Severe Weather Possible Tuesday
Cloudy & 60° Sunday
It’s cloudy and warmer today because winds are blowing in from the south, carrying moisture and warm temps with it.
You can put away the chapstick. At midnight the dewpoint (which measures the dryness/wetness of the air) was 7°; in 8 hours it has risen 30° to 37°.
All the rain Sunday will be south of us.
Rainy & Cloudy Monday: 42°/66°
That south wind will continue to blow in warmer, more humid air.
Rain should remain to our southwest tomorrow morning . . .
. . . then arrive around lunchtime, and linger through the afternoon:
This will be off/on rain, maybe just enough to rain out any outdoor “ball must roll” activities.
A few lightning strikes are possible, but not expected.
Strong/Severe Storms Tuesday
The Storm Prediction Center thinks severe storms are possible in this general area:
What: Damaging winds and hail are the most likely hazards; the tornado and flood risk is lower (but not zero).
Our local NWS office put out this graphic:
When: Models had our ETA after lunch on Tuesday, but now they’re trending toward a morning ETA.
The “when” will change the “what.” If the storms arrive in the morning, their severe potential will be lower than if they arrive in the afternoon, when the severe potential will be higher.
This morning, our NWS wrote:
In all, timing is going to be an issue for now but the main threats will still only be damaging straight line winds and hail as the tornado threat still looks very low.
How Bad Is It Going To Be?
We get this question all time on Twitter, at church, at home, at the ball park. Seriously, it’s the most asked question.
I never exactly know how to answer it because I don’t know what “bad” means to the person asking it. It could mean anything. I think what they are really saying is “Do I need to change my plans for Tuesday?” That question is usually not answerable for most events, this one included. Noone knows whether a storm is going to hit exactly where you are, and I don’t know what kind of storm would have to happen for you to actually change your plans.
So, will this event be “bad?”
It will if it hits you. It only takes one spin-up tornado or hailer to ruin your day if it happens to you. So, yeah, there is no reason to panic, but pay attention in case you lose the bad storm lottery.
That said, and what I’m about to say could change, but I am not alarmed. I’m cautiously optimistic this won’t be a big deal. Reasons:
1. The timing issue explained above. This system won’t have enough instability or strong enough winds aloft to generate much if it gets here Tuesday morning. However, a Tuesday afternoon arrival will be more of a concern, because there would be more instability and a stronger low-level jet (winds).
2. The GFS model has weak shear — enough to make some damaging straight line winds, but the directional shear is pretty weak. The NAM4 model, known for being “Ohhhh Noooeeeess Stormmmsss Move to Marsssss”, is very “meh” on the severe potential of this system.
The one thing preventing us from downplaying the system is the usually-sensible, but not perfect, European model.
The European model predicts substantial instability and wind shear; way more than the other models. Discounting this information and downplaying the event would be a mistake.
The Storm Prediction Center is also not downplaying the event.
So keep an eye on it. We’ll be updating it like crazy, as usual.
One Other Thing…
Some of your apps have had a rain/snow mix show up for Wednesday or Thursday. This is because a few model runs think the cold air coming in on Wednesday will catch the departing edge of some precip on Wednesday night.
This morning, our NWS office wrote:
I`m not real confident in the wintry stuff right now, so I`ll leave it out of the forecast, but it may need to be added in with future forecast packages.
They don’t believe in a rain/snow mix (and neither do I), due to the weight of the evidence against that happening. With another warm up on the way for next weekend, it’s a good bet your sleds will remain unused for the foreseeable future.
Categories: Forecast Blogs