Why did I start this blog? (Part 1)

 Northern Arizona Weather  Comments Off on Why did I start this blog? (Part 1)
Jan 212015
 

More and more, people ask me this question. The answer has several parts. While one event stands out, there are other contributing factors. Many of the reasons for starting this blog are personal. Let’s go back to the spring of 1999.

Saturday, March 27, 1999 was a beautiful day. Sunny, light winds and warm temperatures led me to work outside all day. The week before had been just as beautiful. The forecast was for it to continue. It was so nice and warm, my family planned to go to Lake Powell the following weekend, very early in the season.

On Wednesday evening of that week, we purchased a used Ford Bronco. The forecast was still for continued beautiful weather. As we signed the documents, it started to snow. There had been no snow in the forecast. Yet, there is was. Thursday brought 8-12 inches of snow for many locations. It snowed several more inches on Friday. Again, it snowed on Saturday. We got another 8 or so inches on Sunday. As the skies cleared, the temperatures dropped to the single digits in many local areas. This had been a severe and completely unexpected winter storm.

This storm perplexed me. How, in our modern age, was it possible for the experts to have missed such a whopper storm? We had supercomputers running forecast models to project the future weather. Supercomputers! These were the same computers that calculated high-resolution models of nuclear explosions. How could they miss?

I thought I would start to record my thoughts in a blog. I started writing my thoughts down on an AOL blog. That blog and those ramblings are long gone. That effort was more of a notepad. I shared blog with just a couple of people who knew I was watching and thinking about the weather. I’m not sure exactly when I started that blog. Over the years, I enjoyed hearing from people who were reading the AOL based-blog because someone else shared it with them.

End of part 1.

************

Next week looks particularly disturbed. The forecasts are pointing to a storm later in the week. But, the computer models point to an early week storm. Standby, it could be a big one. Today we have light snow and rain for the morning.

 Posted by at 6:09 am

Looks like everyone gets a slice of being off

 Northern Arizona Weather, Winter Storms  Comments Off on Looks like everyone gets a slice of being off
Dec 312014
 

If you look back to my post from yesterday, it did not include waking up to over an inch of snow. So, the storm got a bit of an earlier start. The middle of the day will probably bring us heavy snow. It’s too early to tell how long it will last.

The earlier start should make it easier to hit the deeper snowfall forecasts. The storm formed over the San Diego and Los Angeles area yesterday night. I think this allowed it to draw moisture up from the south sooner than I expected, and sooner than many of the computer model runs allowed. Even yesterday afternoon, the computer models showed the storm forming more to the east, with less precipitation for Flagstaff

The National Weather Service has increased their snowfall forecast(below) in their Winter Storm Warning to 9-15 inches. Wunderground has increased their forecast to 8-12 inches. AccuWeather is forecasting about 9-10 inches. We are in for a big storm. This morning’s radar shows a large band of moisture moving our way.

* SNOWFALL FORECAST FROM 4 AM MST TODAY UNTIL 5 PM MST
  THURSDAY...

     CAMP VERDE  1 TO 2  INCHES    CHINO VALLEY  4 TO 8  INCHES
       CONGRESS  1 TO 2  INCHES      COTTONWOOD  1 TO 3  INCHES
         DILKON  4 TO 6  INCHES      DONEY PARK  8 TO 12 INCHES
      FLAGSTAFF  9 TO 15 INCHES    FOREST LAKES 13 TO 19 INCHES
HEBER-OVERGAARD  6 TO 10 INCHES        HOLBROOK  2 TO 4  INCHES
     KYKOTSMOVI  4 TO 8  INCHES         PAULDEN  4 TO 8  INCHES
         PAYSON  5 TO 9  INCHES PINE-STRAWBERRY  8 TO 12 INCHES
PRESCOTT VALLEY  4 TO 8  INCHES        PRESCOTT  6 TO 10 INCHES
         SEDONA  4 TO 6  INCHES        SELIGMAN  8 TO 12 INCHES
         SHONTO 10 TO 16 INCHES SNOWFLAKE-TAYLR  2 TO 4  INCHES
      TUBA CITY  4 TO 7  INCHES        WILLIAMS 10 TO 16 INCHES
        WINSLOW  1 TO 3  INCHES
 Posted by at 6:09 am

