000 AXNT20 KNHC 251119 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT JUN 25 2011 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS OFF THE W COAST OF AFRICA EXTENDING FROM 18N22W ACROSS THE CAPE VERDE ISLANDS TO 8N28W. THE WAVE IS MOVING W AT 10-15 KT. CYCLONIC SURFACE WINDS ARE ABOUT THE WAVE AXIS EVIDENT IN SATELLITE IMAGERY AND SATELLITE DERIVED WINDS. THE WAVE ALSO LIES W OF A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY...AS WELL AS AN INTRUSION INTO THE SAHARAN AIR LAYER. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS E OF THE WAVE AXIS FROM 5N-10N BETWEEN 19W-23W. A TROPICAL WAVE EXTENDS FROM 17N47W TO 11N50W IN THE CENTRAL TROPICAL ATLC MOVING W 10-15 KT. THE WAVE PRECEDES A SURGE OF ENHANCED MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. NO DEEP CONVECTION IS ASSOCIATED WITH THE WAVE. A TROPICAL WAVE IS MOVING WNW ACROSS THE NW CARIBBEAN ALONG 85W FROM 12N-20N NEAR 15 KT. THE WAVE LIES IN A LARGE AREA OF DEEP LAYER MOISTURE PRESENT ACROSS THE CENTRAL AND WRN CARIBBEAN BETWEEN 75W-87W. THE WAVE IS ALSO INTERACTING WITH THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS NICARAGUA TO NRN COLOMBIA. THIS INTERACTION ALONG WITH UPPER LEVEL SUPPORT AROUND AN UPPER TROUGH OVER THE FAR NW CARIBBEAN IS ENHANCING NUMEROUS MODERATE/STRONG FROM 10N-15N BETWEEN 78W-84W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 15N-18N BETWEEN 78W-85W... FROM 20N-22N BETWEEN 79W-84W JUST S OF CUBA...AND FROM 15N-17N BETWEEN 86W-90W ACROSS NRN HONDURAS AND GUATEMALA. EXPECT CONTINUED HEAVY SHOWER/THUNDERSTORM ACTIVITY TO IMPACT THE CENTRAL/NW CARIBBEAN AS THE WAVE PROGRESSES WNW. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 22N ALONG 19N10W TO 20N16W. IT PICKS UP W OF A TROPICAL WAVE CONTINUING ALONG 7N30W TO 5N34W. THE ITCZ AXIS CONTINUES FROM 5N34W ALONG 4N45W 3N57W. SCATTERED MODERATE/STRONG CONVECTION WITHIN 90 NM S OF THE AXIS BETWEEN 30W-37W...AND WITHIN 90 NM N...45 NM S OF THE AXIS BETWEEN 42W-47W. ...DISCUSSION... GULF OF MEXICO... ACTIVE WEATHER CONTINUES ACROSS THE GULF OF MEXICO DUE TO AN UPPER LEVEL TROUGH EXTENDING ACROSS THE FAR ERN CONUS WITH THE TAIL END CONTINUING FROM SRN GEORGIA TO JUST E OF THE SRN TIP OF TEXAS. AN UPPER LEVEL RIDGE IS S OF THE TROUGH EXTENDING FROM CENTRAL MEXICO ACROSS SRN FLORIDA. THIS PATTERN CREATES AN AREA OF DIFFLUENCE ALOFT SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 21N-26N BETWEEN 94W-99W...AND FROM 26N-28N BETWEEN 83W-88W. ISOLATED SHOWER ACTIVITY IS BETWEEN THESE TWO AREAS FROM 25N-30N BETWEEN 86W-94W. ISOLATED SHOWERS ALSO REMAIN ACROSS PORTIONS OF THE FLORIDA PENINSULA WHERE MOIST CONDITIONS DOMINATE. THE REMAINDER OF THE BASIN...MAINLY THE FAR NW PORTION AND SE PORTION...IS UNDER MOSTLY FAIR CONDITIONS DUE TO DRIER AIR ALOFT. WHILE THE MAIN UPPER TROUGH IS EXPECTED TO MOVE EWD...MODEL GUIDANCE INDICATES A SHORTWAVE UPPER TROUGH WILL REMAIN ACROSS THE N CENTRAL GULF WHICH WILL LIKELY CONTINUE TO SUPPORT SHOWER/THUNDERSTORM ACTIVITY ACROSS THE BASIN OVER THE NEXT COUPLE OF DAYS. CARIBBEAN SEA... A TROPICAL WAVE MOVING ACROSS THE WRN CARIBBEAN IS FLARING UP SHOWER/THUNDERSTORM ACTIVITY ACROSS MUCH OF THE CENTRAL/WRN PORTIONS OF THE BASIN THIS MORNING. SEE TROPICAL WAVE SECTION ABOVE FOR MORE DETAILS. THE WAVE IS INTERACTING WITH BOTH THE MONSOON TROUGH EXTENDING FROM THE E PACIFIC ACROSS NICARAGUA TO NRN COLOMBIA...AND AN UPPER LEVEL TROUGH EXTENDING FROM ERN CUBA TO GUATEMALA. WEAK UPPER RIDGING IS ACROSS THE CENTRAL CARIBBEAN WHILE BROAD UPPER TROUGHING IS OVER THE ERN CARIBBEAN EXTENDING FROM AN UPPER LEVEL LOW IN THE ATLC N OF THE DOMINICAN REPUBLIC. MOSTLY FAIR CONDITIONS ARE ACROSS THE ERN CARIBBEAN WITH ONLY A FEW ISOLATED TRADEWIND SHOWERS IN 15 KT ELY WINDS. EXPECT CONTINUED SHOWER ACTIVITY ACROSS THE CENTRAL/WRN CARIBBEAN AS THE TROPICAL WAVE MOVES WNW OVER THE NEXT 24 HRS. