Forecast Discussions mentioning ACARS, received at FSL on 01/22/00

...SYNOPSIS... WEST FLOW ALOFT WILL BRING SOME MID AND HIGH CLOUDS THROUGH THE WEEKEND. NIGHT AND MORNING LOW CLOUDS AND FOG WILL ALSO OCCUR.

...DISCUSSION... A MOIST SOUTHWEST FLOW ALOFT CONTINUES TO FEED MID ANDHIGH LEVEL MOISTURE ACROSS THE CWFA. METAR REPORTS AND SATELLITE PHOTOS ALSO SHOW A FAIR AMOUNT OF CUMULUS OVER THE AREA. VISIBLE IMAGERY ALSO SHOWS AN AREAS OF DENSER CLOUDS ASSOCIATED WITH A SPEED MAX JUST MOVING EAST AT 56 KTS THROUGH THE LA/ORANGE COUNTY AREA. BASED ON ACARS SOUNDINGS...APPEARS THIS FEATURE IS AROUND 20K FEET. THE MOISTURE STREAM CONTINUES TO THE SOUTHWEST TO THE EQUATORIAL REGION JUST NORTH OF AUSTRAILIA WITH THE HEAVIER MOISTURE AREA EAST OF 170W.

12Z MODELS DO SHOW SOME HEIGHT RISES FOR THE WEEKEND AS A MINOR S/WV RIDGE MOVES OVER THE COAST. HOWEVER...RIDGE APPEARS TO BE DIRTY AND WILL ALLOW MID AND HIGH CLOUDS TO COVER THE CWFA. ALSO EXCEPT SOME RETURN OF THE LOW CLOUDS AND AREAS OF FOG WEST OF THE MOUNTAINS NIGHTS AND EARLY MORNINGS. OTHERWISE DRY WEATHER THROUGH SUNDAY.

THE MRF PUSHES BACK THE NEXT CHANCE OF RAIN ANOTHER DAY TO WEDNESDAY OR THURSDAY OF NEXT WEEK. IT NOW SHOWS A FAIRLY STRONG RIDGE FOR TUESDAY...INSTEAD OF THE S/WV TROUGH BRUSHING BY TO THE NORTH ON TUESDAY THE MRF RUN ON WEDNESDAY SHOWED. THIS CONTINUES THE PATTERN OF THE MRF DELAYING THE PCPN ANOTHER 24 TO 36 HOURS AS IT HAS BEEN DOING OVER THE PAST SEVERAL DAYS. THE ECMWF BRINGS A S/WV THROUGH LATE TUESDAY INTO WEDNESDAY...MUCH LIKE THE WED RUN OF THE MRF INDICATED...BUT ECMWF IS ALSO DELAYING ANOTHER 24 HOURS. THE CURRENT WORDING OF PARTLY CLOUDY LOOKS GOOD...UNTIL WE GET INFO FROM LATER MODEL RUNS.

ONE MORE ASTRONOMICAL HIGH TIDE IN EXCESS OF 7 FEET SATURDAY MORNING SO THE MWS REMAINS IN PLACE FOR POSSIBLE TIDAL OVERFLOW. SEE LAXMWSSAN FOR DETAILS.

SAN...0000

.SAN...MINOR TIDAL OVERFLOW...SEE LAXMWSSAN.

HORTON

...SYNOPSIS... WEST FLOW ALOFT WILL BRING SOME MID AND HIGH CLOUDS THROUGH THE WEEKEND. NIGHT AND MORNING LOW CLOUDS AND FOG WILL ALSO OCCUR.

...DISCUSSION... A MOIST SOUTHWEST FLOW ALOFT CONTINUES TO FEED MID ANDHIGH LEVEL MOISTURE ACROSS THE CWFA. METAR REPORTS AND SATELLITE PHOTOS ALSO SHOW A FAIR AMOUNT OF CUMULUS OVER THE AREA. VISIBLE IMAGERY ALSO SHOWS AN AREAS OF DENSER CLOUDS ASSOCIATED WITH A SPEED MAX JUST MOVING EAST AT 56 KTS THROUGH THE LA/ORANGE COUNTY AREA. BASED ON ACARS SOUNDINGS...APPEARS THIS FEATURE IS AROUND 20K FEET. THE MOISTURE STREAM CONTINUES TO THE SOUTHWEST TO THE EQUATORIAL REGION JUST NORTH OF AUSTRAILIA WITH THE HEAVIER MOISTURE AREA EAST OF 170W.

