Forecast Discussions mentioning ACARS, received at FSL on 04/01/00

...SYNOPSIS... STRONG UPPER LEVEL WINDS BETWEEN HIGH PRESSURE BUILDING OVER THE PACIFIC NORTHWEST AND LOW PRESSURE OVER ARIZONA WILL CONTINUE TO BRING GUSTY SANTA ANA WINDS TONIGHT AND SATURDAY. SUNNY AND WARMER SUNDAY WITH LIGHTER WINDS.

...DISCUSSION... WINDS HAVE DROPPED OFF PER SURFACE REPORTS AND PRESSURE GRADIENTS ONLY AROUND -7MB BETWEEN KSAN-KTPH. HOWEVER BELIEVE THIS IS TEMPORAL/NORMAL NOCTURNAL DIE OFF AND EXPECT WINDS WILL INCREASE AGAIN BETWEEN MIDNIGHT AND MID MORNING SATURDAY...ALTHOUGH SOMEWHAT DISCONTINUOUSLY. WHILE THE SFC PRESSURE GRADIENT IS NOT FORECAST TO CHANGE SIGNIFICANTLY....THE LOW/MID LEVEL FLOW DOES INCREASE. CURRENTLY PER WSR-88D VAD WINDS...RAOBS...AND ACARS WINDS NE 20-35 KTS BETWEEN 3000-10000 FT AND 40-50 KTS IN THE MID LAYER. NGM AND AVN MODEL INCREASE THESE ANOTHER 15 KTS OVERNIGHT WITH THE ETA SLIGHTLY WEAKER. PLUGGING THE NUMBERS INTO THE LOCAL SANTA ANA WIND MODEL YIELDS 65 TO 75 MPH GUSTS IN WIND PRONE AREAS SO WILL WARNINGS/AND ADVISORIES RIDE. THEREFORE NO UPDATES. FROM WHAT I SAW OF THE 31/00 AND 01/12Z MEDIUM RANGE MODELS...PLUS LATEST SATELLITE LOOP...I VOTE FOR LOW RETROGRADING SW...BUT CENTER PASSING WELL S AND E OF FORECAST AREA.

SAN 000

.SAN...HIGH WIND WARNINGS AND WIND ADVISORIES...SEE LAXNPWSAN.

BALFOUR



STRONG WINDS WILL CONTINUE TO BE THE WEATHER STORY ACROSS THE DISTRICT AT LEAST FOR THE FIRST PART OF THE FORECAST. THINGS DIED DOWN DURING FRIDAY AFTERNOON/EVENING IN THE USUAL DIURNAL PATTERN...BUT STARTING TO SEE SOME STRONG GUSTS IN THE MOUNTAINS AGAIN CURRENTLY AND EXPECT HIGH WINDS TO SPREAD ACROSS FAVORED MOUNTAIN AND VALLEY LOCATIONS AGAIN THIS MORNING.

00Z MODELS APPEAR TO HAVE INITIALIZED WELL AND ARE IN GENERAL AGREEMENT WITH SYNOPTIC SCALE FEATURES...KEEPING UPPER LOW SPINNING OVER SRN AZ TODAY THEN GRADUALLY WEAKENING AND MOVING IT TO THE SOUTH SLOWLY TONIGHT AND SATURDAY. BIG RIDGE STARTS TO BUILD INTO CA FROM THE WEST ON SATURDAY. MODELS ARE SHOWING SOME DIFFERENCES IN THE STRENGTH OF THE LOW/MID LEVEL WINDS AGAIN TODAY...WITH THE AVN ONCE AGAIN 15-20 KT STRONGER AT 850 MB AT 12Z. LOOKING AT RECENT VWP/ACARS DATA...AVN APPEARS TO BE VERIFYING QUITE WELL SO FAR AND WILL GO WITH IT. THIS WOULD GIVE 45 KT WINDS AT 850 MB WITH A SUBSIDENCE MAX OVER LA/VTU COUNTIES THIS MORNING. LAX-DAG GRADIENT IS FORECAST TO BE A LITTLE STRONGER OFFSHORE THIS MORNING...DOWN TO ABOUT -3 MB. BASED ON THESE FACTORS AND RESULTS FROM YESTERDAY MORNING CONTINUATION OF HIGH WIND WARNINGS FOR LA/VTU MOUNTAINS AND VALLEYS IS DEFINITELY IN ORDER. WINDS SHOULD PEAK THIS MORNING THEN DECREASE IN THE AFTERNOON AS PRESSURE GRADS BECOME ONSHORE AGAIN AND UPPER SUPPORT DIMINISHES. COULD SEE SOME RATHER STRONG SEABREEZES AGAIN THIS AFTERNOON ALONG THE COASTS. TONIGHT AND SUNDAY SHOULD HAVE QUIET WX WITH WEAK OFFSHORE FLOW...CLEAR SKIES AND LOCALLY BREEZY CONDITIONS THROUGH/BELOW THE PASSES AND CANYONS.

TEMPS WILL BE VERY WARM TODAY FOR THE COASTS AND VALLEYS...WITH PROFILER SHOWING SOME ADDITIONAL WARMING IN THE LOW LAYERS FROM YESTERDAY. EXPECT SOME COOLING AT THE IMMEDIATE COAST SUNDAY AS WEAKER OFFSHORE FLOW SHOULD ALLOW EARLIER SEABREEZE...BUT OTHER LOCATIONS SHOULD SHOW LITTLE CHANGE...AND CENTRAL COAST INTERIOR AND THE MOUNTAINS/DESERTS WILL WARM A FEW DEGREES AS THICKNESSES INCREASE.

EXTENDED...MODELS IN BETTER AGREEMENT THIS MORNING WITH THE 00Z MRF/UK ALONG WITH THE 31/12Z ECMWF ALL SHOWING STRONG RIDGING OVER CA MON AND TUE...WITH THE OLD UPPER LOW SHEARING OUT AND HAVING NO EFFECT ON THE WEATHER FOR SRN CA. RIDGE THEN FLATTENS WED AS WEAK TROFFING MOVES ACROSS NRN CA. EXPECT PATCHY LOW CLOUDS/FOG TO RETURN TO THE COASTS TUE MORNING...MOVING INTO THE VALLEYS AS WELL TUE NIGHT AND WED MORNING AS THE TROF SLIDES DOWN THE COAST. TEMPS WILL GRADUALLY COOL THRU THE PERIOD...ESPECIALLY WED.

LAX 000. JACOBSON

.LAX...HIGH WIND WARNINGS (SEE LAXNPWLAX).