000 FXCA62 TJSJ 230222 AFDSJU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1022 PM AST SUN NOV 22 2009 .UPDATE...LATEST RADAR OBSERVATIONS SHOWED A FEW LINGERING THUNDERSTORMS ACROSS THE MONA PASSAGE EARLY THIS EVENING...WITH ONLY ISOLATED TO SCATTERED SHOWERS ACROSS THE REST OF THE COASTAL WATERS. NO SIGNIFICANT PRECIPITATION WAS DETECTED OVER LAND AREAS SO FAR THIS EVENING. SATELLITE PICTURES THIS EVENING INDICATED A RELATIVELY DRY AIR MASS ACROSS THE NORTHEASTERN CARIBBEAN EXTENDING EASTWARD ACROSS THE ATLANTIC FOR SEVERAL HUNDRED MILES. THIS DRY AIR WILL CONTINUE TO INHIBIT THE DEVELOPMENT OF SHOWERS ACROSS THE FA DURING THE NEXT FEW DAYS. HOWEVER...THE COMBINATION OF THE LIMITED LOW LEVEL MOISTURE WITH DAYTIME HEATING AND LOCAL TERRAIN EFFECTS WILL INDUCE THE DEVELOPMENT OF SOME AFTERNOON SHOWERS AND A FEW SHORT LIVED THUNDERSTORMS ACROSS WESTERN AND WESTERN INTERIOR SECTIONS OF PUERTO RICO DURING THE AFTERNOON. && .SYNOPSIS...A QUIET WEATHER PATTERN IS IN STORE FOR THE FA FOR THE NEXT SEVERAL DAYS...WITH ONLY LIMITED AFTERNOON SHOWER DEVELOPMENT EXPECTED OVER THE INTERIOR AND WESTERN SECTIONS OF PUERTO RICO EACH DAY...AND A FEW SHOWERS ACROSS THE VIRGIN ISLANDS AND EASTERN SECTIONS OF PUERTO RICO DURING THE OVERNIGHT AND EARLY MORNING HOURS. && .AVIATION...MOSTLY VFR CONDITIONS WILL CONTINUE ACROSS ALL OF THE LOCAL TAF SITES OVERNIGHT AND AT LEAST THROUGH 23/0400Z. THIS WILL BE FOLLOWED BY SOME PASSING SHRA IN AND AROUND TJSJ...TISX... TIST...TNCM...AND TKPK FROM 23/0400Z-23/1100Z. VA AND GAS EMISSIONS CONTINUE TO EXTEND FROM TRPG...BUT LOW LEVEL STEERING...NOW MORE FROM THE EAST DURING THE NEXT 24 HRS...WILL MAINTAIN THE ASH/GAS EMISSIONS WELL SOUTH OF LOCAL FLYING AREA. && .PREV DISCUSSION... /ISSUED 247 PM AST SUN NOV 22 2009/ SYNOPSIS...A FAIRLY QUIET WEATHER WEEK IS IN STORE FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS...WITH LIMITED AFTERNOON SHOWER DEVELOPMENT EXPECTED OVER THE INTERIOR AND WESTERN SECTIONS OF PUERTO RICO EACH DAY...AND A FEW NOCTURNAL SHOWERS EXPECTED ACROSS THE VIRGIN ISLANDS AND EASTERN SECTIONS OF PUERTO RICO DURING THE OVERNIGHT AND EARLY MORNING HOURS. DISCUSSION...THE WINDS HAVE BEGUN TO SHIFT TO A MORE EASTERLY DIRECTION THIS AFTERNOON IN RESPONSE TO AN AREA WEAK AREA OF HIGH PRESSURE BEGINNING TO BUILD ACROSS THE SOUTHWESTERN ATLANTIC. THIS IS HELPING TO STEER EMISSIONS FROM MONTSERRAT SOUTH OF THE LOCAL ISLANDS THIS AFTERNOON. WITH A RETURN TO A MORE TYPICAL EAST NORTHEASTERLY WIND FLOW FOR THE NEXT FEW DAYS ALONG WITH CONTINUED RIDGING IN THE MID TO UPPER LEVELS OF THE ATMOSPHERE...EXPECT FAIRLY LIMITED SHOWER ACTIVITY EACH AFTERNOON...WITH THE BEST CHANCE FOR SHOWERS CONFINED TO THE INTERIOR AND WESTERN SECTIONS OF THE ISLAND. WHILE THERE COULD BE AN INCREASE IN SHOWER ACTIVITY TOWARDS THE END OF THE WEEK AS THE WINDS SHIFT BACK TO A MORE MOIST SOUTHEASTERLY DIRECTION...THE NEXT MAIN WEATHER FEATURE APPEARS TO BE ABOUT A WEEK AWAY...IN THE FORM A WEAK FRONTAL BOUNDARY DROPPING DOWN FROM THE NORTH. AVIATION...TEMPO MVFR AND POSSIBLY BRIEF IFR CONDS WILL REMAIN LIKELY EN ROUTE TO AND AROUND TJBQ AND TJMZ THROUGH 22/22Z. VFR CONDS WILL PREVAIL ELSEWHERE OVERNIGHT AND AT LEAST THROUGH 23/04Z. THIS WILL BE FOLLOWED BY PROB30 OF PASSING SHRA IN AND AROUND TJSJ... TISX... TIST...TNCM...AND TKPK FM 23/04Z-23/11Z. VA AND GAS EMISSIONS CONTINUE TO EXTEND FM TRPG...BUT LOW LEVEL STEERING NOW MORE FROM THE EAST DURG THE NEXT 24 HRS. THIS SHOULD KEEP ASH/GAS EMISSIONS WELL SOUTH OF LOCAL FLYING AREA. && .PRELIMINARY POINT TEMPS/POPS... SJU 76 87 76 85 / 40 40 20 30 STT 78 87 77 86 / 40 40 20 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && $$ 06/72