AXNT20 KNHC 050558
TWDAT
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.
BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC.
...SPECIAL FEATURE...
THE CENTER OF TROPICAL STORM IDA AT 05/0600 UTC IS NEAR
12.5N 83.2W...OR ABOUT 50 MILES/85 KM TO THE NORTHEAST OF
BLUEFIELDS NICARAGUA. T.S. IDA IS MOVING NORTHWESTWARD
6 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 995 MB.
THE MAXIMUM SUSTAINED WIND SPEEDS ARE 55 KT WITH GUSTS TO 65 KT.
PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/
WMO HEADERS MIATCMAT1/WTNT21 AND THE PUBLIC ADVISORY UNDER
MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. IT IS MOST PROBABLE
THAT IDA WILL MAKE LANDFALL DURING THE NEXT FEW HOURS. NUMEROUS
STRONG SHOWERS AND THUNDERSTORMS COVER THE AREA FROM 11N TO 13N
BETWEEN 82W AND 84W. THE WINDS OF IDA MAY REACH HURRICANE
INTENSITY JUST BEFORE MAKING LANDFALL. TROPICAL STORM FORCE
WINDS EXTEND OUTWARD UP TO 50 MILES/85 KM FROM THE CENTER.
IDA IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS RANGING
FROM 5 INCHES TO 7 INCHES ACROSS SAN ANDRES ISLAND WITH MAXIMUM
AMOUNTS OF 12 INCHES POSSIBLE. RAINFALL ACCUMULATIONS RANGING
FROM 15 INCHES TO 20 INCHES ARE EXPECTED IN EASTERN NICARAGUA
AND EASTERN HONDURAS WITH MAXIMUM AMOUNTS OF 25 INCHES POSSIBLE.
THESE RAINS MAY PRODUCE LIFE-THREATENING FLASH FLOOD AND MUD
SLIDES. IT IS POSSIBLE THAT THE STORM SURGE MAY RAISE WATER
LEVELS BY AS MUCH AS 3 FEET ABOVE GROUND LEVEL ALONG THE EAST
COAST OF NICARAGUA...WITH LARGE AND DANGEROUS BATTERING WAVES...
NEAR AND TO THE NORTH OF WHERE THE CENTER OF IDA MAKES LANDFALL.
...TROPICAL WAVES...
A CARIBBEAN SEA TROPICAL WAVE IS ALONG 15N76W 13N77W...SOUTHWARD
ALONG 77W INTO WESTERN COLOMBIA...MOVING WESTWARD 10 TO 15 KT.
ISOLATED MODERATE SHOWERS IN WESTERN COLOMBIA FROM 2N TO 10N
BETWEEN 73W AND THE PACIFIC OCEAN COAST MAY BE RELATED TO THE
WAVE.
...THE ITCZ...
FROM 10N14W TO 7N30W TO 10N45W...INTO NORTHEASTERN VENEZUELA
NEAR 10N62W. STRONG SHOWERS AND THUNDERSTORMS ARE FROM 4N TO 8N
BETWEEN 24W AND 28W. ISOLATED AND DISORGANIZED MODERATE SHOWERS
ARE ELSEWHERE FROM 2N TO 10N TO THE EAST OF 60W.
...DISCUSSION...
THE GULF OF MEXICO...
A LARGE-SCALE UPPER LEVEL TROUGH COVERS THE U.S.A. TO THE EAST
OF 90W. THE BASE OF THE LATEST TROUGH THAT IS MOVING THROUGH THE
AREA REACHES CENTRAL ALABAMA AND CENTRAL GEORGIA. A SEPARATE
UPPER LEVEL TROUGH EXTENDS FROM AN INTERIOR MEXICO 25N101W
CYCLONIC CIRCULATION CENTER TO 17N97W TO 14N97W IN THE EASTERN
PACIFIC OCEAN. UPPER LEVEL SOUTHERLY AND SOUTHWESTERLY WIND FLOW
COVERS THE OPEN GULF WATERS. A SURFACE TROUGH REMAINS FROM THE
FRONTAL BOUNDARY OF THE LAST FEW DAYS...FROM SOUTH FLORIDA TO
THE YUCATAN PENINSULA TO SOUTHEASTERN GUATEMALA. BROKEN TO
OVERCAST MULTILAYERED CLOUDS COVER THE ENTIRE AREA EXCEPT FOR
THE PART TO THE NORTHWEST OF THE LINE FROM SOUTH CENTRAL
LOUISIANA TO THE LOWER TEXAS COAST. SHOWERS ARE POSSIBLE TO
THE SOUTH OF 26N BETWEEN 85W AND 90W.
