Area Forecast Discussion
Issued by NWS Reno, NV

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

000
FXUS65 KREV 270947
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
247 AM PDT MON APR 27 2015

.SYNOPSIS...

HIGH PRESSURE WILL BUILD TODAY AND PUSH TEMPERATURES WELL ABOVE
NORMAL THROUGH WEDNESDAY. TEMPERATURES WILL LIKELY BREAK 80
DEGREES FOR MANY WESTERN NEVADA VALLEYS WITH LOWER 70S IN THE
SIERRA VALLEYS. A WEAK TROUGH WILL DEVELOP NEAR THE WEST COAST FOR
THE END OF THE WEEK WITH TEMPERATURES COOLING A FEW DEGREES AND
THE POSSIBILITY OF THUNDERSTORMS.

&&

.SHORT TERM...

RIDGE AXIS ALONG THE WEST COAST MOVES EAST TODAY AND STARTS A
WARMING TREND FOR THE REGION. EASTERLY FLOW OVER THE MOUNTAINS
THIS MORNING WILL GIVE WAY TO DECREASING WINDS BY THIS AFTERNOON
WITH THE APPROACH OF THIS RIDGE. TUESDAY AND WEDNESDAY ARE LIKELY
TO BE 8-12 DEGREES ABOVE AVERAGE FOR MOST OF THE CWA. THE RIDGE
AXIS BEGINS TO MOVE EAST BY EARLY WEDNESDAY AS ANOTHER AREA OF LOW
PRESSURE DRIVES TOWARD THE COAST OF THE PAC NW.

WITH THE APPROACH OF THIS LOW ON WEDNESDAY THE GRADIENT WILL
TIGHTEN AND RESULT IN STRONGER WINDS ACROSS THE FORECAST AREA.
LOWERING HEIGHTS OVER THE FAR NORTHERN CWA SHOULD DROP HIGH TEMPS
A FEW DEGREES THERE...BUT THE INCREASED MIXING CAUSED BY THE
STRONGER WINDS MAY KEEP TEMPS WELL ABOVE AVERAGE FOR THE CENTRAL
AND SOUTHERN PARTS OF THE CWA.

ALONG WITH LOWERED HEIGHTS AND SLIGHTLY COOLER TEMPS TO THE
NORTH...THE FORECAST MODELS SHOW ENOUGH LIFT TO WARRANT LEAVING
SLIGHT CHANCE SHOWERS NORTH OF GERLACH IN THE FORECAST FOR
WEDNESDAY AND WEDNESDAY NIGHT. THE INSTABILITY DOES NOT APPEAR
SUBSTANTIAL ENOUGH TO MENTION THUNDER AT THIS POINT.

WITH THE PASSAGE OF A SURFACE TROUGH WEDNESDAY NIGHT THE FLOW ONCE
AGAIN SHIFTS TO MORE OF A NORTHERLY DIRECTION...BUT THERE DOES NOT
APPEAR TO A GREAT DEAL OF COOL AIR ADVECTION WITH THIS TROUGH...AT
LEAST IN THE FIRST 12-18 HOURS...SO LOW TEMPS THURSDAY MORNING ARE
NOT LIKELY TO BE MUCH LOWER THAN WEDNESDAY MORNING. 20

.LONG TERM...

ABOVE NORMAL TEMPS WILL PREVAIL THRU NEXT WEEKEND AS FLAT RIDGE
IS LIKELY TO PERSIST OVER THE SOUTHWEST US. A WEAK LOW DEVELOPING
OFF THE CA COAST THURSDAY AND REMAINING IN PLACE THRU NEXT WEEKEND
WILL BECOME THE MAIN FEATURE TO AFFECT WEATHER CONDITIONS FOR THE
FIRST FEW DAYS OF MAY. THIS LOW WILL GRADUALLY PRODUCE INCREASING
INSTABILITY, WITH CUMULUS BUILDUPS LIKELY TO SHOW UP NEAR THE
SIERRA CREST STARTING THURSDAY.

FROM FRIDAY-SUNDAY, FURTHER INCREASES IN MOISTURE AND INSTABILITY
ALONG WITH UPPER LEVEL DEFORMATION ZONE APPEAR TO BE SUFFICIENT TO
GENERATE SOME CONVECTION EACH AFTERNOON AND EVENING, SO WE ADDED A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. THE POTENTIAL
FOR THUNDER APPEARS TO BE LIMITED TO THE SIERRA SOUTH OF TAHOE ON
FRIDAY, THEN SPREADING A BIT NORTH AND EAST (BUT STILL MAINLY
SOUTH OF HIGHWAY 50) FOR NEXT WEEKEND. IN ADDITION, WEAK SHORTWAVE
ENERGY BRUSHING ACROSS THE PACIFIC NORTHWEST MAY GENERATE A FEW
CELLS NORTH OF SUSANVILLE-GERLACH BY NEXT WEEKEND.

THE MEDIUM RANGE GUIDANCE IS IN GENERAL AGREEMENT WITH THE
SCENARIO DESCRIBED ABOVE, BUT THE LOCATION OF THE THUNDERSTORM
POTENTIAL IS LIKELY TO VARY DEPENDING ON WHERE THE UPPER LOW
AND BEST INSTABILITY EVENTUALLY SETS UP AS WE GET CLOSER TO THE
END OF THE WEEK. MJD

&&

.AVIATION...

GENERALLY LIGHT EAST WINDS TODAY EXCEPT FOR THE USUAL EAST FLOW
ENHANCEMENT THIS AFTERNOON AT KCXP-KMMH WITH SUSTAINED WIND
AROUND 10 KT. WITH UPPER TROUGH BRUSHING ACROSS PACIFIC NW ON
TUESDAY, SFC FLOW WILL BECOME WEST WITH AFTN-EVE GUSTS AROUND 20
KT AT MOST TERMINALS.

VFR CONDS TO PREVAIL THRU TUESDAY WITH ONLY POSSIBLE EXCEPTION OF
PATCHY LOCAL FOG AT KTRK EARLY TUES AM AS RIDGE LEVEL FLOW
WEAKENS. 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)



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.