[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270152
TWDAT

TROPICAL WEATHER DISCUSSION...COR
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN NOV 26 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
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...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N13W 6N30W 7N40W 7N50W 6N58W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N EAST
OF 15W. SIMILAR CONVECTION IS FROM 5N-7N BETWEEN 25W-32W.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE ELSEWHERE.

...DISCUSSION...
THE GULF OF MEXICO...
AN UPPER RIDGE EXTENDS FROM THE EPAC ACROSS CENTRAL MEXICO INTO
THE GULF. VERY DRY AIR/SUBSIDENCE COVERS THE ENTIRE AREA. AT THE
SURFACE...HIGH PRESSURE RIDGING EXISTS ACROSS THE SE U.S. AND
THE GULF. MODERATE NE WINDS BLOW ACROSS THE SE GULF AND THE
STRAITS OF FLORIDA WHILE 10-15 KT E-SE WINDS ARE OVER THE
REMAINDER OF THE GULF. PATCHES OF LOW CLOUDS DOTS THE REGION.
ANOTHER PATCH OF MOISTURE WITH EMBEDDED LIGHT SHOWERS IS MOVING
ACROSS SOUTH-CENTRAL FLORIDA UNDER A NE WIND FLOW. THE NEXT COLD
FRONT IS FORECAST TO MOVE OFF THE TEXAS COAST THURSDAY. STRONG
NLY WINDS WILL FOLLOW THE FRONT.

THE CARIBBEAN SEA...
A WEAK LOW PRESSURE TROUGH LIES ALONG 77W SOUTH OF 16N. THIS
FEATURE IS PRODUCING CLOUDINESS AND A FEW SHOWERS OVER THE
SOUTHWESTERN CARIBBEAN SEA. SIGNIFICANT DEVELOPMENT OF THIS
SYSTEM IS NOT ANTICIPATED. A DYING FRONTAL BOUNDARY EXTENDS FROM
E CUBA TO NE HONDURAS WHERE THERE ARE SCATTERED SHOWERS.
ISOLATED MODERATE CONVECTION PERSISTS NEAR JAMAICA FROM 16N-18N
BETWEEN 73W-76W. IN THE UPPER LEVELS...AN UPPER HIGH LOCATED
JUST EAST OF THE ABC ISLANDS EXTENDS A RIDGE OVER MUCH OF
CARIBBEAN SEA AND CENTRAL AMERICA. THE BASE OF AN UPPER TROUGH
THAT LIES EAST OF THE FLORIDA PENINSULA ENTERS THE NW CORNER OF
THE BASIN. ABUNDANT UPPER LEVEL MOISTURE IS OVER THE W-CENTRAL
CARIBBEAN BETWEEN 70W-82W. VERY DRY AIR/STRONG SUBSIDENCE IS
OVER THE REMAINDER OF THE CARIBBEAN SEA. FRESH NE WINDS WILL
CONTINUE OVER THE NW CARIBBEAN AS STRONG HIGH PRES BUILDS TO THE
NORTH. WINDS ARE EXPECTED TO INCREASE ACROSS THE ATLC AND THE
CARIBBEAN SEA BY MID-WEEK AS THE HIGH SHIFTS E AND STRENGTHENS .
THE GFS MODEL INDICATES A SWATH OF ELY 20-25 KT TRADE WINDS OVER
THE ATLC...THE BAHAMAS AND SOUTH FLORIDA AS WELL AS ACROSS THE
CARIBBEAN SEA WED THROUGH FRIDAY.

THE ATLANTIC OCEAN...
AN UPPER TROUGH EXTENDS ACROSS THE WESTERN BAHAMAS/CUBA INTO THE
NW CARIBBEAN. VERY DRY AIR ALOFT COVERS ALL THIS AREA. THE
ASSOCIATED FRONTAL SYSTEM STRETCHES FROM A 1015 MB SURFACE LOW
ALONG 25N65W 22N72W TO E CUBA. MULTILAYERED CLOUDS WITH EMBEDDED
SHOWERS ARE ASSOCIATED WITH THE WEAK FRONTAL BOUNDARY/LOW. SOME
COLD AIR STRATOCUMULUS CLOUDS ARE BEHIND THE FRONT AFFECTING THE
BAHAMAS AND SOUTH-CENTRAL FLORIDA. AN UPPER RIDGE EXTENDS FROM
THE EASTERN CARIBBEAN INTO THE W-CENTRAL ATLC BETWEEN 50W-70W. A
NARROW UPPER TROUGH GOES FROM 31N32 16N54W TO AN UPPER LOW IN
THE DEEP TROPICS LOCATED JUST EAST OF WINDWARD ISLANDS. A LARGE
UPPER LEVEL RIDGE LIES JUST EAST OF THE TROUGH AND EXTENDS NEWD
FROM AN UPPER HIGH LOCATED NEAR 10N40W TO THE CANARY/MADEIRA
ISLANDS. DIFFLUENCE RELATED TO THIS FEATURE IS ENHANCING THE
CONVECTIVE ACTIVITY EMBEDDED IN THE ITCZ. AN UPPER TROUGH IS
OVER WESTERN AFRICA. A 1024 MB SURFACE HIGH IS OVER THE MADEIRA
ISLANDS WITH A RIDGE COVERING THE ATLC EAST OF THE ABOVE
MENTIONED FRONTAL BOUNDARY. UNDER THE INFLUENCE OF THIS SURFACE
HIGH...15-20 KT NE TO E SURFACE WINDS ARE FOUND FROM 10N-25N
BETWEEN 20W-60W. PATCHES OF LOW LEVEL MOISTURE WITH EMBEDDED
SHOWERS ARE JUST EAST OF THE LESSER ANTILLES MOVING SOUTH. VERY
DRY/STABLE AIR ALOFT IS OVER THE CAPE VERDE ISLANDS.

$$
GR





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