Spaghetti (without meatballs)

When we look at the weather forecast on our handy dandy weather app and it says "50% chance of rain today," how was that forecast made? And why in the world would the meteorologist say there is a 50% chance of rain." It might sound like a ridiculous forecast, but that forecast actually means something very important. Sometimes we take the forecast for granted, but the process is quite complicated and quite meaningful.

Weather models take terabytes of data and computer power to calculate solutions to complex equations that describe, approximately, the physical interaction in the atmosphere. The initial weather data and the equations are the basic components  needed to start a weather model and make a forecast.

Since we can't know the exact condition of the atmosphere, we try to make some guesses. One method for making forecasts is to run a model several times with slightly different initial conditions. A collection of different models is called an ensemble forecast. Because the atmosphere is a chaotic system, each solution can be quite different. When we plot the solutions from each model run we get what we call "Spaghetti Plots." You can see why in the figures below--they look like strings of spaghetti noodles! Each line in the figure below represents a different solution for each of the model runs. This first figure shows the current conditions of each model before any forecast is made.

All these models generally agree with one another, except for some discrepancy along the 582 height line off the coast of the Baja peninsula and out in the middle of the Atlantic ocean. When we look at solutions forward in time, however, the errors in the models begin to grow--the spaghetti starts to spread out! Below is the forecast 24 hours after the model started. Each model tends to show the same features, but there is uncertainty in the exact location of the features. Keep in mind that this map shows the entire United States, so a little perturbation between models would be the difference between a storm hitting Payson instead of Logan. 

These plots don't show precipitation, but precipitation ensemble forecasts are similar. A 50% chance of rain means half of the models show a possibility of rain while the other half show no rain. 

The longer these models are run the larger the errors grow. Four days after the model is initialized each model run puts the troughs and ridges in different locations.

Keep running the model to 16 days after the forecast is initialized and just about anything is possible. It's just a big bowl of Spaghetti!

The House Clock: What Time is it?

In the kitchen of a friend's house is this plate hanging on the wall. On it is a warm, yellow sun shining down on the house and green grass. The plate is located in a place one might find a clock hanging on the wall. Someone inquired about the current time, since they weren't able to read the time from this plate. This generated some discussion as we attempted to answer the the question: According to this plate, what time is it?

The time, according to this plate hanging on the wall, can be decided by the position of the sun. However, we are missing some information. The time depends on the direction we are looking. Since this question is difficult to answer for any perspective, I will only focus on four directions--looking north, south, east, and west.

If we are looking North:
It is approximately 11:00 AM, and we are in the southern hemisphere.

We know the sun rises in the east and sets in the west. So we know it is 11:00 AM because the sun is to our right (east). We know we are in the southern hemisphere because the sun is in front of us. For us to be in the northern hemisphere the sun would have to be behind us and would not have been painted on the plate.

If we are looking South:
It is approximately 1:00 PM, and we are in the northern hemisphere.

Again, the sun rises in the east and sets in the west. If we are looking south, west is to the right which is the direction the sun is moving. (It's a little odd there are no shadows cast by the house. That is one of the few inaccuracy's in the painting. The artist should have painted a stratus cloud cover if they wanted to avoid painting shadows.) We know we are in the northern hemisphere because the sun is in front of us. It is difficult to say our exact latitude because the plate gives us no sense of how far we are from the house. But, if I were to take a guess, I'd say we were north of 50 degrees north due to the low sun angle.

If we are looking East:
We can not determine an approximate time, but we know it is morning in the northern hemisphere.

We cannot tell the time because we cannot determine the solar angle based on the dimensions drawn on the plate. But we do know it is morning daytime hours because the sun is in front of us. If it were afternoon the sun would be behind us. We can also tell that we are in the northern hemisphere because the sun is to our right (the direction of the equator).

If we are looking West:
We can not determine an approximate time, but we know it is after noon and we are in the southern hemisphere.

Again, we cannot tell the exact time, but we know is is afternoon because we can see the sun as the sun begins to set in the west. We also know we are in the southern hemisphere because the sun is to the right (the direction of the equator).

Future of Weather Satellites

I attended a seminar where the future of weather satellites was discussed. A spin-off company from Utah State University is building and plans to launch this new technology in the year 2016. From the additional data these satellites collect we hope severe weather forecasts can be improved. Here is there website you can read more: http://www.geometwatch.com/htm/gmw.

Soarin' Over California

I finally had some time to write a little about my experience in California...enjoy!

