Tropical Weather Discussion
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000
AXNT20 KNHC 271039
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN JUL 27 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1030 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS REACHING CENTRAL ATLC WATERS. ITS AXIS EXTENDS
FROM 19N34W TO 10N37W AND HAS BEEN MOVING W AT 15 KT DURING THE
PAST 24 HOURS. METEOSAT SAL TRACKING IMAGERY INDICATE THE WAVE
CONTINUES EMBEDDED IN THE DRY SAHARAN AIRMASS WHICH IS
INHIBITING CONVECTION AT THE TIME.

TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN WITH AXIS EXTENDING
FROM 17N67W TO 10N67W MOVING W AT 20 KT IN THE PAST 24 HOURS.
THE WAVE IS ASSOCIATED WITH DEEP LAYER MOISTURE S OF 16N.
HOWEVER...STRONG DEEP LAYER ENVIRONMENTAL SHEAR ACROSS MOST OF
THE CENTRAL AND EASTERN CARIBBEAN INHIBITS CONVECTION AT THE
TIME.

TROPICAL WAVE IS MOVING ACROSS THE YUCATAN PENINSULA AND
NORTHERN CENTRAL AMERICA. ITS AXIS EXTENDS FROM 21N89W TO 13N91W
AND HAS BEEN MOVING W AT 20-25 KT DURING THE PAST 24 HOURS. THE
WAVE IS EMBEDDED IN A DEEP LAYER MODERATE MOIST ENVIRONMENT
SUPPORTING ISOLATED SHOWERS INLAND AS WELL AS IN THE BAY OF
CAMPECHE S OF 20N.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE COAST OF WEST AFRICA NEAR
11N15W AND THEN CONTINUES ALONG 9N28W TO 9N38W. THE
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 9N39W TO 9N50W
TO 9N61W. SCATTERED MODERATE CONVECTION IS FROM 6N-11N E OF
22W...FROM 6N-11N BETWEEN 26W-35W AND FROM 5N-11N BETWEEN 38W-
51W.

...DISCUSSION...

GULF OF MEXICO...

EXCEPT FOR THE FLORIDA PENINSULA AND THE BAY OF
CAMPECHE...MOSTLY DRY AIR IS ACROSS THE BASIN AT THE LOWER
LEVELS. ALOFT...AN INVERTED TROUGH COVERS GREAT PORTIONS OF THE
GULF S OF 26N WHICH IS SUPPORTING A TROPICAL WAVE MOVING ACROSS THE
YUCATAN PENINSULA. SEE THE TROPICAL WAVES SECTION ABOVE FOR FURTHER
DETAILS. THE INVERTED TROUGH ALONG WITH THE WESTERN PERIPHERY OF
A MID-LEVEL ANTICYCLONE ANCHORED OVER THE NORTHERN BAHAMAS
GENERATE A DIFFLUENT ENVIRONMENT ALOFT IN THE EASTERN GULF. THIS
IS ENHANCING ISOLATED SHOWERS FROM 23N-27N E OF 88W. SURFACE
HIGH PRESSURE PREVAILS ACROSS THE BASIN BEING ANCHORED BY A 1019
MB HIGH NEAR 26N88W THAT IS PROVIDING VARIABLE WINDS OF 5-15 KT.
ELSEWHERE...AN OVERALL STABLE ENVIRONMENT SUPPORTS CLEAR SKIES.
SHOWERS ARE EXPECTED FOR THE SW GULF SUNDAY AND MONDAY MORNING
AS THE TROPICAL WAVE CONTINUES TO MOVE WESTWARD TOWARDS THE BAY
OF CAMPECHE.

CARIBBEAN SEA...

AN ANTICYCLONE CENTERED OVER THE SW N ATLC ALONG WITH AN
INVERTED TROUGH OVER THE WESTERN-CENTRAL CARIBBEAN ARE
GENERATING DIFFLUENT FLOW ALOFT WHICH ALONG MODERATE LOW-LEVEL
MOISTURE SUPPORT ISOLATED SHOWERS AND TSTMS N OF 15N BETWEEN 75W-
84W. A TROPICAL WAVE IS SOUTH OF PUERTO RICO SUPPORTING
CLOUDINESS AND ISOLATED SHOWERS S OF 15N E OF 68W. SEE TROPICAL
WAVE SECTION FOR DETAILS. UPPER-LEVEL DIFFLUENCE JUST WEST OF
THE WAVE AXIS IS SUPPORTING A CLUSTER OF MODERATE CONVECTION AND
TSTMS FROM 12N-15N BETWEEN 68W-72W. A TIGHT PRESSURE GRADIENT
ACROSS THE CENTRAL BASIN SUPPORTS TRADES OF 20-30 KT S OF 17N
BETWEEN 66W-82W AND GALE FORCE WINDS ALONG THE COAST OF
COLOMBIA. SCATTERED HEAVY SHOWERS AND TSTMS ARE OVER COASTAL
WATERS OF COLOMBIA AND PANAMA BEING ENHANCED BY THE MONSOON
TROUGH. STRONG DEEP LAYER ENVIRONMENTAL WIND SHEAR AND DRY AIR
SUBSIDENCE FROM ALOFT SUPPORT CLEAR SKIES ACROSS THE REMAINDER
BASIN. THE TROPICAL WAVE S OF PUERTO RICO IS FORECAST TO MOVE S
OF HISPANIOLA THIS AFTERNOON AND S OF JAMAICA LATE TONIGHT.

...HISPANIOLA...

CLEAR SKIES AND FAIR WEATHER ARE ACROSS THE ISLAND. EXCEPT FOR
AFTERNOON/EARLY EVENING SHOWERS BEING ENHANCED BY DAYTIME
HEATING...FAIR WEATHER CONDITIONS ARE EXPECTED THROUGH EARLY
TUESDAY.

ATLANTIC OCEAN...

A DIFFLUENT ENVIRONMENT ALOFT BEING GENERATED BY AN INVERTED
TROUGH OVER THE EASTERN GULF AND AN ANTICYCLONE CENTERED OVER
THE SW N ATLC SUPPORT ISOLATED SHOWERS AND TSTMS NE OF FREEPORT.
FARTHER EAST...A MID-UPPER LEVEL LOW CENTERED NEAR 25N62W
ENHANCES SCATTERED SHOWERS AND TSTMS FROM 22N-26N BETWEEN 61W-
65W. OVER THE E ATLC...A MID-UPPER LEVEL LOW N OF THE AREA
EXTENDS A TROUGH SW WITH A BASE NEAR 25N. THIS CYCLONIC
CIRCULATION AND ASSOCIATED TROUGH SUPPORT A FRONTAL BOUNDARY
ANALYZED AS A DISSIPATING STATIONARY FRONT FROM 30N30W SW TO
25N40W TO 21N49W WITH NO CONVECTION ASSOCIATED WITH IT. THE
REMAINDER BASIN IS FAIRLY DRY AND UNDER THE INFLUENCE OF SURFACE
RIDGING ANCHORED BY A 1023 MB HIGH NEAR 31N56W AND A 1021 MB
HIGH NEAR 28N24W. THESE TWO FACTORS SUPPORTS FAIR WEATHER
ELSEWHERE IN THE BASIN. OTHERWISE...SEE ABOVE THE TROPICAL WAVES
SECTION. SURFACE RIDGING WILL DOMINATE ACROSS THE CENTRAL AND
WESTERN ATLC THE NEXT THREE DAYS.

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

$$
NR



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