000 AXNT20 KNHC 022349 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN JUL 02 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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. ...TROPICAL WAVES... W ATLC TROPICAL WAVE IS ALONG 55W S OF 16N MOVING W 20 KT. THIS IS A WELL-ORGANIZED WAVE THAT HAS A DISTINCTIVE V-SHAPE ON SATELLITE AND PLENTY OF TSTM ACTIVITY...THOUGH WLY FLOW ALOFT SHOULD INHIBIT ANY TROPICAL DEVELOPMENT. SHOWERS AND TSTM CHANCES IN THE WINDWARD ISLANDS WILL INCREASE OVERNIGHT... OVERSPREADING THE REST OF THE LEEWARDS BY TOMORROW...THOUGH THE BEST CHANCE OF RAIN SHOULD BE S OF 15N. TUE LOOKS TO BE THE DAY WITH THE HIGHEST CHANCE OF RAIN IN PUERTO RICO. A GALE MAY OCCUR NEAR/BEHIND THE WAVE AS IT MOVES INTO THE CENTRAL CARIBBEAN FOR WED. SCATTERED WEAK/MODERATE CONVECTION IS FROM 10N-14N BETWEEN 52W-58W. CENTRAL CARIBBEAN TROPICAL WAVE IS ALONG 73W/74W S OF 11N MOVING W NEAR 20 KT. ANY EFFECTS FROM THIS WAVE ARE CONFINED TO COLOMBIA IN THE FORM OF ISOLATED SHOWERS/TSTMS. A HIGH-AMPLITUDE TROPICAL WAVE IS OVER YUCATAN ALONG 88W/89W S OF 20N MOVING W NEAR 20 KT. THIS WAVE IS LIKELY RESPONSIBLE FOR A LARGE BLOWUP OVER TSTMS OVER THE NORTHERN PART OF CENTRAL AMERICA N OF 16N AND OVER WESTERN YUCATAN TONIGHT. THESE TSTMS SHOULD MOVE OFFSHORE INTO THE BAY OF CAMPECHE SHORTLY AND DIE OUT OVERNIGHT. ...ITCZ... ITCZ AXIS IS ALONG 11N15W 7N25W 7N40W 11N54W 10N60W. ISOLATED MODERATE WITHIN 90 NM OF 5N33W MAY BE RELATED TO A WEAK TROPICAL WAVE THAT COULD BE ANALYZED ON THE NEXT MAP. ISOLATED WEAK/MODERATE CONVECTION IS FROM 7N-13N E OF 22W ALSO PROBABLY ASSOCIATED WITH A TROPICAL WAVE WHICH COULD BE ANALYZED ON THE NEXT MAP. OVERALL ITCZ CONVECTION IS QUITE WEAK OWING TO A STRONGLY NEGATIVE (SINKING) PHASE OF THE MADDEN-JULIAN OSCILLATION. ...DISCUSSION... GULF OF MEXICO... UPPER HIGH PRESSURE IS SITUATED OVER THE GULF WITH AXIS FROM THE YUCATAN CHANNEL TO SE TEXAS. THIS IS QUITE A DIRTY HIGH AROUND THE EDGES HOWEVER WITH PLENTY OF TSTMS IN THE NW AND E GULF. THE FIRST AREA IS BEING ASSISTED BY A WEAK SURFACE TROUGH ALONG 95W/96W AND UPPER DIFFLUENCE PARTIALLY DUE TO AN UPPER LOW OVER CENTRAL TEXAS WITH SCATTERED MODERATE CONVECTION N OF 25N W OF 89W. THE NORTHERN PORTION OF A WAVE.. NOW A WEAK TROUGH OVER CENTRAL FLORIDA ASSISTED THE DEVELOPMENT OF SCATTERED MODERATE CONVECTION OVER MUCH OF THE PENINSULA OF FLORIDA BUT IS NOW WEAKENING WITH OUTFLOW BOUNDARIES LIMITING THE LAND-BASED INSTABILITY. A FEW TSTMS REMAIN IN DEEP S FLORIDA W OF MIAMI. RELATIVELY WET PATTERN SHOULD CONTINUE FOR TEXAS/LOUISIANA AND FLORIDA AS PRECIPITABLE WATER VALUES REMAIN HIGH. AT THE SURFACE.. HIGH PRESSURE RIDGE N OF THE AREA CONTINUES TO GIVE ELY FLOW OF ABOUT 10-15 KT OVER MUCH OF THE REGION. CARIBBEAN SEA... RIDGING CONTROLS THE NW CARIBBEAN WITH A DEEP TROUGH EXTENDING FROM HISPANIOLA TO NW COLOMBIA THROUGHOUT THE CENTRAL CARIBBEAN. WLY FLOW ALOFT CONTROLS THE E CARIBBEAN FROM A SOUTHWARD- DISPLACED RIDGE OVER NE S AMERICA. MODERATE/STRONG SUBSIDENCE IS LIMITING TSTMS OVER WATER SUBSTANTIALLY E OF 81W WITH AREAS IN THE GREATER ANTILLES W OF PUERTO RICO SEEING MORE TYPICAL AFTERNOON TSTMS. UPPER TROUGH HAS DRIVEN THE ITCZ FARTHER S THAN AVERAGE WITH A NOTABLE ABSENCE OF TSTMS IN THE SW CARIBBEAN...MOSTLY NOW OVER PANAMA AND SOUTHWARD. RELATIVELY MOIST ENVIRONMENT SHOULD KEEP DIURNAL TSTMS OVER THE GREATER ANTILLES AND CENTRAL AMERICA WITH THE UPPER TROUGH FORECAST TO REMAIN NEARLY STATIONARY. INCREASING MOISTURE IS LIKELY FOR TOMORROW FOR THE E CARIBBEAN WITH A TROPICAL WAVE ALONG WITH A TRADE WIND SURGE BEHIND THE WAVE... POSSIBLY STRENGTHENING TO NEAR GALE FORCE IN THE CENTRAL CARIBBEAN WITH A STRONG ATLC RIDGE BUILDING IN FOR MIDWEEK. ATLANTIC OCEAN... RIDGING COVERS THE W ATLC WITH SOME UPPER DIFFLUENCE SUPPORTING ISOLATED SHOWERS/TSTMS N OF 25N W OF 70W. PLENTY OF HIGH CLOUDS ARE CAUSING MOSTLY CLOUDY SKIES IN THAT REGION. NARROW UPPER TROUGH EXTENDS FROM JUST E OF BERMUDA TO 25N66W SOUTHWARD TO HISPANIOLA WITH A FEW HIGH CLOUDS ALONG THE TROUGH AXIS. MOST SIGNIFICANT FEATURE IS A STRONG MID/UPPER LOW NEAR 26N47W MOVING NORTHWARD. LARGE CIRCULATION OF THE LOW EXTENDS SOUTHWARD TO 18N WITH WLY FLOW IN THE TROPICAL ATLC S OF THE LOW W OF 45W. THIS STRONG MID-OCEANIC TROUGH IS MUCH DEEPER-THAN-AVERAGE FOR EARLY JULY.. PROBABLY ASSOCIATED WITH THE NEGATIVE MJO. THE WLY FLOW ALOFT HOWEVER IS ENHANCING SHOWERS/TSTMS WITH A WAVE APPROACHING THE LESSER ANTILLES AND OVER NORTHERN S AMERICA. IN THE E ATLC... BROAD UPPER TROUGH IS ALONG 20W N OF 26N CAUSING A WESTWARD-DISPLACEMENT OF THE SUBTROPICAL HIGH.. 1030 MB NEAR 36N46W. STRONGER-THAN-AVERAGE TRADES PERSIST IN THE TRADEWIND BELT S OF 20N W OF 30W N OF THE ITCZ... ONE REASON ATLC WATERS HAVEN'T WARMED AS MUCH AS LAST YEAR. ALOFT... RIDGING IS FROM W MAURITANIA TO 17N40W BRINGING PLENTY OF ELY WINDS IN THE E TROPICAL ATLC. $$ BLAKE