Best source for backcountry weather?
Apr 14, 2021 at 1:13 pm #3708905MarcusBPL Member
NOAA is relatively accurate for most of my travels, but wind and temperature can vary greatly from the mountain ridge to the valley.
Im learning not to be too worried when the NOAA forecast says 30-40mph winds, as that is typically the wind speed at the peak and I never camp on the peaks (no trees to hammock from!). Similarly, I have learned to subtract 5-10 degrees from the predicted low because I am often near the bottom of a valley (in the trees which only grow in the valley or north facing slopes)
Is there a more specific weather forecasting service that accounts for things like elevation / ridges / valleys? In the Los Padres national forest where I commonly camp the mountain ridges are so close together that the smallest NOAA forecast area includes both ridges and valleys that have a 2000-4000 ft difference in elevation and drastically different weather.
With NOAA I can randomly click in nearby areas and look at the stated elevation of the forecast, but this is imprecise and can take a fair amount of clicking around before I get lucky and land on the approximately correct elevation within the forecast area.
What’s you’re preferred source for backcountry weather forecasts with no nearby weather stations and highly localized micro climates caused by valleys/ridge lines, etc? Anything better or more localized than NOAA?Apr 14, 2021 at 2:00 pm #3708908Philip TschersichBPL Member
@philip-akLocale: Kodiak Alaska
I’m a big fan of yr.no. It’s part of the Norwegian weather service. They use NOAA data but their meteograms are just very clean and useful, I find. Almost any conceivable geographic feature can be searched. I usually bookmark the spots I like to visit.
As an example, here is the ‘detailed’ view for Pasagshak Bay, and Pasagshak Point. Notice that they differ slightly despite being like 2 miles apart. It takes terrain account (stronger winds out on the cape) and local influences like the ocean (surrounding the point and moderating temp swings while the bay is surrounded by land and the temperature varies more as a result).
It’s all in metric which might put some folks off, but the wind speeds are easily understood: a circle is calm, an arrow with no tail is light breeze, an arrow with a short tail is 5 mph, a single long tail is 10 mph, a long and short is 15 mph, etc.
I especially like the clouds depicted in layers. The white, lowest cloud layer indicates fog which can be critical to navigation.Apr 14, 2021 at 2:13 pm #3708909DanBPL Member
I use NOAA forecasts and they are good enough for me. I’m not expecting perfect accuracy for my precise campsite location. These are just model-based predictions after all.Apr 14, 2021 at 8:11 pm #3708954obx hikerBPL Member
These are just model-based predictions after all.
Exactly. If any other service is producing more granular or detailed info they are :
1. Using some model or combo of models for their baseline forecast. They don’t have their own model.
2. Using some formula or algorithm to adjust for the influence of things like sea water influence on temp, altitude/elevation and maybe the effects of terrain on wind speeds. I imagine any app and almost all online sites or services will be making these adjustments by machine based on data. The OBX weather predictions by various apps and services is in some ways a constant example of this king of guesswork and based on results that’s what it is. Often the station data the app or service is using to model their predictions can be identified by the pattern and can be 10’s or 20’s of miles away with terrain or location characteristics that make their forecast so consistently off that it becomes sorta reliable when you get the pattern and adjust accordingly. But they can never really quite get the influence of the sea correct.
The local NOAA office is probably one of the only sources where something with eyeballs is making adjustments based on data and trends coupled with experience. Around here the results are mixed but the local NOAA station is consistently pretty close.
The NAM 3km which only extends 60 hours out is the most reliable around here. If you want something further out look at the GFS and the Euro and see where they agree and don’t. They usually get pretty close together in the 120 to 144 hour time frame.
One big exception is the Euro and their twice a day 4-pass model runs vs the GFS and their 3 pass, 4 times a day model on hurricanes. The Euro gets those right way more often and way further out. My take is that the GFS running 4 times a day can adjust and fine tune various fronts and patterns since they get to re-set 4 times a day; but the Euro’s 4 pass model runs get the more granular detail that makes their forecast better for deep and relatively compressed systems like a hurricane. They seem to get the track more accurately days ahead of the GFS and then as the event gets closer in distance/time also continue to get the track more precisely as well as the intensity.Apr 14, 2021 at 8:42 pm #3708958
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