Lightning Strike in California, June 5, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
950 AM PDT TUE JUN 5 2007

.DISCUSSION...
HAVE UPDATED FORECAST TO INCREASE COVERAGE OF SCATTERED AND ISOLATED
SHOWERS OVER FOOTHILLS AND NORTHERN PORTION OF SACRAMENTO VALLEY
...WITH NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS OVER THE HIGHER
SIERRA. SURFACE OBSERVATIONS SHOWING SOME GUSTY WINDS OVER THE
SIERRA RIDGES...SO INCREASED WINDS SOME IN THOSE AREAS AS STRONG JET
MOVES OVER THE AREA TODAY. ADDED PATCHY MORNING FOG TO NORTHERN
SIERRA AS OBS AT BLUE CANYON SHOWING SOME PERSISTENT LOW
VISIBILITIES. WILL BE TAKING A CLOSE LOOK AT SNOW LEVELS FOR THIS
EVENING AND TOMORROW AS VERY COLD AIR ALOFT PUSHES IN. EK

.PREVIOUS DISCUSSION...A HIGHLY AMPLIFIED LONGWAVE PATTERN OVER THE
WEST COAST.  THE STRONG POLAR FRONT JET WITH AN ELONGATED NW TO SE
ORIENTATED JET MAX OF 140-160KT IS DEEPENING UPPER LEVEL TROUGH.
WATER VAPOR SHOWS THE FRONT EDGE OF THE JET MAX IS OVER 130W
CREATING AN AREA OF BROAD CLOUD ENHANCEMENT OVER OREGON AND NORCAL.
THIS AREA OF ENHANCE HAS LED TO SOME ISOLATED TO SCATTERED SHOWERS
OVER THE SIERRA...NORTH OF INTERSTATE 80...AND SHASTA AND TEHAMA
COUNTIES.  ALSO...TO INCLUDE AN ISOLATED THUNDERSTORM OR TWO WITH
ONLY A COUPLE LIGHTNING STRIKES OUT OF OUR AREA IN MODOC COUNTY.
HAVE ADDED ISOLATED THUNDERSTORMS FOR THE NRN SAC VALLEY...NRN
MOUNTAINS AND SIERRA FOR LATE THIS AFTERNOON AND EVENING WITH UPPER
TROUGH PASSAGE AND LOW LEVEL INSTABILITY.  UNSEASONABLE COLD AIR
ALOFT WILL ACCOMPANY THIS SYSTEM.  THIS WILL AID IN CONVECTIVE
DEVELOPMENT.

THE COOLER AND MORE UNSETTLED PATTERN WILL CONTINUE INTO WEDNESDAY
AS THE TROUGH MOVES INLAND ACROSS THE WEST CONTINUING A CHANCE OF
SHOWERS TO MUCH OF THE HIGHER TERRAIN OF NORTHERN CALIFORNIA.
WEDNESDAY WILL SEE A TRANSITION FROM THE SOUTHERLY MARINE WINDFLOW
TO A NORTHERLY FLOW ON THE BACK SIDE OF THIS TROUGH...AT LEAST FOR
THE NEXT FEW DAYS.  THIS LONGWAVE PATTERN WILL KEEP A RIDGE UPSTREAM
UNTIL ABOUT SATURDAY...WHEREBY KEEPING THE DOOR OPEN FOR COOLER AIR
ALOFT TO FUNNEL INTO NORCAL.  MAX TEMPS WILL GRADUALLY REBOUND TO
NORMAL...MID 80S TO LOW 90S... BY FRIDAY OR SATURDAY AFTER THE
INITIAL COOL OFF TODAY.  JCLAPP

&&

.AVIATION...
UNSEASONABLY STRONG LOW PRESSURE SYSTEM MOVES INTO NORTHERN
CALIFORNIA AND THE GREAT BASIN THROUGH TONIGHT WITH VARIABLE
MOISTURE. 120KT JETSTREAM MOVES INTO CENTRAL CALIFORNIA THIS
AFTERNOON. AREAS OF TURBULENCE WITH A MODERATE ICING POTENTIAL OVER
NORCAL TODAY. ISOLATED -TSRA ACROSS THE SHASTA/SISKIYOUS AND IN THE
SIERRA THRU 04Z.  ALONG THE COAST...AREAS MVFR 5SM BKN015 OVC030
-SHRA BR. CENTRAL VALLEYS BKN-SCT060 BKN100 WDLY SCT LIGHT -SHRA
MAINLY N OF INTERSTATE 80. SIERNEV BKN-OVC070 EXC AREAS IFR OVC010
1SM BR...SCT -SHRA WITH WDLY SCT -TSRA. STRONG WIND GUSTS NEAR THE
CREST TO 40KT AND LEE TURBULENCE WITH MOUNTAIN WAVE ACTION. SNOW
LEVELS NEAR 070 LOWERING TO 055 TONIGHT. SG

&&

.STO WATCHES/WARNINGS/ADVISORIES...NONE.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SACRAMENTO CA
625 AM PDT TUE JUN 5 2007

CAZ013>019-063-064-066>069-061400-
SHASTA LAKE AREA/NORTHERN SHASTA COUNTY-
BURNEY BASIN/EASTERN SHASTA COUNTY-NORTHERN SACRAMENTO VALLEY-
CENTRAL SACRAMENTO VALLEY-SOUTHERN SACRAMENTO VALLEY-
CARQUINEZ STRAIT AND DELTA-NORTHERN SAN JOAQUIN VALLEY-
MOUNTAINS SOUTHWESTERN SHASTA TO NORTHERN LAKE COUNTIES-
CLEAR LAKE/SOUTHERN LAKE COUNTY-MOTHERLODE-
EAST FOOTHILLS/NORTH SACRAMENTO VALLEY-
WESTERN PLUMAS COUNTY/LASSEN PARK-WEST SLOPE NORTHERN SIERRA NEVADA-
625 AM PDT TUE JUN 5 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR INTERIOR NORTHERN CALIFORNIA.

.DAY ONE...TODAY

A LATE SEASON TROUGH PASSAGE TODAY WILL TRIGGER ISOLATED
THUNDERSTORMS...OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED AT THIS
TIME.

.DAYS TWO THROUGH SEVEN... WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

THE LATEST WEATHER INFORMATION IS AVAILABLE ON THE INTERNET AT
(LOWER CASE): HTTP://WWW.WRH.NOAA.GOV/STO

JCLAPP