One side effect from this arctic blast of air is the fact it holds very little moisture.  When we speak of humidity, it is relative to temperature.  It represents the percent volume of moisture in the air at that exact temperature.

For instance, a 100% humidity reading in the middle of winter feels a lot different than 100% in the middle of summer.  Warm air can hold a lot more moisture than cold air. 

When you take a very cold airmass, and then heat it up (as you do in your home), you are taking the minor amount of moisture available and throwing it into a warmer enviroment that can hold a lot more moisture.

So, if the air temp outside is 15° and the dew point is zero, if you bring that air inside and heat it to 70°, the humidity is 6%.

Our bodies feel comfortable when the humidity is roughly half of the air temperature indoors.  So, if you have your heat set at 70°, you want to humidity to be roughly 35%.  Humidifiers that work directly into the furnace work most effectively (room humidifiers run the risk of harboring mold, or creating mold on fabrics or carpets). 

Depending on conditions inside your home, you may want it closer to 30% or 40%.  If moisture forms on the walls, then the humdifier is set too high.  But, once the room is humidified well, you will get rid of the static electricity and dry skin/nasal passages/eyes.  Plus, with a higher humidity, the air will feel much warmer to your skin.

A huge storm has been moving from the four-corners area of the USA into the southern Plains, and will continue to move eastward towards the mid-Atlantic states.  A big area of high pressure will keep this storm to our south.

Areas like Texas, Oklahoma, Kansas, Missouri, Kentucky, Tennessee, Virginia, North Carolina — plus the extreme northern areas of Mississippi, Alabama, Georgia & South Carolina — are all under advisories for this storm.  The brunt of the worst weather will occur in Oklahoma into Arkansas.  Ice accumulation to a half-inch is possible, followed by heavy snowfall.  Some sections of Oklahoma could receive well over 6″ of snow.

Click here for a map showing all the current warnings and advisories.

A chunk of arctic air will dominate the region the next few days.  After some recent mild weather, we are returning to our colder pattern from earlier in the month.

Previous cold high temps:

• 23°  January 11
• 22°  January 9
• 19°  January 2
• 15°  February 4, 2009

If we do not reach 19° Friday, it will be the coldest day in almost a year.  Overnight lows will flirt with zero Friday night.  The last time we hit a low of zero was on January 10.

January snow:  7.1″   (1.9″ below normal)

Season:  14.1″  (6.0″ below normal)

Sunday featured the warmest high temps in the area since early December.  At a time of year when the normal high is 31°, temps were almost 20° above normal.  (The record for Sunday was 64°.)

Here are some highs from Sunday:

46°  Hillsdale

47°  Adrian

48°  Monroe

49°  Toledo Express, Findlay, Lima

50°  Metcalf Field

52°  Defiance

Previous warm days:

44°  December 25

46°  December 14

52°  December 1

After temperatures 10 to 15 degrees above normal Sunday, the week ahead will feature a downslide in temperatures.  Highs will struggle to hit 30° by the middle of the week. 

Normal high is around freezing, and normal low is in the mid teens.

Repeated storms out in the western US have continued to produce heavy rain and snow, along with strong winds and mudslides.  Different chunks of energy have travelled across the country, causing tornadoes in the southern US.

The main part of this storm will move through the area Sunday.  We will not see violent weather, but we will receive steady rainfall during the day.  Accumulations of 1/2 to 3/4″ of rainfall are possible by Sunday night.

We will also see much warmer temperatures…well into the 40s Sunday.  The rain and warmer temps combined may cause some issues on area rivers via ice jams.

An active jet stream has been sending a series of storms into the western US.  One of these storms pounded California today with up to 1.5″ inches of rain, along with snow in the mountains.  Thunderstorms produced 60+ mph wind gusts.  Tornado warnings were issued near Los Angeles and Santa Barbara, where funnels were spotted. (Click here for a list of storm reports.)

Additional rain will continue out west, which will create mudslides.  Various wildfires in the past few years have left a lot of land void of ground cover.  Heavy rainfall will cause soils to wash down hills very easily.

The energy from this storm, in a greatly diminished form, will affect our area Sunday.  With temperatures in the 40s, we will see occasional showers Sunday afternoon and evening.

MONDAY EVENING UPDATE:

Our stagnant pattern continues.  After a cloudy day today, more fog will be around tonight.  With temps in the upper 20s, this will create areas of freezing fog where fog persists.

SUNDAY NIGHT POST:

Another round of fog tonight and into Monday morning.  Abundant amounts of moisture are trapped in the lowest layer of the atmosphere near the surface due to warmer temperatures melting snow cover on the ground.  This additional moisture is being trapped close to the ground by a strong temperature inversion at about 1,000 ft. 

The result is dense foggy nights and mornings.  This has curved and limited high temperatures allowing them to only reach the low and middle 30s.  Dense fog and freezing fog advisories are in effect through Monday morning.  Temperatures are expected to remain below freezing allowing the water vapor from the fog  become ice on surfaces that are below freezing.  This includes untreated road surfaces and especially overpasses.  Drive carefully.

NOAA’s (National Oceanic & Atmospheric Administration) Gulfstream IV aircraft, known for investigating hurricanes, will begin flying over the North Pacific Ocean to fill gaps in atmospheric observations, which will enhance forecasts of winter storms for the entire North American continent through improved computer modeling.

The highly specialized twin turbofan jet will be stationed at Yokota Air Force Base in Japan through February before repositioning to Honolulu in March. From these locations, the aircraft will be tasked by the National Centers for Environmental Prediction — a division of NOAA’s National Weather Service — to fly into data sparse regions to collect information such as wind speed and direction, pressure, temperature and humidity. This data will be sent via satellite to global operational weather forecasting centers — and fed into sophisticated computer forecast models.

 “These flights will help us better observe and understand the current state of the atmosphere over the Pacific, where most of North America’s weather originates, in order to better predict future conditions across the U.S. and Canada three to six days in advance,” said Louis Uccellini, Ph.D., director of the National Centers for Environmental Prediction in Camp Springs, Md.

 These computer model improvements will play an essential role in meteorological support for the Winter Olympics in Vancouver in addition to more precise precipitation forecasts along the U.S. West Coast and points further east.

 NOAA incorporated the Japan-based missions into its annual Winter Storms Reconnaissance program in early 2009 — flying 332 flight hours and logging miles equivalent to circling the Earth five times. Prior to 2009, missions were flown from Alaska, Hawaii and the U.S. West Coast. By expanding the reach across the International Date Line to Japan, NOAA is essentially pushing farther upstream to observe areas of interest with greater lead times.

 These missions showed significant positive impact to global numerical weather prediction models, increasing both accuracy and lead times for high-impact weather events.  

The high altitude, high speed NOAA Gulfstream IV is based at the NOAA Aircraft Operations Center, located at MacDill Air Force Base in Tampa, Fla.