[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271053
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED 27 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1030 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N1W 2N35W 2N60W.   SCATTERED
MODERATE/ISOLATED STRONG CONVECTION FROM 1N-6N BETWEEN 18W-21W.
SCATTERED MODERATE CONVECTION FROM 1N-5N BETWEEN 27W-35W.

...DISCUSSION...

GULF OF MEXICO...
A RATHER STORMY PATTERN CONTINUES OVER THE E GLFMEX AND FLORIDA
COURTESY OF A HIGH AMPLITUDE TROUGH EXTENDING FROM THE GREAT
LAKES INTO THE N CENTRAL GLFMEX AND ATTENDANT COLD FRONT FROM
THE BIG BEND AREA OF FLORIDA TO THE COAST OF MEXICO JUST S OF
TAMPICO. CURRENTLY...THE STRONGEST CONVECTION IS MOVING OVER THE
E GLFMEX FROM 24N-26N E OF 86W ACROSS FLORIDA S OF LAKE
OKEECHOBEE.  WATER VAPOR IMAGERY INDICATES THE UPPER TROUGH AND
BEST DYNAMICS ARE BEGINNING TO LIFT NEWD...AND
SHOWERS/THUNDERSTORMS SHOULD GRADUALLY WEAKEN TODAY AS THEY
CONTINUE SWD.  COLD FRONT WILL CONTINUE TO SWEEP ACROSS THE E
GLFMEX CLEARING S FLORIDA LATE TODAY WITH A QUICK SHOT OF
COOLER/DRIER AIR. POST-FRONTAL 1016 MB HIGH CURRENTLY OVER S
LOUISIANA WILL MOVE QUICKLY EWD ACROSS THE N GULF COAST REACHING
N FLORIDA BY THU MORNING.  THIS WILL ALLOW WINDS TO QUICKLY VEER
AND ONCE AGAIN ESTABLISH RETURN FLOW OVER THE W GULF BY LATE
THU.

CARIBBEAN SEA...
STRONG MIDDLE TO UPPER LEVEL RIDGING DOMINATES THE CARIBBEAN
WITH MEAN AXIS EXTENDING E/W ALONG 12N. THIS PATTERN IS
PRODUCING SUBSIDENCE AND A DRY/STABLE ENVIRONMENT ALOFT WHICH IS
EFFECTIVELY CAPPING DEEP CONVECTION OVER MOST OF THE AREA.
EARLIER CELLS OF MODERATE OVER S MEXICO IN ASSOCIATION WITH AN
APPROACHING UPPER TROUGH OVER THE GLFMEX HAVE DISSIPATED AS THE
TROUGH BEGINS TO LIFT NEWD.  IN FACT...NEARLY ALL OF THE
DYNAMICS ASSOCIATED WITH THE TROUGH WILL LIKELY PASS N OF THE
AREA WITH LITTLE OR NO DEEP CONVECTIVE ACTIVITY ALONG THE
ATTENDANT COLD FRONT WHICH WILL MOVE INTO THE NW CARIBBEAN LATE
TODAY.  LOW LEVEL MOISTURE POOLING ALONG THE FRONT MAY INITIALLY
PRODUCE WIDELY SCATTERED SHOWERS/ISOLATED THUNDERSTORM ALONG THE
FRONT ESPECIALLY OVER CUBA.  HOWEVER...THE FRONT WILL QUICKLY
WEAKEN WED NIGHT AND THU.  ELSEWHERE...AN AREA OF LOW LEVEL
MOISTURE MOVING INTO THE E CARIBBEAN IS PRODUCING WIDELY
SCATTERED TO LOCALLY SCATTERED SHOWERS AND A FEW ISOLATED
THUNDERSTORMS E OF 70W. THIS ACTIVITY SHOULD EXPAND WESTWARD
INTO THE CENTRAL CARIBBEAN DURING THE NEXT DAY OR SO.
FINALLY...CLOUDINESS AND SCATTERED SHOWERS SHOULD CONTINUE OVER
HISPANIOLA THROUGH THE END OF THE WEEK AS A FRONT MOVING OVER
THE W ATLC CLIPS THE ISLAND LATE THU AND FRIDAY.

ATLANTIC OCEAN...
A PROGRESSIVE LONGWAVE TROUGH CURRENTLY OVER THE E UNITED STATES
WITH ATTENDANT COLD FRONT MARCHING ACROSS THE GLFMEX WILL BE THE
PRIMARY WEATHER MAKER OVER THE NEXT FEW DAYS.  A LINE OF
SCATTERED SHOWERS/THUNDERSTORMS IN ADVANCE OF THE SYSTEM IS
ALREADY AFFECTING THE EXTREME W ATLC WITHIN 75 NM EITHER SIDE OF
A LINE FROM 32N76W SW ACROSS S FLORIDA.  EXPECT THIS ACTIVITY TO
STRENGTHEN DURING THE NEXT 12-24 HOUR AS A STRONG 130 KT
SUBTROPICAL JET ROUNDS THE BASE OF THE TROUGH TODAY AND THE COLD
MOVES OFF THE SE UNITED STATES COAST LATER THIS MORNING.  THE
FRONT WILL THEN SWEEP RAPIDLY EWD EXTENDING FROM BERMUDA TO
CENTRAL CUBA BY THU MORNING. ELSEWHERE OVER THE W TO CENTRAL
ATLC...BROAD UPPER LEVEL RIDGING PREVAILS WITH SUBSIDENCE
CREATING DRY/STABLE CONDITIONS ALOFT.  UPSTREAM MOISTURE IS
STREAMING UP AND OVER THE RIDGE LEAVING LITTLE CLOUDINESS OVER
THE AREA BETWEEN 50W-70W.  OVER THE E ATLC...A SERIES OF
SHORTWAVE TROUGHS DROPPING SEWD AROUND THE E PERIPHERY OF THE
AFOREMENTIONED RIDGE IS CARVING OUT A BROAD TROUGH PATTERN
BETWEEN 50W AND THE COAST OF AFRICA.  HOWEVER...THE AREA IS
LACKING SIGNIFICANT MOISTURE AND ONLY PATCHY HIGH CLOUDINESS IS
NOTED IN SATELLITE IMAGERY.  OVER THE TROPICAL ATLC...THE ITCZ
IS MOST ACTIVE E OF 35W.  EARLIER VISIBLE SATELLITE IMAGERY
SHOWS SOME DRY LOW LEVEL AIR AND POSSIBLE DUST MOVING OFF THE
COAST OF AFRICA WITH LEADING EDGE NEAR THE CAPE VERDE
ISLANDS.

$$
RHOME



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