000
AXNT20 KNHC 281801
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN OCT 28 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
1715 UTC.

...SPECIAL FEATURES...

THE CENTER OF HURRICANE SANDY AT 28/1800 UTC IS NEAR 32.8N 
71.9W. SANDY IS ABOUT 235 NM TO THE SOUTHEAST OF CAPE HATTERAS 
NORTH CAROLINA...AND ABOUT 500 NM TO THE SOUTH OF NEW YORK CITY. 
SANDY IS MOVING NORTHEASTWARD 12 KT. THE ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 951 MB. THE MAXIMUM SUSTAINED WIND SPEEDS 
ARE 65 KNOTS WITH GUSTS TO 80 KNOTS. PLEASE READ THE 
FORECAST/ADVISORY UNDER THE AWIPS/WMO HEADERS MIATCMAT3/WTNT23 
KNHC...AND THE PUBLIC ADVISORY UNDER MIATCPAT3/WTNT33 KNHC FOR 
MORE DETAILS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO 
STRONG FROM 21N TO 37N BETWEEN 73W AND 78W. 

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH THE COASTAL SECTIONS OF   
GUINEA-BISSAU NEAR 11N15W TO 07N22W TO 06N25W. THE ITCZ EXTENDS 
FROM 06N25W TO 07N35W. SCATTERED MODERATE TO STRONG CONVECTION 
O5N TO 09N E OF 20W. SCATTERED MODERATE CONVECTION FROM 05N TO 
10N BETWEEN 35W AND 40W. 

...DISCUSSION...

THE GULF OF MEXICO...
DRY AIR IS MOVING E ACROSS THE GULF OF MEXICO IN THE MID TO 
UPPER LEVELS OF THE ATMOSPHERE...WRAPPING AROUND A BROAD MID TO 
UPPER LEVEL TROUGH MOVING THROUGH THE TENNESSEE VALLEY...AND 
ACROSS FLORIDA INTO HURRICANE SANDY NOW BETWEEN THE CAROLINAS 
AND BERMUDA. COOLER AND DRIER AIR...ALONG WITH A LARGE FIELD OF 
LOWER STRATOCUMULUS...FOLLOW A COLD FRONT PUSHING THROUGH THE 
SE GULF OF MEXICO THIS MORNING...EXTENDING FROM S FLORIDA TO W 
CUBA TO NORTHERN YUCATAN...THEN STATIONARY OVER THE BAY OF 
CAMPECHE. FRESH TO STRONG NORTHERLY WINDS BEHIND THE FRONT IN 
THE LOWER LEVELS OF THE ATMOSPHERE ARE MIXING TO THE SURFACE AS 
THE COOLER AIR FLOWS OVER THE WARMER WATERS OF THE GULF. A 
SCATTEROMETER PASS FROM EARLIER THIS MORNING INDICATED STRONG TO 
NEAR GALE FORCE WINDS ALONG THE COAST OF VERACRUZ MEXICO. 
MOISTURE LEVELS REMAIN SOMEWHAT HIGHER IN THE SW GULF AND WEAK 
SHOWERS ARE ACTIVE IN THE BAY OF CAMPECHE. WINDS WILL GRADUALLY 
DIMINISH THROUGH LATE MON OVER MOST OF THE GULF OF MEXICO AS 
HIGH PRES PRES BUILDS OVER THE NW GULF.

THE CARIBBEAN SEA...
GENERALLY CALM CONDITIONS PREVAIL ACROSS THE CARIBBEAN SEA THIS 
AFTERNOON WITH LIGHT TO MODERATE W TO NW FLOW PREVAIL ACROSS THE 
AREA. NO APPRECIABLE AREAS OF CLOUDS OR PRECIP ARE NOTED...WITH 
THE EXCEPTION OF RESIDUAL OVERNIGHT CLOUDS AND SHOWERS NEAR THE 
GUAJIRA PENINSULA OF COLOMBIA. SEAS ARE GENERALLY 2 TO 4 FT. A 
COLD FRONT IS MOVING INTO THE YUCATAN CHANNEL AND WILL PUSH INTO 
THE NW CARIBBEAN THROUGH MON FOLLOWED BY FRESH N TO NW WINDS. IN 
ADDITION...NORTHERLY SWELL ASSOCIATED WITH HURRICANE SANDY WILL 
MOVE INTO THE ATLANTIC PASSAGES THROUGH MON. 

