SURFACE RIDGING
DOMINATES ELSEWHERE IN THE GULF WHERE VARIABLE WINDS RANGE FROM
5-15 KT. OVER THE WESTERN GULF...DRY AIR SUBSIDENCE FROM THE MID-
UPPER LEVELS SUPPORT FAIR WEATHER. EXCEPT FOR A TROPICAL WAVE
POSSIBLY EXTENDING TO THE BAY OF CAMPECHE ON TUE
MORNING...SURFACE RIDGING AND HIGH PRESSURE IS FORECAST TO
PREVAIL THE NEXT TWO TO THREE DAYS.

CARIBBEAN SEA...
UPPER LEVEL NORTH-NORTHEASTERLY FLOW IS OVER MUCH OF THE WESTERN
CARIBBEAN W OF AN UPPER LEVEL LOW CENTERED NEAR 18N75W WITH
TROUGH AXIS EXTENDING SOUTHWARD TO A BASE OVER THE SW CARIBBEAN
NEAR 11N77W. THIS WIND PATTERN ALOFT IS GENERATING DIFFLUENCE
ALONG CUBA WHICH ALONG LOW-LEVEL MOISTURE CONVERGENCE SUPPORT
HEAVY SHOWERS AND TSTMS ACROSS THIS ISLAND AND ADJACENT WATERS.
THE AXIS OF A TROPICAL WAVE IS JUST SOUTH OF EASTERN CUBA MOVING
ACROSS JAMAICA AND COLOMBIA COASTAL WATERS. THERE IS NO
CONVECTION ASSOCIATED WITH THE WAVE AT THE TIME. SEE TROPICAL
WAVES SECTION FOR MORE DETAILS. ALOFT AND EAST OF THE WAVE
AXIS...THE SW PERIPHERY OF AN UPPER-LEVEL ANTICYCLONE CENTERED
OVER THE CENTRAL ATLC NEAR 24N48W IS GENERATING A DIFFLUENT
ENVIRONMENT ACROSS PORTIONS OF THE EASTERN CARIBBEAN. THIS
ENVIRONMENT ALOFT IS SUPPORTING ISOLATED SHOWERS AND TSTMS
ACROSS HISPANIOLA. ISOLATED SHOWERS ARE POSSIBLE FOR THE MONA
PASSAGE AND WESTERN PUERTO RICO. SCATTERED MODERATE CONVECTION
IS OVER INLAND AND COASTAL WATERS OF COSTA RICA AND PANAMA BEING
ASSOCIATED WITH THE MONSOON TROUGH. ELSEWHERE...FAIR WEATHER
DOMINATES BEING SUPPORTED BY DEEP LAYER DRY AIR. MODERATE TO
FRESH TRADES CONTINUE AND ARE EXPECTED TO PERSIST THROUGH MUCH
OF THE WEEK AHEAD... OCCASIONALLY WITH STRONGER WINDS 25 TO 30
KT OCCURRING WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA AND
NW VENEZUELA.

...HISPANIOLA...
AN UPPER LEVEL LOW CENTERED NEAR 18N75W WITH TROUGH AXIS
EXTENDING SOUTHWARD TO A BASE OVER THE SW CARIBBEAN ALONG WITH
WIND FLOW ASSOCIATED WITH THE SW PERIPHERY OF AN UPPER-LEVEL
ANTICYCLONE CENTERED OVER THE CENTRAL ATLC GENERATE A DIFFLUENT
ENVIRONMENT ALOFT ACROSS PORTIONS OF THE CENTRAL-EASTERN
CARIBBEAN. THIS ENVIRONMENT ALOFT IS SUPPORTING ISOLATED SHOWERS
AND TSTMS ACROSS HISPANIOLA AND COASTAL WATERS. WEATHER
CONDITIONS ARE EXPECTED TO IMPROVE TUE MORNING.

ATLANTIC OCEAN...
NORTH-NORTHEASTERLY FLOW ASSOCIATED WITH A WEAK MID-UPPER LEVEL
ANTICYCLONE OVER PORTIONS OF THE SW N ATLC AND THE WIND FLOW OF
AN IMMEDIATE MID-UPPER LEVEL LOW IS GENERATING A DIFFLUENT
ENVIRONMENT IN THIS REGION OF THE ATLC. THIS ALONG WITH LOW-
LEVEL MOISTURE CONVERGENCE IS SUPPORTING SCATTERED SHOWERS AND
TSTMS N OF 23N W OF 75W. SIMILAR CONVECTION IS ALONG COASTAL
WATERS OF NORTHERN HISPANIOLA. SEE SECTION ABOVE FOR MORE
DETAILS. THE UPPER LEVEL LOW ALSO SUPPORTS A SURFACE TROUGH
ANALYZED FROM 31N58W TO 24N62W. THE REMAINDER OF THE CENTRAL AND
EASTERN ATLC ARE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED
BY A 1026 MB HIGH CENTERED NEAR 32N39W AND A 1025 MB HIGH
CENTERED NEAR 33N33W.

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

$$
NR



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