warm south of Truckee SNOW 9000 ft Susanville

[donbrown]

Storm rolling into Oregon Northern California Monday 1-2 feet at 9000 feet for Shasta and northern Nevada

Truckee south will be warm and dry

Area forecast discussion
National Weather Service Reno Nevada
232 PM PDT Friday Oct 7 2011


Short term...


Upper ridge building into the Sierra and western Nevada...with a
dry and stable north flow aloft. Ridge to remain over the west
this weekend with afternoon highs warming into the low 70s across
western Nevada and middle 60s in the Sierra. Overnight lows on the
cool side as light winds and clears skies aid in radiational
cooling in valley locations. Fog likely to redevelop in the
Truckee area tonight.


Upper ridge breaks down late Sunday as a strong zonal flow over
the Pacific reaches the West Coast. Models in good agreement in a
1-1.25 inch precipitable water plume reaching northern California
Monday...with a fast moving wave and front tracking through
northwest Nevada. Have increased the chance of rain north of
Susanville-Lovelock...with 0.20-0.50 inches of rain possible. South
of Susanville-Lovelock main impact appears to be breezy afternoon
winds...though there are a few ensemble members generating precipitation
as far south as Reno-Tahoe-Carson. With the jet remaining along
the Oregon border...snow levels should remain above 9000 feet for
this event. Brong


Long term...Tuesday through Friday...
dry conditions through next Thursday as Flat Ridge prevails over the
southwestern US and northern Mexico. The European model (ecmwf) is farther north with the ridge
center than the GFS which would bring even warmer conditions and
push coverage of high clouds farther north. While a warming trend
is still likely...the European model (ecmwf) seems to be too aggressive with
expansion of the ridge considering the active Pacific jet. As a
result...maximum temperatures were kept close to the GFS guidance and previous
forecast with lower elevations near 80 degrees next Wed-thurs.


By Friday...the differences between the European model (ecmwf) and GFS begin to
determine the potential for light precipitation as the GFS swings a
shortwave into northern California-northwestern Nevada by Friday but European model (ecmwf) keeps the trough
axis off the West Coast. Most of the GFS ensemble members are dry
but a few do bring precipitation to the north zones...so as a first
attempt at resolving these differences have added low end slight chance
probability of precipitation to northestern California-northwestern Nevada. With the ridge weakening...temperatures should
begin to decrease but by going with a weaker trough passage compared
to the 12z GFS...the highs would be a few degrees above MOS
guidance. Mjd


&&


Aviation...
VFR with generally light winds through Saturday. Fzfg probable at
ktrk with most likely occurrence time between 12-16z. Mjd


&&


Rev watches/warnings/advisories...
Nevada...none.
California...none.
&&


$$


Http://weather.Gov/Reno

 

[donbrown]

Lots of rain next couple days way up north ... no mention of snow

Temps 70's in the Sierras

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RENO NV 300 AM PDT MON OCT 10 2011 .SHORT TERM... STRONG PACIFIC JET AND DEEP MOISTURE ALREADY BEGINNING TO MOVE INTO NORTHERN CA THIS MORNING. WITH THE STRENGTH OF THIS JET AROUND 150KT...THE MOISTURE IS MOVING A BIT FASTER THAN PREVIOUSLY THOUGHT. CLOUD TOPS COOLING OFF SHARPLY ON IR IMAGERY...AS THE MOISTURE PLUME CLOSER TO THE NORTHERN CA COAST. HAVE INCREASED POPS AND QPF FOR EARLY THIS MORNING...ESPECIALLY FOR AREAS NORTH OF RENO-TAHOE. RADAR RETURNS IN NORTHERN CA ARE ALREADY SHOWING SOME MODERATE SHOWERS NORTH OF REDDING...THESE WILL PROGRESS QUICKLY INTO LASSEN AND MODOC COUNTIES AFTER 4AM. RAIN WILL SPREAD SOUTH INTO THE RENO-CARSON-TAHOE AREA THROUGH THE REST OF THE MORNING-AFTERNOON AND EVENING. PRECIPITABLE WATER AMOUNTS AHEAD OF THIS JET ARE IMPRESSIVE...1.5-2 INCHES. WARM AIR ADVECTION/ISENTROPIC LIFT SHOULD BE PRETTY STRONG...WITH RELATIVELY LITTLE SHADOWING FROM THE SIERRA. LATEST MODEL RUNS SEEM TO BE SHADOWING THE RENO-CARSON CITY AREA MORE THAN PREVIOUS RUNS...BUT FORECAST THINKING REMAINS THE SAME. WARM AIR ADVECTION PRECIP TYPICALLY DOESN`T HAVE ANY TROUBLE SPILLING OVER INTO THE LEE OF THE SIERRA. BEST CHANCES FOR RAIN WILL BE IN THE SIERRA FROM LAKE TAHOE NORTHWARD TO WESTERN LASSEN COUNTY. MODERATE TO HEAVY RAINFALL WILL BE POSSIBLE AT TIMES IN THE HIGHER ELEVATIONS...BETWEEN 0.5-1.0" TOTAL RAINFALL EXPECTED. AS FOR THE LOWER DESERT VALLEYS...RAINFALL AMOUNTS WILL GENERALLY BE BETWEEN 0.10-0.25". THERE IS POTENTIAL FOR DESERT VALLEYS NORTH OF SUSANVILLE/GERLACH COULD GET AS MUCH AS 0.5"...INCLUDING SURPRISE VALLEY. WINDS WILL INCREASE TODAY...ALTHOUGH NOT OVERLY STRONG. DUE TO POOR DOWNWARD MIXING OF WINDS ALOFT IN WARM AIR ADVECTION PATTERNS. GUSTS OF UP TO 30 MPH CAN BE EXPECTED IN MOST AREAS...WITH GUSTS AS HIGH AS 40 MPH IN WIND PRONE AREAS ALONG HIGHWAY 395. RIDGING BEGINS TO BUILD BACK INTO THE WEST COAST ON TUESDAY WITH LINGERING SHOWERS IN THE SIERRA MONDAY NIGHT INTO TUESDAY MORNING. TEMPERATURES WILL BEGIN A WARMING TREND THROUGH THE REST OF THE WEEK WITH HEIGHTS RISING AND TEMPS INCREASING ALOFT. SHOULD MAKE FOR A PLEASANT WEEK OVERALL WITH HIGH TEMPS BACK INTO THE UPPER 70S ACROSS WESTERN NV BY WEDNESDAY...UPPER 60S IN THE SIERRA. HOON .LONG TERM...THURSDAY THROUGH SUNDAY... UPPER RIDGE WILL PERSIST OVER THE SOUTHWESTERN U.S. KEEPING CONDITIONS DRY AND TEMPERATURES ABOVE NORMAL THU-FRI. HIGHS WILL REACH AROUND 80 IN THE LOWER ELEVATIONS OF WESTERN NEVADA AND 70S IN THE SIERRA. MEDIUM RANGE MODEL SOLUTIONS CONTINUE TO SHOW A DIVERSE RANGE OF POSSIBILITIES FOR TEMPERATURES AND WEATHER POTENTIAL THIS WEEKEND AND THE ENSEMBLE SUITES AMONG THE VARIOUS MODELS DO NOT OFFER MUCH HELP. THE 00Z OPERATIONAL ECMWF HAS RETURNED TO A STRONGER TROUGH MOVING THROUGH THE WEST COAST AND IS CLOSE TO THE GEM WHICH HAS SHOWN THIS SCENARIO THE PAST FEW NIGHTS. MEANWHILE THE GFS IS MOST PROGRESSIVE AND LESS AMPLIFIED WITH TROUGH. AT LEAST ANOTHER DAY OF MODEL RUNS WILL BE NEEDED BEFORE THERE CAN BE ANY INCREASE IN THE LOW CONFIDENCE RATING FOR THE WEEKEND FORECAST. FOR NOW FORECAST WILL CONTINUE TO REFLECT A COOLING TREND TOWARD THE MIDDLE OF THE GEFS MOS GUIDANCE AND A SLIGHT CHANCE OF SHOWERS. IF THE COOLER ECMWF/GEM MATERIALIZE...THEN POPS WOULD NEED TO BE INCREASED QUITE A BIT AND TEMPERATURES COOLED EVEN MORE. HOHMANN && .AVIATION... MID CLOUDS WILL CONTINUE TO LOWER THIS MORNING IN WARM ADVECTION PATTERN. RAIN SPREADING ACROSS NORTHERN CA WILL REACH AS FAR SOUTH AS THE HIGHWAY 50 CORRIDOR 16-18Z WITH PERIODS OF LIGHT RAIN AT KRNO/KTRK/KTVL THIS AFTERNOON BEFORE TAPERING THIS EVENING. FURTHER SOUTH AT KMMH...SHOWERS WILL MAINLY STAY CONFINED TO THE SIERRA WEST OF HIGHWAY 395. CONDITIONS SHOULD REMAIN MOSTLY VFR ALTHOUGH MT TOPS COULD BECOME OBSCURED NEAR THE SIERRA. THE MOST WIDESPREAD RAIN AND POTENTIAL FOR LIMITED VSBY (4-6SM) WILL BE NORTH OF A TRUCKEE TO GERLACH LINE. THE RAIN AND CLOUDS WILL HOLD MOST WIND GUSTS DOWN WITH GUSTS 20-25KT. THERE WILL BE LOCAL GUSTS 25-30KT ALONG THE EASTERN SIERRA OF MONO COUNTY. FOR RIDGES...EXPECT GUSTS 50-65KT THROUGH TONIGHT. HOHMANN