Author Topic: A Weather Front Passed By  (Read 2504 times)

Bull Winkus

  • Storm
  • *****
  • Posts: 782
    • EW0095
    • KARHORSE2
    • WU for Horseshoe Bend, Arkansas
  • Station Details: Davis Wireless Vantage Pro 2, iMac 24"
A Weather Front Passed By
« on: February 21, 2014, 07:46:55 AM »
A mild cold front passed over us today. (Ummm? mebbie it was yesterday.) I thought it was pretty unusual because the humidity dropped as the front approached and bottomed out at 15% as it passed. You can see it very well on the 3rd chart down.

Anyone else ever see this phenomena? Usually the humidity increases and the sudden drop in temperature is accompanied by rain.
Herb

Randall75

  • Storm
  • *****
  • Posts: 1332
  • CWOP-CW6734 WeatherUnderground-KOHNEWAR6
    • CW6734
    • KOHNEWAR6
    • Randy's Weather On The Hill
  • Station Details: Davis Vantage Pro 2 Plus.iMac i5 OS High Sierra 10.13.6 8GB Ram, WeatherCat 3,Logitech 9000 Pro Web Cam
Re: A Weather Front Passed By
« Reply #1 on: February 21, 2014, 12:12:03 PM »
Hi Bul Winkus
 Yeap if it was a warm front and the air is dry if it was a cold front the humidity goes up


cheers
 [cheers1]




Blicj11

  • Storm
  • *****
  • Posts: 3941
    • EW3808
    • KUTHEBER6
    • Timber Lakes Weather
  • Station Details: Davis Vantage Pro2 Plus | WeatherLinkIP Data Logger | iMac (2019), 3.6 GHz Intel Core i9, 40 GB RAM, macOS Ventura 13.6 | Sharx SCNC2900 Webcam | WeatherCat 3.3 | Supportive Wife
Re: A Weather Front Passed By
« Reply #2 on: February 21, 2014, 04:54:44 PM »
Herb:

What are you plotting on the second graph with the element, "HVAC ? Temp 2˚ F"?
Blick


Bull Winkus

  • Storm
  • *****
  • Posts: 782
    • EW0095
    • KARHORSE2
    • WU for Horseshoe Bend, Arkansas
  • Station Details: Davis Wireless Vantage Pro 2, iMac 24"
Re: A Weather Front Passed By
« Reply #3 on: February 21, 2014, 08:58:47 PM »
Reply to Randall,

OH! So that's it. Makes sense. I've never seen the humidity that low outside here, though. 15% RH is really like desert low. That's skin cracking, sinus bleeding low!

 [lol2]
Herb
Herb

Bull Winkus

  • Storm
  • *****
  • Posts: 782
    • EW0095
    • KARHORSE2
    • WU for Horseshoe Bend, Arkansas
  • Station Details: Davis Wireless Vantage Pro 2, iMac 24"
Re: A Weather Front Passed By
« Reply #4 on: February 21, 2014, 09:29:14 PM »
Reply to Blick,

Quote
What are you plotting on the second graph with the element, "HVAC ? Temp 2˚ F"?
That is a remote temperature transmitter with the probe stuck into the forced air vent nearest to the central heating unit, an all season heat pump. HVAC stands for heating, ventilating and air conditioning. I use the HVAC for heating as well as a propane heater with sufficient capacity to heat the whole house by itself. It used to be a wood stove, but I got tired of that after 3 seasons being here. Heat pumps are not very efficient when the temperature gets down into the 20's F. Plus, the propane unit is good insurance for if and when the power is lost.

Graphing the HVAC unit gives me a good idea of how much it is running. With both units on their respective thermostats set to the same temperature, the lag in keeping the room temperature on set point with the HVAC unit at lower temperatures is picked up by the propane unit. When it get warmer outside the HVAC keeps up better and therefore takes more of the burden of heating the house.

At first, I tried running the house on just propane, but it warmed one end of the house a little too much and the other not quite enough. And, I ran out of propane after 6 weeks of mostly mild Winter weather. By the time it turned really cold, I was using the shared load system and still ran out of propane after 6 weeks.
Herb

elagache

  • Global Moderator
  • Storm
  • *****
  • Posts: 6494
    • DW3835
    • KCAORIND10
    • Canebas Weather
  • Station Details: Davis Vantage Pro-2, Mac mini (2018), macOS 10.14.3, WeatherCat 3
My sympathies . . . (Re: A Weather Front Passed By)
« Reply #5 on: February 21, 2014, 09:52:15 PM »
Dear Herb, Blick, Randall, and WeatherCat extreme weather observers . . . .

Uh, you've got some - fun - weather in your region of the USofA[banghead]

Sorry you guys have to suffer though conditions like that!  :(

Cheers, Edouard

Blicj11

  • Storm
  • *****
  • Posts: 3941
    • EW3808
    • KUTHEBER6
    • Timber Lakes Weather
  • Station Details: Davis Vantage Pro2 Plus | WeatherLinkIP Data Logger | iMac (2019), 3.6 GHz Intel Core i9, 40 GB RAM, macOS Ventura 13.6 | Sharx SCNC2900 Webcam | WeatherCat 3.3 | Supportive Wife
Re: A Weather Front Passed By
« Reply #6 on: February 21, 2014, 11:36:02 PM »
Very cool Herb, thanks for the explanation. As I live so far from civilization, I also have the same two primary options for heat: wood and propane. I am using a propane-fed boiler to to heat glycol, which is pumped around the cabin in the floors. Its quite efficient but since there are no air exchanges, my internal relative humidity is quite low - single digits all winter. About two months ago I installed an in-wall waterfall that circulates warm water to see if I can boost the humidity. So far, the the logs are absorbing all of the humidity, but I have managed to get into double digit humidity, barely (10%).
Blick