[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 251124
TWDAT

TROPICAL WEATHER DISCUSSION...COR
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT NOV 25 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N13W 7N27W 8N46W 10N57W. A PORTION
OF THE ITCZ IS FAIRLY ACTIVE WITH CLUSTERS OF SCATTERED MODERATE
CONVECTION WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 34W-43W
AND FARTHER NW FROM 6N-15N BETWEEN 43W-52W. ISOLATED MODERATE IS
WITHIN 90 NM N OF THE AXIS E OF 25W.

...DISCUSSION...
THE GULF OF MEXICO...
HIGH PRES RIDGING EXISTS BOTH AT THE SFC AND ALOFT CENTERED
ACROSS THE ERN PORTION OF THE AREA. THIS PATTERN IS PRODUCING
PLENTY OF VERY STABLE/DRY AIR AND LIGHT TO MODERATE WINDS
FLOWING CLOCKWISE AROUND A 1025 MB HIGH CENTERED ACROSS THE
CAROLINAS. THE ONLY AREA OF MOISTURE MENTIONABLE IS ASSOCIATED
WITH LOW-LEVEL NE FLOW ACROSS THE ATLC DRAGGING BROKEN LOW
CLOUDS AND ISOLATED SHOWERS ON THE BREEZE ACROSS THE FL
PENINSULA. DOPPLER RADAR IS SHOWING THESE SHOWERS A LITTLE MORE
ORGANIZED IN THE STRAITS OF FLORIDA. TEMPS ARE BACK TO NEAR
NORMAL VALUES...WHICH IS QUITE A RECOVERY FROM EARLIER THIS
WEEK. CONTINUED WARMING AND SLIGHT MOISTENING IS EXPECTED AS THE
LAYERED RIDGE SLIDES EASTWARD. THE NEXT COLD FRONT IS EXPECTED
TO APPROACH THE NW PORTION OF THE AREA BY MID-WEEK.

THE CARIBBEAN SEA...
A NEARLY STATIONARY 1008 MB LOW PRES SYSTEM IS IN THE SW
CARIBBEAN CENTERED N OF PANAMA NEAR 11N79W. A BURST OF MODERATE
CONVECTION FORMED EARLY THIS MORNING IN THE NRN SEMICIRCLE. THIS
ACTIVITY HAS EXPANDED AND PERSISTED FOR THE LAST SEVERAL HOURS
AND NOW EXTENDS WITHIN 150 NM N OF THE CENTER. OVERALL...THIS
DISTURBANCE HAS BECOME A LITTLE BETTER ORGANIZED AND IT WILL
CONTINUE TO BE MONITORED AS SOME SLOW DEVELOPMENT IS POSSIBLE
OVER THE NEXT DAY OR SO. THIS SYSTEM IS NOW DETACHED FROM THE
PERSISTENT FRONTAL BOUNDARY IN THE AREA WHICH IS STATIONARY FROM
HAITI ACROSS ERN JAMAICA TO NEAR 14N80W. SCATTERED SHOWERS AND
ISOLATED TSTMS ARE WITHIN 150 NM OF THE SLOWLY WEAKENING FRONT.
MUCH OF THE CENTRAL AND ERN CARIBBEAN IS QUIET WITH DRY AIR
ALOFT IN PLACE ENHANCED BY UPPER LEVEL CONFLUENCE BETWEEN AN
UPPER HIGH CENTERED N OF VENEZUELA NEAR 13N68W AND UPPER
LOW/NARROW TROUGH JUST E OF THE WINDWARD ISLANDS. MOISTURE
ASSOCIATED WITH THE TROUGH IS LOCATED E OF THE AREA BUT SOME OF
THIS MAY MOVE ACROSS THE LESSER ANTILLES LATER WEEKEND OR EARLY
NEXT WEEK AS SUGGESTED BY THE GFS.

THE ATLANTIC OCEAN...
VERY DRY STABLE AIR ALOFT COVERS THE SW ATLC W OF A LINE FROM
BERMUDA TO THE CENTRAL BAHAMAS. THIS AREA IS W OF A SLOWLY
WEAKENING STALLED FRONTAL BOUNDARY WHICH EXTENDS FROM 32N62W TO
25N67W TO WRN HAITI. MOISTURE DOES NOT APPEAR VERY DEEP ALONG
THE FRONT...BASED ON IR IMAGERY...BUT THERE ARE LIKELY SCATTERED
SHOWERS WITHIN 240 NM OF THE SFC BOUNDARY. A LARGE AMPLIFIED
LONGWAVE RIDGE LIES E OF THE UPPER TROUGH/SFC FRONT AND COVERS A
LARGE PORTION OF THE CENTRAL AND ERN ATLC BETWEEN 25W-60W
ANCHORED BY A HIGH CENTER NEAR 23N35W. THE WRN EXTENSION OF THIS
RIDGE IS BEING ERODED BY A NARROW UPPER TROUGH WHICH EXTENDS
FROM AN UPPER LOW NEAR 28N54W TO ANOTHER UPPER LOW DEEP IN THE
TROPICS NEAR 13N57W. THIS UPPER TROUGH HAS A WEAK REFLECTION AT
THE SFC WITH THE AXIS DRAWN ALONG 58W/59W FROM 11N-19N. THE
DIFFLUENT UPPER LEVEL PATTERN IS ENHANCING A LARGE AREA OF
CONVECTION EMBEDDED IN THE ITCZ...REFER TO THAT SECTION FOR
DETAILS. SCATTERED SHOWERS ALSO EXIST ON THE MOIST E SIDE OF THE
NRN UPPER LOW FROM 20N-30N BETWEEN 47W-53W. A STRONG MID/UPPER
LEVEL TROUGH COVERS THE ERN-MOST ATLC JUST W OF THE IBERIAN
PENINSULA ACROSS THE CANARY ISLANDS TO NEAR 10N20W. THE
ASSOCIATED COLD FRONT JUST CLIPS THE NE PORTION OF THE AREA WITH
LIMITED LOW-LEVEL MOISTURE. AT THE SFC...HIGH PRES RIDGING
DOMINATES NEARLY THE ENTIRE ATLC SUPPORTED BY A 1024 MB HIGH
NEAR 34N37W AND A 1025 MB HIGH CENTERED IN THE WRN CAROLINAS.
THERE IS A PRONOUNCED WEAKNESS IN THIS RIDGING BETWEEN 60W-75W
DUE TO THE FRONTAL BOUNDARY MENTIONED IN THE CNTRL/WRN ATLC.

$$
CANGIALOSI




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