Marine Weather and Tides
1/26/2021 -- The West Coast Satellite images havd been updated. They now use GEOS-17.
1/1/2021 -- The 7 day forecast are now working well. Thank you NOAA for your support.
|Sunrise 6:21AM||Sunset 6:00PM||Sunday March 7, 2021 12:26 PM PST (20:26 UTC)||Moonrise 3:43AM||Moonset 1:11PM||Illumination 33%|
7 Day Forecast for Marine Location Near Mono City, CAHourly EDIT Help
Area Discussion for - Reno, NV  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS65 KREV 071134 AFDREV
Area Forecast Discussion National Weather Service Reno NV 334 AM PST Sun Mar 7 2021
After a somewhat quiet day today, a pattern change to more active weather looks to occur this week with cooler temperatures, breezy to gusty winds, and periodic chances for rain and snow for much of this coming week.
Changes to the forecast:
* Increased winds Monday afternoon and evening due to better mixing potential.
* Boosted overall QPF and snow amounts along the Sierra from near Interstate 80 south to Mammoth Mountain Tuesday into Wednesday.
Today will be mainly quiet weather-wise besides some breezy conditions this afternoon as the height gradient strengthens across the West Coast, as high pressure builds over the central part of the US and an upper low begins to drop south about 400 miles off the British Columbia coast. High temperatures will be just above average with low 60s for western Nevada valleys, and low 50s for Sierra valley locations. A great day to enjoy the outdoors before the variable weather pattern this week. Late tonight, cloud cover begins to increase from north to south as the upper low continues to drop south off the West Coast. The height gradient over north-central California also compresses as this upper low moves south, increasing winds along Sierra ridges.
As the upper low draws closer to the region Monday, a weak short- wave trough looks to eject away from the parent upper low and across the northern Sierra and western Nevada. Some snow showers will be possible early Monday morning for the upper elevations of western Lassen County. Snow showers look to move over across the northern Sierra and eastern California from about CA Highway 89 north into Lassen County Monday night into early Tuesday. According to the most recent NBM snow probabilities, there is a 30% chance of greater than 4" of snow for Donner Summit and a 40% chance of greater than 2" for south Lake Tahoe by Tuesday morning, with nearly all of western Nevada shadowed by this wave.
The bigger story for Monday is the increased confidence in southwest winds increasing areawide Monday afternoon and evening, during optimal boundary layer mixing hours as a 40-50 kt 700 hPa jet streak moves across the Sierra and western Nevada. For Sierra valleys, gusts look to be in the 30-40 mph range, with Sierra ridges gusting 70-80 mph. For western Nevada valleys, we will likely see gusts 35-45 mph with wind-prone areas seeing 50+ mph gusts.
For Tuesday, medium-range deterministic guidance and ensembles have the leading edge of the upper-low approaching the northern California coast, bringing snow into the Sierra. The current trajectory of this low heavily favors the western slopes and crest of the Sierra, with a pretty sharp snowfall gradient occurring downwind of the Sierra. Current deterministic and ensemble guidance suggests at least moderate accumulations of snow along the Sierra crest, with 8-12" possible west of Lake Tahoe and 4-8" possible for the higher elevations of Mono/Alpine counties. Lower elevations of the Sierra range 2-4" of snowfall. Only very light snow showers will be possible for the far western portions of western Nevada. Strong winds are not expected Tuesday due to the weak pressure gradient associated with the leading edge of the low. Johnston
LONG TERM. Wednesday through next weekend .
No major changes were made to the extended forecast, which features an upper low moving slowly south off the CA coast Wednesday-Thursday, bringing cool temperatures and areas of mainly light snow/snow showers.
Ongoing light to moderate snow over the Sierra is expected to continue through Wednesday, with periods of lighter snow spreading into far western NV. The Wednesday morning commute for the urban areas around Reno-Carson-Minden could be slick even with snowfall amounts likely to be light (about 20-30% probability of 1" or more). For the eastern Sierra including the Tahoe basin, additional snowfall of 1-4" with local amounts to 6" near the crest appears most likely given the offshore track of the low, which would favor higher snow amounts west of the crest. If this system were to track closer to the coast, snow totals could be higher although the higher March sun angles would limit accumulations in the afternoon. Snowfall rates in the Sierra do not look to be very impressive, maybe up to 1"/hour in heavier snow bands.
Then from Wednesday night-Thursday as the low slides farther south, the latest model/ensemble guidance favors the focus for additional snow to areas south of US-50, where a small deformation zone appears most likely to set up. There remain differences in how long this snow area may linger over Mono-Mineral counties but even with the slower departing scenarios (snow ends Thursday afternoon), significant snow accumulations are unlikely. As with the snow earlier in the week, the potential for slick travel conditions will largely be limited to overnight and morning hours, with roads becoming wet during the day.
Both Wednesday and Thursday will remain cooler than average with highs mainly in the 40s to lower 50s for lower elevations, and 30s-near 40 for Sierra valleys. Although winds will be generally light, some gusty northeast to east winds may develop over the Sierra from Wednesday night through Thursday night.
Friday and Saturday look to be dry with some short-duration ridging in place over CA-NV, leading to a steady warming trend with highs near 60 in some lower elevations by Saturday. Another weak weather system is possible late next weekend although multiple scenarios for its location/timing are represented, ranging from a progressive trough passage across the Sierra or northwest US, to another possible cutoff low near the CA coast. MJD
VFR conditions are anticipated today with modest breezes. Patchy FZFG is possible at KTRK between 12Z-16Z although the clear conditions at the KTRK web camera at this time usually indicate a lower potential for notable fog formation through the early morning.
Conditions will become more adverse on Monday with gusty winds developing for increased turbulence and possible LLWS. Periods of snow will then reach the Sierra Monday night and continue at times from Tuesday through Wednesday, producing periods of MVFR/IFR and snow accumulation on paved surfaces mainly overnights/mornings. Some of this snow could spread into the western NV terminals although accumulations on pavement are less likely. MJD
REV Watches/Warnings/Advisories. NV . None. CA . None.
For more information from the National Weather Service visit . http://weather.gov/reno
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|Mammoth Yosemite Airport, CA||36 mi||49 min||S 4||10.00 mi||Fair||52°F||12°F||20%||1018.3 hPa|
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Wind History from MMH (wind in knots)
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