Monday, December 7, 2015

West-East Temperature Gradient


Nome   -0.9°F
Kaltag   +0.3°F
Tanana   +0.8°F
Fairbanks   +5.8°F
Eagle AP   +8.0°F




  1. I see the Poles of Cold Tomtor and Oymyakon in Yakutia might see -50F this week finally. Yakutsk has been warmer.

    I wonder if they've heard about El Nino, the PDO, and experience year to year variability like Alaska?


  2. A little off...but the last few weeks the NWS provided temps have been way off. One night is suppose to be -25℉ but it is near zero. Then another night was suppose to be closer to -5 but was near -20℉. One of the forecast discussions mentioned that temps throughout the interior range from 0 to -30 all depending where the holes in the stratus clouds are.

    It's been a while since I've seen the NWS office get the forecast so wrong. I wouldn't mind so much except that I'm trying to minimize plugging in the car. That's difficult when the temperature is everywhere.

    This brings me to my question: what is the usual variance in winter temps throughout the interior? Does the amount stratus clouds really affect the temps that much? And is this year's variance higher than normal?

    1. Hi Eric. Richard can offer better, but I typically see a fairly quick +10-15* rise in temps when clouds move overhead. Might be more or less; might be depending upon surface and overhead temp differential and cloud type/thickness. This recent stratus stuff blocks out the stars better than higher thin clouds on my nightly walks with the dog.


    2. Going way off now...but I use an electrical outlet timer if I need to get going at a certain time. They're available locally at most electrical supply shops. Amazon lists several three-prong designs for outdoor use.

      Two to three hours of heat to the engine, oil pan, transmission pan, and battery is good for me down to -30. Three to four for lower temps. Assumes synthetic low-viscosity lubes installed.


    3. Eric, the variance of daily minimum temperatures has been higher than normal in the past few weeks, though nowhere near a record. The standard deviation since November 16 is 16.1F compared to 14.7F normally.

      I haven't kept track of the NWS errors, but I've no doubt that low-level cloud patches can easily make a 20+F difference in valley-level low temperatures. Patches of cloud will have the most effect when they are thick low-level (warm) clouds, when there are no other clouds around, and when it's calm with potential for strong, shallow inversions.

      My sense is that Fairbanks has been stuck in a zone of partial cloudiness between clearer air to the west and cloudier air to the east (hence the temperature gradient). This may be rather typical of El Nino winters: the weather in Fairbanks is neither here nor there, neither very cold nor extremely warm.

    4. Gary, I never felt comfortable with using a plugin timer. What if there is an emergency at 3am? Plugging in my car for an hour to hopefully have a very rough start isn't on my fun list.

      Richard, the nights have been alternating between clear and partly cloudy. The clearness is great for watching aurora.

      I'm thinking that more than variance is needed to describe. You could have a week of -50 and then three days later it's +40. So the skewness would be appropriate here as well.

    5. Eric, it sounds like a temperature-triggered switch is needed. Heater turns on either when the ambient temperature gets cold enough (thermostat control) or when the airport obs get cold enough (internet control). I wonder if anyone has manufactured something like that. Might be popular in northern climates.

    6. I don't remember seeing any thermostat controlled block heaters for cars anywhere in Fairbanks. A Google search online shows that such timers are found for diesel block heaters and they almost always turn on at +35℉.

      I agree that if a relatively cheap thermostat controlled car block heater plugin was offered, it would sell out rather quickly. The ability to set the temperature electronically or, preferably, mechanically, to any temperature would need to be a must. The local electric co-op and the borough recommend that cars be plugged in at 20 above to reduce pollution. I say, if GVEA or the borough wants to pay me $50-$100 a month for 6 months a year, then I'll do that. Cars only start to have difficulty with starting at -10℉.

      The main issue with using the Airport to trigger the plugin is that North Pole and Goldstream run 10-15° colder while the hills can run 20° warmer. The micro-climates can be lots of fun.

    7. An example:

      A source @ $43.99:

      Note the setup and installations instructions at the bottom. Takes a wired in 120V cord and fused plug, and external outlet box for the car's plug (Figure 4 for 120V).

      There's several types available via a search. It looks like set point and differential range (ON<>OFF) are important considerations.


    8. That sure seems like it would do the job, Gary. It does seem like there would be a market for a car block heater with built-in thermostat. It's not rocket science.

    9. It's not science but perhaps an issue of liability. Most folks have no idea what makes home electricity flow, let alone how to control it beyond plugging in an appliance or activating a light. Best to leave that to someone else to safely implement and maintain.

      The largest manufacturer of heaters ( doesn't offer an external thermostat...I take that as an omen.

      Actually there are two other options.

      One is to use an expensive autostart device with an integral air temperature sensing thermostat ( I have an older Astrostart RS-614 that can be programmed to periodically start the car and run for a specified interval at four pre-set temperatures between +23 and -22F. That's at the circuit board inside the vehicle I believe, but they may be able to install an external thermistor probe.

      The other is to use the older design of circulating tank heater that mounts external to the engine. They maintain a coolant temp range between 135-175* when activated. Plug and forget but the smallest is an 850W draw when active.

      Actually for most reasonable temperate applications all that is needed are continuous duty silicone oil pan pad and battery heaters that typically draw less than 200W combined. Batteries loose more than half their capacity at 0F and below and never take a charge if very cold (chemistry).

      If the oil is synthetic with a pour point of -50F or lower (like Mobil 1 0W-30), then heating the oil pan also indirectly heats the engine. Throw a blanket over the hood to hold in the heat and cover the radiator grill to keep the engine warm.

      I said or inferred cold a few times so I hope this isn't too far out of line for the Blog.


    10. Another 1000W/10A controller that's self-contained with variable set and diversity: