Forecast Discussions mentioning ACARS, received at FSL on 03/02/01

LIGHT RAIN OR SPRINKLES WILL SPREAD OVER THE AREA THIS EVENING AHEAD OF A COLD FRONT IN THE OVERRUNNING WARM SECTOR. SOMEWHAT HEAVIER RAIN WILL MOVE INTO THE NORTH BAY WITH THE FRONT EARLY FRIDAY MORNING... AND INTO THE REMAINDER OF THE SAN FRANCISCO BAY AREA THE REST OF FRIDAY MORNING. THE COLD FRONT WILL CONTINUE TO THE SOUTHEAST WITH RAIN DEVELOPING OVER THE MONTEREY BAY AREA AROUND MIDDAY. AVN DRIES THINGS OUT QUICKLY BEHIND THE FRONT...BUT MESOETA FORECASTS SOME LINGERING EVENING SHOWERS FRI...ESPECIALLY FROM MONTEREY BAY SWD. FOLLOWING THE FRONT MUCH COLDER AIR AND PARTLY CLOUDY SKIES WILL ALLOW OVERNIGHT TEMPERATURES FRIDAY NIGHT TO LOWER INTO THE 30S AND LOWER 40S. 850 MB TEMPERATURES DROP 3 TO 5 DEGREES.

THE NEXT SYSTEM TO MOVE INTO THE AREA WILL OCCUR ON SATURDAY. THE 12Z MODELS HAVE CHANGED THEIR TUNE WITH RESPECT TO THE UPPER LEVEL FLOW AND WHERE MOST OF THE MOISTURE WILL BE ADVECTED FROM WHEN COMPARED TO THE 00Z RUN. THE MODELS HAVE MOVED THE MAIN PUNCH OF THIS STORM INTO SOUTHERN CALIFORNIA...BUT COLD AIR AND AN UNSETTLED ATMOSPHERE WILL RESULT IN THE POSSIBILITY OF SHOWERS THRU MOST OF THE WEEKEND ACROSS THE FORECAST AREA. THE HIGH-FLYING G-IV AIRCRAFT ASSOCIATED WITH THE PACJET PROJECT WILL BE FLYING THROUGH THIS STORM FRIDAY AFTERNOON GAINING ADDITIONAL DATA FOR THE MODELS THROUGH DROPSONDE REPORTS. TROUGHINESS WILL CONTINUE THROUGH MONDAY OVER CALIFORNIA WITH AMPLE LOW LEVEL MOISTURE AND WEAK SHORTWAVES MOVING ACROSS THE REGION FOR THE CHANCE OF SHOWERS. OTHERWISE...MAINLY PARTLY CLOUDY SKIES WILL RESULT. BEYOND MONDAY THE MEDIUM RANGED MODELS CAN'T AGREE ON THE STRENGTH OF THE BUILDING UPPER LEVEL RIDGE BUT DO AGREE ON MAINLY DRY CONDITIONS. STS 8+33 SFO 7+34 SJC 4+34 LVK 3+34 MRY 3946. EVANS/MILLARD

.SFO...TNGT...SMALL CRAFT ADV...PT ARENA TO PT PIEDRAS BLANCAS FOR HAZARDOUS SEAS.



COLD FRONT APPROACHING THE COAST WILL SPREAD RAIN ACROSS THE NORTH BAY EARLY FRIDAY MORNING THEN INTO THE REMAINDER OF THE SAN FRANCISCO BAY AREA THE REST OF FRIDAY MORNING. THE COLD FRONT WILL CONTINUE TO THE SOUTHEAST WITH RAIN DEVELOPING OVER THE MONTEREY BAY AREA LATER FRIDAY MORNING. A WARM FRONT AHEAD OF THE RAIN WILL CONTINUE TO PUSH MID AND HIGH LEVEL CLOUDS ACROSS THE REGION THROUGH THE NIGHT. FOLLOWING THE FRONT MUCH COLDER AIR AND PARTLY CLOUDY SKIES WILL ALLOW OVERNIGHT TEMPERATURES FRIDAY NIGHT TO LOWER INTO THE 30S AND LOWER 40S. FOR EXAMPLE 850 MB TEMPERATURES DROP 3 TO 5 DEGREES.

THE NEXT SYSTEM TO MOVE INTO THE AREA WILL OCCUR ON SATURDAY. THE 12Z MODELS HAVE CHANGED THEIR TUNE WITH RESPECT TO THE UPPER LEVEL FLOW AND WHERE MOST OF THE MOISTURE WILL BE ADVECTED FROM WHEN COMPARED TO THE 00Z RUN. THE MODELS HAVE MOVED THE MAIN PUNCH OF THIS STORM INTO SOUTHERN CALIFORNIA...BUT COLD AIR AND AN UNSETTLED ATMOSPHERE WILL RESULT IN THE POSSIBILITY OF SHOWERS. THE G-IV AIRCRAFT ASSOCIATED WITH THE PACJET PROJECT WILL BE FLYING THROUGH THIS STORM FRIDAY AFTERNOON GAINING ADDITIONAL DATA FOR THE MODELS THROUGH DROPSONDE REPORTS. TROUGHINESS WILL CONTINUE THROUGH MONDAY OVER CALIFORNIA WITH AMPLE LOW LEVEL MOISTURE AND WEAK SHORTWAVES MOVING ACROSS THE REGION FOR THE CHANCE OF SHOWERS. OTHERWISE...MAINLY PARTLY CLOUDY SKIES WILL RESULT. BEYOND MONDAY THE MEDIUM RANGED MODELS CAN/T AGREE ON THE STRENGTH OF THE BUILDING UPPER LEVEL RIDGE BUT DO AGREE ON MAINLY DRY CONDITIONS. STS 8+33 SFO 4+34 SJC/LVK 3+34 MRY 2946. EVANS

.SFO...TNGT...SCA...PT. ARENA TO PT. PIEDRAS BLANCAS FOR HAZARDOUS SEAS.



ALTHOUGH ONE BATCH OF SHOWERS SLEET AND RAIN MOVED THROUGH OBVIOUS VORT MAX BACK OVER IA AND CONTINUE LOW LEVEL WARM ADVECTION MERITS MAINTAINING POPS OVERNIGHT.

DVN RAOB AND ORD ACARS DATA SHOWING MOIST LOWER TROP JUST A TAD BELOW FREEZING MAKING LIQUID PRECIP THE MOST LIKELY. SOME POTENTIAL YET FOR EVAPORATIVE COOLING NEAR SURFACE TO PRODUCE EITHER SLEET AS EARLIER OR FREEZING PRECIP. WILL UPDATE ZONES ACCORDINGLY.

MINOR TEMPERATURE TWEAKING OVERNIGHT.

KAPLAN