601
FXUS65 KREV 122152
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
252 PM PDT MON AUG 12 2013
.SYNOPSIS...
A FEW THUNDERSTORMS ARE POSSIBLE IN NORTHEAST CALIFORNIA AND
NORTHWEST NEVADA, AND PORTIONS OF MINERAL COUNTY THROUGH EARLY
THIS EVENING. OTHERWISE DRY AND STABLE SOUTHWEST FLOW WITH
TEMPERATURES SLIGHTLY ABOVE NORMAL IS EXPECTED THROUGH THE
UPCOMING WEEK AS HIGH PRESSURE BUILDS OVER THE ROCKIES. AREAS OF
HAZE AND SMOKE FROM THE AMERICAN FIRE MAY AFFECT VISIBILITY AND
AIR QUALITY AROUND RENO AND SOME SIERRA VALLEYS FOR THE NEXT FEW
DAYS.
&&
.SHORT TERM...
WEAK SHORTWAVE MOVING ACROSS NORTHERN CALIFORNIA WILL BRING SOME
INSTABILITY AND FORCING SUFFICIENT FOR GENERATING A FEW SHORT
LIVED THUNDERSTORMS THROUGH EARLY THIS EVENING NORTH OF SUSANVILLE
AND GERLACH. FARTHER SOUTH, CUMULUS BUILDUPS IN MINERAL AND
SOUTHERN LYON COUNTIES WILL HAVE A LITTLE MORE INSTABILITY AND
HEATING TO WORK WITH COMPARED TO YESTERDAY. THEREFORE WILL MENTION
A POSSIBILITY OF THUNDER, BUT WILL USE SLIGHT CHANCE WORDING SINCE
MORE UNCERTAINTY EXISTS IN COMPARISON TO NORTHWEST NV AND
NORTHEAST CA. ALL CONVECTIVE ACTIVITY IS EXPECTED TO END AROUND
SUNSET AS SHORTWAVE CLEARS THE REGION WITH NO ADDITIONAL FORCING
PROJECTED OVERNIGHT.
THE NEXT ROUND OF SMOKE AND HAZE FROM THE AMERICAN FIRE WEST OF
THE SIERRA CREST IS STARTING TO DRIFT TOWARD THE NORTHEAST AND
WILL LIKELY BE CARRIED ACROSS THE I-80 CORRIDOR FROM TRUCKEE TO
RENO LATER THIS AFTERNOON. SMOKE AND HAZE SHOULD ALSO SPREAD
NORTHWARD TOWARD PYRAMID LAKE AND SOUTHERN LASSEN COUNTY THIS
AFTERNOON AND EVENING. FOR THE PEAK VIEWING OF THE METEOR SHOWER
AFTER MIDNIGHT, THE ONLY EXPECTED OBSTRUCTION IS THE PRESENCE OF
SMOKE. DEPENDING ON ITS THICKNESS, VIEWING CONDITIONS COULD BE
GOOD STRAIGHT OVERHEAD, BUT BECOME MORE LIMITED TOWARD THE
HORIZON.
FOR TUESDAY AND WEDNESDAY, DRY AND STABLE SOUTHWEST FLOW ALOFT
WILL PREVAIL AS HIGH PRESSURE STRENGTHENS OVER THE EASTERN GREAT
BASIN. DAYTIME TEMPS WILL CONTINUE TO CLIMB ABOVE NORMAL WITH MOST
OF WESTERN NV REACHING THE MID 90S BY WEDNESDAY. THE AFTERNOON
ZEPHYR BREEZES WILL LIKELY BE WEAKER AND OF SHORTER DURATION
COMPARED TO TODAY, WITH PEAK GUSTS GENERALLY 20-25 MPH.
AREAS AFFECTED BY THE SMOKE AND HAZE COULD BE DEALING WITH SLOWER
DISPERSION DURING THE DAY DUE TO REDUCED MIXING, BUT WEAKER FLOW
ALOFT ALSO MAY LIMIT OR DELAY THE ARRIVAL OF SUBSEQUENT SMOKE
PLUMES. SINCE IT IS UNCERTAIN HOW THE ADDITIONAL FIRE SUPPRESSION
RESOURCES WILL AFFECT ACTIVITY FOR THE NEXT COUPLE OF DAYS, WILL
TAKE A DAY BY DAY APPROACH WHEN IT COMES TO INCLUDING SMOKE AND
HAZE, KEEPING IT MENTIONED THROUGH TUESDAY FOR NOW. MJD
.LONG TERM...THURSDAY THROUGH MONDAY...
ANOTHER ROUND OF MOSTLY MINOR ADJUSTMENTS WERE MADE TO THE
PRECEDING FORECAST. THE MOST SIGNIFICANT CHANGE CONCERNS THE
POTENTIAL FOR THUNDERSTORMS SATURDAY AFTERNOON. INCREASED TO
SLIGHT CHANCE ALONG THE SIERRA AND WEST OF HIGHWAY 395 FROM MONO
COUNTY TO THE TAHOE BASIN. ALSO INCLUDED THE SIERRA CREST FROM THE
TAHOE BASIN THROUGH LASSEN COUNTY. MOISTURE IS NOT IDEAL AS FLOW
IS RELATIVELY DRY FROM THE SOUTHWEST. HOWEVER, THERE IS A THIN
RIBBON OF MID LEVEL MOISTURE PROJECTED. SURFACE CONVERGENCE AND
THE APPROACH OF A DECENT SHORTWAVE SHOULD BE SUFFICIENT TO PRODUCE
A FEW ISOLATED THUNDERSTORMS FROM THE LITTLE MOISTURE AVAILABLE.
IT STILL LOOKS DRY ON FRIDAY SO WILL LEAVE OUT MENTION OF
THUNDERSTORMS FOR NOW.
OTHERWISE, CONCERNS WILL CENTER AROUND WINDS AND DRY CONDITIONS
THURSDAY AND FRIDAY. ON THURSDAY, THE THERMAL GRADIENT HAS BEEN
INCREASING FROM THE SIERRA TO CENTRAL NEVADA. THIS WILL CREATE A
SLIGHTLY STRONGER AFTERNOON ZEPHYR WITH POSSIBLE WIND GUSTS UP TO
30 MPH ACROSS THE SIERRA AND INTO FAR WESTERN NV. FRIDAY'S WINDS
COULD BE A LITTLE STRONGER WITH POSSIBLE GUSTS OVER 30 MPH AS THE
PRESSURE GRADIENT INCREASES AHEAD OF THE APPROACHING SHORTWAVE
WHILE A 50 KNOT JET STREAK MOVES OVER WESTERN NEVADA. THIS
INCREASE IN WINDS COMBINED WITH A DRY SLOT MAY CAUSE SOME FIRE
WEATHER CONCERNS ON FRIDAY.
FOR SUNDAY AND MONDAY, RIDGING BUILDS BACK OVER NORTHERN
CALIFORNIA AND WESTERN NEVADA WITH MORE TYPICAL AFTERNOON ZEPHYR
BREEZES EXPECTED. BOYD
&&
.AVIATION...
ALTHOUGH VFR CONDITIONS SHOULD PREVAIL THRU THIS WEEK, SMOKE FROM
THE AMERICAN FIRE COULD PRODUCE MVFR CONDITIONS AND AFFECT
SLANTWISE VSBY AROUND KRNO AND KTRK DURING THE NEXT FEW EVENINGS
AND MORNINGS. THE MOST LIKELY PERIODS FOR REDUCED VSBY ARE DURING
THE 00-06Z AND 12-18Z TIME RANGES. TYPICAL ZEPHYR BREEZES WITH
GUSTS 20-25 KT ARE EXPECTED THRU AROUND 04Z TODAY, WITH A SLIGHT
DECREASE IN WIND SPEEDS TUESDAY. MJD
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)