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH OVER THE ERN CONUS CONTINUES TO MOVE EWD AND HAS ALMOST EMERGED OFF THE COAST SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ALONG A LINE FROM THE NW BAHAMAS NEAR 26N77W ALONG 31N76W 34N72W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 90 NM EITHER SIDE OF THE LINE OF STRONG ACTIVITY. A FEW ISOLATED SHOWERS ARE FROM 18N-28N BETWEEN 61W-70W DUE TO AN UPPER LEVEL LOW NEAR 24N69W. A WEAK UPPER LEVEL RIDGE IS TO THE E ALONG 59W SANDWICHED BETWEEN THE UPPER LEVEL LOW AND ANOTHER WEAK UPPER LEVEL TROUGH IN THE CENTRAL ATLC ALONG 49W. THE ERN ATLC IS DOMINATED BY A WEAK SURFACE RIDGE CENTERED AROUND A PAIR OF 1021 MB HIGHS NEAR 28N51W AND 33N48W MAINTAINING FAIR CONDITIONS ACROSS THIS AREA. ALOFT...AN UPPER LEVEL RIDGE IS CENTERED NEAR 32N52W SUPPORTING THE SURFACE RIDGE. ANOTHER UPPER LEVEL RIDGE DOMINATES THE TROPICAL ATLC CENTERED NEAR 14N34W...WHILE AN UPPER LEVEL TROUGH EXTENDS FROM THE AZORES ISLANDS TO NEAR 24N36W 20N53W. A LARGE SAHARAN AIR LAYER CONSISTING OF DRY AND DUSTY AIR IS ACROSS THE ERN TROPICAL ATLC SURROUNDING THE TROPICAL WAVE THAT RECENTLY MOVED OFF THE COAST OF AFRICA FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 251119 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT JUN 25 2011 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS OFF THE W COAST OF AFRICA EXTENDING FROM 18N22W ACROSS THE CAPE VERDE ISLANDS TO 8N28W. THE WAVE IS MOVING W AT 10-15 KT. CYCLONIC SURFACE WINDS ARE ABOUT THE WAVE AXIS EVIDENT IN SATELLITE IMAGERY AND SATELLITE DERIVED WINDS. THE WAVE ALSO LIES W OF A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY...AS WELL AS AN INTRUSION INTO THE SAHARAN AIR LAYER. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS E OF THE WAVE AXIS FROM 5N-10N BETWEEN 19W-23W. A TROPICAL WAVE EXTENDS FROM 17N47W TO 11N50W IN THE CENTRAL TROPICAL ATLC MOVING W 10-15 KT. THE WAVE PRECEDES A SURGE OF ENHANCED MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. NO DEEP CONVECTION IS ASSOCIATED WITH THE WAVE. A TROPICAL WAVE IS MOVING WNW ACROSS THE NW CARIBBEAN ALONG 85W FROM 12N-20N NEAR 15 KT. THE WAVE LIES IN A LARGE AREA OF DEEP LAYER MOISTURE PRESENT ACROSS THE CENTRAL AND WRN CARIBBEAN BETWEEN 75W-87W. THE WAVE IS ALSO INTERACTING WITH THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS NICARAGUA TO NRN COLOMBIA. THIS INTERACTION ALONG WITH UPPER LEVEL SUPPORT AROUND AN UPPER TROUGH OVER THE FAR NW CARIBBEAN IS ENHANCING NUMEROUS MODERATE/STRONG FROM 10N-15N BETWEEN 78W-84W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 15N-18N BETWEEN 78W-85W... FROM 20N-22N BETWEEN 79W-84W JUST S OF CUBA...AND FROM 15N-17N BETWEEN 86W-90W ACROSS NRN HONDURAS AND GUATEMALA. EXPECT CONTINUED HEAVY SHOWER/THUNDERSTORM ACTIVITY TO IMPACT THE CENTRAL/NW CARIBBEAN AS THE WAVE PROGRESSES WNW. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 22N ALONG 19N10W TO 20N16W. IT PICKS UP W OF A TROPICAL WAVE CONTINUING ALONG 7N30W TO 5N34W. THE ITCZ AXIS CONTINUES FROM 5N34W ALONG 4N45W 3N57W. SCATTERED MODERATE/STRONG CONVECTION WITHIN 90 NM S OF THE AXIS BETWEEN 30W-37W...AND WITHIN 90 NM N...45 NM S OF THE AXIS BETWEEN 42W-47W. ...DISCUSSION... GULF OF MEXICO... ACTIVE WEATHER CONTINUES ACROSS THE GULF OF MEXICO DUE TO AN UPPER LEVEL TROUGH EXTENDING ACROSS THE FAR ERN CONUS WITH THE TAIL END CONTINUING FROM SRN GEORGIA TO JUST E OF THE SRN TIP OF TEXAS. AN UPPER LEVEL RIDGE IS S OF THE TROUGH EXTENDING FROM CENTRAL MEXICO ACROSS SRN FLORIDA. THIS PATTERN CREATES AN AREA OF DIFFLUENCE ALOFT SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 21N-26N BETWEEN 94W-99W...AND FROM 26N-28N BETWEEN 83W-88W. ISOLATED SHOWER ACTIVITY IS BETWEEN THESE TWO AREAS FROM 25N-30N BETWEEN 86W-94W. ISOLATED SHOWERS ALSO REMAIN ACROSS PORTIONS OF THE FLORIDA PENINSULA WHERE MOIST CONDITIONS DOMINATE. THE REMAINDER OF THE BASIN...MAINLY THE FAR NW PORTION AND SE PORTION...IS UNDER MOSTLY FAIR CONDITIONS DUE TO DRIER AIR ALOFT. WHILE THE MAIN UPPER TROUGH IS EXPECTED TO MOVE EWD...MODEL GUIDANCE INDICATES A SHORTWAVE UPPER TROUGH WILL REMAIN ACROSS THE N CENTRAL GULF WHICH WILL LIKELY CONTINUE TO SUPPORT SHOWER/THUNDERSTORM ACTIVITY ACROSS THE BASIN OVER THE NEXT COUPLE OF DAYS. CARIBBEAN SEA... A TROPICAL WAVE MOVING ACROSS THE WRN CARIBBEAN IS FLARING UP SHOWER/THUNDERSTORM ACTIVITY ACROSS MUCH OF THE CENTRAL/WRN PORTIONS OF THE BASIN THIS MORNING. SEE TROPICAL WAVE SECTION ABOVE FOR MORE DETAILS. THE WAVE IS INTERACTING WITH BOTH THE MONSOON TROUGH EXTENDING FROM THE E PACIFIC ACROSS NICARAGUA TO NRN COLOMBIA...AND AN UPPER LEVEL TROUGH EXTENDING FROM ERN CUBA TO GUATEMALA. WEAK UPPER RIDGING IS ACROSS THE CENTRAL CARIBBEAN WHILE BROAD UPPER TROUGHING IS OVER THE ERN CARIBBEAN EXTENDING FROM AN UPPER LEVEL LOW IN THE ATLC N OF THE DOMINICAN REPUBLIC. MOSTLY FAIR CONDITIONS ARE ACROSS THE ERN CARIBBEAN WITH ONLY A FEW ISOLATED TRADEWIND SHOWERS IN 15 KT ELY WINDS. EXPECT CONTINUED SHOWER ACTIVITY ACROSS THE CENTRAL/WRN CARIBBEAN AS THE TROPICAL WAVE MOVES WNW OVER THE NEXT 24 HRS. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH OVER THE ERN CONUS CONTINUES TO MOVE EWD AND HAS ALMOST EMERGED OFF THE COAST SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ALONG A LINE FROM THE NW BAHAMAS NEAR 26N77W ALONG 31N76W 34N72W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 90 NM EITHER SIDE OF THE LINE OF STRONG ACTIVITY. A FEW ISOLATED SHOWERS ARE FROM 18N-28N BETWEEN 61W-70W DUE TO AN UPPER LEVEL LOW NEAR 24N69W. A WEAK UPPER LEVEL RIDGE IS TO THE E ALONG 59W SANDWICHED BETWEEN THE UPPER LEVEL LOW AND ANOTHER WEAK UPPER LEVEL TROUGH IN THE CENTRAL ATLC ALONG 49W. THE ERN ATLC IS DOMINATED BY A WEAK SURFACE RIDGE CENTERED AROUND A PAIR OF 1021 MB HIGHS NEAR 28N51W AND 33N48W MAINTAINING FAIR CONDITIONS ACROSS THIS AREA. ALOFT...AN UPPER LEVEL RIDGE IS CENTERED NEAR 32N52W SUPPORTING THE SURFACE RIDGE. ANOTHER UPPER LEVEL RIDGE DOMINATES THE TROPICAL ATLC CENTERED NEAR 14N34W...WHILE AN UPPER LEVEL TROUGH EXTENDS FROM THE AZORES ISLANDS TO NEAR 24N36W 20N53W. A LARGE SAHARAN AIR LAYER CONSISTING OF DRY AND DUSTY AIR IS ACROSS THE ERN TROPICAL ATLC SURROUNDING THE TROPICAL WAVE THAT RECENTLY MOVED OFF THE COAST OF AFRICA FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON