[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221153
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU JAN 22 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC.

...THE ITCZ...
FROM 5N3W ALONG THE SOUTHEASTERN COAST OF THE IVORY COAST TO
3N10W...CROSSING THE EQUATOR ALONG 25W...TO 1S30W 1S40W INTO
NORTHEASTERN BRAZIL NEAR 2S46W. NUMEROUS STRONG SHOWERS AND
THUNDERSTORMS ARE SOUTH OF 2N BETWEEN 39W AND 50W. SCATTERED
STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN 30 NM TO 60 NM ON
EITHER SIDE OF THE ITCZ BETWEEN 17W AND 35W.

...DISCUSSION...

THE GULF OF MEXICO AND THE ATLANTIC OCEAN WEST OF 56W...
A DEEP-LAYER TROUGH STILL SUPPORTS THE MOST RECENT COLD FRONT
TO VISIT THE AREA. A SHORTWAVE TROUGH IS MOVING THROUGH THE EAST
CENTRAL TO NORTHEASTERN WATERS AT THIS TIME. MIDDLE TO UPPER
LEVEL DRY AIR IN SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS.
THE COLD FRONT NOW IS IN THE ATLANTIC OCEAN...PASSING THROUGH
32N60W TO CENTRAL HISPANIOLA...INTO THE WEST CENTRAL CARIBBEAN
SEA. THIS COLD FRONT HAS BROUGHT TO THE SOUTHEASTERN U.S.A.
THE FIRST SIGNIFICANT SHOT OF COLD AIR FOR THE 2008-2009 WINTER
SEASON. LIGHTER WINDS WITH SURFACE HIGH PRESSURE IN FLORIDA AND
THE EASTERN GULF OF MEXICO. TEMPERATURES THIS MORNING IN FLORIDA
AND OTHER SECTIONS OF THE SOUTHEASTERN U.S.A. HAVE BEEN POSSIBLY
A BIT LOWER EVEN THAN THE TEMPERATURES OF 24 HOURS AGO.
A SURFACE TROUGH...THE REMNANTS OF AN EARLIER FRONTAL
BOUNDARY...PASS THROUGH 32N57W TO 28N60W TO 22N65W TO THE
MONA PASSAGE NEAR 17N68W. SHOWERS ARE POSSIBLE WITHIN 30 NM
ON EITHER SIDE OF 20N65W 25N62W 27N60W BEYOND 32N57W.
GALE FORCE WIND CONDITIONS ARE BEING EXPERIENCED IN THE
GULF OF TEHUANTEPEC ON THE PACIFIC OCEAN SIDE OF MEXICO.

THE CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA...AROUND
A RIDGE ALONG 65W/66W. THE RIDGE REALLY IS NOT MOVING MUCH DUE
TO THE FACT THAT ATLANTIC OCEAN MIDDLE TO UPPER LEVEL CYCLONIC
FLOW IS ADVANCING WESTWARD AT A SLOW RATE. THE CYCLONIC FLOW
THAT NOW REACHES THE EASTERN CARIBBEAN SEA ISLANDS IS AROUND
A 15N52W CYCLONIC CIRCULATION CENTER. OUR ANALYSIS OF THE
FRONTAL SCENARIO HAS CHANGED DURING THE LAST SIX HOURS. THE COLD
FRONT NOW CUTS ACROSS THE DOMINICAN REPUBLIC...CURVING TO 17N80W
16N81W AND TO THE SOUTHEASTERN COAST OF NICARAGUA. A SURFACE
TROUGH HAS BEEN ANALYZED NOW ALONG 16N73W 13N77W TO THE PANAMA
COAST ALONG 78W/79W. UPPER LEVEL MOISTURE AND POSSIBLE SHOWERS
ARE SOUTH OF 15N BETWEEN 73W AND 80W. THE SOUTHERN END OF
A SURFACE TROUGH...THE REMNANT OF AN EARLIER FRONTAL BOUNDARY...
REACHES THE MONA PASSAGE FROM THE ATLANTIC OCEAN. THE SAME
AMOUNT OF CLOUDINESS FROM SIX HOURS AGO IS NOT EVIDENT AT THIS
TIME.

THE REST OF THE ATLANTIC OCEAN EAST OF 56W...
A SURFACE RIDGE GOES FROM 32N15W TO A 1031 MB HIGH PRESSURE
CENTER NEAR 31N28W TO 28N43W TO 25N50W TO 22N60W...INTO THE
EASTERN CARIBBEAN SEA NEAR 16N64W. A MIDDLE TO UPPER LEVEL
CYCLONIC CIRCULATION CENTER IS NEAR 15N52W. BROAD CYCLONIC
FLOW COVERS THE AREA BETWEEN 45W AND 62W. THIS CYCLONE IS
MOVING UNDER AN UPPER LEVEL LEVEL RIDGE ALONG 33W/34W.
THE WESTERN END OF A MIDDLE TO UPPER LEVEL TROUGH PASSES FROM
NORTHERN MAURITANIA TO 18N29W IN THE ATLANTIC OCEAN...TO THE
NORTHWEST OF THE CAPE VERDE ISLANDS.

$$
MT






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