[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 251627
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN NOV 25 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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 1545 UTC.

...TROPICAL WAVES...
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 62W SOUTH OF 13N
MOVING WEST 10 KT. THIS WAVE IS BECOMING MORE AND MORE
DIFFICULT TO SPOT IN SURFACE-TO-LOW LEVEL CYCLONIC FLOW.
THE WAVE IS NOT THAT APPARENT IN THE VISIBLE SATELLITE
IMAGERY. SOME SURFACE OBSERVATIONS STILL HINT AT A WAVE.
SHOWERS ARE MOVING WESTWARD THROUGH THE AREA WHERE
THE WAVE IS UNDER BROAD EASTERLY SURFACE WIND FLOW.

...THE ITCZ...
7N12W 4N20W 3N30W 2N40W TO THE EQUATOR AT 50W...AND ALONG THE
EQUATOR TO 55W IN NORTHEASTERN BRAZIL. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND WIDELY SCATTERED TO SCATTERED MODERATE
SHOWERS WITHIN 120 TO 180 NM ON EITHER SIDE OF 7N12W 5N20W 4N30W
3N40W...AND WITHIN 120 NM ON EITHER SIDE OF 9N40W 7N46W 5N54W.

DISCUSSION...

THE GULF OF MEXICO...
MIDDLE TO UPPER LEVEL CYCLONIC FLOW FROM A TROUGH MEXICO/TEXAS/
NEW MEXICO AND ARIZONA NORTH OF 22N BETWEEN 97W AND 113W. THIS
FLOW IS AROUND A CYCLONIC CIRCULATION CENTER IN WEST TEXAS IN
THE NORTHERN PART OF THE TEXAS BIG BEND. A 70 KT JET STREAM IS
ON THE EASTERN SIDE OF THE CYCLONIC FLOW...WITHIN 120 NM ON
EITHER SIDE OF 23N106W 28N98W TO 32N96W. ALL THE UPPER LEVEL
FLOW IS SOUTHWESTERLY. THE MIDDLE LEVEL FLOW IS SOUTHWESTERLY
ALSO WEST OF 90W...AND SOUTHWESTERLY EAST OF 90W IN RELATION
TO THE ANTICYCLONIC CENTER IN THE SOUTHERN BAHAMAS. A WARM FRONT
STRETCHES FROM A 1008 MB NORTHWESTERN GULF OF MEXICO LOW
PRESSURE CENTER NEAR 29N94W TO SOUTHEASTERN COASTAL LOUISIANA
TO 29N87W TO THE FLORIDA WEST COAST NEAR 28N ACROSS FLORIDA TO
THE EAST COAST NEAR 27N...AND INTO THE ATLANTIC OCEAN. A COLD
FRONT EXTENDS FROM THE LOW CENTER TO 25N94W AND 22N97W.
A STATIONARY FRONT CONTINUES FROM 22N97W TO A 1006 MB LOW
PRESSURE CENTER NEAR 23N101W...CONTINUING TO 28N109W IN
MEXICO AND TO 33N113W. STRONG SHOWERS AND THUNDERSTORMS ARE
WITHIN A 30 NM RADIUS OF 24.5N93W...28N92.5W...AND WITHIN
A 30 TO 60 NM RADIUS OF 30N91.5W. ISOLATED MODERATE SHOWERS
ARE ALONG THE FRONT AS FAR SOUTH AS 21N95.5W.

THE CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE ENTIRE AREA.
THIS ANTICYCLONIC FLOW IS ON TOP OF A MIDDLE LEVEL TROUGH
IN THE SOUTHWESTERN CORNER OF THE AREA ALONG 15N83W 7N85W
IN THE EASTERN PACIFIC OCEAN...AND A MIDDLE LEVEL ANTICYCLONIC
CIRCULATION CENTER OVER THE WATERS BETWEEN THE CROOKED ISLAND
PASSAGE AND THE MAYAGUANA PASSAGE IN THE BAHAMAS. BROKEN TO
OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE SHOWERS ARE
SOUTH OF SOUTH OF 18N BETWEEN 78W AND 84W. ISOLATED MODERATE
TO STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN 15 TO 30 NM ON
EITHER SIDE OF 11N66W 12N70W 13N72W 15N73W 18N74W THROUGH THE
WINDWARD PASSAGE. IT IS POSSIBLE THAT THE PRECIPITATION MAY BE
DUE TO SOME MIDDLE LEVEL DIFFLUENT FLOW. THE SURFACE PRESSURE
GRADIENT IS ONLY SLIGHTLY STRONGER NOW THAN IT WAS YESTERDAY
AFTERNOON/ YESTERDAY EVENING.

THE ATLANTIC OCEAN...
A DEEP LAYER CENTRAL ATLANTIC TO EAST-CENTRAL ATLANTIC OCEAN
TROUGH IS AND HAS BEEN THE MAIN FEATURE ON THE SURFACE MAP
ANALYSIS FOR THE LAST FOUR TO FIVE DAYS. THE TROUGH PASSES
THROUGH 32N35W TO 26N43W 19N46W TO 11N52W. A SURFACE TROUGH
REMAINS...PASSING THROUGH 32N38W TO 29N40W 25N45W AND 21N50W.
ISOLATED MODERATE SHOWERS...SOME DISSIPATING AND SOME DEVELOPING
WITH TIME...FROM 19N TO 22N BETWEEN 40W AND 46W. BROKEN TO
OVERCAST MULTILAYERED CLOUDS ARE WITHIN 300 NM ON EITHER SIDE
OF 10N41W 20N34W BEYOND 32N31W. SHOWERS ARE POSSIBLE IN THIS
AREA OF CLOUDS. MODERATE SHOWERS FROM 25N TO 27N BETWEEN 40W
AND 42W. THE DEEP LAYER TROUGH THAT IS GIVING UPPER AIR SUPPORT
TO THE WESTERN ATLANTIC OCEAN COLD FRONT PASSES THROUGH 34N45W
TO 30N50W. THE COLD FRONT...NOW MOVING INTO THE CENTRAL
ATLANTIC OCEAN...PASSES THROUGH 32N47W TO 28N56W TO 27N71W.
A WARM FRONT CONTINUES FROM 27N71W...JUST NORTH OF THE NORTHERN
BAHAMAS...TO THE FLORIDA EAST COAST ALONG 27N/28N. BROKEN LOW
TO MIDDLE LEVEL CLOUDS AND POSSIBLE SHOWERS WITHIN 200 NM TO
THE NORTH/NORTHWEST OF THE FRONT. SURFACE HIGH PRESSURE BUILDS
OVER THE ATLANTIC OCEAN NORTH OF THIS FRONT. BROAD UPPER LEVEL
ANTICYCLONIC FLOW COVERS THE ATLANTIC OCEAN TO THE WEST OF THE
DEEP LAYER CENTRAL ATLANTIC OCEAN TROUGH. A SURFACE TROUGH
EXTENDS FROM EASTERN COASTAL FLORIDA FROM 28N81W BEYOND 31N79W.
AN UPPER LEVEL RIDGE IS EAST OF THE CENTRAL ATLANTIC OCEAN
TROUGH...ALONG 10N35W 22N30W BEYOND 32N30W. A SURFACE RIDGE
IS ALONG 15N37W 22N32W 27N29W BEYOND 33N26W. BROAD MIDDLE
TO UPPER LEVEL CYCLONIC FLOW IS EAST OF 24W.

$$
MT




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