THE CARIBBEAN SEA...
AN UPPER LEVEL TROUGH PASSES FROM THE ATLANTIC OCEAN NEAR 24N73W
THROUGH THE WINDWARD PASSAGE TO 18N75W. THE FLOW ON THE
SOUTHEASTERN SIDE OF THIS TROUGH HAS SENT SHEARING WINDS ACROSS
THE CENTRAL CARIBBEAN SEA WATERS...TO AN AREA THAT HAD SHOWERS
AND THUNDERSTORMS ABOUT SIX HOURS AGO. ONLY ISOLATED MODERATE
SHOWERS REMAIN FROM 14N TO 16N BETWEEN 66W AND 69W. A SURFACE
TROUGH GOES FROM 24N63W TO 18N66W ON THE EASTERN SIDE OF PUERTO
RICO...TO NORTH CENTRAL COASTAL VENEZUELA. ISOLATED MODERATE
SHOWERS ARE FROM 19N JUST TO THE NORTH OF PUERTO RICO TO 22N IN
THE ATLANTIC OCEAN BETWEEN 62W AND 67W.
THE ATLANTIC OCEAN...
A LOT OF THE UPPER LEVEL SUPPORT FOR THE CURRENT ATLANTIC OCEAN
COLD FRONT IS TO THE NORTH OF THE AREA. THE FRONT PASSES THROUGH
32N58W TO 30N63W TO 28N70W. A STATIONARY FRONT CONTINUES FROM
28N70W TO THE NORTHERN BAHAMAS NEAR 26N77W. ISOLATED MODERATE
SHOWERS ARE FROM 26N TO 28N BETWEEN 70W AND 80W. ONE CYCLONIC
CIRCULATION CENTER IS NEAR 32N44W. ISOLATED MODERATE SHOWERS AND
POSSIBLE THUNDERSTORMS ARE FROM 22N TO 29N BETWEEN 51W AND 52W.
A SECOND CYCLONIC CENTER IS NEAR 27N32W. ISOLATED MODERATE
SHOWERS ARE FROM 27N TO 30N BETWEEN 26W AND 43W. LARGER-SCALE
CYCLONIC FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 15N TO
THE EAST OF 60W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG
THUNDERSTORMS COVER THE AREA FROM 10N TO 14N BETWEEN 42W AND 54W.


forecast by MT
updated at 105 AM EST THU NOV 05 2009

AXPZ20 KNHC 050319
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU NOV 05 2009
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N...EAST OF 140W.
BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0315 UTC.
...TROPICAL LOW...
.LOW PRES IS CENTERED NEAR 11N92W ESTIMATED AT 1009 MB AND IS
DRIFTING W TOWARDS AN UPPER LEVEL TROUGH WITH INCREASING
SOUTHWESTERLY WIND SHEAR. CURRENTLY SCATTERED MODERATE AND
ISOLATED STRONG CONVECTION IS NOTED WITHIN 60 NM 11N91W WITH THE
CONVECTION OCCASIONALLY BANDING N OF THE CENTER.
...ITCZ...
THE ITCZ AXIS EXTENDS ALONG 11N86W TO 08N99W TO 14N111W TO
08N119W TO 11N134W TO 07N140W. SCATTERED MODERATE ISOLATED
STRONG CONVECTION IS NOTED WITHIN 90 NM OF 12N90W AND FROM 06N
TO 11N BETWEEN 95W AND 111W AND FROM 07N TO 11N BETWEEN 120W AND
130W.
...DISCUSSION...
AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 13N120W WITH A SHORT
WAVE RIDGE AMPLIFYING N TO A CREST NEAR 32N109W. THE SHORT WAVE
RIDGE IS MERGING INTO A LONG WAVE RIDGE THAT HAS ITS MEAN AXIS N
TO S ALONG 110W OVER ALL OF N AMERICA. A TROPICAL RIDGE EXTENDS
SW FROM THE ANTICYCLONE TO A SHARP CREST OVER THE ITCZ AT
08N134W WITH ANOTHER RIDGE EXTENDING SE FROM THE ANTICYCLONIC
CENTER TO 12N108W. DEBRIS MOISTURE FROM ITCZ CONVECTION BETWEEN
120W AND 132W...AND FROM FORMER ITCZ CONVECTION W OF THE AREA
NEAR 06N148W...IS ADVECTED NE ALONG THE W PERIPHERY OF THIS
TROPICAL RIDGE...ROUGHLY WITHIN 60 NM EITHER SIDE OF LINE
10N140W TO 17N130W WHERE IT WIDENS AS IT CONTINUES NE WITHIN 150
NM OF LINE 14N126W TO 24N111W WHERE THE PLUME SPLITS. ONE
BRANCH TURNS SE ACROSS THE SHORTWAVE RIDGE BACK OVER THE TROPICS
TO NEAR 15N106W. THE SECOND BRANCH OF MOISTURE CONTINUES N
FANNING OUT OVER NW OLD MEXICO AND CONTINUING NE OVER SOUTHERN
ARIZONA AND CALIFORNIA. UPPER DIFFLUENCE ENHANCED A CLUSTER OF
CONVECTION EARLIER NEAR 16N115W AND NEAR 13N113W WITH THE DEBRIS
MOISTURE ADVECTED E ACROSS THE RIDGE TO NEAR 16N110W.
OTHERWISE...SUBSIDENCE IS INDICATED OVER THE S SEMICIRCLE OF THE
ANTICYCLONE AND IS SUPPRESSING ITCZ CONVECTION BETWEEN 110W AND
119W.
TO THE NW OF THE ANTICYCLONE...AN UPPER SHORTWAVE TROUGH HAS
MOVED INTO THE AREA WITH ITS AXIS ALONG 138W TO THE N OF 20N.
UPPER MOISTURE PRECEDES THIS SECOND TROUGH...ROUGHLY WITHIN 120
NM EITHER SIDE OF LINE 32N127W TO 20N140W. OTHERWISE...THE UPPER
LEVELS ARE DRY BETWEEN THE TROPICAL RIDGE AND THE UPPER TROUGH.
A LONG WAVE TROUGH IS MOVING ACROSS EASTERN N AMERICA WITH ITS
AXIS EXTENDING S INTO THE AREA ALONG 32N95W INTO A SMALL UPPER
CYCLONE AT 18N96W WITH THE TROUGH CONTINUING S TO A BASE OVER
THE DEEP TROPICS AT 10N99W. TROPICAL STORM IDA CONTINUES OVER
THE SW CARIBBEAN. CONVECTION IS ENHANCED ALONG THE ITCZ BETWEEN
91W AND 111W. SOME OF THE RESULTANT DEBRIS MOISTURE IS SPREADING
N AND NE ACROSS CENTRAL AMERICA ALONG 90W.
AT THE LOW LEVELS...A SURFACE HIGH PRES IS NEAR 26N119W 1018 MB.
AN INITIAL COLD FRONT IS LOSING ITS PUSH ALONG 32N132W TO
26N140W WHILE A SECONDARY FRONT IS RAPIDLY APPROACHING ALONG
32N137W TO 29N140W. NW WINDS ARE EXPECTED TO INCREASE BRIEFLY
TO 20 KT OVER THE DISCUSSION AREA NW OF THE FRONT WITH NW SWELLS
RESULTING IN SEAS TO 11 FT WITH LARGER LONG PERIOD SWELLS
ARRIVING LATE FRI BUILDING TO ABOUT 20 FT NEAR 30N133W SAT.
GAP WINDS...
STRONG GALE FORCE WINDS EXPECTED TO CONTINUE THROUGH THE GULF OF
TEHUANTEPEC THROUGH FRI,


forecast by NELSON