[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 080031
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI SEP 07 2012

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
2245 UTC.

...SPECIAL FEATURES...

HURRICANE MICHAEL IS CENTERED NEAR 31.4N 41.3W AT 07/2100 UTC OR
ABOUT 810 NM NW OF THE AZORES MOVING NW AT 03 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 970 MB. MAXIMUM SUSTAINED WIND SPEED
IS 90 KT WITH GUSTS TO 110 KT. NUMEROUS MODERATE CONVECTION IS
FROM 31N-32N BETWEEN 40W-42W. SCATTERED MODERATE CONVECTION IS
ELSEWHERE FROM 30N-33N BETWEEN 40W-43W. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC
FOR MORE DETAILS.

TROPICAL STORM LESLIE IS CENTERED NEAR 27.6N 62.2W AT 08/0000
UTC OR ABOUT 310 NM SSE OF BERMUDA MOVING N AT 04 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 981 MB. MAXIMUM SUSTAINED WIND SPEED
IS 55 KT WITH GUSTS TO 65 KT. SCATTERED MODERATE CONVECTION IS
FROM 25N-31N BETWEEN 58W-63W. SEE LATEST NHC INTERMEDIATE PUBLIC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 AND
THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/
WTNT22 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 23N16W TO A 1009 MB SURFACE LOW AT
15N17W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH A SURGE OF
DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY.
THERE IS ALSO A CLEARING IN THE SAHARAN AIR LAYER INDICATING THE
WAVES PRESENCE. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS
NEAR THE LOW CENTER FROM 14N-17N BETWEEN 18W-20W. SCATTERED
MODERATE CONVECTION IS ELSEWHERE FROM 13N-18N BETWEEN 15W-21W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE LOW ATTACHED
TO A TROPICAL WAVE AT 15N17W CONTINUING TO A SECOND 1012 MB
SURFACE LOW AT 17N29W TO 11N43W. THE ITCZ BEGINS AT 11N43W
CONTINUING ALONG 11N53W 9N61W. BESIDES CONVECTION NEAR THE
TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS FROM 10N-11N
BETWEEN 29W-37W.

...DISCUSSION...

GULF OF MEXICO...
MAINLY DRY AIR AND NORTHEASTERLY FLOW ALOFT COVER THE GULF OF
MEXICO TONIGHT HELPING MAINTAIN FAIR CONDITIONS ACROSS A GOOD
PORTION OF THE BASIN. HOWEVER...A WEAK 1009 MB SURFACE LOW IS
CENTERED IN THE NORTH CENTRAL GULF NEAR 28N89W WITH A SURFACE
TROUGH EXTENDING TOWARDS THE SW ALONG 26N91W TO 25N93W...AS OF
2100 UTC. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE MAINLY
SOUTH OF THE LOW FROM 24N-27N BETWEEN 89W-93W...WITH ISOLATED
SHOWERS FROM 26N-29N BETWEEN 84W-88W. CLUSTERS OF
SHOWERS/THUNDERSTORMS HAVE ALSO POPPED UP OVER THE FLORIDA
PENINSULA MAINLY ON THE NE SIDE. WEAK SURFACE RIDGING COVERS THE
REMAINDER OF THE BASIN EXTENDING ACROSS THE SOUTHERN GULF TO THE
NW CORNER ON THE WEST SIDE OF THE SURFACE LOW. THE SURFACE LOW
IS EXPECTED TO MOVE NE AND LINGER IN THE N CENTRAL/NE GULF
BEFORE BEGIN ABSORBED BY A FRONTAL BOUNDARY THAT WILL REACH THE
NORTHERN GULF EARLY SUNDAY.

CARIBBEAN SEA...
MUCH OF THE CARIBBEAN IS UNDER FAIR CONDITIONS DUE TO DRY AIR
ALOFT COVERING THE BASIN AROUND AN UPPER LEVEL TROUGH IN THE
WESTERN CARIBBEAN FROM CENTRAL CUBA TO GUATEMALA...AND AN UPPER
LEVEL RIDGE OVER THE EASTERN CARIBBEAN. HOWEVER...STRONG
SHOWERS/THUNDERSTORMS ARE OCCURRING OVER PORTIONS OF CENTRAL
AMERICA INCLUDING GUATEMALA...EL SALVADOR...HONDURAS...NORTHERN
NICARAGUA...AND PANAMA. SOME OF THIS ACTIVITY IS LIKELY
INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS THROUGH COSTA RICA
AND PANAMA. THE ACTIVITY OVER NORTHERN CENTRAL AMERICA IS LIKELY
DUE TO DIFFLUENCE ALOFT AROUND THE BASE OF THE UPPER TROUGH OVER
THE WESTERN CARIBBEAN. TRADEWIND FLOW OF 10-15 KT IS ACROSS THE
MAJORITY OF THE BASIN WITH SOME STRONGER WINDS UP TO 20 KT NEAR
THE COAST OF COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24
HOURS.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH COVERS THE FAR W ATLC CONTINUING INTO THE
NW CARIBBEAN. THE UPPER TROUGH IS SUPPORTING A FEW ISOLATED
SHOWERS N OF THE NW BAHAMAS FROM 27N-30N BETWEEN 75W-79W. AT THE
SURFACE...WEAK SURFACE RIDGING EXTENDS FROM A 1018 MB HIGH AT
33N71W TO A 1016 MB HIGH OVER THE BAHAMAS AT 25N78W. MOSTLY FAIR
WEATHER EXISTS BESIDES THE AREA OF SHOWERS ALREADY MENTIONED. TO
THE EAST...TROPICAL STORM LESLIE SPINS IN THE CENTRAL ATLC
PRODUCING A LARGE AREA OF WINDS...SEAS...AND CONVECTION. MUCH
SMALLER...BUT STRONGER...HURRICANE MICHAEL SPINS NE OF LESLIE.
SEE SPECIAL FEATURES SECTION FOR MORE DETAILS ON BOTH SYSTEMS.
THE REMAINDER OF THE EASTERN ATLC IS DOMINATED BY SURFACE
RIDGING EXTENDING FROM A 1022 MB AZORES HIGH...WHICH IS
PROVIDING FAIR CONDITIONS ACROSS THE EASTERN ATLC AND SOUTH
CENTRAL ATLC SOUTH OF THE TWO TROPICAL CYCLONES.

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

$$
WALTON




This weather bulletin was brought to you by:
www.nashvilleweather.net