[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171134
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT DEC 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N10W 6N17W 8N33W 3N50W 4N55W.
SCATTERED MODERATE CONVECTION WITHIN 200 NM N OF THE AXIS
BETWEEN 21W-28W AND WITHIN 200 NM S OF THE AXIS BETWEEN 28W-36W.
WIDELY SCATTERED SHOWERS/TSTMS WITHIN 100 NM OF THE COAST OF
FRENCH GUIANA.

...DISCUSSION...

GULF OF MEXICO...
A STRONG MID/UPPER LEVEL TROUGH HAS DUG S OVER THE ROCKY
MOUNTAINS TO A MEAN POSITION ALONG 103W N OF 20N. THE
SUBTROPICAL JET RIDES ALONG THE E SIDE OF THE TROUGH FROM NE
MEXICO ALONG THE TEXAS COAST TOWARDS THE SRN APPALACHIANS WITH
CORE SPEEDS OVER 130 KT OVER PENNSYLVANIA. THIS IS PRODUCING
MODERATE SWLY UPPER LEVEL FLOW OVER THE GULF WATERS WITH
MOISTURE LIMITED TO THE NW GULF NEAR THE JET. THE COLD FRONT
WHICH PUSHED THROUGH THE AREA OVER THE PAST COUPLE OF DAYS HAS
NOW BEGUN TO LIFT BACK TO THE N AS A WARM FRONT AND EXTENDING
FROM THE STRAITS OF FLORIDA NW TO A 1013 MB LOW WHICH HAS
DEVELOPED OFF THE TEXAS COAST NEAR 26N96W. A STATIONARY FRONT
EXTENDS S OF THE LOW INTO THE BAY OF CAMPECHE SEPARATING COOL
CONTINENTAL AIR OVER MEXICO FROM WARM TROPICAL AIR OVER THE
GULF. AREAS OF TSTMS HAVE BEGUN TO BREAK OUT ALONG THE FRONT
WITH WIDELY SCATTERED MODERATE CONVECTION FROM 24N-28N BETWEEN
88W-97W AND ISOLATED SHOWERS/TSTMS OVER THE SE GULF WITHIN 60 NM
OF THE FRONT BETWEEN 82W-87W. THE FRONT WILL CONTINUE TO LIFT N
TODAY AND THEN BECOME STATIONARY THIS EVENING FROM N FLORIDA TO
THE W GULF...THEN MOVE LITTLE OVER THE NEXT FEW DAYS. THIS WILL
ENHANCE THE CHANCES FOR SHOWERS OVER THE GULF WATERS AND FLORIDA
AT LEAST THROUGH NEXT THU.

CARIBBEAN...
A STRONG UPPER LEVEL ANTICYCLONE IS CENTERED NEAR ERN PANAMA AND
NW COLOMBIA WITH A RIDGE AXIS EXTENDING NWD TO THE WINDWARD
PASSAGE AND THEN NE INTO THE W ATLC. MODERATE/STRONG SUBSIDENCE
DOMINATES THE ENTIRE AREA BENEATH THE ANTICYCLONE. THE GREATEST
CONCENTRATION OF TRADE SHOWERS ARE LOCATED NEAR TRINIDAD AND
TOBAGO AND MOVING ONSHORE INTO NICARAGUA AND COSTA RICA. LITTLE
CHANGE IS EXPECTED IN THE OVERALL PATTERN EXCEPT THAT AN
INCREASE IN MOISTURE OVER THE NW CARIBBEAN BEGINNING SUN NIGHT
COULD RAISE THE CHANCE FOR SHOWERS.

ATLANTIC...
A TILTED UPPER LEVEL RIDGE LIES OVER THE W ATLC EXTENDING FROM E
CUBA TO BERMUDA WITH A VIGOROUS JET RIDING AROUND THE N SIDE OFF
THE U.S. MID-ATLC COAST. THE COLD FRONT WHICH MOVED INTO THE W
ATLC YESTERDAY HAS LIFTED N AS A WARM FRONT AND NOW EXTENDS FROM
SE FLORIDA TO 31N74W...BUT STRONG SUBSIDENCE ASSOCIATED WITH THE
UPPER RIDGE HAS ONLY ALLOWED ISOLATED OVERRUNNING SHOWERS ALONG
THE E COAST OF FLORIDA. HIGH PRES IS IN CONTROL OVER MUCH OF THE
W/CNTRL ATLC BETWEEN 50W-70W WITH SCATTERED/BROKEN STRATOCUMULUS
COVERING THE AREA. FARTHER E...A LARGE AND ELONGATED UPPER LOW
IS LOCATED SW OF THE AZORES NEAR 30N37W WITH A TROUGH EXTENDING
SW TO THE LESSER ANTILLES. THE SUBTROPICAL JET TO THE SE OF THE
TROUGH EXTENDS FROM 15N50W NE TO WESTERN SAHARA WITH CORE SPEEDS
NEAR 110 KT. THIS IS PRODUCING A BROKEN BAND OF HIGH CIRRUS OVER
THE TROPICS AND SPREADING ACROSS THE CAPE VERDE ISLANDS TO W
AFRICA. A SURFACE TROUGH...POSSIBLY A LATE SEASON TROPICAL
WAVE?...LIES ALONG 42W S OF 11N AND IS MOVING W 15 KT PRODUCING
WIDELY SCATTERED MODERATE CONVECTION FROM 9N-11N BETWEEN
39W-44W. ELSEWHERE...TWO 1010 MB LOWS ARE CENTERED WSW OF THE
CANARY ISLANDS NEAR 27N26W AND 26N33W...CONNECTED BY A TROUGH
WHICH CONTINUES NW TO 25N40W 32N45W. CLUSTERS OF SCATTERED
MODERATE CONVECTION ARE UP TO 180 NM N OF THE TROUGH BETWEEN
19W-33W WITH ADDITIONAL ISOLATED SHOWERS WITHIN 75 NM OF THE
TROUGH BETWEEN 33W-39W. THE LOW AND TROUGH ARE EXPECTED TO
CONSOLIDATE OVER THE NEXT FEW DAYS AND LIFT NE TOWARDS MADEIRA
ISLAND...THEN DROP BACK S TOWARDS THE CANARY ISLANDS BY WED.

$$
BERG



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