[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301749
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT APR 30 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS IS ANALYZED ALONG 5N8W 2N19W CROSSING THE EQUATOR NEAR
19W CONTINUING S OF THE EQUATOR TO INLAND OVER SOUTH AMERICA.
CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM THE
EQUATOR TO 3N BETWEEN 10W-16W WITH SMALL CLUSTERS FROM THE
EQUATOR TO 4N BETWEEN 21W-35W. CLUSTERS OF SCATTERED MODERATE/
ISOLATED STRONG CONVECTION ARE FROM S OF THE EQUATOR TO INLAND
OVER SW AFRICA E OF 10W ACROSS THE PRIME MERIDIAN AD FROM 2N-6N
BETWEEN 45W-49W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS AN
AXIS N OVER MEXICO COVERING THE GULF WITH NW FLOW ALOFT. A
STATIONARY FRONT REMAINS OVER THE SE GULF EXTENDING ACROSS
EXTREME S FLORIDA JUST S OF MIAMI N OF THE FLORIDA KEYS TO
24N84W GENERATING ISOLATED SHOWERS MAINLY INLAND OVER S FLORIDA
AND OVER THE FLORIDA KEYS. A SURFACE RIDGE IS BUILDING OVER THE
NE GULF GIVING THE GULF WATERS E TO SE FLOW. WATER VAPOR
SATELLITE IMAGERY SHOWS THE GULF COVERED WITH DRY STABLE AIR
ALOFT. HOWEVER...THE SURFACE FLOW IS BANKING LOW LEVEL CLOUDS
WITH ISOLATED SHOWERS OVER THE NW GULF N OF 27N W OF 91W.
VISIBLE SATELLITE IMAGERY SHOWS SIGNS OF SMOKE OVER THE W GULF
MAINLY W OF 90W WITH SURFACE AND SHIPS OBSERVATIONS INDICATING
SMOKE/HAZE/FOG FROM THE MANY FIRES OVER S MEXICO. THIS IS
LEAVING THE E GULF UNDER MOSTLY CLEAR SKIES THIS AFTERNOON.
SURFACE RIDGE IS EXPECTED TO REMAIN OVER THE NE GULF THROUGH
LATE MON. THE NEXT COLD FRONT WILL MOVE OFF TEXAS TUE AND EXTEND
FROM THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE WED.

CARIBBEAN SEA...
NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE CARIBBEAN THIS
AFTERNOON WITH WATER VAPOR SATELLITE IMAGERY SHOWING DRY STABLE
AIR ALOFT. THE SURFACE RIDGE OVER THE CENTRAL ATLC IS GIVING THE
CARIBBEAN LIGHT EASTERLY TRADE WINDS. REMNANT LOW LEVEL MOISTURE
REMAINS OVER THE E CARIBBEAN AND COUPLED WITH THE CONVERGENCE OF
THE WINDS AT THE SURFACE AND ALOFT ARE GENERATING SCATTERED
SHOWERS MAINLY FROM 13N-18N E OF 68W TO OVER THE LESSER
ANTILLES. THIS SAME TYPE OF SCENARIO IS PLAYING OUT OVER
NICARAGUA AND HONDURAS WITH SCATTERED SHOWERS DEVELOPING FROM
13N-16N BETWEEN 84W-87W. THIS IS LEAVING THE REMAINDER OF THE
CARIBBEAN UNDER FAIR WEATHER CONDITIONS THIS AFTERNOON. SURFACE
RIDGE OVER THE CENTRAL ATLC WILL WEAKEN TODAY AND SHIFT EAST.
LIGHT TRADE WINDS WILL CONTINUE TODAY BUILDING TO MODERATE TRADE
WINDS SUN THROUGH TUE THEN WILL PREVAIL THROUGH WED.

ATLANTIC OCEAN...
A DEEP LAYERED TROUGH EXTENDS FROM NEW ENGLAND STATES INTO THE W
ATLC SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA AT
30/1500 UTC NEAR 32N68W ALONG 27N75W ACROSS THE BAHAMAS TO
25N80W CONTINUING AS A STATIONARY BOUNDARY ACROSS S FLORIDA INTO
THE GULF OF MEXICO JUST S OF MIAMI. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE WITHIN 90/120 NM SE OF THE COLD FRONT. A WEAK
SURFACE RIDGE AND CLEAR SKIES ARE BEHIND THE FRONT. A BROAD
SURFACE RIDGE DOMINATES THE CENTRAL ATLC N OF 20N BETWEEN
30W-65W ANCHORED BY A 1030 MB HIGH N OF THE REGION NEAR 37N47W.
A BENIGN UPPER LOW REMAINS IN THE CENTRAL ATLC NEAR 30N55W WITH
A SECOND MORE SIGNIFICANT UPPER LOW IN THE E ATLC N OF THE
CANARY ISLANDS NEAR 34N18W SUPPORTING A 999 MB SURFACE LOW N OF
THE MADEIRA ISLANDS EXTENDING A SURFACE TROUGH INTO THE
DISCUSSION AREA NEAR 32N15W OVER THE CANARY ISLANDS ALONG 28N16W
TO 25N28W. ISOLATED SHOWERS ARE FROM THE CANARY ISLANDS
NORTHWARD BETWEEN THE W COAST OF AFRICA TO 18W LEAVING THE
REMAINDER OF THE ATLC WITH FAIR WEATHER THIS AFTERNOON. THE W
ATLC FRONT WILL DISSIPATE S OF 27N TONIGHT. SURFACE RIDGE WILL
BUILD IN BEHIND THIS FRONT AND PREVAIL SUN THROUGH TUE THEN
SHIFT E WED AS ANOTHER COLD FRONT MOVES OFF THE SE U.S. COAST.

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

$$
PAW





This weather bulletin was brought to you by:
www.nashvilleweather.net