[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 011752
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST WED 01 DEC 2004

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.

SPECIAL FEATURE...

TROPICAL STORM OTTO...THE 15TH NAMED STORM OF THE SEASON...
FORMED YESTERDAY FROM A GALE CENTER OVER THE CENTRAL ATLC.  OTTO
IS CURRENTLY LOCATED NEAR 31.4N 50.2W AT 01/1500 UTC MOVING SE
AT 03 KT.  MAXIMUM SUSTAINED WINDS ARE NEAR 40 KT WITH GUSTS TO
50 KT AND THE ESTIMATED MINIMUM PRESSURE IS 998 MB.  SEE LATEST
FORECAST/ADVISORY UNDER AWIPS/WMO HEADER TCMAT1/WTNT21 KNHC FOR
MORE DETAILS.   OTTO REMAINS LOCATED NEAR A MID/UPPER
LOW...WHICH IS PRODUCING SOME NLY SHEAR OVER THE SYSTEM.  AS A
RESULT...DEEP CONVECTION IS DISPLACED SE OF THE NOW EXPOSED LOW
LEVEL CIRCULATION.  NUMEROUS MODERATE CONVECTION WITHIN 120 NM
SE SEMICIRCLE.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N7W 5N25W 6N40W 10N53W 8N70W
6N80W.  SCATTERED STRONG CONVECTION FROM 5N-7N BETWEEN 37W-43W.
WIDELY SCATTERED MODERATE CONVECTION FROM 4N-6N BETWEEN 26W-37W.
SCATTERED MODERATE CONVECTION FROM 7N-11N BETWEEN 40W-46W.

...DISCUSSION...

GULF OF MEXICO...
A WELL-DEFINED MIDDLE TO UPPER LEVEL RIDGE EXTENDS FROM THE
YUCATAN PENINSULA NEWD OVER W CUBA INTO THE W ATLC NEAR THE
BAHAMAS.  A 110-130 KT SUBTROPICAL JET EXTENDS AROUND THE N
PERIPHERY OF THE RIDGE ADVECTING COPIOUS PACIFIC MOISTURE ACROSS
THE N HALF OF MEXICO INTO THE SE UNITED STATES.  A POTENT
SHORTWAVE TROUGH IS LIFTING RAPIDLY NEWD OVER THE E UNITED
STATES WITH ATTENDANT COLD FRONT BISECTING THE GLFMEX FROM N
FLORIDA NEAR JACKSONVILLE TO THE BAY OF CAMPECHE.  UPPER LEVEL
DYNAMICS/LIFT ARE ABSENT OVER THE ENTIRE GLFMEX LEAVING THE COLD
FRONT VOID OF DEEP CONVECTION.  BEHIND THE FRONT...STRONG HIGH
PRESSURE HAS WEDGED SWD FROM TEXAS ALONG THE E SLOPES OF THE
SIERRA MADRE ORIENTAL MOUNTAIN CHAIN IN MEXICO SUPPORTING
MODERATE NLY FLOW TO 25 KT AND COLD AIR ADVECTION. OVERCAST LOW
TO MID LEVEL CLOUDS ACCOMPANY THIS FLOW REGIME EXTENDING FROM
THE LEADING EDGE OF THE FRONT ALL THE WAY TO THE N GULF COAST.
SE OF FRONT...MAINLY CLEAR SKIES PREVAIL UNDER THE INFLUENCE OF
STRONG MIDDLE TO UPPER LEVEL SUBSIDENCE AND DRY AIR.  BROKEN
STRATOCUMULUS CLOUDS AND A FEW SHOWERS ARE FUNNELING THROUGH THE
FLORIDA STRAITS FROM ATLC WATERS E OF 82W.

CARIBBEAN...
A SHARP MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE CENTRAL
ATLC SWD ENTERING THE E CARIBBEAN NEAR THE VIRGIN ISLANDS TO E
PANAMA.  THE TROUGH DELINEATES STRONG SUBSIDENCE AND DRY NE FLOW
TO THE WEST FROM MOIST SW FLOW TO THE EAST ASSOCIATED WITH A 70
KT SUBTROPICAL JET FROM VENEZUELA NEWD INTO THE CENTRAL ATLC.
MOST OF THE DYNAMICS/LIFT ASSOCIATED WITH THE TROUGH/JET ARE
LOCATED JUST E OF THE AREA BUT STREAKS OF HIGH CLOUDS ARE NOTED
OVER THE EXTREME SE CARIBBEAN.  THE OVERALL PATTERN IS
SUPPRESSING DEEP CONVECTIVE ACTIVITY LEADING TO MAINLY CLEAR
SKIES ACROSS MUCH OF THE CARIBBEAN SEA. THE ONLY FEATURE OF NOTE
IS A WEAK LOW LEVEL TROUGH EXTENDING FROM PUERTO RICO WSW OVER
JAMAICA WITH BROKEN CLOUDINESS AND SCATTERED SHOWERS.
ELSEWHERE...MODERATE LOW LEVEL NE FLOW IS PRODUCING THE TYPICAL
CLOUDINESS AND SHOWERS ALONG THE WINDWARD SIDE OF HIGH TERRAIN
OVER CENTRAL AMERICA.

ATLANTIC...
MIDDLE TO UPPER LEVEL RIDGE DOMINATES THE W ATLC EXTENDING FROM
THE N BAHAMAS NEWD OVER BERMUDA.  THE SUBTROPICAL JET AND
UPSTREAM MOISTURE RIDES UP AND OVER THE RIDGE LEAVING THE ENTIRE
W ATLC UNDER MODERATE TO STRONG SUBSIDENCE AND DRY/STABLE
CONDITIONS.  OVER THE CENTRAL ATLC...DEEP-LAYERED TROUGH EXTENDS
SW FROM T.S. OTTO INTO THE E CARIBBEAN NEAR THE VIRGIN ISLANDS.
CONFLUENT FLOW ON THE BACK SIDE OF THE TROUGH IS PRODUCING
STRONG SUBSIDENCE AND VERY DRY AIR.  E OF THE TROUGH...A 70 KT
SUBTROPICAL JET EXTENDING NWD FROM S AMERICA IS ADVECTING
COPIOUS TROPICAL MOISTURE INTO THE CENTRAL AND E ATLC. AT THE
SURFACE...BROAD TROUGH LIES OVER THE CENTRAL ATLC WITH
CONVERGENT FLOW SUPPORTING WIDESPREAD CLOUDINESS AND SCATTERED
SHOWERS/THUNDERSTORMS WITHIN 250 NM EITHER SIDE OF A LINE FROM
15N50W TO 30N35W.  A DISSIPATING 1021 MB HIGH IS LOCATED ALONG
THE E COAST OF FLORIDA. OVER THE E ATLC...RIDGE EXTENDS SWD FROM
THE AZORES TO 15N45W.

$$
RHOME




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