Marine Weather and Tides
3/30/2021 -- ANZ330 has been split into ANZ331 and ANZ332. Click EDIT in Marine Forecast and select your new zone.
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 6:44AM||Sunset 7:02PM||Sunday September 19, 2021 6:22 AM PDT (13:22 UTC)||Moonrise 6:49PM||Moonset 5:09AM||Illumination 96%|
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 191007 AFDREV
Area Forecast Discussion National Weather Service Reno NV 307 AM PDT Sun Sep 19 2021
Isolated to scattered rain showers are expected early this morning, mainly north of Interstate 80 and for the Lake Tahoe area. It will be breezy and cooler today as a cold front moves through the region. Sub-freezing temperatures are on tap for some rural and suburban lower valleys Monday and Tuesday morning. Warmer weather returns for Tuesday afternoon through the rest of the week.
Main change to the short term forecast was to raise a lake wind advisory for Lake Tahoe this AM.
Low pressure is currently moving into Oregon with a rather ill- defined surface cold front pushing into northeast CA and northwest NV in response to the incoming low. Ahead of the front, winds over Sierra ridges are peaking in the 50-85 mph range (and briefly to around 100 mph at a sensor near the crest west of Tahoe), with wind-prone areas near Hwy 395/I-580 peaking between 35-55 mph in the past hour. Elsewhere, wind gusts have generally been 30 mph or less.
The low passing by to the north today will shove a cold front through northern/western NV and northeast CA this morning, with the front working its way in a shallow fashion (below 700 mb) through Mono and Mineral counties this afternoon and evening. With winds remaining elevated until FROPA later this morning, winds on Lake Tahoe look sufficient (15-20 mph with gusts to 35 mph) for small boating concerns so a lake wind advisory was hoisted there for the morning. It will remain breezy today, although peak winds look mainly 30 mph or less. The main exceptions could be in the Soda Spring (Hwy 95) and Chalfant (Hwy 6) valleys from mid afternoon into the evening where winds could briefly get up to 30-40 mph immediately post-frontal.
As for precipitation this morning, it looks to remain light and mainly north of I-80 and around the west side of the Lake Tahoe Basin (mostly due to upslope lift west of crest) as the main area of deep forcing/instability is over extreme northern CA/NV and up into Oregon. Snow levels have bottomed out near 10,000 feet over the Tahoe area and perhaps down to ~8,000 feet over far northeast CA. As the upper low passes by to the north by mid to late morning, any remaining showers should fall apart rapidly.
Tonight into Tuesday, an upper ridge builds back overhead. With cooler highs and calming winds, radiational cooling should allow lows to fall below freezing for some rural and suburban lower valleys (and WELL below freezing for Sierra valleys) for the next couple nights. If you have gardens still going (my tomatoes are still cranking out plenty!), be sure to watch the forecast for your location and consider covering your plants if the forecast is for temperatures below 40 degrees. -Snyder
LONG TERM. Wednesday through next weekend .
Other than a weak shortwave passage across the Pacific Northwest bringing increased breezes (gusts 30-35 mph) Wednesday afternoon- evening, the mid-late portion of the upcoming week will feature warm and dry conditions with lighter winds Thursday-Friday. Highs should mainly be in the 80s for lower elevations and mid-upper 70s for Sierra valleys, although Thursday might be a bit cooler behind the shortwave passage as the winds shift to a northeast direction.
As we get into next weekend, there are a couple of potential scenarios that would yield varied results. The first keeps high pressure in the vicinity of CA-NV which would result in continued warm and dry conditions with generally light winds. The second scenario is more complex with a closed low off the CA coast moving inland toward the Sierra next weekend. This would produce cooler and showery conditions and possibly some thunder with wetting rainfall depending on the track of this low. While the first scenario remains more likely among the ensemble guidance, we can't ignore the second possibility either. Therefore, we have trended highs a bit lower and increased cloud cover for next Sunday but held rain chances below 15% for now. MJD
Main impact to aviation will be wind-related today as a cold front passes through western NV with surface winds shifting to NW-N in the afternoon, while stronger ridge level winds shift more slowly from west to northwest through the day. This will keep mountain wave turbulence going along with periods of wind shear. The shear may occur at lower levels especially through midday today. Later this afternoon into early evening, increased north winds area expected to push across eastern portions of Mineral- Mono counties with gusts around 30 kt. At the main terminals, wind gusts are more likely to remain in the 20-25 kt range except briefly stronger around the time of frontal passage.
Current shower activity mainly north of I-80 and west of Tahoe will weaken through the morning. Ceilings could briefly dip into MVFR category especially for KTRK-KTVL through 15Z when light rain showers move overhead, but otherwise VFR conditions are likely to prevail although with some mountain top obscurations.
Afterward, VFR conditions will prevail for the upcoming week. Most days will see lighter winds, except for Wednesday when gusts could increase to near 25 kt at the main terminals as a shortwave trough brushes across the northwest US. MJD
While the main gusty wind/low RH event of the weekend has already passed, we will still be dealing with breezy conditions through today. However, humidity will not be as low, with most areas remaining above 20% through this afternoon. The only exception is for eastern Mono County and central-southern Mineral County, where the drier air mass will hang on through this afternoon with minimum RH between 10-20%. As north winds increase later this afternoon, there may be a 1-2 hour overlap of wind/RH reaching low-end critical criteria especially in the Chalfant Valley/Benton area and the US-95 corridor from Mina-Luning southward, but then humidity values will rise with the post-frontal air mass.
After today, warm and dry conditions will prevail but winds will be lighter most days through the upcoming week. The only exception could be Wednesday due to a fast-moving shortwave passage across the Pacific Northwest which could produce elevated fire weather concerns. Current projections show potential for a marginal/low end wind and RH event in some areas of western NV north of US-50. MJD
REV Watches/Warnings/Advisories. NV . Lake Wind Advisory until noon PDT today for Lake Tahoe in NVZ002.
CA . Lake Wind Advisory until noon PDT today for Lake Tahoe in CAZ072.
For more information from the National Weather Service visit . http://weather.gov/reno
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|Mammoth Yosemite Airport, CA||36 mi||50 min||SSE 10 G 23||10.00 mi||Fair||57°F||25°F||29%||1020.3 hPa|
Link to 5 minute data for KMMH
Wind History from MMH (wind in knots)
|1 day ago||Calm||Calm||N||Calm||Calm||E||E|
|2 days ago||Calm||N||SE||Calm||SE||SE||E||SE||SE||SE||NW|
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