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March 31, 2011

My Concern Is Increasing For A Potential Severe Weather Event

In the short term, cold will dominate our weather but with a significant push of warm air late this weekend our attention will rapidly change toward severe weather. I am becoming more concerned that the setup could allow for a severe weather event and this will be the main point of discussion over the next few days.


Short Term Forecast Discussion


I don't want to forget about the next couple of days, so I do briefly want to touch on that. Our normal high this time of the year is in the lower 60s, so it has been quite a cold stretch here as of late. We will be dominated by clouds today and tomorrow, so unfortunately we won't get a ton of relief. Notice the extensive cloud cover again in our region as of 6 am this morning, which should lock us in the clouds for this day.




A weak clipper type system will slip through the Ohio Valley and generate a few showers tomorrow. Notice the widespread light showers developing after around midday tomorrow. That will keep things chilly again with the possibility of a few showers tomorrow. :(




If you have out door plans, then Saturday is your day because scattered storms will begin Sunday in advance of our next event which leads us into that severe weather discussion.



Severe Weather Forecast Discussion


I have been talking about the severe weather potential for Monday on the blog since early this week and each day I have become more concerned. To be honest, I am really starting to get concerned that in the mid south there will be a severe weather outbreak and it could very easily include the Ohio Valley. We are on the northern edge of the system, so it is a bit more complicated to definitively say how bad it will be, but the ingredients look like they are coming together for a significant event. The Storm Prediction Center appears they agree with my assessent as well as they have now placed us in the risk for severe weather for Monday.


Let's get into some of the details. Just a quick reminder of the Severe Weather Ingredients needed for severe storms in the Ohio Valley.


Severe Ingredients 


We know forcing will not be a problem with a very strong low pressure moving across the Ohio Valley. The front this storm has with it will be very powerful.


The wind shear is remarkably strong on this storm system. I normally show winds about 1 mile off the ground, but let me show you winds even closer to the ground this morning. Let's look at winds about 2000 feet off the ground.



GFS Winds At About 2000 Feet Off The Ground For Monday

Note the winds at 2000 feet are a bearish 60 - 70 mph over the Ohio River. That is very, very strong.



GFS Winds At About 1 Mile Off The Ground For Monday

Note the winds 1 mile off the ground increase to near 70 mph. Again, these are tremendously strong winds.

I speak regularly that wind energy without instability is like having a Corvette running poor gas. If you don't use high octane fuel in that very powerful Corvette engine, then it will never run right and never reach its potential. The atmosphere can have very strong winds, but if there is not good fuel then it will never produce much if any severe weather in the Ohio Valley. Fuel for storms comes in the form of instability, and with this huge wind energy I would like to see at least 1000 units of instability to produce severe weather in this situation.



GFS Instability For Monday

Note the GFS is now indicating a large area of moderate instability. Notice the  1500 - 2000 units of instability over the Ohio Valley which would be a would be a major problem.


Gfs CAPE 1 



Looking at the data, we are starting to see a real threat developing for Monday. If the timing for the storms is late then that would increase that threat more. I want to show you the last two runs of the GFS noting when it is indicating the greatest threat of storms.


GFS Precipitation for Late Monday (Yesterday's Run)

Note the GFS dialing in an outbreak of storms late Monday right over our area. From the GFS, this is a strong signal of severe weather outbreak for at least the region.




GFS Precipitation for Late Monday (1AM Run From Today)

Note the incredibly consistent GFS showing almost the same exact solution two runs in a row and very consistent with the past few days. I will say it again, the GFS is showing significant severe weather outbreak for the region in a time that is very favorable for severe weather.





Yesterday, the Storm Prediction Center mentioned this severe weather threat in their wording, but today they have actually included our area in the severe weather threat. Our concern is Monday, and that labeled as day 5 on their severe weather threat.


SPC 4-8 


In addition, the Storm Prediction Center is using strong wording as well.

