[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251038
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON MAY 25 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 W OF THE ITCZ FROM 01N TO 11N WITH AXIS NEAR
39W...MOVING W AT 13 TO 15 KT DURING THE LAST 24 HOURS. SSMI TPW
IMAGERY SHOW HIGH CONCENTRATION OF MOISTURE AT MIDDLE TO LOWER
LEVELS W AND E OF ITS AXIS. IN THE IMMEDIATE ENVIRONMENT OF THE
WAVE AXIS...THIS MOISTURE CONCENTRATES FROM THE CENTER TO THE
SOUTHERN PORTION OF IT. THE MOISTURE ALONG WITH A DIVERGENT
ENVIRONMENT ALOFT SUPPORT SCATTERED MODERATE CONVECTION WITHIN
400 NM E OF THE WAVE AXIS FROM 04N TO 09N AND WITHIN 120 NM W OF
IT FROM 03N TO 05N. METEOSAT DUST AND SAL TRACKING IMAGERY
INDICATE THE PRESENCE OF DUST AND DRY AIR IN THE NORTHERN REGION
OF THE WAVE...THUS RESULTING IN THE LACK OF CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL
ATLANTIC NEAR 11N16W TO 08N19W. THE ITCZ BEGINS NEAR 08N19W AND
CONTINUES ALONG 05N27W TO EAST OF A TROPICAL WAVE NEAR 06N36W.
SCATTERED MODERATE CONVECTION IS WITHIN 100 NM EITHER SIDE OF
THE MONSOON TROUGH AND THE ITCZ E OF 26W. FOR CONVECTION
ASSOCIATED WITH THE TROPICAL WAVE SEE THE SECTION ABOVE. WEST OF
THE TROPICAL WAVE...A SURFACE TROUGH IS ANALYZED FROM 05N42W TO
0.5N45W WITH SCATTERED MODERATE CONVECTION WITHIN 120 NM EITHER
SIDE OF ITS AXIS.

...DISCUSSION...

GULF OF MEXICO...

A MIDDLE TO UPPER LEVEL LOW OVER THE NORTHERN AND CENTRAL
ROCKIES EXTENDS A TROUGH SE ACROSS TEXAS AND INTO THE W
GULF...THUS SUPPORTING A SURFACE TROUGH ALONG 22N90W TO 17N94W.
SURFACE HIGH PRESSURE ANCHORED BY A CENTER OF 1032 MB OVER THE
NW ATLANTIC EXTENDS A RIDGE AXIS SW ACROSS THE FLORIDA PENINSULA
INTO THE EASTERN GULF TO 90W. LOW LEVEL MOISTURE CONVERGENCE
ALONG WITH A DIFFLUENT ENVIRONMENT ALOFT SUPPORT SCATTERED
MODERATE CONVECTION AND TSTMS N OF 26N BETWEEN 87W AND 92W.
ISOLATED SHOWERS ARE OBSERVED IN THE SW GULF S OF 25N W OF 91W
AND IN THE SE GULF S OF 27N E OF 84W. SURFACE RIDGING WILL BE
THE DOMINANT FEATURE THE NEXT THREE DAYS.

CARIBBEAN SEA...

BROAD SURFACE HIGH PRESSURE ACROSS THE ATLANTIC CONTINUES TO
EXTEND INTO THE NORTHERN AND CENTRAL CARIBBEAN...THUS GENERATING
A TIGHTER PRESSURE GRADIENT IN THE SW BASIN...RESULTING IN WINDS
OF 20 TO 30 KT FROM 11N TO 13.5N BETWEEN 73W AND 77W WITH SEAS
FROM 10 TO 12 FT AND WINDS OF 20 TO 25 KT S OF 18N W OF 85W WITH
SEAS LESS THAN 8 FT. SSMI TPW IMAGERY SHOW PATCHES OF LOW LEVEL
MOISTURE ACROSS CUBA AND HISPANIOLA...THUS ENHANCING ISOLATED
SHOWERS AND TSTMS. LOW PRESSURE OVER NORTHERN COLOMBIA ALONG
WITH A DIVERGENT ENVIRONMENT ALOFT SUPPORT SCATTERED MODERATE
CONVECTION AND ISOLATED TSTMS S OF 12N BETWEEN 74W AND 84W.
ISOLATED SHOWERS ARE POSSIBLE FOR THE NE BASIN...ENHANCED BY
SHALLOW MOISTURE. FAIR WEATHER IS ELSEWHERE BEING SUPPORTED BY
DEEP LAYER DRY AIR. NO SIGNIFICANT WEATHER IS EXPECTED IN THE
NEXT TWO DAYS.

...HISPANIOLA...

SHALLOW MOISTURE CONTINUE TO SURROUND THE ISLAND AND ENTERS HAITI
...THUS ENHANCING ISOLATED SHOWERS MAINLY OVER COASTAL WATERS
THIS MORNING. DEEP LAYER DRY AIR IS OVER THE REMAINDER ISLAND AS
DEPICTED BY SSMI TPW AND WATER VAPOR IMAGERY...WHICH IS
CURRENTLY SUPPORTING FAIR WEATHER. SHOWERS AND THUNDERSTORMS
ACTIVITY ARE EXPECTED DURING THE AFTERNOON AND EARLY EVENING
HOURS DUE TO OROGRAPHIC LIFTING AND DAYTIME HEATING...NO
SIGNIFICANT WEATHER IS EXPECTED THE NEXT TWO DAYS.

ATLANTIC OCEAN...

A STATIONARY FRONT EXTENDS FROM 30N61W SW TO 29N64W WHERE IT
TRANSITIONS TO A SURFACE TROUGH TO 29N69W. SCATTERED MODERATE
CONVECTION AND ISOLATED TSTMS ARE WITHIN 145 NM AHEAD OF THE
FRONT N OF 28N. SOUTHEAST OF THE TROUGH...A WEAK 1021 MB LOW IS
NEAR 26N57W LACKING CONVECTION...WHICH IS EXPECTED TO DISSIPATE
LATER TODAY. ELSEWHERE SURFACE HIGH PRESSURE AND FAIR WEATHER
PREVAILS. THE SURFACE TROUGH WILL LINGER OVER THE CENTRAL ATLC
FOR THE NEXT TWO DAYS. SURFACE RIDGING WILL DOMINATE ELSEWHERE.

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

$$
NR
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