[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280542
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT APR 28 2012

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN 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
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA ENTERING THE E
TROPICAL ATLC NEAR 9N13W TO 8N14W WHERE THE ITCZ AXIS CONTINUES
ALONG 4N21W 4N30W 3N41W THEN S OF THE EQUATOR NEAR 48W.
SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 75/90 NM EITHER
SIDE OF THE ITCZ BETWEEN 25W-30W. CLUSTERS OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION DOT THE AREA FROM 1N-6N
BETWEEN 11W-38W.

...DISCUSSION...

GULF OF MEXICO...
A VERY NARROW UPPER TROUGH EXTENDS FROM NE FLORIDA SSW ACROSS
THE E GULF INTO THE CARIBBEAN OVER NE YUCATAN PENINSULA/W
YUCATAN CHANNEL. A BROAD UPPER RIDGE DOMINATES THE REMAINDER OF
THE GULF WITH A RIDGE AXIS EXTENDING FROM THE E PACIFIC REGION
ACROSS MEXICO NEAR TAMPICO TO THE N GULF COAST NEAR THE
FLORIDA/ALABAMA BORDER. A SURFACE RIDGE EXTENDS FROM W ATLC
ACROSS THE GULF TO 93W WITH A 1019 MB HIGH OFF THE FLORIDA COAST
JUST N OF TAMPA. THIS SURFACE RIDGE CONTINUES TO PRODUCE
SOUTHERLY RETURN FLOW ACROSS MOST OF THE N GULF. MODERATE/STRONG
SUBSIDENCE AND DRY STABLE AIR COVERS MOST OF THE GULF GIVING THE
AREA CLEAR SKIES AGAIN TONIGHT. THE SURFACE RIDGE WILL LIFT N TO
ACROSS THE N COASTAL PLAINS ON SAT THEN SHIFT N OF AREA ON SUN.
A BROAD TROUGH WILL MOVE W INTO THE STRAITS OF FLORIDA SUN
CONTINUE W TO THE S CENTRAL GULF ON TUE BEFORE WEAKENING OVER
THE NW GULF WED.

CARIBBEAN SEA...
THE VERY NARROW UPPER TROUGH EXTENDS OVER THE FAR W CARIBBEAN
FROM THE E GULF OF MEXICO ACROSS THE NE YUCATAN PENINSULA/W
YUCATAN CHANNEL TO OVER HONDURAS. A BROAD UPPER RIDGE DOMINATES
THE REMAINDER OF THE CARIBBEAN BASIN E OF 83W ANCHORED OVER THE
WINDWARD ISLANDS. A WEAK SURFACE TROUGH EXTENDS FROM THE STRAITS
OF FLORIDA ACROSS CENTRAL CUBA NEAR 22N78W JUST E OF THE CAYMAN
ISLANDS TO 17N79W. THE UPPER RIDGE IS DRAWING TROPICAL MOISTURE
N ACROSS THE CARIBBEAN GENERATING SCATTERED SHOWERS BETWEEN
73W-84W WITH SCATTERED THUNDERSTORMS WITHIN 45/60 NM OF LINE
FROM 17N80W 19N83W TO 19N86W. THIS IS LEAVING THE E CARIBBEAN
UNDER MOSTLY CLEAR SKIES AGAIN TONIGHT. FRESH EASTERLY TRADE
WINDS COVER THE E INTO THE CENTRAL CARIBBEAN THROUGH SUN WHEN
THEY WILL DIMINISH SLIGHTLY THROUGH WED.

ATLANTIC OCEAN...
THE BROAD UPPER RIDGE OVER THE CARIBBEAN EXTENDS TO OVER THE W
AND CENTRAL ATLC S OF 32N W OF 45W ENHANCING SCATTERED SHOWERS
AND POSSIBLE ISOLATED THUNDERSTORMS S OF 26N TO OVER THE GREATER
ANTILLES BETWEEN 70W-81W. BENEATH THIS UPPER RIDGE IS A WEAK
SURFACE TROUGH THAT EXTENDS FROM 31N62W TO 25N66W. A SURFACE
RIDGE EXTENDS FROM THE CENTRAL ATLC W ACROSS THE W ATLC INTO THE
GULF OF MEXICO WITH A WEAKNESS IN THE IMMEDIATE VICINITY OF THE
ABOVE SURFACE TROUGH. THE UPPER TROUGH OVER THE E ATLC EXTENDS S
TO 10N E OF 40W SUPPORTING A COLD FRONT THAT ENTERS THE REGION
OFF MOROCCO AFRICA NEAR 30N10W E OF THE CANARY ISLANDS TO 15N19W
WITH A SURFACE TROUGH FURTHER S EXTENDING FROM 20N40W TO 14N42W.
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE MOSTLY
INLAND OVER AFRICA WITHIN 250 NM E OF THE COLD FRONT. SURFACE
RIDGE OVER THE W ATLC WILL SHIFT N TO ALONG 31N ON SAT THEN
WEAKEN AND SHIFT E SUN AHEAD OF A COLD FRONT THAT WILL PASS
THROUGH BERMUDA ON MON AND STALL ALONG 30N E OF 75W ON TUE. A
BROAD TROUGH S OF 25N ALONG 78W AMPLIFY OVER THE NW BAHAMAS ON
SUN AND DRIFT W THROUGH THE FLORIDA STRAITS THROUGH MON NIGHT.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
PAW





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