"Widespread severe storms are becoming increasingly probably Day 5. Gulf Moisture will advect northward through the Lower-Mid Mississippi Valley... Southeastern States and Ohio Valley in association with very strong eastward migrating low level jet. More widespread thunderstorm development will become probable as forcing for deep ascent attending the upper trough shifts east of strong elevated mixed layer. Threat will exist for supercells and line segments with tornadoes... large hail and damaging wind."




My Severe Weather Forecast Discussion


It appears more and more likely with each passing day that severe weather will affect the Ohio Valley on Monday, and could potentially be a significant severe weather event. All signals point toward winds that will be remarkably strong on Monday. The GFS continues to indicate moderate instability which is more than sufficient to support severe weather in this scenario. The low pressure is a very powerful system with a rock solid cold front. We will be located in the warm sector of the storm in a location that is normally a climotological location that is favored for severe weather.

To be honest, I am concerned. I think Monday at the bare minimum will have severe weather in our area. At the worst case, we could see a severe weather outbreak. The wind shear and moderate instability support large hail, damaging winds, and tornadoes. At this point, everything remains on the table and I will be monitoring this storm system very, very closely.



Full Forecast Discussion


In contrast to what we just discussed, today will be quiet and chilly. Skies will be mainly cloudy with a cool high near 48.




Tonight skies will remain mostly cloudy and temperatures will dip again into the mid 30s. Brrrrr!




Showers are possible tomorrow although nothing looks heavy. I think Saturday looks like a great start to the weekend with a high near 58 under partly cloudy skies. Sunday we will see the warm front move through allowing warmer air to push into the area with scattered t-storms. I do not think it will rain all day on Sunday at all. After a potential bout with severe weather on Monday, temperatures will cool significantly again on Tuesday and Wednesday.







I cannot emphacize enough how important it is to stay up to date on the storm approaching Monday. We will be discussing this heavily on Fox41 on TV in the days leading up to the storm and the blog will be active with an in depth discussion to keep you prepared for the storm.



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Mark, Thanks for keeping us updated on this approaching weather. I'm always very concerned when a severe outbreak is predicted; I survived the 1974 tornado in Brandenburg, KY. The devastation was indescribable, not to mention the years of anxiety the citizens of Brandenburg have endured. I'm definitely a weather watcher and appreciate your concern. Thanks again.

Donna, no problem at all. There are lots of details that will determine the severity of the event that still are out there, but this one needs to be watched closely.

That must have been a terrible experience to go through the 1974 event. I cannot imagine the horror you saw when you came out of your house. :(

what do you predict in the near future as far as severe weather ,tornadoes ,etc?

Glen, on Monday all modes of severe are on the table. As we get close, we will be able to focus on the greatest threat.

thanks for keeping us updated this sounds pretty serious....so are we talking tornadic activity

ahuffman0001, speaking about the what specifically would be the main threat is still impossible. Small details like thunderstorms ahead of the front can really change things considerably. As we close in I should be able to dial in the specific threats.

Thanks for keeping us informed, Marc! I will be watching closely on Monday.

Thanks for the details Mark! Also, thanks for taking so much time to put nice details into your blog.

Great job Marc. I see others are starting to report. Thanks for putting the information out there.

Lisa, you are very welcome. :)

Revillusion00, I am just glad everyone is enjoying it!

Snowman, now that SPC has mentioned the threat, I suspect everyone else will start to talk about this now.

This is my first visit to this blog, very good set up and easy to follow format. Also good LR reporting. If someone isn't ready for the POTENTIAL Monday it can't be for lack of information.
I like Weinberg's enthusiasm for the weather especially in his time slot. I couldn't get excited about anything this time of day even if Jennifer Anniston delivered a certified letter in her birthday suit to my front door.
Anyway just wanted to weigh in and also say thanks to Weinberg for checking out and "liking" our site on Facebook (Ohio Valley Weather Net) and all things Chatzy. We are lucky to have some great Mets on all our local stations. Now I would like to see a countdown to Fall please.

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