[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 161814
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT DEC 16 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...
NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...THE ITCZ...
8N12W 4N23W 3N34W 2N46W INTO NORTHEASTERN BRAZIL NEAR 1N52W.
ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE
WITHIN 150 NM ON EITHER SIDE OF 3N10W 5N26W 4N38W 5N46W
6N56W.

...DISCUSSION...
THE GULF OF MEXICO...
AN UPPER LEVEL SHORTWAVE TROUGH EXTENDS FROM 30N85W TO 27N87W
TO THE CENTRAL GULF WATERS NEAR 24N90W. MULTILAYERED MOISTURE
IS EAST OF THE TROUGH...EAST OF 87W. UPPER LEVEL MOISTURE HAS
BEEN MAKING ITS WAY INTO THE SOUTHWESTERN GULF...SOUTH OF SOUTH
OF 25N WEST OF 87W. DRY AIR IS IN THE WESTERN GULF WATERS MOVING
FROM MEXICO EASTWARD...COVERING THE NORTHWESTERN SECTOR.
BROAD SURFACE HIGH PRESSURE COVERS THE AREA. SCATTERED MODERATE
SHOWERS TO ISOLATED STRONG THUNDERSTORMS IN A CLUSTER IS IN THE
WATERS JUST OFF THE WESTERN CUBA COAST FROM 22N TO 23N BETWEEN
84W AND 86W. MODERATE SHOWERS ARE POSSIBLE SOUTH OF 28N EAST OF
87W IN THE MULTILAYERED MOISTURE AND UPPER LEVEL SOUTHWESTERLY
FLOW.

THE CARIBBEAN SEA...
WATER VAPOR SATELLITE IMAGERY AND 16/1500 UTC CIMSS SATELLITE
DERIVED WIND DATA SHOW A 500 MB TO 350 MB LEVEL ANTICYCLONIC
CIRCULATION CENTER NEAR 15N74W...ROUGHLY IN THE CENTRAL
CARIBBEAN SEA. MIDDLE TO UPPER LEVEL DRY AIR IS EVERYWHERE...
WITH THE COMPARATIVELY DRIER AIR SOUTH OF 18N EAST OF 80W.
A SURFACE TROUGH ENTERS THE AREA FROM CENTRAL CUBA TO 21N80W
TO THE NORTHEASTERN YUCATAN PENINSULA...AND THE CENTRAL INTERIOR
SECTIONS OF THE YUCATAN PENINSULA. ISOLATED MODERATE SHOWERS ARE
FROM 18N TO 20N BETWEEN 78W AND 80W...PROBABLY NOT REALLY
RELATED JUST TO THE TROUGH. SURFACE TO LOW LEVEL EASTERLY TRADE
WINDS AND POSSIBLE SHOWERS ARE SEEN LARGELY FROM 12N TO 18N.
SOME OF THE SAME CLOUDINESS REACHES 20N EAST OF 66W. WIND SPEEDS
MAY INCREASE A BIT IN THE NORTHWESTERN CORNER OF THE AREA
EARLY IN THE NEXT WEEK AS MODERATE HIGH PRESSURE BECOMES NEARLY
STATIONARY TO THE NORTH OF THE AREA. LOW LEVEL MOISTURE MAY
INCREASE SLIGHTLY IN THE EASTERN CARIBBEAN SEA LATER TODAY AND
TOMORROW BUT OVERALL MAINLY DRY CONDITIONS ARE EXPECTED TO
PREVAIL.

THE ATLANTIC OCEAN...
THE SOUTHERN END OF A DEEP LAYER TROUGH ON WATER VAPOR IMAGERY
REACHES 33N66W. AN ANTICYCLONIC-CURVED JET STREAM...16/1500 UTC
CIMSS SATELLITE DERIVED WIND DATA SHOW WIND SPEEDS RANGING FROM
90 TO 110 KT WIND SPEEDS...IS WITHIN 180 NM ON EITHER SIDE OF
27N80W 29N69W 26N58W. A RIDGE EXISTS FROM 28N58W BEYOND 31N56W.
A COLD FRONT PASSES OVER BERMUDA TO 31N67W...A SURFACE TROUGH
CONTINUES FROM 31N67W TO 28N70W TO THE BAHAMAS NEAR 23N75W...
CROSSING CENTRAL CUBA TO 21N80W...TO THE NORTHEASTERN YUCATAN
PENINSULA AND ENDING INLAND OVER THE CENTRAL YUCATAN PENINSULA.
ISOLATED MODERATE SHOWERS ARE NORTH OF 25N BETWEEN 64W AND THE
SOUTHEASTERN U.S.A. SCATTERED MODERATE SHOWERS TO ISOLATED
STRONG THUNDERSTORMS IN TWO CLUSTERS ARE FROM 28N TO 30N
BETWEEN 60W AND 64W. A DEEP LAYER CYCLONIC CIRCULATION CENTER
IS NEAR 33N30W. ONE TROUGH FROM THIS CENTER PASSES THROUGH
27N32W 26N28W TO 18N28W. A SECOND DEEP LAYER TROUGH GOES FROM
33N30W TO 27N39W TO 21N45W TO 15N54W. A COLD FRONT PASSES
THROUGH 30N24W TO 22N27W TO 16N34W. A TROUGH GOES FROM 16N34W
TO 12N40W. A 1010 MB LOW PRESSURE CENTER IS NEAR 27N27W. BROKEN
LOW TO MIDDLE LEVEL CLOUDS AND POSSIBLE PRECIPITATION ARE WITHIN
30 TO 60 NM ON EITHER SIDE OF THE FRONT WEST OF 27W. WIDELY
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE
NORTH OF 22N BETWEEN 22W AND 26W. MODELS SHOW THE 1010 MB LOW
CENTER MOVING NORTHWARD AND BECOMING ABSORBED BY ANOTHER LOW
CENTER NOW NORTH OF THE AREA. STORM FORCE WINDS ARE ASSOCIATED
WITH THE 1004 MB LOW PRESSURE CENTER NEAR 35N28W NORTH OF THE
AREA. AN UPPER LEVEL RIDGE IS ALONG 12N24W 20N20N 27N20W BEYOND
31N22W. AN UPPER LEVEL RIDGE PARALLELS THE ITCZ. UPPER LEVEL
SOUTHWESTERLY FLOW MOVES FROM NORTHEASTERN SOUTH AMERICA
NORTHEASTWARD...TO THE SOUTHEAST OF THE DEEP LAYER EASTERN
ATLANTIC OCEAN TROUGH...ACROSS THE CAPE VERDE ISLANDS...
TOWARD AFRICA.

$$
MT


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