12Z MODELS DO SHOW SOME HEIGHT RISES FOR THE WEEKEND AS A MINOR S/WV RIDGE MOVES OVER THE COAST. HOWEVER...RIDGE APPEARS TO BE DIRTY AND WILL ALLOW MID AND HIGH CLOUDS TO COVER THE CWFA. ALSO EXCEPT SOME RETURN OF THE LOW CLOUDS AND AREAS OF FOG WEST OF THE MOUNTAINS NIGHTS AND EARLY MORNINGS. OTHERWISE DRY WEATHER THROUGH SUNDAY.

THE MRF PUSHES BACK THE NEXT CHANCE OF RAIN ANOTHER DAY TO WEDNESDAY OR THURSDAY OF NEXT WEEK. IT NOW SHOWS A FAIRLY STRONG RIDGE FOR TUESDAY...INSTEAD OF THE S/WV TROUGH BRUSHING BY TO THE NORTH ON TUESDAY THE MRF RUN ON WEDNESDAY SHOWED. THIS CONTINUES THE PATTERN OF THE MRF DELAYING THE PCPN ANOTHER 24 TO 36 HOURS AS IT HAS BEEN DOING OVER THE PAST SEVERAL DAYS. THE ECMWF BRINGS A S/WV THROUGH LATE TUESDAY INTO WEDNESDAY...MUCH LIKE THE WED RUN OF THE MRF INDICATED...BUT ECMWF IS ALSO DELAYING ANOTHER 24 HOURS. THE CURRENT WORDING OF PARTLY CLOUDY LOOKS GOOD...UNTIL WE GET INFO FROM LATER MODEL RUNS.

ONE MORE ASTRONOMICAL HIGH TIDE IN EXCESS OF 7 FEET SATURDAY MORNING SO THE MWS REMAINS IN PLACE FOR POSSIBLE TIDAL OVERFLOW. SEE LAXMWSSAN FOR DETAILS.

SAN...0000

.SAN...MINOR TIDAL OVERFLOW...SEE LAXMWSSAN.

HORTON

...SYNOPSIS... WEST FLOW ALOFT WILL BRING SOME MID AND HIGH CLOUDS THROUGH THE WEEKEND. NIGHT AND MORNING LOW CLOUDS AND FOG WILL ALSO OCCUR...ESPECIALLY THIS MORNING. SOME COOLING WILL OCCUR TODAY AND SATURDAY.

...DISCUSSION... THE ONSHORE FLOW...NOW ABOUT +4 OR 5 MB FROM SAN TO OUR DESERTS...HELPED THE LOW CLOUDS DEVELOP AND BECOME WIDESPREAD WEST OF THE MOUNTAINS. ACARS AND OBS INDICATE THAT THE MARINE LAYER IS AROUND 2000 FEET...BUT THIS IS SOMEWHAT POORLY DEFINED. THERE SHOULD BE SOME DECREASE IN THE LOW CLOUDS TONIGHT DUE TO MORE NW FLOW IN THE LOW-LEVELS AND A SLIGHT WEAKENING IN THE ONSHORE FLOW.

THE SUBTROPICAL/TROPICAL CONNECTION CONTINUES OVER THE E PAC...BUT THE SOURCE REGION KEEPS GETTING FURTHER AWAY AS THE FLOW IS NOW MORE WESTERLY THAN SOUTHWESTERLY. THUS...THE AMOUNT OF MID/HIGH CLOUDS WILL NOT BE TOO GREAT...AND PARTLY CLOUDY IS ALMOST PESSIMISTIC...EXCEPT TODAY SOME OF THE LOW CLOUDS MAY NOT CLEAR ENTIRELY IN SOME AREAS. DESPITE LESS CLOUDINESS SATURDAY...EXPECT NO WARMING OVER FRIDAY SINCE THE 850 MB TEMPS COME DOWN A FEW DEGREES. WARMING WILL FINALLY OCCUR AROUND MON/TUE AS GOOD RIDGING DEVELOPS AHEAD OF THE NEXT E-PAC SYSTEM AND TEMPS ALOFT INCREASE. THE ECM/MRF BOTH HAVE THE NEXT SYSTEM WAITING UNTIL LATE WED/THU...A DELAY FROM YESTERDAY...SO FUTURE MODEL RUNS VERY WELL COULD HAVE FURTHER DELAYS. FOR NOW...NO PRECIP IS MENTIONED THROUGH THE END OF THE EXTENDED PERIOD...TUESDAY.

SAN...000

.SAN...MINOR TIDAL OVERFLOW...SEE LAXMWSSAN.

