562
FXUS65 KREV 292240
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
240 PM PST MON DEC 29 2025
KEY MESSAGES
* COLD MORNINGS, DRY WEATHER CONTINUING, FREEZING FOG IN THE SIERRA
AGAIN TONIGHT.
* HAZY INVERSIONS RETURN DAILY THROUGH THIS WEEK OVER WESTERN NV
VALLEYS.
* ROUNDS OF STORMS ARRIVING LATE DAY ON NEW YEARS EVE, LOOK TO
LINGER THROUGH WEEKEND.
DISCUSSION
COLD AIR GREETED OUR FACES THIS MORNING, BUT WITH AN INFLUX OF
WARMER AIR ON THE WAY, TOMORROW MORNING'S COLD AIR WON'T BITE QUITE
AS HARD AS THIS MORNING. THE COLDER AIR TRAPPED IN SOME SIERRA
VALLEYS WILL ONCE AGAIN PRODUCE FREEZING FOG TOMORROW MORNING.
OTHERWISE, SKIES ARE CLEAR AND DRY THROUGH WEDNESDAY AFTERNOON.
A GLANCE AT TODAY'S SATELLITE IMAGERY REVEALS OUR NEXT FORECASTING
PUZZLE TO ASSEMBLE. FIRST, THE EYE IS DRAWN TO A CIRCULATION
RESIDING OVER THE 20N/~130W REGION, JUST WEST OF THE BAJA PENINSULA.
THE NEXT FEATURE TO NOTICE IS THE INCOMING TROUGHING PATTERN THAT IS
DRAWING COLD, POLAR AIR SOUTHWARD. OUR OBJECTIVE TODAY IS TO SORT
OUT THE BASIC FRAMEWORK OF THE PROGRESSION OF THE NEXT ROUND OF
SYSTEMS TO APPROACH THE REGION.
ACCORDING TO ENSEMBLE GUIDANCE, THE SOUTHERN FEATURE WILL APPROACH
FIRST, DRAWING WARM, MOIST AIR FROM A TROPICAL SOURCE REGION. THIS
WILL TRANSLATE TO WARMING TEMPERATURES, AS MENTIONED STARTING TODAY
AND CONTINUING INTO THE NEW YEAR. SNOW LEVELS WILL BEGIN TO CLIMB
WEDNESDAY AFTERNOON, AS THE SUBTROPICAL LOW ARRIVES WITH RAIN BELOW
9000 FEET, MAYBE EVEN HIGHER. THIS WILL BRING WITH IT CONCERNS FOR
RAIN ON SNOW, WHICH COULD PRODUCE AREAS OF FLOODING. THE SNOW LEVELS
REMAIN ELEVATED ABOVE 8000 FEET THROUGH AT LEAST EARLY FRIDAY
MORNING, WHEN THE COLDER TROUGH POSITIONS TO TAKE OVER AS THE WARMTH
OF THE SUBTROPICAL LOW EXITS TO THE EAST. THE FRIDAY INTO SATURDAY
TIMEFRAME DURING THIS REPLACEMENT OF AIRMASS WILL BE CRITICAL, AS WE
EXPECT VARIOUS PRECIPITATION TYPES TO BE ON THE TABLE. AREAS MAY
BEGIN WITH RAINFALL, TRANSITION TO RAIN/SNOW MIX, OR EVEN SOME
POCKETS OF ICING, THEN AS SNOW LEVELS FINALLY TUMBLE EARLY SATURDAY
MORNING, CHANGING TO SNOW ABOVE 5500-6000 FEET, WITH RAIN/SNOW MIX
TO VALLEY RAIN AS WE TRAVEL DOWN THE MOUNTAIN SLOPE. THIS DURATION
OF CHANGE BETWEEN SYSTEMS WILL PRODUCE TRAVEL IMPACTS, INCLUDING
SLIPPERY MOUNTAIN ROADWAYS AND SIDEWALKS, AND BUMPY FLIGHTS ON
SATURDAY. AS FOR DETAILS ON SNOW AMOUNTS, RAIN AMOUNTS, EVEN SOLID
UNDERSTANDING OF HOW THESE SYSTEMS WILL INTERACT AND AFFECT
PRECIPITATION TYPE, WE WILL NEED A BIT MORE INFORMATION IN THE
COMING DAYS. HRICH
AVIATION
* VFR CONDITIONS THIS AFTERNOON INTO TUESDAY, WITH LIGHT WINDS.
INVERSIONS MAY BE INHIBITING SLANTWISE VISIBILITY ACROSS WESTERN
NEVADA VALLEY TERMINALS. KTRK WILL SEE FZFG AGAIN TUESDAY
MORNING, LIKELY THROUGH 18Z. HRICH
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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