High Wind in Nevada, October 10, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
340 AM PDT WED OCT 10 2007

.SHORT TERM...
WELL DEFINED COLD FRONT EXTENDS THROUGH EXTREME WESTERN LASSEN
COUNTY SOUTH TO WEST OF BLUE CANYON AND MODESTO (NICE NCFR IN THE
RADAR IMAGE AT 10Z). THE WINDS HAVE REALLY INCREASED THE LAST COUPLE
HOURS FROM RENO AND LAKE TAHOE SOUTH THROUGH THE WIND ADVISORY AREA.
WITH THE FRONT STILL ON THE WEST SIDE OF THE SIERRA...I HAVE
EXTENDED THE WIND ADVISORY UNTIL 11 AM. WINDS SHOULD DIMINISH
RAPIDLY WITHIN A COUPLE HOURS OF FROPA...WHICH IS EXPECTED IN RENO
BETWEEN 6 AND 8 AM AS THE FRONT SURGES EAST AHEAD OF THIS SYSTEMS
STRONG UPPER FORCING (POSITIVE LIGHTNING STRIKE NEAR REDDING).

UPPER FORCING FOR THE COLD FRONT IS NOW MOVING ASHORE NEAR UKIAH
EARLY THIS MORNING. THIS WILL BOTH SURGE THE NORTHERN END OF THE
FRONT INTO THE BASIN OVER NORTHEAST CALIFORNIA FAR NORTHWEST NEVADA
AND AT THE SAME TIME SPELL THE DEATH OF THE SOLID PRECIPITATION BAND
FURTHER SOUTH (WITH JUST ISOLATED TO SCATTERED SHOWERS EEKING INTO
FAR WESTERN NEVADA THIS MORNING). THE BEST FORCING FOR THE FRONT IS
EVIDENCED IN THE INFRARED SATELLITE BY THE COLDEST CLOUD TOPS NORTH
AND EAST OF LAKE TAHOE. SPILLOVER IN THE LEE OF THE SIERRA SOUTH OF
TAHOE IS BECOMING UNLIKELY AS THE UPPER FORCING EXITS...WITH JUST
SOME CLOUDS BANKING RIGHT UP TO THE SIERRA RIDGELINE THIS MORNING.

THE REGION WILL MOVE UNDER A SHORT WAVE RIDGE WEDNESDAY NIGHT AND
THURSDAY AS TODAYS SYSTEM QUICKLY SCOOTS AWAY TO THE EAST. THURSDAY
NIGHT AND FRIDAY...ANOTHER TIGHTLY WOULD SYSTEM WILL APPROACH THE
CALIFORNIA COAST. MODELS VARY GREATLY IN THE EVENTUAL TRACK OF THE
SYSTEM...WHICH IS CRITICAL IN GIVING OUR REGION PRECIPITATION. THE
ECWMF TRACKS THE LOW THROUGH CENTRAL CALIFORNIA...CLOSE ENOUGH FOR
PRECIPITATION OVER AT LEAST THE WESTERN HALF OF THE CWA...WHILE THE
NAM AND 00Z GFS ARE FURTHER WEST WHICH WOULD MEAN NO PRECIPITATION
AT ALL. I HAVE LEFT POPS MOSTLY AS IS FOR NOW WITH MASSIVE
UNCERTAINTY IN THE EVENTUAL OUTCOME OF THE NEXT SHORT WAVE. SNYDER

.LONG TERM...SATURDAY THROUGH TUESDAY...
EXITING UPPER LOW AND APPROACHING SHORTWAVE RIDGE WILL BRING QUIET
WEATHER PATTERN FOR THE WEEKEND WITH WARMING TEMPERATURES IN THE
UPPER ELEVATIONS SATURDAY NIGHT GRADUALLY SPREADING TO VALLEY FLOORS
SUNDAY UNDER LOTS OF SUNSHINE AND SUFFICIENT SOUTH/SOUTHWEST FLOW TO
MIX THE BOUNDARY LAYER AS RIDGE AXIS SHIFTS EASTWARD.

FOR NEXT WEEK...LONGWAVE PATTERN CONTINUES TO SUPPORT STRONG
WESTERLY FLOW OVER THE NORTH PACIFIC WITH MEAN TROUGH AXIS FROM THE
GULF OF ALASKA TO THE EAST PACIFIC. THUS A CONTINUATION OF AN
UNSETTLED WEATHER PATTERN IS LIKELY FOR THE NORTHWEST CORNER OF THE
U.S. WITH SOME DIFFICULTY IN TIMING AND PLACEMENT OF FRONTS FURTHER
SOUTH INTO OUR AREA. MODELS INCLUDING MANY ENSEMBLE MEMBERS SHOW
SOME HINT OF WEAK SHORTWAVE MONDAY FOLLOWED BY A MUCH COLDER AND
STRONGER SYSTEM NEAR MID WEEK. FORECAST WAS REMAINED MOSTLY
UNCHANGED WITH CHANCES FOR PRECIPITATION BEGINNING MONDAY. MOST
LIKELY AREA FOR RAIN AND MOUNTAIN SNOW WOULD BE THE NORTHERN SIERRA
AND NORTHEAST CALIFORNIA. IT WILL BE BREEZY/WINDY AT TIMES WITH
TEMPERATURES MOST LIKELY TO STAY AT THE UPPER END OF MOS ENSEMBLE
GUIDANCE (NEAR NORMAL) MONDAY AND TUESDAY. HOHMANN
&&

.AVIATION...
S-SW WIND GUSTS TO 35-40 KNOTS ERN SIERRA AND EXTREME WESTERN NV AT
TIMES THROUGH 16Z BEFORE SHIFTING MORE WESTERLY BEHIND FRONTAL
PASSAGE 16Z-18Z. VFR IN LOWER ELEVATIONS IN ISOLD-SCT RW-. MVFR
CIGS AND VSBYS WITH MT OBSCUREMENT IN THE NORTHERN SIERRA INCLUDING
KTVL/KTRK THRU 16Z WITH CEILINGS/VSBYS IMPROVING 16Z-18Z AS SHOWERS
DIMINISH. HOHMANN
&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...LAKE WIND ADVISORY UNTIL 1 PM PDT THIS AFTERNOON FOR PYRAMID
     LAKE.
     WIND ADVISORY UNTIL 11 AM PDT THIS MORNING FOR NVZ002-003.

CA...WIND ADVISORY UNTIL 11 AM PDT THIS MORNING FOR CAZ072-073.
&&

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