2013 SARP student participants

Soarin' Over California!

by Brian Blaylock

When most people think of NASA they think of astronauts on the moon, rovers on Mars, and satellites that orbit earth. Few people think of NASA as a leader in research closer to home. This summer I had the opportunity to be a part of NASA’s earth science research program by participating in the Student Airborne Research Program (SARP). SARP is a program designed to give undergraduate seniors and juniors in various scientific disciplines earth science research experience.

For two months I worked with thirty other students from thirty different schools from across the country. The first two weeks we worked in Palmdale, California at the Dryden Aircraft Operations Facility were we worked with the DC-8 crew. The DC-8 is one of NASA’s earth research airplanes. We learned about airborne research from NASA scientists and were involved with integrating various instruments on the plane.

Me in front of the DC-8 before our first flight.

The students were divided into four different research groups: land, ocean, whole-air-samples, and air quality. I was in the air quality group and worked on the ozone, nitrous oxide, and carbon dioxide sensors. To make measurements of these trace gasses from the plane we essentially stuck a tube out the window and sucked the air inside to the instruments. In five flights we flew approximately 4,600 miles over the Central Valley, the Santa Barbara Channel, and Los Angeles basin.

The remaining six weeks we lived at the University of California in Irvine. Aside from going to the beach every weekend, we were busy every day working on individual research projects. Most of us used data we collected on our science flights on the DC-8. My project, instead, focused on weather influences on ozone air quality in Los Angeles over the past five years.

Matt and me watching the ozone monitor on the third flight.

The Student Airborne Research Program gave me an opportunity to use knowledge and skills I’ve developed in my undergraduate studies. It also cultured an atmosphere for learning that cannot be taught in a classroom and gave me valuable research experience. Airborne research is one of my new found passions. I don’t think that was my last time flying on the DC-8!

Temperature Converter

Do you ever get confused with the Fahrenheit and Celsius temperature scales? Temperature scales are a bit ambiguous. Here's a little history...
In 1742 Anders Celsius created a temperature scale based on the freezing and boiling point of water. Today, 100 °C is the boiling temperature of water and 0 °C is water's freezing temperature. Earlier, in 1724, Daniel Gabriel Fahrenheit invented the mercury-in-glass thermometer. 100 °F was the hottest day in Germany, and 0 °F was the coldest day in German. Today, only the United States uses the Fahrenheit scale and everyone else in the world uses the Celsius scale.

Use the calculators below to convert temperatures between the different scales.
Enter a number in the first box and click the equal sign to see the conversion.

Convert from °C to °F.

°C °F

Convert from °F to °C.

°F °C

Here is a summary of how Celsius compares to the Fahrenheit scale:

0°C	32°F	Freezing
10°C	50°F	Jacket Weather
20°C	68°F	Comfortable Weather
30°C	86°F	Warm Summer Day
40°C	104°F	VERY HOT!

Shutdown

The government shutdown has limited weather forecasting abilities. Weather forecasts and warnings are still issued, but the National Weather Service is running on minimum resources. The link is an interesting article that brings to light how important the National Weather Service really is to protecting life and property.

What if NOAA were completely Shutdown?

WX Discussion

I enjoyed reading the weather discussion today. It's been a beautiful autumn day.

  .DISCUSSION...BASICALLY A STRAIGHT FORWARD FORECAST FOR TODAY WITH 
  SUNNY SKIES AND TEMPERATURES WARMING TO NEAR NORMAL LEVELS. THE 
  ONLY ODDITY FOR TODAY IS THAT THE TEMPERATURES ALOFT HAVE WARMED 
  NICELY OVERNIGHT AND THE MOUNTAINS AND ANY ELEVATION ABOVE ABOUT 
  6K FT SHOULD SEE A 10-15 DEGREE WARM UP OVER YESTERDAY. MEANWHILE 
  THE VALLEY INVERSION IS STRONG AND WITH LIGHT WINDS ALOFT NO 
  MIXING IS EXPECTED TODAY SO VALLEY TEMPERATURES WILL BE INHIBITED. 
  SO IF ANY PORTION OF THE FORECAST CAN GO WRONG IS THAT VALLEY 
  TEMP FORECASTS MAY BE A LITTLE ON THE OPTIMISTIC SIDE. WILL LET IT 
  RIDE AS ITS NOT A BIG DEAL...IT WILL FEEL WARM DUE TO NEARLY CALM 
  CONDITIONS AND BRIGHT SUNSHINE. 
   
  OTHERWISE FORECAST IN MARVELOUS SHAPE.