[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 300549
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST TUE DEC 30 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 0530 UTC.

...THE ITCZ...

THE ITCZ AXIS IS ANALYZED FROM THE CENTRAL COAST OF SIERRA LEONE
NEAR 8N12W TO 4N20W 3N30W 1.5N40W TO NORTHEASTERN BRAZIL NEAR
THE CITY OF BELEM AT EQ47W. SATELLITE IMAGERY SHOWS STRONG
CONVECTION FROM 1N TO 3.5N BETWEEN 42W AND 48W. ISOLATED WEAK TO
MODERATE CONVECTION IS FOUND EMBEDDED IN THE ITCZ FROM 1.5N TO
5N BETWEEN 27W AND 30W.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL TROUGH COVERING MUCH OF THE CENTRAL UNITED STATES
PREPARES TO ENTER THE NORTHWEST GULF OF MEXICO OVER THE NEXT 6
HOURS. SOUTHWEST FLOW ALOFT RELATED TO THIS TROUGH IS BRINGING
MID TO UPPER LEVEL MOISTURE TO THE BASIN. DOPPLER RADAR IMAGERY
ALREADY SHOWS MODERATE TO HEAVY SHOWERS MOVING NORTHEASTWARD
ENTERING THE NORTHWEST BASIN NEAR CORPUS CHRISTI. SHIP AND BUOY
OBSERVATIONS DISPLAY EASTERLY WINDS 10 TO 15 KTS ACROSS THE
BASIN. COMPUTER MODELS SHOW THIS TROUGH SWINGING NORTH OF THE
GULF. THEREFORE...CONVECTION IS MORE LIKELY TO REMAIN ON THE
NORTHERN HALF OF THE BASIN NORTH OF 24N.

THE CARIBBEAN SEA...

AN UPPER LEVEL RIDGE OF HIGH PRESSURE COVERS MOST OF THE
CARIBBEAN BASIN FROM THE LESSER ANTILLES TO 81W...SUPPRESSING
DEEP CONVECTION IN THIS REGION. WATER VAPOR IMAGERY SHOWS STRONG
SUBSIDENCE OF AIR OVER THE EAST AND CENTRAL BASIN...WITH SOME
MID TO UPPER LEVEL MOISTURE MOVING INTO THE NNW BASIN. INFRA-RED
IMAGERY SHOWS AND AREA OF WEAK CONVECTION FROM 16N TO 19N
BETWEEN 84W AND 88W. ANOTHER AREA OF SHOWERS IS FOUND OVER THE
NE BASIN NEAR PUERTO RICO. DOPPLER RADAR IMAGERY SHOWS A CLUSTER
OF WEAK TO MODERATE SHOWERS MOVING SOUTH ACROSS THE ISLAND OF
PUERTO RICO. THESE SHOWERS ARE RELATED TO A COLD FRONT MOVING 50
NM NORTH OF SAN JUAN. CONDITIONS ARE EXPECTED TO IMPROVE OVER
THE NEXT 24 HOURS IN THIS AREA...AS COLD FRONT CONTINUES ITS
CRUISE EASTWARD INTO THE CENTRAL ATLANTIC OCEAN. SHIP AND BUOY
OBSERVATIONS SHOW EASTERLY WINDS 10 TO 15 KT ACROSS THE BASIN.
COMPUTER MODELS KEEP HIGH PRESSURE WEATHER ACROSS THE BASIN FOR
THE NEXT FEW DAYS.

THE ATLANTIC OCEAN...

A COLD FRONT IS ANALYZED OVER THE WESTERN ATLANTIC ALONG 32N55W
TO 25N59W TO NORTH OF THE ISLAND OF PUERTO RICO. THIS FRONT IS
MOVING TO THE CENTRAL ATLANTIC IN THE NEXT 12 HOURS. WEAK
CONVECTION IS SEEN 50 NM EAST OF THIS FRONT COVERING AN AREA
FROM 24N TO 32N BETWEEN 50W AND 55W. GALE FORCE WINDS WILL
CONTINUE TO DEVELOP NORTH OF 28N WITHIN 300 NM EAST OF THE FRONT
OVER THE NEXT 24 HOURS. A SURFACE 1025 MB HIGH IS FOUND OVER THE
CENTRAL ATLANTIC NEAR 30N38W. THIS HIGH PRESSURE WILL SLOWLY
DISSIPATE AS IT MOVES TO THE EAST. ANOTHER COLD FRONT IS FOUND
OVER THE EASTERN ATLANTIC ENTERING TO NORTHWEST AFRICA. THIS
TROUGH IS DISSIPATING AS IT ENTERS THE NORTH AFRICAN REGION.
LOOK FOR THE WESTERN ATLANTIC FRONT TO SLOWLY WEAKEN...BECOMING
ALMOST STATIONARY...ONCE IT REACHES THE CENTRAL ATLANTIC REGION.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE.

$$

GARCIA




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