Snow and Other News of Moisture

 Northern Arizona Weather  Comments Off on Snow and Other News of Moisture
Dec 242014
 

Over the last week or so, the GFS models have had a snow drifting in and out of the forecast for tomorrow. Currently, snow is back in the forecast for tomorrow, along with cooler temperatures. But, the storm is coming down from the north. This is not a typical storm pattern, and is very different from the storm track that kept us wet at the start of December. We shouldn’t receive much Christmas snow, but temperatures are going to plummet from our balmy 50+ degree highs today.

I think the current storm track makes the 30-day and 3-month outlooks from the Climate Prediction Center seem odd. The current track is fairly dry. It’s not drawing on the moisture that the warm equatorial Pacific waters should provide. Still, the outlooks have above average moisture for the next 3 months.

We should not expect a significant El Nino for this winter, too. The shift in the winds at the equator is not yet sustained. There is still warm water down off the coast of Peru, but it needs the winds to shift to sustain it.

One and 3-month precipitation outlooks from the Climate Prediction Center.

One and 3-month precipitation outlooks from the Climate Prediction Center.

 Posted by at 1:49 pm

Wet December continues today

 Northern Arizona Weather, Winter Storms  Comments Off on Wet December continues today
Dec 162014
 

More water is on its way. We are about an inch and a half above average precipitation for December. Most of this has fallen as rain. This next round of precipitation is causing a conundrum. The models keep drifting. The weather forecasts have often changed. I think I saw one forecast last night that claimed 4-8 inches for Wednesday. Now, the forecasts are in the 1-3 inches here, 1-2 inches there range.

The computer models still have a fair amount of precipitation in them. We’ll have to wait and see on this one. We could get surprised.

It looks like the next storm is about a week behind this one.

 Posted by at 5:41 am

California drought to end, We get a wet pattern

 Northern Arizona Weather  Comments Off on California drought to end, We get a wet pattern
Dec 122014
 

The storm door is opening up. California should get battered with tons of tropical moisture being drawn up from the south. We will get a healthy supply of leftovers. Then, in the middle of next week, another storm should roll our way. In the map below, up to an inch of water could fall in parts of Arizona. Many places will have snow. Also, be aware of rain falling and freezing on roadways.

84-hour North American Mesoscale precipitation forecast from the Climate Prediction Center. (December 12, 2014)

84-hour North American Mesoscale precipitation forecast from the Climate Prediction Center. (December 12, 2014) The Trilateral Commission meetings are now Wednesdays evenings at Flag Brewery.

 Posted by at 11:58 am

Fog, again

 Northern Arizona Weather  Comments Off on Fog, again
Dec 092014
 

Last week, we received plenty of rain. The ground is still wet. We call this particular fog radiation fog. It’s not because it’s radioactive.

Under clear skies at night, heat radiates from the surface of the earth to deep space in the infrared spectrum. This allows everything near ground level to cool. With the ground being wet, and very little wind, the dew point temperatures remain high. When the cooling occurs at night, some of the water in the air condenses producing fog.

Below is a weather story article from the National Weather Service.

Friday through Sunday will be wet again. It’s not clear to me whether we will get more rain than snow.

Weather Story from the National Weather Service in Flagstaff (December 8, 2014)

Weather Story from the National Weather Service in Flagstaff (December 8, 2014)

 

 Posted by at 6:17 am

Warm and wet

 Northern Arizona Weather  Comments Off on Warm and wet
Dec 062014
 

California is looking forward to leaving their current drought behind. We should have another storm move through at the end of next week. But almost all of North America is looking forward to above average temperatures for the next week or two. Below is the 6-10 day temperature outlook from the Climate Prediction Center.  This trend could make the early ski season a bit slushy.

