[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 140544
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST WED JAN 14 2009

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.

...THE ITCZ...

FROM SIERRA LEONE NEAR 8N13W TO 3N20W TO 3N35W...CROSSING
THE EQUATOR ALONG 45W...INTO NORTHEASTERN BRAZIL NEAR 2S48W.
SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS ARE
WITHIN A 15 TO 30 NM RADIUS OF 5N10W...FROM 4N TO 5.5N
BETWEEN 15W AND 17W...FROM 3N TO 4N BETWEEN 23W AND 30W.
ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE
ELSEWHERE SOUTH OF 10N EAST OF 40W.

...DISCUSSION...

THE GULF OF MEXICO...AND THE ATLANTIC OCEAN WEST OF 60W...
A DEEP LAYER TROUGH IS DIGGING INTO SOUTHWARD INTO NORTHERN
FLORIDA ALONG 30N. UPPER LEVEL SOUTHWESTERLY WIND FLOW MOVES
FROM THE SOUTHWESTERN CORNER OF THE AREA INTO NORTH FLORIDA
NEAR 29N. MIDDLE TO UPPER LEVEL DRY AIR IN SUBSIDENCE IS
NORTHWEST OF 30N80W 25N90W 23N98W...WITH BROKEN TO OVERCAST
MULTILAYERED CLOUDS TO THE SOUTHEAST OF THE SAME LINE.
ONE COLD FRONT PASSES THROUGH 32N75W TO SOUTH FLORIDA TO
THE NORTHEASTERN YUCATAN PENINSULA TO THE EASTERN ISTHMUS
OF TEHUANTEPEC. THE SOUTHERNMOST PART OF A SECOND COLD FRONT
IS NEAR THE FLORIDA BIG BEND. SURFACE HIGH PRESSURE IS
PUSHING ITS WAY SOUTHWARD FROM EASTERN TEXAS TO THE NORTHERN
ISTHMUS OF TEHUANTEPEC. GALE-FORCE WIND CONDITIONS ARE BEING
EXPERIENCED IN THE GULF OF TEHUANTEPEC ON THE EASTERN PACIFIC
OCEAN SIDE OF MEXICO.

THE CARIBBEAN SEA...
MIDDLE TO UPPER LEVEL DRY AIR IN SUBSIDENCE COVERS THE AREA EAST
OF 80W. A MIDDLE TO UPPER LEVEL TROUGH IS IN THE ATLANTIC OCEAN
FROM 14N50W TO 9N60W. NORTHEASTERLY WIND FLOW THAT IS ON THE
NORTHERN SIDE OF THE CYCLONIC FLOW FOR THE TROUGH EVENTUALLY
MAKES ITS WAY INTO THE CARIBBEAN SEA...AND ENDS UP BECOMING
SWALLOWED UP INTO THE BROAD UPPER LEVEL ANTICYCLONIC FLOW IN
THE AREA. A TINY BIT OF THE ATLANTIC OCEAN TO GULF OF MEXICO
COLD FRONT PASSES THROUGH THE YUCATAN CHANNEL...REACHING THE
NORTHEASTERN YUCATAN PENINSULA...INTO THE EASTERN ISTHMUS OF
TEHUANTEPEC OF MEXICO. WINDS FROM THE NORTHEAST TO EAST RANGING
FROM 20 TO 30 KTS AND SEA HEIGHTS RANGING FROM 8 TO 12 FT ARE
FORECAST FOR THE NEXT 48 HOURS FROM 10N TO 18N EAST OF 82W.
THE WINDS AND SEAS ARE RELATED TO A TIGHT SURFACE PRESSURE
GRADIENT BETWEEN HIGH PRESSURE NORTH OF THE AREA AND THE
SEMI-PERMANENT SURFACE LOW PRESSURE IN COLOMBIA AND PANAMA.

THE ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM 28N25W TO 20N42W
TO 14N50W TO 9N60W. ISOLATED MODERATE SHOWERS ARE FROM 5N TO 20N
BETWEEN 35W AND 50W. MIDDLE TO UPPER LEVEL DRY AIR IN SUBSIDENCE
SURROUNDS THIS TROUGH...FROM 4N IN THE GUYANAS AND VENEZUELA TO
30N BETWEEN UPPER LEVEL SOUTHWESTERLIES SOUTH OF 24N BETWEEN
30W AND 50W AND 80W. HIGH LEVEL CLOUDS UNDER UPPER LEVEL
SOUTHWESTERLY WIND FLOW ARE ON TOP OF LOW CLOUDS...FROM 4N
TO 26N BETWEEN AFRICA AND 53W. A SURFACE RIDGE EXTENDS FROM
A 1029 MB HIGH PRESSURE CENTER NEAR 32N20W TO 30N42W TO 26N63W
TO 23N71W.

$$
MT





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