THE ATLANTIC OCEAN...
W OF 60W...CLOUD COVER IS DIMINISHING S OF 29N AS DRIER MID TO 
UPPER LEVEL AIR PUSHES ACROSS INTO THE AREA S OF HURRICANE 
SANDY...LOCATED N OF THE AREA BETWEEN THE CAROLINAS AND BERMUDA. 
BUOY...SHIP AND SCATTEROMETER DATA SHOW GALE FORCE WINDS STILL 
ACTIVE OVER THE AREA N OF 25N. THESE WINDS WILL DIMINISH 
GRADUALLY FROM S TO N THROUGH TUE AS SANDY CONTINUES TO MOVE N 
OF THE AREA AND INTERACT WITH A BROAD MID TO UPPER LEVEL TROUGH 
MOVING INTO THE EASTERN UNITED STATES. AN UPPER JET WILL 
INTENSIFY ON THE SE EDGE OF THE UPPER JET...WITH THE RIGHT REAR 
ENTRANCE AREA OVER THE SOUTHERN BAHAMAS AND TCI. NO SIGNIFICANT 
CONVECTION IS ANTICIPATED DUE LIMITED DEEP LAYER MOISTURE.
BETWEEN 30W AND 60W...A WARM FRONT EXTENDS FROM 31N58W TO 
28N43W...THEN AS A DISSIPATING STATIONARY FRONT TO 31N34W. A 
LARGE AREA OF DEEP LAYER CLOUDINESS IN PART SIPHONED FROM SANDY 
PERSISTS N OF 20N ALONG THE FRONTAL BOUNDARY...BETWEEN AN UPPER 
LOW NEAR 35N45W AND A DEEP LAYER ANTICYCLONE CENTERED NEAR 
31N58W. AN ASSOCIATED SURFACE HIGH PRES IS CENTERED NEAR 12N54W 
WITH AN ESTIMATED PRES AROUND 1015 MB. THIS HAS BEEN BLOCKING 
THE WESTERN PROGRESS OF A TROPICAL WAVE NEAR 43W BETWEEN 10N AND 
15N. THIS HAS BEEN ALMOST STALLED FOR A WHILE AND HAS BEEN 
LOSING DEFINITION ON SATELLITE IMAGERY. THE 12 UTC SURFACE 
ANALYSIS SHOWS THIS FEATURE AS A TROUGH. GLOBAL MODELS SHOW THIS 
FEATURE CONTINUING TO DAMPEN OUT AS IT DRIFTS W TO THE S OF THE 
HIGH PRES. A MORE PROFOUND FEATURE HAS EMERGED FARTHER TO THE SE 
NEAR 40W BETWEEN 05N AND 10N ON THE LEADING EDGE OF AN EASTERLY 
WIND SURGE IN THE DEEP TROPICS AND IS EXPECTED TO DRIFT N 
THROUGH 24 HOURS. E OF 30W...A LATE SEASON BUT WELL DEFINED 
TROPICAL WAVE IS EMERGING OFF THE COAST OF AFRICA...INTERACTING 
WITH AN UPPER TROUGH OVER THE CANARY ISLANDS AND MODERATE TO 
FRESH SW FLOW S OF THE MONSOON TROUGH. THIS FEATURES LOOKS LIKE 
IT WILL HOLD ITS CONSISTENCY AND WILL LIKELY BE ADDED TO THE 
SURFACE MAP AS IT SHIFT FARTHER W. 

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

$$
CHRISTENSEN