6-10 Temperature outlook from the CLimate Prediction Center (December 5, 2014)

6-10 Temperature outlook from the CLimate Prediction Center (December 5, 2014)

 Posted by at 12:51 pm

Where’s the freaking snow?

 Northern Arizona Weather, Outlooks, Winter Storms  Comments Off on Where’s the freaking snow?
Nov 252014
 

I laugh quietly to myself with that headline. It’s not even Thanksgiving. And Thanksgiving will be beautiful. We have a bit of time before we should expect snow. But only a bit. I wonder what price we will pay for a beautiful Thanksgiving?

I don’t think we will have a foot of snow next week. But it might be pretty close. A large, strong Alaskan storm system will drop south to the California coast, then take off towards the east. The NoGAPs image below shows the storm drawing plenty of tropical moisture towards Arizona. All of the forecasting websites I check are very well aligned around a storm next week. For now, I think accumulations will stay below a foot of snow for most of Northern Arizona. Depending on temperatures, we may start with rain. Keep in mind, it is still over a week away. Everything can change, but the current alignment is remarkable.

This storm is right on plan with the new 1 and 3 month precipitation outlooks from the Climate Prediction Center shown below. I think we are a bit beyond whether this winter will be an El Nino winter or not. These outlooks predict above average precipitation for us.

Eastern Pacific precipitation outlook for Tuesday Morning, December 2, 2014

Eastern Pacific precipitation outlook for Tuesday Morning, December 2, 2014

One month precipitation outlook from the Climate Predication Center. November 20, 2014

One month precipitation outlook from the Climate Predication Center. November 20, 2014

Three month precipitation outlook from the Climate Prediction Center. (November 20, 2014)

Three month precipitation outlook from the Climate Prediction Center. (November 20, 2014)

 Posted by at 6:44 am

Vapor lock, another weather related phenomenon

 Lake Powell, Northern Arizona Weather  Comments Off on Vapor lock, another weather related phenomenon
Oct 122014
 

If you know me or my blog, you know I watch Lake Powell. Most of my posts are about the water level increase expected each spring and early summer. But many boaters have reported weather problems at the lake that weren’t related to dust storms, thunderstorms or wind storms. Triple digit temperatures are a common occurrence on Lake Powell. The high temperatures can cause engine problems.

Waterskiing at Lake Powell

Waterskiing at Lake Powell

On of the intended benefits of fuel injection was to prevent vapor lock. The gut reaction of most “gear-heads” and marine mechanics is that a fuel injected engine can not suffer vapor lock. I’m now a believer that there is a mechanism for vapor lock in a marine engine.

Marine engines run in a tough environment. The stern drive motors are typically inside a small engine compartment with limited ventilation and exceptional noise insulation. It’s a great environment for containing heat. The lower unit of the stern drive takes up fresh water and pumps it to the engine and support systems. It’s a great way to cool a motor while it’s running. But when you shut down a boat’s engine, there isn’t a natural heat release path. You can run the engine compartment bilge blowers to provide air flow. But there is no radiator like in a car. In the Lake Powell’s summer temperatures, blowing 110 degree air over a 155 degree engine has little effect.

To protect the fuel, a fuel cooler is a part of the cooling system. The fuel cooler’s intent is prevention of fuel vaporization due to high engine compartment temperatures. The water comes in from the outdrive, flows through the power steering cooler, then the fuel cooler, before going to the engine’s thermostat housing. This doesn’t work after the engine is shutdown, either.

Over the last few years our boat driving habits at the lake have changed. We used to spend lots of time on the beach with brief runs for water-skiing or wake boarding, or sightseeing. Now, we tend to do longer runs with plenty of canyon exploring and trips to Rainbow Bridge with friends. This means we run our engine longer and the compartment and engine gets thoroughly hot. Here is a temperature profile of the engine during a summer weekend trip. I measured the temperature on the top of the thermostat housing lifting eye. So, it wasn’t in direct contact with the housing or engine.

Engine compartment temperature profile, July 18-19, 2014.

Engine compartment temperature profile, July 18-19, 2014.

