[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 081747
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT SEP 08 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...

HURRICANE MICHAEL IS CENTERED NEAR 32.6N 42.1W AT 08/1500 UTC OR
ABOUT 810 NM WSW OF THE AZORES MOVING NW AT 04 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 971 MB. MAXIMUM SUSTAINED WIND SPEED
IS 90 KT WITH GUSTS TO 110 KT. SCATTERED TO NUMEROUS MODERATE
CONVECTION IS FROM 31N-34N BETWEEN 41W-44W. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC
FOR MORE DETAILS.

TROPICAL STORM LESLIE IS CENTERED NEAR 29.0N 62.5W AT 08/1800
UTC OR ABOUT 230 NM SSE OF BERMUDA MOVING N AT 07 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 988 MB. MAXIMUM SUSTAINED WIND SPEED
IS 55 KT WITH GUSTS TO 65 KT. SCATTERED MODERATE CONVECTION IS
FROM 27N-33N BETWEEN 62W-66W. WIDELY SCATTERED MODERATE
CONVECTION IS ELSEWHERE FROM 24N-34N BETWEEN 58W-66W. 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 WAVE EXTENDS FROM 13N21W TO A 1012 MB LOW NEAR 14N21W
TO 21N19W MOVING W AT 15 KT. MANY OF THE GLOBAL MODELS SUGGEST A
BROAD LOW-LEVEL CYCLONIC CIRCULATION CONTINUING TO TRACK W-NW
ACROSS THE SOUTHERN CAPE VERDE ISLANDS OVER THE NEXT 24 HOURS.
THE WAVE AXIS ITSELF IS EVIDENT IN TOTAL PRECIPITABLE WATER WITH
MAXIMUM DEEP LAYER MOISTURE FROM 13N-19N BETWEEN 17W-26W.
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM
14N-18N BETWEEN 21W-27W. ISOLATED MODERATE CONVECTION IS FROM
05N-14N BETWEEN 20W-27W. THE SYSTEM HAS POTENTIAL FOR
DEVELOPMENT AND CONTAINS A MEDIUM CHANCE OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

...TROPICAL WAVES...

SEE SPECIAL FEATURES SECTION ABOVE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 14N22W TO 14N32W TO 09N50W. A
SURFACE TROUGH EXTENDS N-NW FROM 14N32N TO 22N35W AND CONTINUES
TO REMAIN WEAK NORTHWARD EXTENDING LOW TO MIDDLE LEVEL ENERGY
EMBEDDED WITHIN THE MONSOON TROUGH. SCATTERED MODERATE
CONVECTION IS FROM 17N-19N BETWEEN 34W-36W IN ASSOCIATION WITH
THE SURFACE TROUGH AXIS. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 09N50W TO 08N60W. WIDELY SCATTERED MODERATE
CONVECTION IS FROM 07N-10N BETWEEN 29W-32W...AND FROM 07N-11N
BETWEEN 38W-48W.

...DISCUSSION...

GULF OF MEXICO...
MOSTLY NORTHEASTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY
ACROSS MUCH OF THE GULF THIS AFTERNOON ON THE EASTERN PERIPHERY
OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER SE
TEXAS NEAR 29N95W. EMBEDDED WITHIN THE NE FLOW ALOFT OVER THE
CENTRAL GULF IS A 1009 MB LOW CENTERED NEAR 29N88W. SURFACE
TROUGHING EXTENDS SW FROM THE LOW CENTER TO 26N92W. SATELLITE
IMAGERY AND LIGHTNING DATA INDICATE SCATTERED SHOWERS AND
ISOLATED TSTMS OCCURRING FROM 23N-30N BETWEEN 85W-92W. THE LOW
IS FORECAST TO LINGER OVER THE NE GULF THROUGH LATE SATURDAY AND
BECOME ABSORBED BY A COLD FRONTAL BOUNDARY CURRENTLY ANALYZED
FROM CENTRAL LOUISIANA SW INTO SE TEXAS ALONG THE GULF COAST.
THE FRONT IS SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH EXTENDING
FROM THE OHIO RIVER VALLEY SOUTHWESTWARD TO NORTH TEXAS. THE
FRONT IS FORECAST TO SWEEP ACROSS THE NORTHERN GULF LATE
SATURDAY THROUGH SUNDAY AND ACROSS NORTHERN AND CENTRAL FLORIDA
LATE SUNDAY INTO MONDAY. OTHERWISE FOR THIS AFTERNOON...THE
REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF A WEAK SURFACE
RIDGE EXTENDING FROM THE SW NORTH ATLC IN THE VICINITY OF THE
BAHAMAS INTO THE FLORIDA STRAITS...THEN WESTWARD ALONG 24N TO
EAST-CENTRAL MEXICO NEAR 22N98W. OUTSIDE OF THE CONVECTIVE
ACTIVITY ASSOCIATED WITH THE LOW CENTERED OVER THE NE GULF...
FAIR CONDITIONS AND MOSTLY CLEAR SKIES PREVAIL THIS AFTERNOON.

