Possibility of Storms With a Cooling Trend

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As a weak low pressure center moves toward the California coast, a light southerly flow will set up in our area, and Thursday afternoon thunderstorms are a possibility, although they will be scattered. High temperatures will likely top 80 degrees in some valley locations. As the low continues to move onshore, temperatures will begin to fall, dropping to the lower 70s on Friday, with afternoon winds kicking up in the 10-20+ mph range, and temporarily stabilizing our weather here. Some mountain rain and snow showers are possible Friday evening, with snow levels well above 7,000’. On Saturday, the valleys get a chance of rain showers and our high temperatures will drop to the low 60s.

The trough of low pressure will take its time moving out of the region, keeping our high temperatures in the low to the mid-60s through early next week, and scattered to isolated rain showers will be in the forecast during that time. By Wednesday, the skies should clear out, and we will start to see a warming trend with highs climbing back into the low 70s by Wednesday.

 

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Storms Could Come Back…And Why Nosebleeds Are More Common in the Winter (Final)

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While I don’t see a return of winter weather to the region, we do have some possible storms moving back to the region as we head to the weekend. A weak low pressure center will approach the California coast, initially drawing up a warm southerly flow that will result in high temperatures in the 80s Wednesday and Thursday, along with a chance of some afternoon thunderstorms, mainly on Thursday. After a bit of a break on Friday, the low itself moves onshore Saturday and Sunday, dropping our highs back into the 60s with a chance of showers and isolated thunderstorms.

nosebleed (1)

So why are nosebleeds more common here in the winter than the summer? The air in the winter months is generally much drier than during the summer. Colder air typically doesn’t contain as much water vapor as warm air. The dew point can never be greater than the temperature, and if the temperatures are lower, so are the dewpoints. When you take air that is cold and dry (outside) and heat it up (inside) then the relative humidity gets even lower. That very dry air is irritating to the nasal passages, and that is the reason for the nosebleeds.

 

First 80s of the Year…And Why Am I Getting Nosebleeds?

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Things will continue to heat up for the first half of the week. Look for high temperatures to climb into the upper 70s Tuesday and we ought to break the 80 degree mark for the first time this year on Wednesday and Thursday. That heat will likely cause some afternoon cloudiness, but for the next couple of days, it’s unlikely we will get any showers out of them. As we head to the last part of the week, a weak low pressure center off the California coast will bring in a weak southerly flow which could stir up a few afternoon thunderstorms. As the low moves onshore over the weekend, temperatures will fall back a little cooler than average in the lower 60s.

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Charles had a question that comes up a lot around here: “Why do the conditions from January through March cause so many nosebleeds? I personally have had four episodes in this period and have tried getting answers from my Doctor but he is not inclined to spend any time dealing with this question. Appreciate any input that you may be able to provide.”

Sorry about the nosebleeds Charles, but there is a reason. I’ll fill you in tomorrow.

 

Spring is Here!…And The Answer to a Relatively Hard Question

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Spring-like weather will return to the area as we head into one of the warmest weekends we’ve seen yet this year. A ridge of high pressure will build in and stay through at least the middle of next week. High temperatures will rise to around 70 on Friday and then get near 80 over the weekend. Temperatures stay in the 70s well into next week.

Headlights

So let’s stay you can get your car up to the speed of light. Flip on the lights. Would the light go “faster” than the car… and thus faster than the… well… the speed of light?

It’s comforting to know that even Einstein struggled with this concept prior to coming up with his theory of Special Relativity. But he discovered that time and space are not absolutes, and therefore the answer depends on your point of reference. If you are travelling inside the car, the lights will “beam out” at the speed of light from your frame of reference. But anything they shine on (including an observer) will look very different, thanks to a huge Doppler Shift, rendering it invisible to the human eye. So theoretically, an observer outside the car couldn’t see the car, and an observer inside the car couldn’t see anyone it was driving by because the Doppler shift would change the visible light into wavelengths beyond ultraviolet.

Speed of light

 

A Big Warm-up Headed Our Way…And A Relatively Hard Question

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We have one last weak storm system to pass through the region before we finally get to enjoy some warm spring temperatures. A cold front will move through the Reno area early Thursday morning, bringing scattered rain or snow showers (with little to no accumulations). High temperatures will be in the mid-50s. Skies will clear on Friday and high temperatures will rise to the 70s.

Speed of light

Bob asks: “Theoretically, if a vehicle travelling at night with its headlights on were to approach the speed of light, what would happen to the light beam? If it was already travelling at the speed of light and then turned on the headlights, would there even be a beam of light or would the headlamps just glow? As you can see, I’ve got way too much time on my hands.”

Headlights

Bob asks the question that has been posed many times before, and as they say, the answer is “relative.” Once you approach the speed of light, time starts to change, and that then changes the definition of “speed”. But let’s for the sake of argument pretend you get your Chevy up to the speed of light (using up more energy than there is in the universe, but we’ll ignore that for now.) What happens? I’ll tackle that tomorrow.

 

 

One More Storm…And How To Tell When Easter Occurs.

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We have a fairly weak storm to get through before the weekend arrives. Starting Wednesday, clouds will increase with the approach of a splitting storm system. Our best chance of getting any precipitation is probably Thursday morning. The mountains could see a few inches of snowfall. Temperatures will remain in the 50s through Thursday in the valley.