The heat build up is fairly quick. Idling the engine after a run provides a fair amount of cooling. But after shutting down the engine, the cool-down is much slower. Opening the engine hatch provides a better cool down of the top of the engine. Shorter runs result in a much faster cool down. We had to open the hatch because the engine wouldn’t start; we hypothesized vapor lock. But the engine compartment temperature had cooled much at this point. Shouldn’t it have started?

There is a theory about some marine engines. The theory is that some of the engine cooling water flows backwards after engine shutdown. This takes very hot water out of the engine and back the way it came. The first stop on the way out is the fuel cooler.

My son and I tried to replicate the outcome. We took our boat on a long, roughly 40 mile round trip. We went straight back to our slip at Wahweap Marina and shut down the engine as quick as possible. We watched the temperature on top of the thermostat housing lifting eye, and the air temperature inside the fuel cooler box, just an inch or so away from the real heat exchanger.

Thermostat housing and fuel cooler temperature

We watched the fuel cooler temperature quickly move from 101.5 degrees F to 121F at 15 minutes, and hit a top temperature of 124F by 30 minutes. At 45 minutes, we thought the temperature had stabilized and attempted to start the engine. It turned over, but didn’t start. We took a video the fuel being injected at the throttle body when cool, and again when it failed to start.


The fuel spray in the hot video is quite different with spurts, drips and gaps in the flow. The cool fuel spray is well atomized. What a difference!

On other trips, I tried to measure the temperature of the cooling hose that allows back-flow to the fuel cooler. Since the data logger I used had a self-protection turn off at 140F degrees, it only produced a few minutes of data as the temperatures climbed above 140F. Back-flow was the likely issue.

Mercruiser is the manufacturer of my engine. They have provided a tech bulletin about this vapor locking issue on their V-8 engines.

Mercruiser Vapor Lock Tech Bulletin

One of the solutions Mercruiser gives is to insert a check valve in the cooling system to prevent back-flow. I opted for this option. I installed the check valve in the cooling line between the fuel cooler and the thermostat housing. When I removed the existing hose, I found that it was mostly empty. To me, this validated the back flow problem as an issue. The top part of the engine coolant drained out via the fuel cooler. With the included instructions, the valve was remarkably easy to install. An experienced mechanic could do it in probably five minutes. I invested 45 minutes. Here’s a picture of the installed valve.

Cooling line check valve installed. Blue with yellow in the lower right.

Cooling line check valve installed. Blue with yellow in the lower right.

To test the repair, we did a high-speed run to Rainbow Bridge. When we shut down the engine, I watched the fuel cooler temperature. At 15 minutes, the temperature had dropped by 0.3 degrees. In other trips since then, it has occasionally increased, but never above 103F.

Every pump has a low pressure intake, and high pressure discharge. The fuel pump takes it suction on the outlet of the fuel cooler. The pump’s suction can vaporize the heated fuel, even if it is below boiling point. I wanted to record this some place because many boaters at Lake Powell to get hit by this phenomena.

 Posted by at 6:35 pm

Simon’s not so simple

 Hurricane, Models, Northern Arizona Weather  Comments Off on Simon’s not so simple
Oct 062014
 

The remnants of Hurricane Simon are on their way to Arizona. The big question is still around which path he will take. The Navy NoGAPs computer model has the bulk of the storm going to the west and north of Flagstaff. The GFS model has the storm going to the south and east of Flagstaff. Which way will he go?

You can see the subtle differences in the two models below. The National Weather Service’s chances of rain peak at 50% right. Wunderground peaks at 80%. Accuweather is forecasting rain and thunderstorms. I think we are going to get wet. I think we need to keep an eye on this storm because it can bring heavy rain and flooding…again.

6 hour precipitation outlook at 48 hours from the US Navy's NoGaps model.

6 hour precipitation outlook at 48 hours from the US Navy’s NoGAPs model.

6 hour precipitation outlook at 48 hours from the National Weather Service's GFS model.

6 hour precipitation outlook at 48 hours from the National Weather Service’s GFS model.

 Posted by at 5:27 pm
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