[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161759
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI DEC 16 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN SECTIONS
OF SOUTH AMERICA...AND 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 4N8W 5N18W 4N41W 3N51W. CLUSTERS OF
MODERATE ISOLATED/SCATTERED SHOWERS ARE WITHIN 120 NM OF THE
AXIS FROM 15W-33W. MANY OF THESE SHOWERS APPEAR TO BE WEAKENING
OVER THE PAST 6 HOURS.

...DISCUSSION...

GULF OF MEXICO INTO THE W ATLANTIC...
A FLAT DEEP LAYERED TROUGH CONTINUES TO MOVE TO THE SE INTO THE
NW ATLC.  ASSOCIATED COLD FRONT EXTENDS INTO THE W ATLC NEAR
32N75W PAST SOUTH FLORIDA AND THE KEYS TO THE SW GULF NEAR
22N88W. A STATIONARY FRONT EXTENDS SW OF THE COLD FRONT TO
NEAR 19N94W. AHEAD OF THE FRONT THERE ARE SOME SCATTERED
SHOWERS. FRONT IS EXPECTED TO BECOME STATIONARY AS THE UPPER
TROUGH LEAVES THE AREA.  BEHIND THE FRONT HIGH PRESSURE OVER THE
TX/LA BORDER IS CAUSING MOSTLY FAIR CONDITIONS OVER THE NORTH
PORTION OF THE AREA. A WEAK COASTAL TROUGH IS LOCATED NEAR THE
MEXICAN COAST FROM 26N97W TO 20N95W. SOME OF THE GLOBAL MODELS
DEVELOP THIS TROUGH INTO A WEAK AREA OF LOW PRESSURE OVER THE
NEXT DAY OR SO KEEPING THE SOUTHERN GULF SOMEWHAT UNSETTLED
THROUGH THE WEEKEND. IN THE UPPER LEVELS... MUCH OF THE GULF OF
MEXICO AND WESTERN ATLANTIC IS DOMINATED BY A WSW TO WLY FLOW
AROUND A CARIBBEAN UPPER HIGH.

CARIBBEAN SEA...
A MID-LEVEL RIDGE IS LOCATED OVER THE SWRN CARIBBEAN. DRY AIR,
STRONG SUBSIDENCE AND FAIR WEATHER DOMINATE MUCH OF THE
CARIBBEAN. THE ONLY EXCEPTION ARE SOME SCATTERED SHOWERS
OFFSHORE OF THE YUCATAN PENINSULA TO CUBA ASSOCIATED WITH A WEAK
PRE-FRONTAL TROUGH. 15-20 KT TRADES COVER MUCH OF THE AREA E OF
80W... SLACKENING OVER THE NW CARIBBEAN WITH THE FRONTAL
BOUNDARY NEARBY.  BEST CHANCE OF RAIN SHOULD LIFT NORTHWARD AWAY
FROM CUBA TOMORROW.

REMAINDER OF ATLANTIC...
A SURFACE HIGH N OF THE AREA IS LOCATED NEAR 34N59W. TO ITS EAST
THERE IS A DISSIPATING AREA OF LOW PRESSURE NEAR 34N44W WITH A
TRAILING COLD FRONT FROM THE LOW TO NEAR 28N48W. STRATOCUMULUS
CLOUDS ARE BUILDING IN BEHIND THE FRONT AND ARE OVER MOST OF THE
SUBTROPICAL ATLC N OF 25N E OF 63W. FARTHER EAST... AN
ORGANIZING 1010 MB LOW PRESSURE SYSTEM NEAR 24N27W IS PRODUCING
MODERATE SCATTERED SHOWERS AND 30 KT WINDS IN THE NE SECTOR PLUS
MUCH LIGHTER TRADES THAN AVERAGE S OF THE LOW E OF 45W. THE GFS
STRENGTHENS THIS SYSTEM SLIGHTLY AND FORECAST IT TO SLOWLY MOVE
TO THE NE OVER THE NEXT COUPLE OF DAYS BUT KEEPS IT
EXTRATROPICAL.  IN BETWEEN THESE TWO AREAS OF LOW PRESSURE THERE
ARE SOME SCATTERED SHOWERS AND BROKEN TO OVERCAST CONDITIONS
FROM 31N42W TO 25N28W ASSOCIATED WITH A WEAK TROUGH. THE
REMAINDER OF THE UPPER LEVEL FLOW IN THE TROPICS IS DOMINATED BY
A ZONAL WESTERLY JET WITH WINDS OF 70 TO 90 KT WHICH EXTENDS
ALONG 20N45W 21N26W TO INLAND OVER AFRICA NEAR 20N16W.  TO THE
SOUTH OF THIS WESTERLY JET THERE ARE SOME MODERATE ISOLATED
SHOWERS N OF THE ITCZ IN A LINE FROM 11N40W 10N60W.

$$
JC/EB


This weather bulletin was brought to you by:
www.nashvilleweather.net