000 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