[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 272355
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU OCT 27 2011

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 2345 UTC.

...SPECIAL FEATURE...

T.S. RINA IS CENTERED NEAR 20.1N 87.2W AT 28/0000 UTC OR ABOUT
35 MI...55 KM SSW OF COZUMEL MEXICO MOVING N AT 6 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WIND SPEED
IS 75 KT WITH GUSTS TO 90 KT. PLEASE SEE THE LATEST NHC
INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT3/WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS.
SCATTERED STRONG CONVECTION IS FROM 19N-23N BETWEEN 84W-88W. THE
OUTER BANDS EXTEND TO 27N BETWEEN 81W-88W. MODERATE TO STRONG
VERTICAL WIND SHEAR IS LIKELY TO PERSIST NEAR OR OVER RINA FOR
THE NEXT 72 HOURS OR SO. THIS...ALONG WITH LAND INTERACTION AND
DRY AIR ENTRAINING INTO THE CYCLONE...SHOULD CAUSE CONTINUED
WEAKENING.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH REMAINS OVER NRN AFRICA. A SMALL PORTION OF
ITCZ IS ANALYZED FROM 9N23W TO 7N37W. SCATTERED SHOWERS AND
THUNDERSTORMS ARE WITHIN 100-150 NM ON EITHER SIDE OF THE ITCZ
AXIS. A CLUSTER OF SIMILAR CONVECTION IS MOVING OFF THE COAST OF
LIBERIA...SIERRA LEONE...AND GUINEA.

...DISCUSSION...

GULF OF MEXICO...
THE BROAD CYCLONIC WIND FIELD AROUND T.S. RINA COVERS THE SE
GULF BASIN. THIS FLOW IS BRINGING LOW LEVEL MOISTURE TO THIS
REGION AND GENERATING SCATTERED WEAK SHOWERS AND ISOLATED
THUNDERSTORMS S OF 28N E OF 91W. THE OVERALL ACTIVITY IS
HINDERED BY VERY DRY AIR AND STRONG SUBSIDENCE IN THE MID AND
UPPER LEVELS OF THE ATMOSPHERE. SURFACE RETURN FLOW IS OBSERVED
W OF 93W ALONG WITH A FEW SCATTERED SHOWERS OFF THE COAST OF
TEXAS AND WRN LOUISIANA. THE CONVECTION OVER THE SE WILL LINGER
AS A WEAK FRONTAL BOUNDARY ENTERS THE NW GULF OVER THE NEXT
12-24 HOURS.

CARIBBEAN SEA...
T.S. RINA CONTINUES TO GENERATE CONVECTIVE WEATHER ACROSS THE
COASTAL WATERS OF THE ERN YUCATAN PENINSULA AND CHANNEL. SEE
SPECIAL FEATURE DISCUSSION ABOVE FOR MORE DETAILS. TO THE SE OF
T.S. RINA...A BROAD AREA OF LOW LEVEL MOISTURE MOVES ACROSS THE
WRN CARIBBEAN NOTICED ON TPW PRODUCT. WITHIN THIS AREA OF DEEP
MOISTURE...A SURFACE TROUGH IS ANALYZED FROM 18N82W TO NEAR
12N81W. THE COMBINATION OF LOW LEVEL CONVERGENCE AROUND THE
SURFACE TROUGH AND PLENTY OF MOISTURE AVAILABLE IS GENERATING A
BROAD AREA OF SCATTERED HEAVY SHOWERS AND THUNDERSTORMS FROM
12N-20N BETWEEN 75W-85W. THIS TROUGH IS INTERACTING WITH THE
MONSOON TROUGH ANALYZED ACROSS THE FAR SW BASIN ALONG COSTA RICA
TO NRN COLOMBIA. SHORT RANGE COMPUTER MODELS SUGGEST THE MONSOON
TROUGH WILL REMAIN IN THIS REGION OVER THE NEXT 24 HRS WITH
CONVECTION. FAIR WEATHER CONDITIONS ARE ELSE ACROSS THE BASIN
WITH ISOLATED SHOWERS EMBEDDED IN THE TRADE WIND FLOW.

ATLANTIC OCEAN...
OUTFLOW FROM T.S. RINA COVERS THE FAR WRN ATLC WITH WIDELY
SCATTERED WEAK SHOWERS W OF 75W S OF 28N. OTHERWISE...A SURFACE
RIDGE COVERS THE WRN ATLC ANCHORED BY A 1019 MB HIGH NEAR
32N55W. WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH MOVING
ACROSS THE NORTH CENTRAL ATLC WATERS SUPPORTING A COLD FRONT
EXTENDING INTO THE AREA ALONG 32N38W TO 25N52W DISSIPATING TO
23N70W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN
30 NM ON EITHER SIDE OF THE FRONT AXIS N OF 25N. AN UPPER LEVEL
LOW IS IN THE CENTRAL TROPICAL ATLC SUPPORTING ITS 1010 MB
SURFACE REFLECTION NEAR 19N38W GENERATING A SMALL CLUSTER OF
SCATTERED MODERATE CONVECTION FROM 18N-22N BETWEEN 35W-40W. TO
THE SW OF THIS FEATURE...A SURFACE 1009 MB LOW IS NEAR 15N45W. A
SURFACE TROUGH IS ANALYZED FROM 17N42W ACROSS THE LOW CENTER TO
12N47W. THESE SYSTEM IS PRODUCING SCATTERED SHOWERS WITHIN 40 NM
ON EITHER SIDE OF THE SURFACE TROUGH. OTHERWISE...A BROAD UPPER
RIDGE COVERS THE CENTRAL AND ERN ATLC ANCHORED BY A WEAK 1021 MB
HIGH CENTERED NEAR 32N25W PRODUCING FAIR WEATHER ACROSS THE
REMAINDER OF THE DISCUSSION AREA.

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

$$

GARCIA




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