Expires:No;;106874 FPUS56 KEKA 222038 ZFPEKA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EUREKA CA 1230 PM PST MON FEB 22 2010 .SYNOPSIS...HIGH PRESSURE WILL BUILD BRIEFLY OVER THE REGION TODAY. A FRONT WILL BRING RAIN TO THE AREA ON TUESDAY...WITH THE THREAT OF SHOWERS CONTINUING THROUGH THE END OF THE WEEK. && .DISCUSSION...HIGH PRESSURE OVER THE REGION TODAY WILL MAINTAIN THE NICE LATE WINTER WEATHER BEFORE CLOUDS ASSOCIATED WITH THE NEXT FRONTAL SYSTEM INVADE THE SKIES FROM WEST TO EAST. CLOUD COVER WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON HOWEVER INITIAL RAINFALL AT THE COAST WILL HOLD OFF UNTIL AFTER MIDNIGHT...AND SHOULD NOT FALL IN EARNEST UNTIL CLOSER TO SUNRISE. AS THE FRONT MOVES ACROSS THE CWA TOMORROW RAIN WILL SPREAD INLAND LATER IN THE MORNING HOWEVER FREE AIR SNOW LEVELS SHOULD REMAIN WELL ABOVE PASS LEVEL. ONCE AGAIN THE TRICKY FORECAST WILL BE HOW MUCH COLD AIR RESIDES ACROSS THE INTERIOR VALLEYS TONIGHT AND THE RESULTING THREAT OF LOW TRAPPED SNOW DURING THE MORNING HOURS. BASED ON THIS MORNINGS LOW TEMPERATURES TONIGHT AND EARLY TOMORROW MAY BE CLOSE TO FREEZING AGAIN HEIGHTENING THE CHANCE OF SNOW LOWER THAN 5000 FEET. HOWEVER AT THIS TIME SAT PICTURES SUGGEST THE ADVECTION OF HIGHER CLOUDS THROUGHOUT THE DAY AND MODELS ALSO DEPICT DECENT CLOUD COVER TONIGHT OVER THE INTERIOR SO THOUGHTS ARE THE RADIATIVE COOLING PROCESSES WILL BE LIMITED. WILL KEEP THE HIGHER SNOW LEVELS AND NOT ISSUE ANY NON ROUTINE PRODUCTS TO ADDRESS SNOW. AS FAR AS RAIN AMOUNTS WITH THIS SYSTEM MODELS INDICATE ABUNDANT MOISTURE WITH THE FRONT. THIS COMBINED WITH NEARLY ONSHORE FLOW WILL LEAD TO GOOD OROGRAPHIC LIFT. SO HIGH RAINFALL AMOUNTS ARE EXPECTED. TOTAL QPF WILL BE NEAR 0.5 INCH ACROSS DEL NORTE COUNTY, 0.5-1.0 INCH ACROSS HUMBOLDT COUNTY, NEAR 1 INCH ACROSS TRINITY COUNTY, AND JUST OVER 1 INCH ACROSS MENDOCINO COUNTY. THE MORE RAIN FAVORED SPOTS WILL RECEIVE 2-3 INCHES. THE TUESDAY SYSTEM WILL PASS THROUGH BY TUESDAY NIGHT AND BE FOLLOWED BY ANOTHER BRIEF BREAK WED AND EARLY THURSDAY. MORE RAIN LATE THURSDAY AND FRIDAY AS A SIMILAR FRONTAL SYSTEM APPROACHES FROM THE WEST. && .AVIATION...VFR CONDITIONS EXPECTED TO PREVAIL...HOWEVER CEILINGS WILL LOWER TO NEAR MVFR BY MID MORNING TUESDAY AS A STORM SYSTEM APPROACHES FROM THE WEST. SOUTHERLY WINDS WILL INCREASE AND BECOME GUSTY AS WELL TUESDAY...WITH SOME MODERATE LLWS POSSIBLE. TIMING ON RAIN IS INCONSISTENT IN THE MODEL RUNS...BUT HAVE FORECAST EARLY TO MID MORNING FOR RAIN ONSET ATTM. CONDITIONS WILL LIKELY DETERIORATE AFTER 18Z TUESDAY AS THE RAIN INTENSITY INCREASES. HENRY && .MARINE...SOUTHERLY WINDS WILL INCREASE TONIGHT AND TUESDAY AS A WARM FRONT LIFTS NORTH AHEAD OF AN APPROACHING STORM SYSTEM. WINDS WILL BECOME STRONG AND GUSTY TUESDAY HOWEVER....THERE HAVE BEEN SOME INCONSISTENCIES IN THE MODELS ON THE STRENGTH OF THE WIND. HAVE ISSUED A SMALL CRAFT ADVISORY FOR WIND AND WAVES FOR NOW...BUT A GALE WARNING MAY STILL BE NEEDED. MODERATE SWELL TRAIN OF 10 TO 12 FT WILL BUILD FOR WEDNESDAY AND THURSDAY...ALONG WITH INCREASING WINDS AHEAD OF THE NEXT APPROACHING SYSTEM FOR THURSDAY AND FRIDAY. MODELS STILL CONSISTENT IN BRING A LARGE SWELL OF 19 FT FOR SATURDAY. HENRY && .EKA WATCHES/WARNINGS/ADVISORIES... CA...NONE. NORTHWEST CALIFORNIA COASTAL WATERS... SMALL CRAFT ADVISORY ALL WATERS. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA