459
FXUS65 KREV 131902
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
1202 PM PDT MON JUL 13 2026
KEY MESSAGES
* SHOWERS THIS AFTERNOON, WITH ANTICIPATED INCREASES IN COVERAGE AND
INTENSITY INTO THIS EVENING. CONCERNS FOR FAST-MOVING STORMS
PRODUCING DRY LIGHTNING, HEAVY RAINFALL, AND GUSTY OUTFLOW WINDS.
* TUESDAY, WIDESPREAD STORM ACTIVITY BRINGS MORE CONCERNS FOR HEAVY
RAINFALL LEADING TO LOCALIZED FLOODING POTENTIAL.
* STORM ACTIVITY CONTINUES MIDWEEK WITH STORM CHANCES PERSISTING
FOR MONO AND MINERAL, WHILE WINDS INCREASE FOR AREAS NEAR THE OR
BORDER. MONSOONAL MOISTURE MAY RETURN THIS WEEKEND AND NEXT
WEEK.
DISCUSSION
HAZY SKIES ACROSS THE REGION THIS MORNING FROM NEARBY FIRES, WITH
CLOUDS AND RAIN ABOVE, KEEPING THE SKIES DARK AND GLOOMY. THERE WAS
NOTICEABLE RESIDUE FROM RAIN CONTAINING ASH AND SMOKE PARTICLES
COVERING VEHICLES ACROSS THE RENO/SPARKS AREA THIS MORNING. LUCKILY
THE MORNING SHOWERS SO FAR HAVE BEEN CONCENTRATED NEAR THE
ELEPHANT FIRE, WHICH SHOULD HELP EFFORTS. RECENT HRRR NEAR-SURFACE
SMOKE MODELING SUGGESTS THE SMOKE TAPERS AFTER THESE SHOWERS, SO
LET'S HOPE THE MOISTURE CONTINUES TO ABATE THE SMOKE.
IN THE PAST 12 HOURS, RAINFALL AT SOUTH LAKE TAHOE HAS ACCUMULATED
TO 0.10 INCHES, AND THE RADAR SHOWS MORE ON THE WAY. HOWEVER,
NAILING DOWN EXACT AMOUNTS AND WHERE THEY WILL FALL TENDS TO BE
MORE DIFFICULT WITH THE CONVECTION EXPECTED TO DEVELOP THIS
AFTERNOON. THERE COULD BE STORMS THAT PRODUCE HEAVY RAINFALL, BUT
WITH FAST-MOVING STORM MOTIONS, IT IS HARD TO SAY JUST HOW MUCH
MEASURABLE PRECIPITATION ANY GIVEN POINT MAY REALIZE. PWATS AT NWS
RENO WERE ALREADY MEASURING 0.99 INCHES AT 12Z THIS MORNING,
WHICH IS A TAD HIGHER THAN GUIDANCE SUGGESTED WOULD BE AVAILABLE
AT THAT HOUR. SO, WE ARE THINKING STORMS COULD PRODUCE LOCALIZED
RAINFALL AMOUNTS OF 0.1-0.5 INCHES ACROSS THE GENERAL AREA, BUT IF
TRAINING STORMS DEVELOP, AMOUNTS COULD BE MUCH HIGHER. THIS LEADS
US TO CONSIDERING A LOCALIZED FLOODING THREAT UNDER WET STORMS,
ESPECIALLY IF OCCURS. THIS AFTERNOON IS A GREAT OPPORTUNITY TO
MAKE SURE YOUR STORM DRAINS ARE CLEARED AND READY TO HANDLE ANY
HEAVY RAINS THAT MAY FALL. ANOTHER ISSUE FOR THE AFTERNOON
CONVECTION IS THE POTENTIAL FOR DRY LIGHTNING, ESPECIALLY OVER
NORTHEASTERN CALIFORNIA AND NORTHWESTERN NEVADA, FROM THE I-80
CORRIDOR NORTH TO THE OREGON BORDER. FROM I-80 TO THE SOUTH, THE
EXISTING MOISTURE FIELD SUGGESTS THIS IS THE HIGHLIGHTED AREA FOR
FLOODING POTENTIAL, ALTHOUGH ANY STORM TODAY IS PRIMED TO CREATE
FLOODING CONCERNS. WIDESPREAD SHOWERS ARE MODELED TO CONTINUE INTO
THE OVERNIGHT HOURS, TAPERING BEFORE SUNRISE ON TUESDAY.
FOR TUESDAY, WE EXPECT THE SHOWERY NATURE OF THE SYSTEM TO CONVERT
TO A MORE CONVECTIVE LOOK THAN EVEN TODAY, WITH EVEN MORE EMPHASIS
ON A WIDESPREAD HEAVY RAINFALL THREAT AS MOISTURE CONTINUES TO
STREAM IN. BLENDED GUIDANCE SUGGESTS THE PWATS NUDGE OVER 1.00 INCH,
ALTHOUGH THE 12Z SOUNDING FROM LAST NIGHT EXCEEDED THE PREDICTED
AMOUNTS, SO WE THINK THIS MIGHT BE A TAD UNDERDONE. AT ANY RATE,
THERE WILL BE MOISTURE. AS FOR INSTABILITY, THERE IS AN APPRECIABLE
INCREASE TUESDAY AFTERNOON, SUGGESTING SOME CLOUDS CLEARING TUESDAY
MORNING TO ALLOW FOR THE HEATING TO BUILD AT THE SURFACE. IF CLOUDS
HANG OUT LONGER THAN EXPECTED FROM THE OVERNIGHT SHOWERS, THIS
COULD WORK TO LIMIT THE OVERALL INSTABILITY VALUES, BUT ANY
CLEARING WILL HELP THE NUMBERS. THE BEST CLEARING LOOKS TO OCCUR
OVER THE SIERRA FRONT, THE BASIN AND RANGE AND ALONG THE SIERRA
CREST TO THE WEST, ALTHOUGH THERE ALSO APPEARS TO BE A FEW POCKETS
WHERE CLOUDS LINGER OVER MONO COUNTY AND THE TAHOE BASIN. FOR
THAT REASON, NAILING DOWN WHERE THE BEST CAPE VALUES WILL BE FOUND
WILL BOIL DOWN TO WHERE THE SUN SHINES THE LONGEST BEFORE
CONVECTIVE INITIATION. THE EXPECTATION IS TO SEE CAPE VALUES
RANGING 100-800 J/KG, BUT THE AFOREMENTIONED CAVEATS WILL DICTATE
THE LOCATIONS OF THESE FIELDS. ANOTHER KICKER IS AN INBOUND TROUGH
FROM THE NORTHWEST THAT COULD PROVIDE A BIT MORE LIFT, BUT TBD ON
EXACTLY WHERE AND WHEN THIS MAY INFLUENCE STORM DEVELOPMENT.
WEDNESDAY, THE INFLUENCE FROM THE NORTHERLY TROUGH WILL BE MORE
PRONOUNCED AS THE RIDGE TO OUR EAST ADVANCES, BRINGING A DRIER
AIRMASS TO THE NORTHERN SIERRA. THE SHOWER AND STORM CHANCES
FOLLOW, WITH FAR SOUTHERN MONO COUNTY, FAR SOUTHEASTERN MINERAL
COUNTY AND OUT TO EASTERN CHURCHILL AND PERSHING COUNTIES, WITH
CHANCES RANGING 5-15%. THE POSITION OF THE RIDGE'S CENTER OF
CIRCULATION IS FORECAST TO BUILD OVER THE FOUR CORNERS AREA
THURSDAY, WHICH WILL RETROGRADE THE SHOWER AND STORM THREAT. FOR
THURSDAY THE FOCUS IS ALONG AND SOUTH OF I-80 WITH CHANCES RANGING
10-20%. WHILE THIS REESTABLISHMENT OF RIDGING OVER THE FOUR
CORNERS IS A FAVORABLE POSITION TO REINTRODUCE WIDESPREAD SHOWERS
AND STORMS, SIGNALS BECOME MORE MURKY INTO THE WEEKEND. WHAT WE
CAN SAY FOR NOW, THERE WILL BE SHOWERS AND STORMS IN THE VICINITY.
WHETHER OR NOT THEY WILL STILL REMAIN TO THE EAST OR CONTINUE TO
RETROGRADE AS THE HIGH PRESSURE BUILDS REMAINS THE QUESTION. WE
WILL BE MONITORING THIS AS THE WEEK PROGRESSES. HRICH
AVIATION
* LIGHT SHRA TODAY WITH A 15-50% CHANCE OF TSRA THIS AFTERNOON,
ESPECIALLY FOR TAF SITES SOUTH OF US-50 INCLUDING KMEV, KHTH, KBAN
AND KMMH. GUSTY WINDS UP TO 35 KTS ARE POSSIBLE NEAR SHRA/TSRA.
OTHERWISE, WINDS WILL BE SOUTH TO SOUTHWEST 7-12 KTS WITH GUSTS TO
20 KTS.
* SHOWER AND STORM COVERAGE INCREASES TUESDAY WITH SIMILAR TSRA
POTENTIAL TO MONDAY ON MOST SITES AFTER 18Z. GUSTY OUTFLOW WINDS,
HEAVIER RAIN SHOWERS, SMALL HAIL AND TERRAIN OBSCURATION CONTINUE
TO BE THE MAIN CONCERNS. HRICH/HC
FIRE WEATHER
* STORMS TREND WETTER TODAY AND TUESDAY, INCREASING THE POTENTIAL
FOR WETTING RAINFALL. HOWEVER, STORM MOTIONS WILL REMAIN ON THE
FASTER SIDE TODAY, SO NEW LIGHTNING IGNITIONS ARE POSSIBLE AWAY
FROM MAIN RAIN CORES. STORMS WILL BE SLOWER AND WETTER ON TUESDAY
LIMITING THE FIRE RISK.
* GUSTY AND ERRATIC OUTFLOW WINDS UP TO 45 MPH COULD ALSO ACCOMPANY
THUNDERSTORMS. MOREOVER, AN INCREASINGLY UNSTABLE ENVIRONMENT THIS
AFTERNOON AND AGAIN TUESDAY WILL BE MORE FAVORABLE FOR DEEPER
VERTICAL PLUME GROWTH/MORE ACTIVE PLUME BEHAVIOR ON ANY
NEW/EXISTING FIRES THAT BECOME INTENSE.
* WINDS ALSO APPEAR TO INCREASE MIDWEEK WITH THE APPROACH OF AN
UPPER TROUGH LEADING TO BRIEF PERIODS OF ELEVATED TO CRITICAL
CONDITIONS OVER PORTIONS OF NE CA, ESPECIALLY OVER MOUNTAIN
RIDGES DUE TO GUSTS TO 30-35 MPH, AND A 20-50% CHANCE OF
EXCEEDING 35 MPH. HRICH/SALAS/HC
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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