[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 051141
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST WED DEC 05 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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...METEOROLOGICAL ANALYSIS...
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N11W 4N20W 3N40W 1N45W EQUATOR50W.
SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE AXIS
BETWEEN 20W-33W. ISOLATED MODERATE IS WITHIN 180 NM OF THE AXIS
E OF 16W AND WITHIN 150 NM N OF THE AXIS BETWEEN 38W-45W.

DISCUSSION...

THE GULF OF MEXICO...
WITH THE GOES-E SATELLITE IMAGERY STILL DOWN THIS MORNING ITS
DIFFICULT TO OBTAIN A COMPREHENSIVE PICTURE OF THE WEATHER
DETAILS. BASED UPON SFC OBS...SCATTEROMETER OVERPASSES AND SAT
IMAGERY FROM YESTERDAY...WX CONDITIONS APPEAR FAIRLY QUIET
BEHIND A DISSIPATING STATIONARY FRONT WHICH EXTENDS FROM THE
FLA STRAITS TO JUST N OF THE YUCATAN PENINSULA AND THEN SURGING
SWD TO S MEXICO ALONG 25N80W 23N88W 19N92W. THE SFC FLOW IS
VERY LIGHT AND VARIABLE ACROSS MUCH OF THE AREA. USING A
COMBINATION OF GOES-W WV IMAGERY AND MODEL DATA...A WELL DEFINED
CUT OFF MID TO UPPER LOW IS SPINNING OVER CENTRAL MEXICO LIKELY
ADVECTING A PLUME OF CLOUDINESS INTO THE WRN GULF. THE REMAINDER
OF THE REGION IS UNDER W TO NW UPPER FLOW INDUCING STABLE
CONDITIONS.

THE CARIBBEAN SEA...
STREAMS OF LOW-MID LEVEL CLOUDINESS AND EMBEDDED SCATTERED
SHOWERS/ISOLATED TSTMS ARE AFFECTING PORTIONS OF THE LEEWARD
ISLANDS AND MUCH OF THE AREA E OF ABOUT 72W OR SO. SAN JUAN
DOPPLER RADAR REVEALS A FAIR AMOUNT OF SHOWER/TSTM ACTIVITY BOTH
N AND S BUT LITTLE OVER THE ISLAND AT THE MOMENT. LIKE THE GULF
OF MEXICO...THERE IS NO GEOSTATIONARY SAT IMAGES THIS MORNING
OVER THE REGION W OF 70W-75W WHICH MAKES IT CHALLENGING TO
DETERMINE THE CURRENT STATE. THE LAST IMAGE AT 1645 Z YESTERDAY
SHOWED A FAIR AMOUNT OF CLOUDINESS AND SOME SPIN TO THE CLOUDS
IN THE SW CARIB SUGGESTING A SFC LOW NEAR THE N COAST OF
COLOMBIA. THIS HAS LIKELY HELD TOGETHER TO SOME DEGREE AS MODEL
DATA AND SFC OBS SUGGEST A WEAK LOW NEAR 11N77W...ANALYZED 1009
MB. WINDS ARE LIGHT ACROSS THE ENTIRE REGION DUE TO THE WEAK
PRES PATTERN BROUGHT ABOUT BY THE FRONTAL BOUNDARY N OF THE
AREA.

THE ATLANTIC OCEAN...
COLD FRONT CONTINUES TO TRACK SE ACROSS THE AREA EXTENDING FROM
32N59W SWWD TOWARD THE CENTRAL BAHAMAS WHERE IT THEN BECOMES
STATIONARY AND INCREASINGLY DIFFUSE THRU THE FLA STRAITS. A 01Z
ASCAT PASS REVEALED 20-25 KT SW WINDS WITHIN 180 NM AHEAD OF THE
FRONT N OF 27N. A FAIR AMOUNT OF CLOUDINESS AND ISOLATED SHOWERS
ARE ALSO WITHIN 180 NM AHEAD OF THE FRONT. FARTHER E...A
PERSISTENT 1012 MB LOW IS STILL SPINNING IN THE CENTRAL ATLC
NEAR 24N52W. THIS LOW HAS BEEN MEANDERING FOR THE PAST FEW
DAYS...BUT NOW APPEARS TO BE PULLING NWD AND MAY EVENTUALLY
MERGE WITH THE APPROACHING FRONT. ONLY ISOLATED SHOWERS ARE
NOTED WITHIN 150 NM OF THE LOW BUT A FEW TSTMS HAVE DEVELOPED
ALONG AN ASSOCIATED TROUGH AXIS N OF THE LOW FROM 26N-29N
BETWEEN 51W-52W. SLIGHTLY MORE ORGANIZED ACTIVITY LIES FURTHER E
IN AN UPPER DIFFLUENT AREA FROM 21N-24N BETWEEN 41W-44W. ANOTHER
WEAK NEARLY STATIONARY SFC TROUGH IS ALONG 57W/58W FROM 9N-17N.
THIS FEATURE IS ALSO ONLY PRODUCING A FEW SHOWERS WITHIN 90 NM
OF THE AXIS.

THE WEAK FRONT IN THE E ATLC HAS NOW LIFTED BACK N OF THE AREA
AS A WARM FRONT. THIS HAS ALLOWED SFC RIDGING TO DOMINATE
EXTENDING SW FROM A 1030 MB HIGH ABOUT 250 NM SW OF THE CANARY
ISLANDS NEAR 32N22W. IN THE MID AND UPPER LEVELS ABOVE THE
CENTRAL AND E ATLC...A HIGHLY AMPLIFIED RIDGE/TROUGH PATTERN
EXISTS IN THE SUBTROPICS AND MID-LATITUDES. THESE FEATURES ARE
ENHANCING STRONG ZONAL FLOW IN THE TROPICS WHICH IS ADVECTING A
CONSIDERABLE AMOUNT OF HIGH LEVEL CLOUDINESS S OF 20N.

$$
CANGIALOSI




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