[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 070530
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST TUE 07 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...ITCZ...

ITCZ AXIS ALONG 10N10W 5N45W 9N70W 6N80W.  SCATTERED
MODERATE/ISOLATED STRONG CONVECTION FROM 5N-8N BETWEEN 22W-30W
AND FROM 2N-11N BETWEEN 30W-40W. WIDELY SCATTERED MODERATE
CONVECTION FROM 5N-10N BETWEEN 40W-55W.

...DISCUSSION...

GULF OF MEXICO...
AFTER BLOCKING UPSTREAM DISTURBANCES FOR THE LAST FEW DAYS...THE
LARGE SCALE MIDDLE TO UPPER LEVEL RIDGE OVER THE GLFMEX IS
FINALLY GIVING SOME GROUND AS A POTENT SOUTHERN STREAM SHORTWAVE
MOVES THROUGH THE CENTRAL UNITED STATES.  STRONG DYNAMICS/LIFT
ASSOCIATED WITH THIS SYSTEM IS PRODUCING AN IMPRESSIVE LINE OF
THUNDERSTORMS OVER THE MISSISSIPPI VALLEY TRAILING SW INTO E
TEXAS BUT THE LINE WEAKENS AS IT NEARS THE N GULF COAST.  THE
ATTENDANT COLD FRONT LIES JUST INLAND OVER TEXAS AND MEXICO AND
WILL EMERGE INTO THE NW MEXICO LATER TONIGHT.  HOWEVER...THE
ASSOCIATED UPPER LEVEL SHORTWAVE IS NOW LIFTING RAPIDLY NEWD
WHICH WILL LIMIT THE AMOUNT OF DYNAMICS/LIFT OVER THE AREA.  AS
A RESULT...ONLY WIDELY SCATTERED SHOWERS AND A FEW ISOLATED
THUNDERSTORMS ARE EXPECTED ALONG THE FRONT PRIMARILY N OF 26N.
ALSO...THE FRONT WILL NOT MAKE MUCH SWD PROGRESS OVER THE GLFMEX
PULLING UP STATIONARY ON WED FROM THE FLORIDA PANHANDLE TO THE
COAST OF MEXICO NEAR TAMPICO.  A SECOND SHORTWAVE TROUGH NOW
MOVING INTO MEXICO OVER THE BAJA PENINSULA WILL CARVE OUT A
SLIGHTLY MORE ZONAL PATTERN OVER THE GLFMEX BY MID-WEEK.

CARIBBEAN SEA...
CENTRAL ATLC TROF STRETCHES INTO THE CARIBBEAN SEA FROM THE
LEEWARD ISLANDS TO CENTRAL AMERICA NEAR HONDURAS/NICARAGUA.
MUCH OF THE CARIBBEAN REMAINS UNDER EXTREMELY DRY/STABLE
CONDITIONS ESPECIALLY WEST OF THE UPPER TROUGH WHERE STRONG
SUBSIDENCE PREVAILS.  HOWEVER...THERE IS JUST ENOUGH LOW LEVEL
MOISTURE TO PRODUCE WIDELY SCATTERED SHOWERS ESPECIALLY WITHIN A
FEW DEGREES EITHER SIDE OF THE UPPER TROUGH WHERE INSTABILITY IS
LARGEST.  LOW LEVEL MOISTURE HAS ALSO MOVED INTO CENTRAL AMERICA
SUPPORTING INCREASING CLOUDINESS AND SHOWERS/THUNDERSTORMS
ESPECIALLY ALONG WINDWARD FACING SLOPES.  MODERATE TO STRONG ELY
TRADES ARE EXPECTED TO CONTINUE OVER THE CARIBBEAN THROUGH THE
NEXT SEVERAL DAYS OWING TO STRONG HIGH PRESSURE OVER THE W ATLC
WATERS.

ATLANTIC OCEAN...
THE SUBTROPICAL ATLC FEATURES A BROAD/FLAT RIDGE-TROUGH-RIDGE
PATTERN WITH RIDGING OVER THE E UNITED STATES/W ATLC...TROUGH
OVER THE CENTRAL ATLC BETWEEN 50W-70W...AND A HIGH OVER LOW
REGIME IN THE E ATLC BETWEEN 20W-50W.  THE MAIN WEATHER TONIGHT
IS LOCATED OVER THE CENTRAL ATLC WHERE A SHORTWAVE TROUGH ALONG
BETWEEN 50W-55W IS PRODUCING AN AREA OF SCATTERED MODERATE
CONVECTION WITHIN 90 NM EITHER SIDE OF A DISSIPATING STATIONARY
FRONT FROM 33N45W 28N51W.  THE BOUNDARY CONTINUES AS A FRONTAL
TROUGH TO PUERTO RICO WITH SCATTERED SHOWERS WITHIN 90 NM EITHER
SIDE.  THE REMNANT LOW OF OTTO MERGED WITH THE FRONTAL TROUGH
EARLIER TODAY NEAR 25N.  OVER THE E ATLC...A LARGE UPPER LOW
CUTOFF FROM THE WLY FLOW IS LOCATED NEAR 20N33W.  THIS FEATURE
CONTINUES TO PRODUCE A LARGE AREA OF STRONG SUBSIDENCE AND
MIDDLE TO UPPER LEVEL DRY/STABLE AIR TO ITS WEST EXTENDING TO
50W.  E OF THE UPPER LOW...DIFFLUENT UPPER LEVEL FLOW AND A
STRENGTHENING SUBTROPICAL JET FROM 15N35W INTO W AFRICA NEAR
MAURITANIA CONTINUES TO SUPPORT WIDESPREAD CLOUDINESS AND
SCATTERED MODERATE CONVECTION FROM THE ITCZ NWD TO THE CAPE
VERDE ISLANDS BETWEEN 20W-40W. THE OVERALL UPPER PATTERN WILL
BECOME MORE AMPLIFIED DURING THE NEXT FEW DAYS AS THE CENTRAL
ATLC TROUGH DIGS SWD.

$$
RHOME


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