WWU076 - (SEVERE WEATHER SATURDAY)

Good evening weenies. We've got the spiciest event of the season chugging towards us. 

WWU076

Friday Night through Sunday Morning 

(3/14 and 3/15) 

Tomorrow

Saturday

Weenies, this could really be a bad one. The National Weather Service and Storm Prediction Center offices don't throw these kinds of words around lightly. 

Words like: 

"Outbreak" 

"Numerous Significant Tornadoes"

"A Particularly Volatile Scenario" 

Yeah those aren't normal words. They use those specifically to get your attention for days like Saturday.

Let's look at what our local office has to say. 

Hey see that? Did you notice it on the graphic? I'm making you notice it. When the local office says "outbreak", you listen. 

----------------------------------------------------------------------------------------

I want to discuss what you should expect in the next few days. We'll have a constant threat somewhere in the state from this morning through Sunday morning, and that honestly gets super confusing. 

Friday night is our next threat. And when I say Friday night, I mean LATE Friday night, nearly Saturday morning in most of the area. 

Saturday MORNING is where we will either use up the energy or leave it festering and growing for the evening. Severe threat is moderately low for the morning, but we're hoping the sun doesn't come out. 

Saturday AFTERNOON/EVENING is our main event. This is the one to worry about if you can only handle worrying about one. 

___________________________________________________________

Now some tornado graphics. Top graphic is Friday. That is a LARGE significant tornado threat over our lovely country. We are on the edge of that line for Friday. The first graphic shows FRIDAY UNTIL MIDNIGHTish (it might be 1 am -- the time change makes things weird, it's early regardless) . 

The second graphic is ALL SEVERE HAZARDS - NOT. JUST. TORNADOES. 

So yeah it's still 45% hatched, and I expect that to become a high probability in the next few updates, but that includes the threat of hail, tornadoes, and wind. 

-----------------------------------------------------------------------------------------------------

Map reading comprehension time: These maps do not dictate what the storms or atmosphere decide to do. As good as the forecasters are - the storms don't know what our homies at the SPC write.

Think of it as a picture of a taco, but you only know that there is beef, cheese, and a taco shell. We don't know where the cheese will specifically land, but there will be cheese. We only know what the final result looks like after it happens - but we know we're having tacos before it happens. 

Since this is a multi-day threat, and is not just one line that will pass through, these graphics should be read as the maximum danger probability for the entire forecasted 'day', midnight to midnight. 

Let's get into the nerdiness. 

Weenieings

Ok so I took a sounding from this blue box, this is the HRRR 00z model run. I wrestled with Gmail until this run was loaded because each run has gotten a little closer to what the end of the event looks like and I wanted to wait to share the most up-to-date version. 

Hey, has anyone seen my coffee cup or keyboard mat? 

It looks like this. 

Predicted sounding for Saturday, March 25th at 6pm

Time to review, weenies. 

Yes it says PDS Tornado in purple (Purple=BIG BAD), but why? How did the model pick that? 

Looking at the green, red, and dotted white lines on the far left of the sounding. That shows temperature, dew point, and an imaginary parcel floating through the atmophere. What you need to know from that is the larger the area is between the white dotted line and red line, the worse it is. There's a lot more we can learn from that chart, but that's the part that proves the point right now. 

(That area equates to about 1,200 J/kg CAPE - plenty for storms)

The second important part is the squiggly angry snail/jellyfish/mouse shape in the top right corner. That is wind speed and direction at different levels of the atmosphere. If you see it going around in a circle, it's bad. That's the spin in the atmosphere. The other important line on that chart is the part that is either the foot of the snail, the side of the jellyfish, or the tummy of the mouse, the straight teal line. That is the storm motion. 

If the storms are going one way, and the winds are going a different direction, we get spins. 

The composite of those factors give us the purple PDS tornado, it also creates the graphic below, showing the Significant Tornado Parameter (from the NAM 3km)

Remember the spins? I hope you do. It was a paragraph ago. 

This graphic (Storm Relative Helicity) shows how much the atmosphere wants to spin through the evening. As you can see, that will NOT be a limiting factor for Saturday. 

"Kaila, you've got me scared now." 

Yeah a little. But what will the limiting factors be? What could chill this system out? 

Moisture return.

You thought I'd make a report without the Hot Ham Air™, didn't you? Nonsense. 

The three events thing? That's where it comes into play. Friday night will do what Friday night wants. Watch the weather, but I wouldn't panic. Saturday morning is the major question mark. 

If the rain from Friday lingers into Saturday morning, and it just rains and rains and rains Saturday morning, I think the NWS will be doing backflips. If the moisture is used up, it won't have time to return before Saturday evening. 

But if it doesn't rain? And if the sun comes out? Bad news. Start snapping your suspenders. Get your helmets on. Put the mattress on the family. 

We don't know yet what Saturday morning will do - that is predicated on what Friday night does. See how this works? It's horrible. Welcome to spring. 

I guarantee this will be my whole day Saturday, sooooo have a way to see your email Saturday morning. 

Updates to follow. Check Slack often. 

(For my weenies outside of SPOC, message me if you have questions)

------------------------------------------------------------------------------------------

As always - watch your local news during the day - I'm not your primary source for emergency alerts.

Be safe and stay Weather Weenie Aware

KR4BZF :)