This week’s “Question of the Week” comes from Trevor Gramling and Ryan Vaughan.

• Climatologically, where is the most likely location to experience the first Storm Prediction Center Moderate Risk of a given year?
• What about High Risk?

Since I do not know the answer ahead of time, this may end up being a two week “Question of the Week” as I write the code to create the answers…

This ought to be fun!

The answers to this week’s “Question of the Week” might surprise some of you. But first, here are the graphs that answer these questions

Here is a choropleth map of January tornadoes by state:

Here is a bar graph showing January tornado counts by state, ordered from most to least:

Keeping the states in descending order of most January tornadoes to fewest tornadoes, here is a bar graph depicting the number of injures by state:

And, once again, keeping the states in descending order of most January tornadoes to fewest tornadoes, here is a bar graph depicting the number of fatalities by state:

And even though this plot is a bit crowded, here is a bar chart that combines the three previous charts into one:

Could you figure out the answers? Well, if not, here they are:

• Which state(s) had the most January tornadoes? Florida (151)

• Which state(s) had the most January tornado injuries? Mississippi (580)

• Which state(s) had the most January tornado fatalities? Mississippi (42)

• Which state(s) had the most injuries per tornado? Deleware (7 per tornado)

• Which state(s) had the most fatalities per tornado? Oklahoma (0.62 per tornado)

And here are the raw numbers,

The answer to last week’s “Question of the Week” sparked a lot of posts on Twitter and at least one question posed in the comments. These comments and questions got me thinking about more ways to dissect the tornado database. Thus, I thought for this week’s installment of QOTW, I would continue with the same theme.

After a small spike from the mid-1960s through the mid-1970s, injuries from January tornadoes decreased slightly and has held relatively steady around 20-25 per year. The exception to this was 1999, which holds the record for most number of January tornadoes, including the largest January tornado outbreak on record. Fatalities appear to follow a similar trend as injuries, albeit with much lower numbers. In total

• January Injuries: 2455 (40.9 per year)
• January Fatalities: 138 (2.3 per year)

We can break down January tornado casualties even more and examine them by F/EF-Scale ratings.

As one might expect, a general increase in casualties is found as F/EF-Scale rating increases. This leads me to this week’s questions.

Above is an image depicting the number of January tornadoes between 1950 and 2009 broken down by county. Using the above image as a guide, between 1950 and 2009:

1. Which state(s) had the most January tornadoes?
2. Which state(s) had the most January tornado injuries?
3. Which state(s) had the most January tornado fatalities?
4. Which state(s) had the most injuries per tornado?
5. Which state(s) had the most fatalities per tornado?

(Hint: A tornado that crosses a county boundary is counted in both counties. Thus, one cannot sum the number of tornadoes per county in a state to find the number of tornadoes per state.)

I apologize that this week’s answer is a day late. I was traveling yesterday and unable to access the Internet. But without further adieu, here is this week’s answer.

• Since 1950, how many (official) tornadoes have occurred in January?

  • There have been 1193 tornadoes during the month of January in the 60 years spanning 1950 to 2009. This equates to an average of 19.88 tornadoes per year in January. Broken down by rating:
  • F/EF-Unknown: 30
  • F/EF-0: 391
  • F/EF-1: 443
  • F/EF-2: 251
  • F/EF-3: 67
  • F/EF-4: 11
  • F/EF-5: 0

As you can see, 1999 was a very active year in terms of January tornadoes. There were several tornado outbreaks that January, including the largest January outbreak on record, which affected parts of Arkansas, Tennessee, Mississippi, and Louisiana.

Back in December I started experimenting with producing precipitation type graphics from the 00 UTC initialization of a 4km WRF run daily at the National Severe Storms Laboratory (NSSL) based on suggestions from Jack Kain and Scott Dembek. The idea was to take the dominant hydrometeor from the lowest model level from the microphysics scheme (WSM6) and then assign a precipitation type. Currently I’m creating 9 different precipitation types based on the 5 different hydrometeor types from the model.

How these 9 precipitation types are calculated are given below:

1. Rain: Rain water is the dominant hydrometeor type
2. Snow: Snow is the dominant hydrometeor type
3. Graupel: Grapuel is the dominant hydrometeor type
4. Fog: Cloud water is the dominant hydrometeor type
5. Ice Fog: Cloud ice is the dominant hydrometeor type
6. Mix: Snow == Rain or Snow == Graupel or Rain == Graupel
7. Ice: Rain water is the dominant hydrometeor type, and the temperature is at or below 273.15K
8. Freezing Fog: Cloud water is the hydrometeor and the temperature is at or below 273.15K
9. Mixed Fog: Fog == Ice Fog, Fog == Freezing Fog, or Ice Fog == Freezing Fog

This EXPERIMENTAL output is updated in the morning (not when the typical model output is available) and is currently linked on the main NSSL-WRF webpage on the left hand side (second of the products). A 36 hour loop is here.

I’d ask those who tend to look at weather maps on a daily basis to consider looking at this product and provide feedback on it. We know there are issues regarding the over-forecast of “ice fog” (and possibly even other fog), but are there other problems? Again, this is highly experimental and may not always be up to date. (The model initialization time will always be plotted on the image.) Any/all feedback is greatly appreciated.