KANSAS CITY, Mo. — Good morning bloggers,
There is a slight risk of severe thunderstorms later tonight as a storm system develops and tracks across the plains. This is a level two out of five risk of severe weather and there are quite a few questions concerning this risk of severe weather. We will take a look at that risk in this blog entry.
For severe thunderstorms to develop at all we must have thunderstorm ingredients come together. Let's begin with moisture. If there is no low-level moisture (higher humidity), then there will be no thunderstorms. The Gulf of Mexico air is the first ingredient to monitor when we are predicting thunderstorms. As you can see below on this dewpoint forecast map, there is limited moisture supply for this storm system:
The dewpoints are forecast to be in the 50s. The closest 60-degree dewpoints are way south in Texas, and this is the forecast for 6 p.m. this evening. Now, this could be a few degrees too low, but if it is at all close to correct then thunderstorms will have a limited moisture supply to maintain any strength, initially. I say initially because the moisture will be increasing after sunset tonight and then it will be only a bit higher on Wednesday, as you can see below:
Now, I know this is a bit complex. Take a look at the sliver of higher dewpoints near Memphis at 4 p.m. tomorrow. This shows the higher dewpoints just ahead of the advancing storm. This will lead to a much higher risk of severe weather. Again, today, this is lacking, and tomorrow, it is just enough for a bad severe weather day. How much moisture will be available when the front moves through overnight? This is a limiting factor for severe thunderstorms in our area.
There will be a developing zone way out west later this afternoon and evening as you can see here.
On this map above, we are showing the developing surface cyclone. A low pressure center will be strengthening near the Kansas-Nebraska border. A warm front will move through today and be way north of Kansas City by 5 p.m. This will allow us to warm up into the middle and upper 70s with 80s just west of our region this afternoon. The development zone for thunderstorms will be ahead of the dry line (the brown line with the semicircles). This will be well west of our area and this ensures that it will be dry through sunset at least.
The cold front is forecast to catch up with the dry line by 9 p.m., and this is the most likely time for thunderstorms to begin forming near that line.
On this next map, which is valid at 2 a.m., the cold front has taken over the dry line. The thunderstorms on this model are not severe and fairly weak. They are stronger in Oklahoma.
Look at what is forecast to happen by noon Wednesday:
By noon Wednesday, the thunderstorms are not being supplied with that thin surge of higher humidity and the thunderstorms are intensifying.
Severe weather risks for tonight and wednesday:
The risk significantly increases later tonight and Wednesday as the system passes through our region and encounters better conditions east and southeast of Kansas City.
What does all of this mean?
- We will be monitoring the ingredients for severe thunderstorms to see if anything looks different by tonight. As of right now, our risk of severe thunderstorms is low. Whenever we have thunderstorms, we must monitor them closely and we will be doing just that. The low-level moisture is an inhibiting ingredient at the moment, but other conditions are favorable for severe thunderstorms. If this were later in April or May there would be more moisture available, but it is still early and this set up is lacking on that one big ingredient
- The timing of the thunderstorms right now appears to be closer to midnight for Kansas City. We will be monitoring the first development of thunderstorms closely later this evening to see if that timing changes at all, but right now I think it will be after 10 p.m.
- The main risks of any severe thunderstorm development will be some larger hail and damaging winds. The risk of tornadoes is 2% within 25 miles of any location, which means there is a 98% chance of no tornadoes near you, which is a very low risk.
Kansas City forecast:
- Today: There will be a few periods of clouds mixed with sun. Temperatures will warm up to near 77 degrees later today with winds gusting to 35 miles per hour from the south. Hold onto your hats!
- Tonight: There is a 70% chance of a few showers and thunderstorms between around 11 p.m. and 6 a.m. There is just a slight chance of severe weather in your area. The wind will shift to the northwest and west by morning. Low: 52 degrees
- Wednesday and Thursday: There is a chance of rain showers and much colder with temperatures dropping into the 40s Wednesday. There is a chance of a period of light snow Wednesday night or early Thursday with no accumulation expected.
Thank you for sharing this weather experience and spending a few minutes of your day reading the weather blog. Have a great day and we will update you on KSHB 41 News as this system gets closer.
Gary
