[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 222352
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON APR 22 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 7N12W ALONG 4N14W TO 3N17W WHERE THE ITCZ BEGINS AND
CONTINUES ALONG 4N35W 2N44W TO INLAND OVER SOUTH AMERICA NEAR
1N50W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM
3N TO THE EQUATOR E OF 6W TO ACROSS THE PRIME MERIDIAN. CLUSTERS
OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 90
NM EITHER SIDE OF THE ITCZ BETWEEN 20W-34W AND WITHIN 60 NM
ALONG THE COAST OF SOUTH AMERICA N OF 2N W OF 57W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH EXTENDS FROM THE E CONUS TO OVER THE FLORIDA
PENINSULA SUPPORTING A REMNANT SURFACE TROUGH THAT EXTENDS FROM
THE W ATLC ACROSS FLORIDA BETWEEN BOCA RATON TO EVERGLADES CITY
THEN TO 25N83W. THIS UPPER TROUGH COUPLED WITH AN UPPER RIDGE
ANCHORED IN THE E PACIFIC REGION IS GIVING THE GULF W-NW FLOW
ALOFT. A SURFACE TROUGH REMAINS IN THE CENTRAL GULF EXTENDING AT
22/2100 UTC FROM 28N90W TO 24N88W. WATER VAPOR IMAGERY INDICATED
STRONG SUBSIDENCE AND DRY STABLE AIR OVER THE N GULF...THUS NO
SHOWER ACTIVITY IS ASSOCIATED WITH THIS SURFACE TROUGH.
SCATTERED LOW CLOUDS DOT MOST OF THE NE GULF BUT WITH LIMITED
SHOWER ACTIVITY. A BROAD SURFACE RIDGE COVERS THE N GULF
ANCHORED WELL N OF THE DISCUSSION AREA. SURFACE TROUGH OVER THE
CENTRAL GULF WILL SLOWLY DISSIPATE THROUGH TUE. A COLD FRONT
WILL MOVE INTO THE NW GULF WED WEAKEN FROM W FLORIDA TO W
CENTRAL GULF THU THEN BECOME STATIONARY AND DISSIPATE OVER THE
NE GULF FRI.

CARIBBEAN SEA...
AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION COVERS THE S
GULF OF MEXICO INTO THE W CARIBBEAN. A SECOND UPPER RIDGE
ANCHORED IN THE TROPICAL ATLC COVERS THE FAR SE CARIBBEAN
INDUCING A BROAD UPPER TROUGH BETWEEN THAT EXTENDS FROM
HISPANIOLA TO PANAMA. AFTERNOON SHOWERS/ISOLATED THUNDERSTORMS
ARE DEVELOPING INLAND OVER CUBA...HAITI...AND JAMAICA. THE TRADE
WINDS ARE ENHANCING SCATTERED SHOWERS GENERATED BY THE UPPER
TROUGH OVER THE SE CARIBBEAN FROM 11N-15N E OF 67W TO OVER THE
WINDWARD ISLANDS. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN
WITH MOSTLY CLEAR SKIES THIS EVENING. BROAD SURFACE RIDGE IN THE
W AND CENTRAL ATLC WILL SLIDE E THROUGH WED AS A BROAD TROUGH
DEVELOPS N OF THE AREA ALONG 70W. MODERATE TRADE WINDS WILL
PERSIST ACROSS MOST OF THE REGION THROUGH SAT.

ATLANTIC OCEAN...
AN UPPER TROUGH EXTENDS FROM OVER THE E CONUS OVER THE FLORIDA
PENINSULA COVERING THE E GULF OF MEXICO INTO THE W ATLC AND
SUPPORTING A REMNANT SURFACE TROUGH THAT EXTENDS AT 22/2100 UTC
THROUGH 32N76W TO ACROSS FLORIDA NEAR BOCA RATON. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE OVER S FLORIDA WITHIN 45 NM
OF THE SURFACE TROUGH. THE UPPER RIDGE OVER THE CARIBBEAN
EXTENDS A RIDGE AXIS INTO THE W ATLC FROM E CUBA TO BEYOND
32N60W PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS N OF 23N BETWEEN 71W-78W. A
SURFACE RIDGE DOMINATES THE REMAINDER OF THE W ATLC INTO THE
CENTRAL ATLC W OF 50W ANCHORED WELL N OF THE DISCUSSION AREA. A
BROAD UPPER TROUGH IS OVER E/CENTRAL ATLC WITH THE TROUGH AXIS
EXTENDING FROM A PAIR OF UPPER LOWS NEAR 32N35W AND 31N41W TO
THEN SW TO 21N55W SUPPORTING A 1007 MB SURFACE LOW NEAR 30N36W
AND A SURFACE TROUGH THAT EXTENDS ALONG 25N40W TO 22N47W.
SCATTERED SHOWERS ARE N OF 30N BETWEEN 27W-37W. A WEAK SURFACE
TROUGH IS TO THE E EXTENDING FROM 32W22W TO OVER THE CANARY
ISLANDS NEAR 28N16W. W ATLC SURFACE TROUGH WILL DRIFT E THROUGH
FRI AND SLOWLY WEAKEN. A WEAK COLD FRONT IS EXPECTED TO REACH N
FLORIDA FRI.

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

$$
PAW


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