[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291137
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST TUE JAN 29 2008

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N10W 5N20W 4N30W 1N40W 2S50W.
WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE
OF THE AXIS BETWEEN 17W-30W. SIMILAR CONVECTION IS FOUND WITHIN
80 NM N OF AXIS BETWEEN 33W-39W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 09Z...A 1022 MB SURFACE HIGH PRES IS CENTERED OVER CENTRAL
FLORIDA PRODUCING CLEAR SKIES AND LIGHT WINDS. THIS FEATURE
EXTENDS A RIDGE ACROSS THE ENTIRE GULF OF MEXICO INCLUDING THE
YUCATAN PENINSULA. THIS HIGH ALSO DOMINATES THE W ATLC W OF
70W...THE BAHAMAS...CUBA AND THE NW CARIBBEAN. SLY RETURN FLOW
ON THE WESTERN PERIPHERY OF THIS SYSTEM AFFECTS THE W PORTION OF
THE GULF. SATELLITE IMAGERY SHOWS BROKEN TO OVERCAST COLD AIR
STRATOCUMULUS CLOUDS COVERING THE SE COAST OF THE SUNSHINE STATE
AND THE STRAITS OF FLORIDA. ALOFT...BROAD UPPER RIDGE DOMINATES
THE ENTIRE GULF AND THE FLORIDA PENINSULA GIVING THE AREA NWLY
WIND FLOW. A SUBTROPICAL JET STREAM IS TRANSPORTING ABUNDANT
UPPER LEVEL MOISTURE FROM THE EPAC ACROSS NW MEXICO...TEXAS AND
THE SE U.S. INTO THE W ATLC. HIGH PRES OVER THE AREA WILL
CONTINUE TO MOVE E OVER THE ATLANTIC OCEAN AND THE NEXT FRONT IS
EXPECTED TO ENTER THE GULF LATER TODAY. MODERATE TO STRONG NW
WINDS OF 20 TO 30 KT AND BUILDING SEAS UP TO 8 FT ARE EXPECTED
IN THE WAKE OF THE FRONT.

CARIBBEAN SEA...
BROAD DEEP LAYERED TROUGH IN THE W ATLC EXTENDS SOUTH INTO THE
CARIBBEAN THROUGH HISPANIOLA AND PUERTO RICO. THE BASE OF THIS
TROUGH REACHES 16N. THE ASSOCIATED COLD FRONT ENTERS THE
CARIBBEAN SEA ACROSS THE MONA PASSAGE/WESTERN PUERTO RICO THEN
CONTINUES SW TO NORTHERN NICARAGUA WHERE IT BEGINS TO WEAKEN.
FRAGMENTS OF LOW LEVEL CLOUDS WITH EMBEDDED LIGHT SHOWERS ARE
ASSOCIATED WITH THE FRONTAL ZONE MORE CONCENTRATED OVER THE
MONA PASSAGE/PUERTO RICO...AND OVER NORTHERN NICARAGUA.
SCATTERED COLD AIR STRATOCUMULUS CLOUDS ARE W OF THE FRONT
COVERING THE NW CARIBBEAN AND THE CAYMAN ISLANDS. THIS FRONT
WILL CONTINUE TO MOVE SE AFFECTING PUERTO RICO TODAY WITH AN
INCREASE IN SHOWER ACTIVITY. THIS FRONT IS ALSO FORECAST TO
DISSIPATE OVER THE CENTRAL CARIBBEAN TONIGHT. A SFC TROUGH...
REMNANTS OF A PREVIOUSLY FRONTAL BOUNDARY...EXTENDS FROM THE N
LEEWARD ISLANDS TO THE ABC ISLANDS. PATCHES OF LOW LEVEL CLOUDS
ARE ASSOCIATED WITH THIS TROUGH. HIGH PRES N OF THE AREA IS
PRODUCING MODERATE NE AND E WINDS. AN EARLIER ASCAT PASS SHOWED
NE WINDS OF 20 TO 25 KT JUST OFFSHORE THE COLOMBIAN COAST.

ATLANTIC OCEAN...
A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE FORECAST REGION. A
DEEP LAYERED TROUGH IS OVER THE W ATLC INTO THE CARIBBEAN SEA.
THE ATTENDANT COLD FRONT ENTERS THE AREA NEAR 31N56W EXTENDING
SW INTO THE CARIBBEAN ACROSS THE MONA PASSAGE. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 80 NM EITHER SIDE OF
THE FRONT. UPPER DIFFLUENCE BETWEEN THE TROUGH AND A RIDGE
ACROSS THE CENTRAL ATLC IS ENHANCING THIS CONVECTIVE ACTIVITY.
CONSIDERABLE COLD AIR STRATOCUMULUS CLOUDS ARE BEHIND THE FRONT
COVERING THE W ATLC AND THE BAHAMAS. LOW LEVEL NELY WINDS ARE
ADVECTING PART OF THIS CLOUDINESS TOWARD THE N COAST OF CUBA. A
SFC TROUGH...REMNANTS OF FRONTAL SYSTEM IS JUST TO THE SE WITHIN
160-18O NM OF THE MAIN FRONT. BROAD UPPER LEVEL RIDGE COVERS THE
CENTRAL ATLC ANCHORED DEEP IN THE TROPICS WITH THE MEAN AXIS
ALONG 50W. BROAD UPPER TROUGH REMAINS OVER THE E ATLC WITH A
CUT-OFF LOW CENTERED NEAR 31N20W. A SHORTWAVE TROUGH IS ALSO
MOVING INTO THE REGION NEAR 31N29W GENERATING SCATTERED SHOWERS.
A COLD FRONT GENERATED BY THIS SHORTWAVE CLIPS THE AREA BETWEEN
30W-38W.  A SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC
DISCUSSION AREA AND WEST AFRICA.

$$
GR





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