[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260530
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST WED 26 JAN 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N8W 4N15W 2N26W 7N49W 4N54W. NARROW
BAND OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION CLUSTERS
ARE WITHIN 60 NM OF THE AXIS FROM 13W-23W. SCATTERED CLUSTERS OF
SCATTERED MODERATE CONVECTION ARE S OF THE AXIS TO THE EQUATOR
BETWEEN 30W-50W.

...DISCUSSION...

GULF OF MEXICO...
THERE HAS BEEN LITTLE OVERALL CHANGE IN THE PATTERN DURING THE
LAST 24 HOURS AS A 1020 MB SURFACE HIGH PRES REMAINS ANCHORED
OVER THE GULF NOW ALONG THE SW COAST OF FLORIDA. RESULTING
PRESSURE GRADIENT HAS RELAXED CONSIDERABLY SINCE THE WEEKEND
WITH WIND/SEAS NOW DOWN OVER THE ENTIRE GULF. EAST OF THE
SURFACE HIGH...NW FLOW IS MAINTAINING THE COOL/DRY PATTERN OVER
THE E GULF AND FLORIDA WHILE RETURN FLOW HAS HAS BECOME
ESTABLISHED OVER THE W GULF PRODUCING S FLOW AND A WARMING
TREND. A WEAK COASTAL TROF AND A SMALL AREA OF BROKEN LOW CLOUDS
WITH ISOLATED SHOWERS HAS FORMED JUST OFFSHORE OF MEXICO FROM
THE BAY OF CAMPECHE TO TO JUST N OF TAMPICO AND ALONG THE COAST
OF LOUISIANA. OTHERWISE...THE AREA IS RELATIVELY CLEAR. AT THE
UPPER LEVELS...BROAD MID/UPPER LEVEL RIDGING PREVAILS WITH MEAN
AXIS ALIGNED OVER MEXICO. CONFLUENCE E OF THE AXIS IS PRODUCING
SUBSIDENCE AND DRY/STABLE CONDITIONS ALOFT.

CARIBBEAN...
CENTRAL ATLC COLD FRONT ENTERS THE NE CARIBBEAN NEAR THE
VIRGIN/LEEWARD ISLANDS WHERE IT DISSIPATES AS A STATIONARY FRONT
TO OFF THE COAST OF COLOMBIA NEAR 13N73W. WHILE THE FRONT LACKS
SIGNIFICANT MID/UPPER LEVEL SUPPORT...LOW LEVEL MOISTURE POOLING
ALONG THE BOUNDARY IS PRODUCING BROKEN/OVERCAST LOW CLOUDS WITH
ISOLATED SHOWERS OVER THE E CARIBBEAN FROM 63W-76W INCLUDING
PUERTO RICO...HISPANIOLA AND THE LEEWARD ISLANDS. BEHIND THE
FRONT...HIGH PRESSURE OVER THE GULF OF MEXICO HAS PUSHED S INTO
THE W CARIBBEAN WITH LITTLE OF THE POST-FRONTAL CLOUDINESS FROM
YESTERDAY REMAINING AS DRIER AIR MOVES IN. THE UPPER LEVEL
PATTERN OVER THE CARIBBEAN IS PRIMARILY ZONAL WITH A WEAK RIDGE
ALIGNED ALONG CENTRAL AMERICA.

ATLANTIC OCEAN...
A BROAD MID/UPPER TROUGH COVERS THE W HALF OF THE ATLC WITH THE
ATTENDANT COLD FRONT EXTENDING FROM 32N43W TO THE VIRGIN/
LEEWARD ISLANDS. UPPER LEVEL SHORTWAVE TROUGH IS EMERGING OFF
THE SE UNITED STATES INTO THE W ATLC WITH THE ATTENDANT COLD
FRONT EXTENDING JUST E OF BERMUDA NEAR 32N63W TO 29N75W ERODING
THE SURFACE RIDGE SLIGHTLY. THE STRONGEST DYNAMICS/LIFT WITH THE
UPPER TROUGH REMAINS N OF THE AREA WITH NO DEEP CONVECTION NOTED
ALONG THE FRONTAL BOUNDARY. HOWEVER...BROKEN LOW/MID CLOUDS WITH
SCATTERED SHOWERS CONTINUE WITHIN 200 NM E OF THE FRONT N OF
25N. BEHIND THE FRONT...POST-FRONTAL NORTHERLY FLOW AND COLD AIR
ADVECTION CONTINUE TO PRODUCE A FIELD OF OPEN CELLULAR
STRATOCUMULUS CLOUDS WITH THE REINFORCING FRONT/SHORTWAVE
TROUGH. FARTHER E...A HIGH AMPLITUDE RIDGE EXTENDING FROM THE
CENTRAL TROPICAL ATLC NEAR 10N47W NE TOWARD THE AZORES BEYOND
32N34W IS MAINTAINING DRY/TRANQUIL CONDITIONS. AT THE SURFACE...
A BROAD 1023 MB SURFACE HIGH IS LOCATED NEAR 29N28W WITH
ASSOCIATED RIDGE EXTENDING SW TO 15N50W. ENHANCED PRESSURE
GRADIENT BETWEEN SURFACE RIDGE AND AFOREMENTIONED CENTRAL ATLC
FRONT IS MAINTAINING STRONG S FLOW TO NEAR GALE FORCE WITHIN 180
NM E OF THE EASTERN FRONT N OF 28N. OVER THE FAR E ATLC...
EARLIER VISIBLE IMAGERY CONTINUES TO INDICATED A PLUME OF DUST
OFF THE AFRICAN W COAST SE OF A LINE ALONG 28N23W 20N33W INTO
THE DEEP TROPICS. THE ASSOCIATED DRY AIR IS PRODUCING A
NOTICEABLE ABSENCE OF CLOUDINESS OVER THIS AREA.

$$
WALLACE


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