Forecast Discussions mentioning "ACARS", "MDCRS", or "AIRCRAFT" received at FSL on 02/08/02

LOCAL DENSE FOG FORMED OVER PORTIONS OF THE LOS ANGELES COUNTY COAST THIS MORNING...AND OVER SOME PARTS ON THE CENTRAL COAST...AND IN PRB. MARINE LAYER QUITE SHALLOW THIS MORNING...AROUND 850 FEET AT VBG...AND SURFACE BASED AT NKX. LATEST ACARS SOUNDINGS OVER LAX SHOW A WEAK SURFACE BASED INVERSION. THERE APPEARS TO BE A WEAK EDDY CIRCULATION OVER THE SOCAL BIGHT THIS MORNING...WHICH MAY KEEP LOW CLOUDS AND FOG FAIRLY PERSISTENT ALONG THE L.A. COUNTY COAST PERHAPS EVEN INTO EARLY THIS AFTERNOON. GRADIENTS HAVE TRENDED ONSHORE MOST EVERYWHERE THE PAST 24 HOURS...SO THE COOLING TREND WHICH STARTED YESTERDAY WILL CONTINUE TODAY. SOME CLOUDS ASSOCIATED WITH AN UPPER TROF OFF THE NORCAL/PAC NW COAST MAY DRIFT OVER NORTHERN PARTS OF THE DISTRICT... OTHERWISE MOSTLY SUNNY SKIES ARE EXPECTED FOR MOST AREAS THIS AFTERNOON.

UPPER TROF MOVES TO THE NORTH OF THE DISTRICT TONIGHT...WITH THE AVN A BIT DEEPER AND MORE MOIST THAN THE ETA. IN FACT...THE AVN BRINGS MEASURABLE PCPN TONIGHT TO PORTIONS OF THE CENTRAL COAST...WITH CHANCE POPS IN THIS AREA. AT THIS TIME...THE DRIER ETA SOLUTION LOOKS REASONABLE...ESPECIALLY WITH THE MORNING SOUNDING AT VBG SHOWING SUCH A DRY AIRMASS OVER THE REGION. IN ADDITION...THE LATEST SATELLITE TRENDS SHOW THE UPPER TROF STEERING MORE NORTHEAST INTO OREGON THAN NORTHERN CA. SOCAL SHOULD REMAIN FAR ENOUGH SOUTH OF THE SYSTEM TO HAVE ANY PCPN. THE TROF MOVES INTO THE NORTHERN GREAT BASIN FRI...WITH AN UPPER RIDGE DEVELOPING OVER CA SAT INTO SUN. THE ONSHORE FLOW OVER THE DISTRICT WILL TURN SHARPLY OFFSHORE FRI NITE AND SAT MORNING FOR GUSTY CANYON WINDS. TEMPS WILL WARM UP SIGNIFICANTLY THIS WEEKEND AS WELL...WITH HIGHS NEAR 80 POSSIBLE OVER THE VTU/L.A. VALLEYS. SOME DIFFERENCES IN THE EXTENDED MODELS FOR NEXT WEEK...BUT FOR NOW WILL KEEP THINGS DRY. WILL ELABORATRE MORE ON THE EXTENDED PERIOD WITH THE AFTERNOON DISCUSSION.

WILL DO A MINOR ZONE UPDATE BY 10 AM TO ADJUST WORDING IN THE FIRST PERIOD FOR SEVERAL COASTAL ZONES...OTHERWISE THE BALANCE OF THE ZONES LOOK REASONABLE.

LAX 000. SIRARD.

.LOX...SMALL CRAFT ADVISORY (SEE LAXCWFLAX).



ACARS SOUNDING SHOW SOUTHWEST WINDS AT LOW LEVELS BELOW 850 MB. THERE WILL BE INCREASING WARM AIR ADVECTION THROUGH THIS MORNING. WARM AIR IS TO THE WEST OF NORTHERN ILLINOIS AS SEEN ON THE 850 MB ANALYSIS AT 0000 UTC. WITH WARM AIR OVER THE SNOW THERE IS FOG ACROSS THE FORECAST AREA. WILL MENTION PATCHES OF FOG.

THE AVN MODEL IS PREFERRED FOR THE CYCLONE THIS WEEKEND. USING THE UV SATELLITE LOOPS...ANALYSIS OF JET STREAKS AT 250 MB AND 500 MB ANALYSIS. THE MOVEMENT OF THE UPPER AIR CIRCULATION FROM 140 W TO NORTHERN NEVADA GIVES EASTWARD SPEED CLOSE TO THE AVN FORECAST. WITH A JET STEAK MOVING INTO THE CENTRAL US BY SATURDAY EVENING WILL FORECAST PRECIPITATION FOR SATURDAY AND SUNDAY. THE SURFACE CYCLONE WILL MOVE OVER ILLINOIS WITH THE FIRST PERIOD OF PRECIPITATION SATURDAY AFTERNOON. THE SOUNDING FORECAST DO NOT SHOW DEEP MOISTURE TILL AFTER 18Z. 1000-850 AND 850-700 THICKNESS FORECAST SHOW RAIN. THERE IS ISENTROPIC LIFT AS EARLY AS EARLY SATURDAY MORNING. WILL INCREASE THE CLOUDS FRIDAY NIGHT. OVER SATURDAY NIGHT INTO SUNDAY COLD AIR MOVES IN AND THE PRECIPITATION CHANGES TO SNOW AS SEEN BY THICKNESS AND SOUNDING FORECAST.

THE NEXT WAVE AT 500 MB WITH A JET STREAK COMES TO THE FORECAST AREA THURSDAY NIGHT. WILL KEEP A CHANCE OF SNOW FOR THAT THURSDAY NIGHT AND FRIDAY.

CHI...NONE

WHW