Tropical Weather Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
AXNT20 KNHC 271008
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED MAY 27 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
1000 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS W OF THE ITCZ FROM THE EQUATOR TO 10N WITH
AXIS NEAR 48W...MOVING W AT 5 TO 10 KT DURING THE LAST 24 HOURS.
SSMI TPW IMAGERY SHOW THE WAVE IS EMBEDDED WITHIN ABUNDANT
MOISTURE IN THE MIDDLE TO LOWER LEVELS. SATELLITE DERIVED WINDS
AND MODEL GUIDANCE SHOW A DIFFLUENT ENVIRONMENT ALOFT THAT
SUPPORT SCATTERED MODERATE CONVECTION WITHIN 160 NM AHEAD OF THE
WAVE AXIS AND ISOLATED MODERATE CONVECTION E OF IT. FURTHER
CONVECTION IS BEING HINDERED MAINLY BY STRONG DEEP LAYER WIND
SHEAR.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL
ATLANTIC NEAR 10N14W TO 06N20W. THE ITCZ BEGINS NEAR 06N20W AND
CONTINUES ALONG 05N30W TO EAST OF A TROPICAL WAVE NEAR 04N45W.
SCATTERED MODERATE CONVECTION AND TSTMS ARE FROM 04N TO 10N E OF
20W. FOR CONVECTION ASSOCIATED WITH THE TROPICAL WAVE SEE THE
SECTION ABOVE.

...DISCUSSION...

GULF OF MEXICO...

SURFACE LOW PRESSURE OVER MEXICO EXTENDS E TO THE SW GULF WHILE
HIGH PRESSURE OVER THE W ATLANTIC CONTINUES TO EXTEND A RIDGE
AXIS SW ACROSS THE FLORIDA PENINSULA AND INTO THE NORTHERN AND
EASTERN GULF. EASTERLY TO SOUTHEASTERLY WIND FLOW OF 15 TO 20 KT
ASSOCIATED WITH THE RIDGE DOMINATES THE GULF AND ADVECTS LOW
LEVEL MOISTURE FROM THE NW CARIBBEAN. A SURFACE TROUGH IS OVER
THE BAY OF CAMPECHE WATERS WITH AXIS ALONG 21N93W TO 14N94W WITH
ISOLATED SHOWERS AND TSTMS AHEAD OF IT S OF 20N. SCATTERED
MODERATE CONVECTION AND ISOLATED TSTMS ASSOCIATED WITH TWO
FORMER TROUGHS ARE N OF 26N E OF 87W. HAZE AND FOG CONTINUE TO
BE REPORTED IN THE NW GULF N OF 27 W OF 90W. SURFACE RIDGING
WILL CONTINUE TO BE THE DOMINANT FEATURE DURING THE NEXT THREE
DAYS.

CARIBBEAN SEA...

BROAD SURFACE HIGH PRESSURE ACROSS THE ATLANTIC CONTINUES TO
EXTEND S INTO THE NORTHERN AND CENTRAL CARIBBEAN...THUS
SUPPORTING A TIGHTER PRESSURE GRADIENT IN THE SW
BASIN...RESULTING IN NE TO E WINDS OF 20 TO 25 KT FROM 11N TO
13N BETWEEN 73W AND 77 WITH SEAS UP TO 9 FT. ELSEWHERE...TRADES
OF OF 15 KT AND SEAS LESS THAN 8 FT DOMINATE. SSMI TPW IMAGERY
SHOW MODERATE LOW LEVEL MOISTURE OVER THE NW BASIN...WHICH ALONG
WITH TROUGHING ALOFT SUPPORT ISOLATED SHOWERS AND TSTMS OVER
WESTERN CUBA AND ALONG SOUTHERN COASTAL WATERS. SIMILAR
CONVECTION IS OVER SOUTHERN HAITI ADJACENT WATERS. SHALLOW
MOISTURE OVER THE NE CARIBBEAN SUPPORTS ISOLATED SHOWERS OVER
PUERTO RICO AND NORTHERN LESSER ANTILLES. FAIR WEATHER IS
ELSEWHERE BEING SUPPORTED BY DEEP LAYER DRY AIR. NO SIGNIFICANT
CHANGES ARE EXPECTED IN THE NEXT TWO DAYS.

...HISPANIOLA...

UPPER LEVEL TROUGHING AND SHALLOW MOISTURE ACROSS THE SW ISLAND
ENHANCE ISOLATED SHOWERS OVER SOUTHERN HAITI AND ADJACENT
WATERS. DEEP LAYER DRY AIR IS OVER THE REMAINDER ISLAND AS
DEPICTED BY SSMI TPW AND WATER VAPOR IMAGERY...THUS SUPPORTING
FAIR WEATHER. SHOWERS AND THUNDERSTORMS ACTIVITY ARE EXPECTED
DURING THE AFTERNOON AND EVENING HOURS THROUGH THURSDAY BEING
ENHANCED BY OROGRAPHIC LIFTING AND DAYTIME HEATING AND SUPPORTED
BY UPPER LEVEL TROUGHING.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL LOW ANCHORED NEAR 26N60W CONTINUE TO
SUPPORT A SURFACE TROUGH WITH AXIS EXTENDING FROM 34N59W TO
23N60W. NUMEROUS MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM
22N TO 32N BETWEEN 51W AND 59W. A TROPICAL WAVE IS W OF THE
ITCZ. SEE THE TROPICAL WAVES SECTION ABOVE. N OF THE TROPICAL
WAVE SCATTERED MODERATE CONVECTION IS FROM 11N TO 16N BETWEEN
32W AND 52W. ELSEWHERE SURFACE HIGH PRESSURE AND FAIR WEATHER
PREVAILS. THE SURFACE TROUGH WILL CONTINUE TO DRIFT W TOWARDS
THE SW N ATLC DURING THE NEXT THREE DAYS. SURFACE RIDGING WILL
DOMINATE ELSEWHERE.

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

$$
NR


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.