CARIBBEAN SEA...
AN ELONGATED UPPER LEVEL TROUGH AXIS EXTENDS FROM THE SW NORTH
ATLC NEAR 30N73W TO OVER CENTRAL CUBA AND INTO THE NW CARIBBEAN
INTO A UPPER LEVEL LOW CENTERED NEAR 17N85W. MOSTLY DRY AIR IS
NOTED ON WATER VAPOR IMAGERY WITH THIS UPPER LEVEL LOW AND
TROUGH AS GENERALLY E TO SE WINDS OF 10 TO 15 KT ARE OBSERVED N
OF 17N W OF 80W. LOW-LEVEL MOISTURE CONVERGENCE IS MAXIMIZED
OVER THE SW CARIBBEAN AND PORTIONS OF CENTRAL AMERICA AS
SCATTERED SHOWERS AND TSTMS ARE FOCUSED NEAR A SURFACE TROUGH
ANALYZED FROM 10N81W TO 15N85W. THE CONVECTION IS OCCURRING S OF
17N WEST OF A LINE FROM 10N76W TO 17N83W. THE REMAINDER OF THE
CARIBBEAN BASIN E OF 80W AND THE CONVECTION ASSOCIATED WITH THE
SURFACE TROUGH IS UNDER MOSTLY DRY AIR ALOFT AND GENERALLY 10 TO
15 KT TRADEWINDS. NE TO E WINDS ARE HOWEVER A BIT STRONGER...IN
THE RANGE OF 15 TO 20 KT...PER AN EARLIER ASCAT AND WINDSAT PASS
S OF 15N BETWEEN 70W-80W. CLEAR SKIES DOMINATE ELSEWHERE THIS
AFTERNOON AND CONDITIONS REMAIN TRANQUIL FOR THE GREATER AND
LESSER ANTILLES. THE E TO SE MODERATE TO FRESH TRADEWINDS ARE
FORECAST TO PERSIST THROUGH THE WEEKEND INTO EARLY NEXT WEEK.

ATLANTIC OCEAN...
AN UPPER LEVEL LOW IS CENTERED NEAR 30N73W AND EXTENDS A TROUGH
AXIS SW TO OVER CENTRAL CUBA NEAR 22N78W. WHILE A WEAK SURFACE
RIDGE AXIS EXTENDS FROM WEST OF THE INFLUENCE OF TROPICAL STORM
LESLIE NEAR 26N73W TO THE FLORIDA STRAITS NEAR 24N83W...THE
MIDDLE TO UPPER LEVEL DYNAMICS REMAIN STRONG ENOUGH TO SUPPORT
ISOLATED SHOWERS AND TSTMS FROM 27N-31N BETWEEN 75W-79W. FARTHER
EAST...THE RATHER LARGE EXTENT OF TROPICAL STORM LESLIE REMAINS
N OF 22N BETWEEN 53W-70W. SE OF LESLIE...A WEAK SURFACE RIDGE
EXTENDS FROM 23N43W TO THE LESSER ANTILLES NEAR 16N63W.
FINALLY...AS HURRICANE MICHAEL REMAINS ALONG THE DISCUSSION
BORDER BETWEEN 39W-46W...THE REMAINDER OF THE EASTERN ATLC N OF
22N IS UNDER THE INFLUENCE OF SURFACE RIDGING ANCHORED BY A PAIR
OF 1023 MB HIGHS CENTERED NEAR 33N15W AND 32N30W. THE WESTERN-
MOST HIGH LINKS UP TO THE SOUTHWEST WITH THE PREVIOUSLY
MENTIONED SURFACE RIDGE AXIS THAT EXTENDS INTO THE EASTERN
CARIBBEAN SEA.

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

$$
HUFFMAN




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