[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 012327
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN JAN 01 2006

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2300 UTC.

...SPECIAL FEATURE...

TROPICAL STORM ZETA IS NEAR 25.0N 38.2W OR ABOUT 1115
MILES...1790 KM...SOUTHWEST OF THE AZORES AT 01/2100 UTC. ZETA
HAS BEEN MEANDERING OVER THE PAST SEVERAL HOURS. THE ESTIMATED
MINIMUM CENTRAL PRESSURE IS 1000 MB. THE MAXIMUM SUSTAINED WIND
SPEED IS 45 KT WITH GUSTS TO 55 KT. PLEASE REFER TO THE LATEST
FORECAST/ ADVISORY LISTED UNDER THE AWIPS/WMO HEADERS MIATCMAT5/
WTNT25 KNHC FOR MORE DETAILS. ZETA CONTINUES TO MAINTAIN ITS
INTENSITY DESPITE WESTERLY VERTICAL WIND SHEAR IMPACTING ITS
CIRCULATION. THE SHEAR IS RESTRICTING CONVECTION TO THE NORTHERN
SEMI-CIRCLE...IN THE DOWN-SHEAR LEFT AREA OF THE CIRCULATION.
THE LOW-CLOUD CIRCULATION REMAINS QUITE VIGOROUS...WITH THE
CENTER LOCATED NEAR THE EDGE OF THE DENSE CONVECTIVE OVERCAST.
SCATTERED MODERATE CONVECTION IS FROM 25N-28N BETWEEN 35W-39W.

...ITCZ...

THE ITCZ IS ACTIVE THIS EVENING...HOWEVER SOME OF THE SHOWERS
ARE BEGINNING TO WEAKEN. THE AXIS IS CENTERED ALONG 8N13W
4N25W 3N34W 4N40W 5N49W. SCATTERED MODERATE AND POCKETS OF
ISOLATED STRONG CONVECTION IS LOCATED WITHIN 250 NM ON EITHER
SIDE OF THE AXIS. THE STRONGEST CONVECTION IS ALONG THE AXIS
BETWEEN 23W-31W.

...DISCUSSION...

THE GULF OF MEXICO...
SURFACE RIDGING FROM A WESTERN ATLANTIC NARROW EAST-WEST
ELONGATED 1021 MB HIGH IS PRODUCING MOSTLY FAIR MILD WEATHER AND
SOUTHERLY RETURN FLOW OVER THE ENTIRE GULF OF MEXICO.  A WEAK
STATIONARY FRONT IS INLAND OVER SOUTH GEORGIA. ONLY SOME
ISOLATED SHOWERS ARE IN THE VICINITY OF THE FRONT. IN THE UPPER
LEVELS...SOUTHWESTERLY FLOW IS COVERING THE GULF IN RESPONSE TO
A SHORTWAVE TROUGH OVER NEBRASKA. THIS SOUTHWESTERLY UPPER LEVEL
FLOW IS TRANSPORTING MOISTURE FROM THE EAST PACIFIC IN THE FORM
OF BROKEN MID-HIGH CLOUDS ACROSS THE GULF AND ISOLATED/SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS FROM TAMPA TO PENSACOLA. SOME
OF THESE THUNDERSTORMS ARE STRONG TO SEVERE. THESE SHOWERS ARE
QUICKLY MOVING TO THE NORTHEAST. GLOBAL MODELS ARE IN AGREEMENT
IN MAINTAINING SURFACE RIDGING OVER THE WESTERN ATLANTIC FOR AT
LEAST THE NEXT 24 HOURS. FAIR AND MILD CONDITIONS ARE EXPECTED
FOR TOMORROW SOUTH OF 28N. NORTH OF 28N...CONDITIONS MAY
BE SOMEWHAT UNSETTLED AS A LOW OVER KANSAS MOVES TO THE EAST.

THE CARIBBEAN SEA...
EASTERLY TRADES OF 15-20 KT ARE OVER THE CARIBBEAN SEA. PATCHY
AREAS OF LOW LEVEL CLOUDS WITH EMBEDDED LIGHT SHOWERS ARE
QUICKLY MOVING WESTWARD ACROSS THE EASTERN AND CENTRAL CARIBBEAN
E OF 80W. IN THE UPPER LEVELS...AN UPPER HIGH IS CENTERED OVER
CUBA NEAR 22N79W. THIS UPPER HIGH IS PRODUCING DRY UPPER LEVEL
AIR AND STRONG SUBSIDENCE ACROSS MOST OF CARIBBEAN WITH THE
DRIEST AIR EAST OF 75W.  THE UPPER HIGH HAS BEEN FAIRLY
STATIONARY OVER THE PAST DAY OR SO...BUT GLOBAL MODELS FORECAST
IT TO DRIFT TO THE WEST.  CONTINUED FAIR WEATHER IS LIKELY OVER
MUCH OF THE CARIBBEAN SEA ESPECIALLY EAST OF 75W.

THE ATLANTIC OCEAN WEST OF 50W...
A 1021 MB SURFACE HIGH IS CENTERED OVER THE CENTRAL ATLANTIC
NEAR 28N50W. THIS HIGH IS PRODUCING FAIR WEATHER ACROSS MUCH OF
THE ATLANTIC OCEAN WEST OF 50W. A SURFACE TROUGH IS LOCATED
NEAR SOUTH AMERICA ALONG 59W-60W FROM 5N-12N. THERE ARE SOME
SCATTERED SHOWERS TO THE EAST OF THE TROUGH AXIS. IN THE UPPER
LEVELS...THE UPPER HIGH PRODUCING DRY UPPER LEVEL AIR IN THE
CARIBBEAN IS DOING THE SAME IN THE WESTERN ATLANTIC SOUTH OF
26N. STRONG SUBSIDENCE AND WESTERLY UPPER LEVEL FLOW IS
WIDESPREAD ACROSS THE ATLANTIC. ONE EXCEPTION IS IN THE WESTERN
ATLANTIC...WEST OF 75W...WHERE SOUTHWESTERLY FLOW OVER THE GULF
OF MEXICO IS ADVECTING MOISTURE ACROSS FLORIDA...THE NORTHERN
BAHAMAS AND THE WESTERN ATLANTIC NORTH OF 26N.

THE ATLANTIC OCEAN EAST OF 50W...
TROPICAL STORM ZETA...THE 27TH NAMED STORM OF THE 2005
YEAR...AND THE THIRD TROPICAL OR SUBTROPICAL CYCLONE OCCURRING
IN JANUARY REMAINS THE MAIN FEATURE OF INTEREST IN THE EASTERN
ATLANTIC WATERS AS IT MAINTAINS ITS INTENSITY. THE OTHER
TWO JANUARY SYSTEMS WERE HURRICANE ALICE IN 1955 AND A
SUBTROPICAL STORM IN 1978. IN THE UPPER LEVELS...THERE IS A WEAK
AND NARROW MID-LEVEL RIDGE TO THE NORTH OF ZETA. A TROUGH
EXTENDS ALONG 30N30W 23N37W 16N50W TO JUST EAST OF THE WINDWARD
ISLANDS. WESTERLY UPPER LEVEL FLOW COVERS A GOOD PORTION OF THE
TROPICAL ATLANTIC FROM 10N-30N BETWEEN 10W-50W.

$$
CANGIALOSI











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