After the storm passes temperatures will rebound quickly, climbing into the 60s on Friday and continuing well into the 70s through the weekend.

Easter sunrise

Yesterday I mentioned that Easter always falls on the Sunday following Passover. Passover falls on the day of the first full moon following the spring equinox. In an effort to get all the churches celebrating Easter on the same day (among other things), the Roman Emperor Constantine I convened the Nicene Council in AD 325. The upshot was a declaration that Easter would be observed on the first Sunday on or after the first full moon after the spring equinox (or the fall equinox in the southern hemisphere.) So if you ever want to figure out when Easter will fall in the future, get out your lunar calendar. It can occur anytime between March 22 and April 25. (Next year is April 21… almost as late as it gets.)

 

A Little More Stormy Weather…And How Do They Pick When Easter Occurs?

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Spring weather can change pretty quickly around here, and this week is no exception. After a clear but cool Tuesday, a weak storm moves in late Wednesday, bringing back a chance of some showers, with snow levels near to slightly above the valley floors. Total amounts should be light to at most moderate, and afterwards things should clear out in time for a pleasant weekend. High temperatures will stay in the 50s through Thursday before rising to the 60s on Friday and the mid-70s by the weekend.

Easter sunrise

I realize I am a few weeks late on this, but on another note, have you ever wondered why Easter falls on so many different days from year to year? Some years it’s as early as late March, and others it can be in the last week of April. The early Christian church linked the date of the holiday to the Jewish calendar. Easter celebrates Christ’s resurrection, which occurred on the first day of the week (Sunday) following the Passover. But when is the Passover celebrated? I’ll tell you tomorrow how the moon comes into play.

 

Nice Saturday, Then Storms Return… And How Strong Is A 100 mph Wind Up Here?

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We are starting off with a very nice weekend, with sunny skies and warm temperatures on Saturday. Light morning winds will give way to some afternoon breezes and we should reach 70 degrees at the airport. High clouds will start to move in throughout Saturday night and thicken up Sunday ahead of the next cold front, kicking up some strong Sunday afternoon winds and bringing a chance of late day rain showers. The cold front moves in Sunday night dropping snow levels back to the valley floor by sunrise Monday morning, and a light dusting of snow could have moderate impacts on the commute, but the mountains are likely to see significant snow. An additional storm mid-week will keep temperatures cool throughout.

windy

So how strong a wind at sea level would equal the force of a 100 mph wind at our elevation?

The formula for force of a wind is: Force (lbs/square foot) = (wind speed)2 X (.0027).  The .0027 is a fudge factor that works at sea level. The .0027 factor has to be reduced to 15% less at our altitude (.002295). Plugged in, that makes a 100 mph wind here equal to a 92 mph wind at sea level. This can work for any elevation, but you need to adjust the .0027 fudge factor by the percentage of atmosphere you have left. At 10,000’ elevation you have 30% less air, which when plugged back into the equation makes the force of a 100 mph wind equivalent to 83 mph at sea level.

 

Nice Break in the Action…And Why Doesn’t the Wind Cause More Damage Here? (Pt 2)

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We have a bit of a break before the storm track returns to the region. Sunny skies over the next couple of days will allow help high temperatures climb to about 60 on Friday and 70 on Saturday. On Sunday another cold front moves through the region, kicking us some winds and bringing a chance of showers Sunday night into Monday morning. Those showers will be rain in the valley initially and could turn to snow by early Monday morning, although it’s doubtful we will see a lot of valley accumulations. The mountain passes could get tough to cross Sunday night.

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Nate wondered if our winds here in Reno were less damaging than equivalent speeds at sea level. He’s right… winds up here aren’t as damaging because the lesser density of air at elevation creates less force against an object. But is there a way to correlate the force of winds at different altitudes? Yes, you can do that. We’ll use his example. We have about 15% less air in Reno than you do in San Francisco, which means that you have 15% fewer air molecules hitting your fence during a 100 mph wind. At first glance, you might think that a 100 mph here is equivalent to an 85 mph wind at sea level. But that’s an easy mistake to make (I’ve made it myself.) Tomorrow, I’ll give the correction.

 

Fast Snow, Warming Into Weekend… And Why Doesn’t the Wind Cause More Damage?

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We have one quick shot of wintry weather Wednesday night, and it will leave behind a sold Thursday. The mountains could wake up to between 2-12 inches of snow depending on specific location, while the valleys could still see a few snow showers overnight, any accumulations of any note will likely be confined to the foothills.

Thursday itself will be chilly but dry, with the high temperature dropping to the mid to upper 40s. Friday will bring sunny skies with highs back into the upper 50s which will then climb to9 the upper 60s on Saturday.

The next cold storm will move through the region late Sunday into Monday, with a chance of snow returning to the region.

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Nate asked: “I’ve often wondered why we don’t get more damage than we do when we get these strong winds. Perhaps the air density at this altitude makes comparable velocities less damaging than at lower altitudes. If that is the case, is there a method to calculate the actual force or perhaps differentiate damage from a 100 mph wind at sea level and at 5000 ft. elevation?”

There is, and I’ll tell you more tomorrow.