Severe Thunderstorm Warning 16, NWS Sacramento, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
250 PM PDT MON OCT 9 2000

FRONTAL BAND MOVING THROUGH THE VALLEY ATTM AND INTO THE FOOTHILLS...
AND SURFACE WINDS HAVE COME AROUND TO THE NORTH WITH FROPA AT KRDD
AND KRBL. LIGHT TO MODERATE PRECIP IN THE FOOTHILLS WILL MAKE ITS WAY
INTO THE SIERRA THIS EVENING. HAVE ALREADY SEEN SOME VALLEY
THUNDERSTORMS ALONG THE FRONT WITH MORE POSSIBLE OVERNIGHT AS MUCH
COLDER AIR BEGINS TO MOVE INTO THE CWA. MODELS SHOW 8 TO 10 DEGREE C
MID LEVEL COOLING OVER THE AREA TONIGHT AS JET BECOMES FOCUSED INTO
SOUTHERN CALIFORNIA AND LFQ SETS UP OVER THE CENTRAL CALIFORNIA.
MODELS MAINTAIN GOOD DEAL OF LOW LEVEL MOISTURE OVER THE AREA
TONIGHT TO KEEP THREAT OF SHOWERS AND THUNDERSTORM. ON TUESDAY UPPER
LOW CONTINUES OVER NORTHERN CALIFORNIA WITH MESO-ETA SURFACE BASED
CAPES NEARING 600 J/KG BY THE AFTERNOON. WITH 5H TEMPS PROGGED TO BE
IN THE LOWER -20S C AND WET-BULB ZERO NEAR 5 TO 6K...LIKELY TO SEE
SOME HAIL WITH THE THUNDERSTORMS TUESDAY.

HAVE UPGRADED WATCH TO A WARNING FOR THE SIERRA NEVADA. QPFS LOOK
MARGINAL AT PASS LEVELS BUT DIFFICULT TO DETERMINE HOW MUCH PRECIP
WILL OCCUR IN A SHOWERY REGIME. HAVE ALSO INCLUDED 13-14 AND 63 IN
SNOW ADVISORY FOR TONIGHT AND TUESDAY AS FIRST STORM REQUIREMENTS
ONLY CALL FOR 1 TO 2 INCHES IN 12 HOURS OR 2 TO 4 IN 24.

UPPER LOW REMAINS OVER NEVADA ON WEDNESDAY...HOWEVER FLOW ALOFT TURNS
NORTHERLY. WITH NO REAL SYNOPTIC FORCING ADVERTISED HAVE LIMITED
CHANCE OF PRECIP ON WEDNESDAY TO THE MOUNTAIN ZONES. THREAT CONTINUES
INTO THURSDAY FOR THE MOUNTAINS...THEN RIDGING BEGINS TO BUILD IN
FRIDAY AND INTO THE WEEKEND. LOOKS LIKE MODERATING OF TEMPS DAYS 3
THROUGH 5.

.STO...WINTER STORM WARNING FOR TONIGHT AND TUESDAY FOR WESTERN
       PLUMAS COUNTY/LASSEN PARK AREA AND WEST SLOPES NORTHERN SIERRA
       NEVADA.
    ...SNOW ADVISORY TONIGHT AND TUESDAY FOR THE MOUNTAINS OF SHASTA
       COUNTY TO NORTHERN LAKE COUNTY.

BLU OE 038/043 033/046 035 749953
RBL WB 052/066 048/072 051 749830
SAC WB 054/068 049/072 051 747730

HINTZ

N

CAZ013>019-064-066-067-101200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SACRAMENTO CA
130 PM PDT MON OCT 09 2000

...LARGE STORM MOVING ONSHORE WILL BRING RAIN...SNOW...AND ISOLATED
THUNDERSTORMS FOR NORTHERN CALIFORNIA...

AS A LARGE PACIFIC STORM SYSTEM MOVES ONSHORE THIS EVENING... IT
WILL DRAG A COLD FRONT ACROSS THE REGION. THIS SYSTEM WILL BRING
MUCH COOLER AIR...ALONG WITH PERIODS OF RAIN TONIGHT...EVEN A FEW
THUNDERSTORMS.

THIS STORM SYSTEM WILL SLOW DOWN AND STALL ACROSS THE REGION FOR THE
NEXT FEW DAYS.  AS A RESULT...CLOUDY AND UNSEASONABLY COOL
TEMPERATURES WILL CONTINUE. SCATTERED SHOWERS ARE POSSIBLE THROUGH
TUESDAY NIGHT...AND COULD LINGER THROUGH WEDNESDAY OVER THE
MOUNTAINS. ISOLATED THUNDERSTORMS COULD ALSO DEVELOP DURING THIS TIME
AND MAY CONTAIN SMALL HAIL AND LOCALLY HEAVY RAINFALL.

IN ADDITION...BREEZY SOUTHWEST WINDS CAN BE EXPECTED THIS EVENING
THROUGH TONIGHT IN THE CENTRAL VALLEY AND FOOTHILLS...WITH GUSTS
OVER 25 MPH POSSIBLE.

RAIN SHOWERS...AND MOUNTAIN SNOW SHOWERS WILL LIKELY LINGER INTO
THURSDAY.  A RIDGE OF HIGH PRESSURE WILL BUILD IN ON FRIDAY WITH A
WARMING AND DRYING TREND.

RESIDENTS AND TRAVELERS CAN STAY ABREAST OF THE CURRENT FORECASTS
AND POSSIBLE WINTER STORM WARNINGS OR ADVISORIES BY LISTENING TO
NOAA WEATHER RADIO OR LOCAL MEDIA. VISIT THE NATIONAL WEATHER
SERVICE WEB SITE AT WWW.WRH.NOAA.GOV/SACRAMENTO (USE L OWER CASE).

BASIL