[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091749
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT 09 APR 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1700 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N1W 4N30W 6N40W 2N60W.  SMALL AREA
OF WIDELY SCATTERED MODERATE CONVECTION WITHIN 60 NM EITHER SIDE
OF AXIS FROM 27W-33W.

...DISCUSSION...

GULF OF MEXICO...
DEEP-LAYERED LOW OVER THE W ATLC CONTINUES TO PULL AWAY FROM THE
AREA WITH MIDDLE TO UPPER LEVEL RIDGING BUILDING OVER THE
GLFMEX.  SUBTROPICAL JET ASSOCIATED WITH AN UPSTREAM TROUGH
MOVING INTO THE W UNITED STATES CUTS ACROSS CENTRAL MEXICO WITH
ASSOCIATED MOISTURE PRODUCING SOME STREAKS OF HIGH CLOUDINESS
MAINLY OVER CENTRAL MEXICO AND THE S GLFMEX.  OTHERWISE...MAINLY
CLEAR SKIES PREVAIL ACROSS THE AREA.  AT THE LOWER
LEVELS...POST-FRONTAL NLY FLOW IS QUICKLY VEERING AS A SURFACE
RIDGE MOVES ACROSS THE CENTRAL GLFMEX.  RESULTING RETURN FLOW IS
NOW PRESENT IN EARNEST ACROSS THE W GLFMEX AND IS EXPECTED TO
INCREASE DURING THE WEEKEND AHEAD OF DEVELOPING LOW PRESSURE
OVER THE CENTRAL UNITED STATES.  NEXT FRONTAL SYSTEM WILL
APPROACH THE AREA ON MONDAY WITH INCREASING CLOUDINESS AND
POSSIBLE SHOWERS/THUNDERSTORMS IN ADVANCE.

CARIBBEAN SEA...
LITTLE CHANGE OVER THE CARIBBEAN WATERS DURING THE LAST 24 HOURS
WITH A WELL-DEFINED MIDDLE TO UPPER LEVEL RIDGE EXTENDING E/W
OVER N PORTIONS OF S AMERICA ALONG 10N.  RESULTING FLOW ALOFT IS
PRIMARILY ZONAL WITH LITTLE UPSTREAM MOISTURE ADVECTION.  LOW
LEVEL MOISTURE ALSO REMAINS LARGELY LIMITED CONTRIBUTING TO THE
ABSENCE OF SHOWERS SAVE THE NW CARIBBEAN WHERE WIDELY SCATTERED
ACTIVITY ACCOMPANIES A WEAKENING STATIONARY FRONT EXTENDING FROM
CENTRAL CUBA TO N BELIZE.  THE FRONT SHOULD WEAKEN FAIRLY
RAPIDLY THIS AFTERNOON AND TONIGHT.  HOWEVER...A WEAKNESS IN THE
LOW LEVEL RIDGE CREATED BY THE FRONT WILL ALLOW SOME MOISTURE
FROM S AMERICA TO PUSH NWD TOWARD HISPANIOLA.  THIS SHOULD
ENHANCE SHOWER ACTIVITY OVER THE CENTRAL CARIBBEAN SUN AND
MONDAY ESPECIALLY ALONG THE TAIL END OF AN ATLC COLD FRONT WHICH
WILL MOVE ACROSS HISPANIOLA LATE SUN.

ATLANTIC OCEAN...
HIGHLY AMPLIFIED TROUGH-RIDGE-TROUGH PATTERN PREVAILS OVER THE
MAJORITY OF THE SUBTROPICAL ATLC WITH A DEEP-LAYERED LOW OVER
THE SE COAST OF THE UNITED STATES...RIDGE EXTENDING FROM THE E
CARIBBEAN NEWD 32N55W...AND A SECOND DEEP-LAYERED LOW OVER THE E
ATLC NEAR 31N36W.  AT THE SURFACE....1005 MB OCCLUDED LOW OFF
THE COAST OF THE CAROLINAS EXTENDS A COLD FRONT INTO THE AREA
NEAR 31N72W OVER THE CENTRAL BAHAMAS WHERE IT BEGINS DISSIPATING
OVER CENTRAL CUBA.   LARGE AREA OF SCATTERED SHOWERS/
THUNDERSTORMS ARE OCCURRING OUT AHEAD OF THE FRONT N OF 24N
BETWEEN 64W-71W.   WRAP-AROUND MOISTURE IS ALSO PRODUCING WIDELY
SCATTERED SHOWERS BEHIND THE FRONT MAINLY N OF 25N TO 80W.  THE
FRONT SHOULD WEAKEN TODAY AS IT MOVES EWD EXTENDING FROM BERMUDA
TO E CUBA AROUND MIDNIGHT.   HOWEVER...A SECONDARY PUSH SHOULD
REINFORCE THE FRONT SUN AND MON HELPING TO MAINTAIN SCATTERED
SHOWERS/THUNDERSTORMS ALONG AND TO THE EAST OF THE BOUNDARY.  A
SECOND AREA OF ACTIVE WEATHER EXISTS OVER THE E ATLC IN
ASSOCIATION WITH A 1014 MB LOW NEAR 31N36W AND TRAILING COLD
FRONT ALONG 27N34W 21N40W THEN DISSIPATING TO 18N50W.  SCATTERED
SHOWERS/THUNDERSTORMS ARE OCCURRING WITHIN 150 NM AHEAD OF FRONT
N OF 25N.  SIMILAR ACTIVITY ALSO NOTED N OF 30N BETWEEN
32W-37W.  EXPECT THIS SYSTEM TO DRIFT SLOWLY SWD OVER THE NEXT
DAY OR SO.

$$
RHOME



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