840
FXUS65 KREV 020958
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
258 AM PDT FRI JUN 2 2023
SYNOPSIS
DRY CONDITIONS ARE EXPECTED TODAY, FOLLOWED BY INCREASING CHANCES
FOR PRECIPITATION IN THE SIERRA AND WESTERN NV ON SATURDAY AND
SUNDAY. TEMPERATURES WILL INCREASE ABOVE AVERAGE THIS WEEKEND,
INCREASING SNOWMELT RATES. THE CHANCES FOR PRECIPITATION INCREASE
BY MONDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK, WITH TEMPERATURES
RETURNING TO AVERAGE.
DISCUSSION
CURRENT WATER VAPOR IMAGERY IS SHOWING A MUCH DRIER AIRMASS OVER
THE REGION WITH A WEAK SHORTWAVE TROUGH CENTERED OVER NORTHERN
NV. THE 6/1 AFTERNOON SOUNDING ALSO PICKED UP ON THIS NOTABLE
DRYING, AS PRECIPITABLE WATER VALUES DECREASED BY ~0.30" COMPARED
TO PRIOR DAYS. THE GOOD NEWS IS THAT TODAY LOOKS TO BE THE DRIEST
DAY REGION-WIDE WE'VE HAD IN WELL OVER A WEEK! NO PRECIPITATION
IS EXPECTED TODAY, ALONG WITH NORMAL TEMPERATURES AND LIGHT WINDS.
LOOKING AT THE OVERALL EVOLUTION OF THE SYNOPTIC PATTERN THERE
ARE TWO SEPARATE AREAS OF FOCUS; ONE IS OVER OUR AREA, AND THE
OTHER IS TO THE SOUTH. BY SATURDAY THE AFOREMENTIONED SHORTWAVE
TROUGH OVER NORTHERN NV MOVES EAST INTO UT, AS A SHORTWAVE RIDGE
MOVES OVERHEAD. THIS RIDGE AXIS CONTINUES ITS EASTWARD TRACK ON
SUNDAY INTO CENTRAL NV AS THE TROUGH MOVES NORTH INTO ID.
MEANWHILE TO OUR SOUTH, THE ENSEMBLES ARE SHOWING AN UPPER LEVEL
LOW PRESSURE MOVING JUST OFF THE SOCAL COAST BY SUNDAY NIGHT.
EVENTUALLY, THE SOUTHERN UPPER LEVEL LOW PRESSURE WILL BECOME THE
DOMINATE WEATHER MAKER INTO NEXT WEEK.
FOR THIS WEEKEND, WITH RIDGING ALOFT TEMPERATURES WILL INCREASE A
FEW DEGREES EACH DAY, RETURNING TO ABOVE AVERAGE FOR EARLY JUNE.
AFTER ONE ENTIRE DAY OF DRY WEATHER REGION-WIDE, ISOLATED
THUNDERSTORMS WILL RETURN TO THE SIERRA ON SATURDAY, WITH
INCREASING CHANCES FOR PRECIPITATION INTO FAR WESTERN NV ON
SUNDAY. THIS IS A COMBINATION OF AFTERNOON INSTABILITY AS WELL AS
INCREASING MID-LEVEL MOISTURE PUSHING NORTHWARD DUE TO THE UPPER
LEVEL LOW OVER SOCAL.
ENSEMBLES SHOW THAT THE UPPER LEVEL LOW WILL MOVE INTO SOCAL ON
MONDAY, THEN EVENTUALLY STALL AROUND SOUTHERN TO CENTRAL
CALIFORNIA THROUGH THE MIDDLE OF NEXT WEEK. THIS FEATURE WILL
INTRODUCE A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS ALONG WITH
SEASONAL TEMPERATURES.
- MCKELLAR
AVIATION
* MUCH LOWER STORM CHANCES (<5%), VFR CONDITIONS, AND TYPICAL
AFTERNOON BREEZES WILL PREVAIL ACROSS ALL CA/NV TERMINALS TODAY.
SATURDAY WILL SEE A RETURN OF ISOLATED SHOWERS AND THUNDERSTORMS
OVER HIGHER MOUNTAIN AREAS, WITH THE BEST CHANCE (15-25%) FOR
AFTERNOON AND EVENING THUNDER IN AND AROUND SIERRA TERMINALS.
* WE'LL HAVE SLIGHTLY GREATER OVERALL COVERAGE FOR AFTERNOON
SHOWERS AND THUNDERSTORMS ON SUNDAY. THERE IS A 25-35% CHANCE OF
PRECIPITATION FOR THE SIERRA TERMINALS AND 15-25% CHANCE FOR
THE WESTERN NV TERMINALS.
* PERIODS OF PATCHY FOG AND ATTENDANT MVFR/IFR CONDITIONS ARE
STILL POSSIBLE FOR KTRK THE NEXT FEW NIGHTS, PARTICULARLY
BETWEEN THE 10Z-15Z TIMEFRAME.
- MCKELLAR
HYDROLOGY
WITH A DRIER AIRMASS MOVING INTO THE REGION INTO THIS WEEKEND,
THE OVERALL RISK OF THUNDERSTORMS WILL REMAIN MOSTLY CONFINED TO
THE SIERRA. SOME OF THESE STORMS HAVE THE RISK OF LOCALLY HEAVY
RAIN, WHICH WILL BE PROBLEMATIC FOR BURN SCARS, STEEP CANYONS, AND
SMALLER STREAMS IN THE SIERRA ARE AMONG THOSE AREAS MOST
VULNERABLE TO FLASH FLOODING.
WITH THE EXPECTED INCREASE IN TEMPERATURES, RIVER STAGES WILL RISE
INTO THE WEEKEND. MODERATE FLOODING WILL PERSIST ALONG THE EAST
FORK AND MAINSTEM WALKER RIVER, WITH ELEVATED FLOWS AND MINOR
FLOODING FOR OTHER PORTIONS OF THE WALKER RIVER SYSTEM. ELEVATED
FLOWS TO NEAR MINOR FLOOD STAGE WILL ALSO BE POSSIBLE ALONG
PORTIONS OF THE EAST AND WEST FORKS OF THE CARSON RIVER. CONTINUE
WITH RIVER SAFETY PRACTICES AND FOLLOW ANY RECOMMENDATIONS FROM
LOCAL OFFICIALS. PROLONGED FLOOD CONCERNS REMAIN AS WE CONTINUE TO
MELT THE RECORD SIERRA SNOWPACK.
THE HUMBOLDT RIVER WILL BE ANOTHER MAINSTEM RIVER TO MONITOR AS
ELEVATED FLOWS SLOWLY MIGRATE DOWNSTREAM. THE LATEST FORECAST AT
IMLAY APPROACHES MINOR FLOOD STAGE BY SATURDAY MORNING.
- MCKELLAR
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page