MAXWELL

LATEST SATELLITE IMAGE SHOWS HIGH CLOUDS QUICKLY SHIFTING EAST THROUGH THE OHIO VALLEY. FOLLOWING BEHIND THIS AREA OF HIGH CLOUDS SLEET AND FREEZING DRIZZLE HAS FORMED OVER CENTRAL MO. THIS AREA OF PRECIPITATION WILL QUICKLY SLIDE EAST TO THE CWFA DURING THE MORNING. IT APPEARS THIS AIR MASS IS SATURATING UP FAIRLY QUICKLY WITH CIGS ALREADY AT 8KFT AT PAH. UPPER LEVEL SHORTWAVE ASSOCIATED WITH THESE CLOUDS WILL CONTINUE TO SHEAR OUT AS IT HEADS EAST. RUC DEPICTS A STRAIGHT JET STREAK PATTERN IN OK WITH THE PRECIPITATION TRYING TO GET GOING ON THE LEFT EXIT REGION IN MO. MEANWHILE...THERE IS A SECONDARY ANTICYCLONICALLY CURVED JET IN OH WITH THE RIGHT ENTRANCE REGION PRODUCING SOME DIVERGENCE OVER THE OHIO VALLEY AT THE PRESENT TIME. THIS JET STREAK IN ADDITION TO THE ONE STREAKING THROUGH THE OK WILL HELP ENHANCE THE ISENTROPIC LIFT OVER THE REGION THIS AFTERNOON. RUC IS ALREADY PICKING UP ON A 50KT LLJ IN OK WHICH IS HELPING PRODUCE GOOD ISENTROPIC LIFT IN AR AND OK WHICH IS DEPICTED WELL ON THE IR SATELLITE LOOP.

FOR TODAY ALL THREE MODELS ON THE 295K LEVEL SHOW THIS AREA OF ISENTROPIC LIFT SHIFTING EAST TO THE LOWER OHIO AND TENNESSEE VALLEYS. MODEL SOUNDING AND ACARS DATA SHOW THAT THE AIR MASS WILL INITIALLY START OUT AS SNOW ESPECIALLY AS THINGS START SATURATING UP. WOULD EXPECT MOST OF SNOW TO OCCUR IN NORTHERN KY AND SOUTHERN INDIANA DUE TO A COLDER AIR MASS IN PLACE AT THE LOW LEVELS. FURTHER SOUTH THE AIR IS NOT QUITE AS COLD...THUS THEY COULD HAVE A THREAT OF MIXED PRECIPITATION DURING THE AFTERNOON. WE ALSO FOLLOWED FAIRLY CLOSE TO THE ETA SOLUTION IN WARMING THE 800-900MB LAYER THIS AFTERNOON. THIS COULD CAUSE A MIXTURE OF PRECIP TO DEVELOP OVER SOUTHERN KY LATE THIS AFTERNOON. ALTHOUGH THIS MIXTURE SHOULD GRADUALLY TURN TO ALL RAIN BEFORE ENDING EARLY THIS EVENING. MODEL QPF'S SHOW ABOUT A QUARTER TO ONE HALF INCH OVER THE CWA WITH THE HIGHEST AMOUNTS FURTHERN SOUTH. FOR NOW WE WILL MENTION 1 TO 3 INCH SNOW AMOUNTS IN SOUTHERN KY DUE TO A MIXTURE DEVELOPING LATE IN THE DAY TO AROUND 3 INCES OF SNOW NORTH. WE UNDERCUT FWC A COUPLE OF DEGREES TODAY DUE TO CURRENT TREND AND THE AMOUNT OF ADIABATIC COOLING THAT WILL BE TAKING PLACE.

TONIGHT THIS PRECIPITATION SHOULD END FAIRLY QUICKLY AS THE COLD FRONT ALOFT PASSES THROUGH BEFORE SURFACE TROF. THUS...TEMPERATURES WILL NOT FALL TO MUCH TONIGHT DUE TO WEAK WARM AIR ADVECTION IN PLACE. THERE COULD BE SOME DRIZZLE MIXED IN WITH THE FLURRIES AS MOISTURE COLUMN GRADUALLY BEGINS TO DRY OUT. WE FOLLOWED FAIRLY CLOSE TO FWC NUMBERS FOR THIS TREND.

SUNDAY WE WILL SEE CLOUDS BEGINNING TO DECREASE SOME FROM WEST TO EAST AS THE DRY WEST FLOW KICKS IN AND SURFACE HIGH BUILDS IN FROM THE CENTRAL PLAINS.

.SDF...WINTER WEATHER ADVISORY SOUTH CENTRAL KENTUCKY...SNOW ADVISORY NORTHERN KENTUCKY AND SOUTHERN INDIANA.

COX