Tropical Weather Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 221751
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT AUG 22 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...
HURRICANE DANNY IS CENTERED NEAR 15.4N 52.0W AT 22/1500 UTC OR
ABOUT 575 NM E OF THE LEEWARD ISLANDS...MOVING WNW AT 10 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 984 MB. MAXIMUM SUSTAINED
WIND SPEED IS 80 KT WITH GUSTS TO 95 KT. NUMEROUS MODERATE
CONVECTION EXTENDS FROM 14N TO 18N BETWEEN 49W AND 53W. SEE
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

AN EASTERN ATLC TROPICAL WAVE EXTENDS FROM 18N28W THROUGH A 1010
MB LOW NEAR 12N27W TO 08N26W...MOVING W AT AROUND 20 KT. SSMI
TPW INDICATES A DEEP SURGE OF MOISTURE THROUGH THE CAPE VERDE
ISLANDS TO 18N IS ASSOCIATED WITH THIS WAVE. THE WAVE IS
EMBEDDED IN A LARGE LOW LEVEL MONSOON GYRE. SCATTERED MODERATE
CONVECTION IS FROM 10N TO 18N BETWEEN 24W AND 31W.

A WESTERN CARIBBEAN TROPICAL WAVE EXTENDS FROM 19N83W TO
08N82W...MOVING W AT 20 TO 25 KT OVER THE PAST 24 HOURS. THIS
WAVE COINCIDES WITH A BROAD 700 MB TROUGH BETWEEN 80W AND 90W.
DEEP MOISTURE IS CONFINED S OF 14N IN THE ENVIRONMENT OF THE
WAVE. SCATTERED MODERATE CONVECTION IS S OF 11N W OF 76W. SOME
OF THIS CONVECTION IS LIKELY ASSOCIATED WITH THE E PACIFIC
MONSOON TROUGH OVER PANAMA.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR
17N16W INTO A 1010 MB LOW CENTERED NEAR 12N27W TO 08N30W TO
07N41W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVE
ALONG 26/27W...SCATTERED MODERATE CONVECTION IS FROM 06N TO 12N
BETWEEN 13W AND 24W. CLUSTERS OF STRONG CONVECTION ARE MOVING
OFFSHORE AFRICA FROM 16N TO 20N E OF 18W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER LOW IS CENTERED OVER THE SW GULF NEAR 20N92W WHILE AN
UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 29N79W WITH A RIDGE
AXIS EXTENDING ACROSS THE NORTHERN GULF. THE UPPER LOW SUPPORTS
ISOLATED THUNDERSTORMS FROM 20N TO 24N W OF 95W...AND FROM 22N
TO 27N BETWEEN 82W AND 91W. A 1017 MB SURFACE HIGH IS CENTERED
NEAR 28N87W...SUPPORTING ANTICYCLONIC SURFACE WINDS OVER THE GULF
BASIN. GENTLE TO MODERATE E TO SE WINDS COVER THE WESTERN GULF.
LIGHT TO GENTLE WINDS COVER THE EASTERN GULF. THE UPPER LEVEL
RIDGE AXIS WILL REMAIN IN PLACE WHILE THE UPPER LOW MOVES W OVER
MEXICO OVER THE NEXT 24 HOURS. UPPER LEVEL DIFFLUENCE BETWEEN
THESE TWO FEATURES WILL SUPPORT CONVECTION OVER THE CENTRAL GULF
TONIGHT THROUGH SUNDAY.

CARIBBEAN SEA...

AN ELONGATED UPPER LEVEL TROUGH EXTENDS FROM THE CENTRAL ATLC TO
THE CENTRAL CARIBBEAN. AN UPPER LEVEL ANTICYCLONE COVERS THE SW
CARIBBEAN AND CONNECTS ACROSS THE WESTERN CARIBBEAN WITH THE
WESTERN ATLC UPPER LEVEL ANTICYCLONE. UPPER LEVEL DIFFLUENCE
ASSOCIATED WITH THE RIDGE OVER THE SW CARIBBEAN IS COMBINING
WITH A TROPICAL WAVE TO SUPPORT SCATTERED MODERATE CONVECTION
OVER THAT PORTION OF THE BASIN. PLEASE SEE THE TROPICAL WAVES
SECTION FOR MORE DETAILS. DRY AIR AND SUBSIDENCE COVERS THE
CENTRAL AND EASTERN CARIBBEAN. MODERATE TO FRESH TRADE WINDS ARE
S OF 18N ACROSS THE CARIBBEAN. GENTLE TO MODERATE TRADE WINDS
ARE FOUND N OF 18N. OVER THE NEXT 24 HOURS CONVECTION WILL
CONTINUE OVER THE SW CARIBBEAN. GRADUALLY INCREASING SEAS WILL
BEGIN TO AFFECT THE LESSER ANTILLES TONIGHT WELL IN ADVANCE OF
HURRICANE DANNY.

...HISPANIOLA...
SHALLOW MOISTURE SUPPORTS ISOLATED THUNDERSTORMS OVER THE ISLAND
TODAY. THIS ACTIVITY WILL DIMINISH AFTER SUNSET. EXPECT
SIMILAR CONDITIONS ON SUNDAY.

ATLANTIC OCEAN...

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 29N79W WITH A LARGE
UPPER LOW CENTERED NEAR 31N66W. THE UPPER LOW SUPPORTS A SURFACE
TROUGH THAT ENTERS OUR AREA OF DISCUSSION NEAR 31N65W TO 25N73W.
ISOLATED MODERATE CONVECTION IS WITHIN 150 NM OF THE SURFACE
TROUGH W OF 65W. SCATTERED MODERATE AND ISOLATED STRONG
CONVECTION ARE WITHIN 200 NM SE OF THE SURFACE TROUGH E OF 65W.
A CENTRAL ATLC SURFACE TROUGH EXTENDS FROM 21N46W TO 27N49W AND
IS A SURFACE REFLECTION OF AN UPPER LOW NEAR 34N49W. ISOLATED
MODERATE CONVECTION IS WITHIN 100 NM OF THE TROUGH N OF 29N.
HURRICANE DANNY IS OVER THE CENTRAL TROPICAL ATLC. PLEASE REFER
TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS. A TROPICAL
WAVE IS OVER THE EASTERN ATLC. PLEASE REFER TO THE TROPICAL
WAVES SECTION FOR MORE DETAILS.

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

$$
LATTO


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