LRC Forecast Experience
The Gary Lezak Weather Blog
Good morning Weather2020 bloggers,
This radar image, from 12:40 AM, says it all! A band of late March snow just northeast of KC? If you live in Chicago, Boston, New York City, or Erie Pennsylvania, you will not really know what I am talking about. Look at that band of snow, and it is not much. It is just 50 miles northeast and east of KC. Did it come in from the west? No! Kansas City ended up with a few snow flurries and once again we were not in the right spot!
Now, what was happening in that blue band, a band of snow? It was above freezing with snow falling, but with a dusting to 1/2″ at the most and not on the roads. This system is very similar to one that tracked about 30 miles farther west and did produce around 1″ of snow near Kansas City a couple of weeks ago. This fast moving disturbance has now moved off to the southeast.
The Cycling Weather Pattern
The rainy season is just about over for most of California. As we move into April the rainy season shuts down almost every year. The jet stream retreats a bit north. Now, this doesn’t mean strong storm systems can’t make it into California, they are just more likely to track across Oregon and Washington during April into May.
The graph above shows the experimental Eastern Pacific Blocking Index (EPBI). Since around January 1st, this index has been mostly positive, but it is right now forecast to take a dip to neutral or negative, and if this happens it will likely result in storm systems finally making it into the west coast, but due to the time of the year California will likely have minimal impacts.
The graph below clearly shows the cycling pattern, and this is the LRC Index we introduced earlier this year:
We are currently in, what we have called, the warm phase of this year’s LRC. There has been a well defined cold phase in LRC Cycles 1, 2, and 3, and we are now moving into the 4th cold phase within the next week or so. The coldest air of the season has come down from Canada in each of the first three cold phases. Let’s see how this develops in the April version.
Have a great day! We will continue this discussion in Sunday’s blog entry. Let us know if you have any questions.
Good morning Weather2020 bloggers,
If you have ever wanted an example of what we have been experiencing, weather wise, in Kansas City, then you just need to look at this one rather complex computer model forecast for early tomorrow morning.
Winter and spring are going to have a battle tonight into the first part of the weekend. To get a big storm in this annual seasonal battle you would like to see the tremendous temperature contrast oriented from north to south, and not east to west. This battle is from east to west and showcases what has been wrong with Kansas City since this year’s LRC set up last fall. It’s almost as if Boston winter is just “laughing” at Kansas City. Maybe I could come up with a better analogy, but it’s how it feels to me as a meteorologist trying to enjoy our weather. Forecasting the weather in Kansas City, just in the past five days, has been ridiculously difficult. There was an article that came out in the past few months that had an analysis of the most unpredictable weather in the United States, and Kansas City is #1 on this list for larger cities.
Now, again, look at the forecast map at 5,000 feet above the surface valid Saturday morning. The darker brown shaded area, by the way, shows the topography that is at or above this 5,000 foot level. The temperature contrast is huge. Southwest Kansas will warm up to a 20°C reading by Saturday morning which will likely lead into a 75 or 80 degree day out near Dodge City, while at the same time it will be -10°C near Northeastern Missouri. The green shades show saturation at the 850 mb level and conditions will become favorable for an area of snow, but look at the white shaded area that I drew in. This is just northeast of Kansas City which means we have a 99% chance of being frustrated and a 1% chance of letting it go. Well, I will let it go fast, but it will certainly be frustrating with this being so close. It isn’t a big storm, but it would be fun to see, and some of you just to the northeast will likely have snow early Saturday with some accumulation possible.
So, it is a battle between winter and spring this weekend. It’s March Madness! That’s it for today! Let’s see how this sets up. Have a great weekend and we will look ahead Saturday and Sunday as baseball season approaches.
Good morning Weather2020 bloggers,
After a very quiet beginning to severe weather season, we had an active day on Wednesday. A surface low was near Oklahoma City during the early evening hours and Moore, OK had yet another tornado. This one was not a strong one, thank goodness. And a suburb of Tulsa, OK got hit with one fatality and some damage. Here is the surface map I showed on the air at 6 PM last night:
In the wake of this first severe weather set-up of the year is a cold northwest flow pattern. Could there be a few snowflakes tonight?
This map above shows the 500 mb flow valid at 1 AM. There is a strong, yet small disturbance racing our way from the north right now. The X along the Missouri River, on the Iowa/Nebraska border, is oriented in such a way that there will be some nice lifting along it’s path. It is approaching at 1 AM, and with this solution it would produce an organized band of precipitation. And, you can see the second disturbance that will approach the area in Friday. This is coming over the blocking ridge near the west coast.
On the surface map below notice the small area of precipitation forecast for tonight. This is for the period of 7 PM to 1 AM. The third dashed blue line is located between Kansas City and Maryville, MO. This is the 528 thickness line. I would expect some snow in this area of precipitation. The only layer that will be above freezing will be in the lower 2,000 feet of the atmosphere. Let’s track this tonight.
Have a great day. We are back in training on our new computer system at 41 Action News. So, I have two 14 hour days ahead of me. I will check in from time to time. Have a great day!
Good morning Weather2020 bloggers and welcome to the LRC Forecast Experience blog,
We continue to share this new weather forecast technology with you through this blog experience and we appreciate your participation. d, but it will no longer be a winter version of the cold phase. We will be getting the same pattern cycling through, but it will be a bit different given the seasonal differences.
Another storm system will begin developing today across the plains states and then spread east and northeast across the Missouri River Valley into the Ohio River Valley and northeast later in the week. Today will be another rather fascinating weather day to see how it all comes together. Is Kansas City not quite in the right spot once again? We will discuss today’s storm below, but first let’s see where we are within the cycling weather pattern.
The LRC Index, still in it’s development stage, clearly shows the cycling weather pattern. There is organization to the chaos in the river of air above us…..
There has been a roughly 17 day cold phase and a longer 30 day warmer phase of this year’s LRC. The coldest air of the winter season blasted south during the cold phase stretches. What will happen in this next cold phase part of the pattern, as it is no longer winter. The days are longer, and we are going to move into April. There is something to monitor closely in the weather pattern as forecast by the error ridden models. Look for that big ridge to develop, first inland over the west, and then it will pop up over the eastern Pacific Ocean extending high into northwestern Canada. This has happened in all three previous cycles just as the cold phase begins, and it’s due to return within ten days to two weeks.
The Eastern Pacific Blocking Index (EPBI) is another index that we have in development. It also shows the cycling pattern, and when it goes higher into the positive it indicates that storm systems will likely get blocked from the west coast. The Sierra Nevada mountains have around 18% of their average seasonal snow pack and the wet season is just about over for that part of the country. Early on, the EPBI was oscillating up and down and there were a few wet storms that came through in December, but with very high snow levels. Once we hit January 1st this index has lived mostly in the blocking positive, and California dried out.
A wet storm is going to develop today and there is a risk of severe thunderstorms, increased to moderate from the SPC:
From the Storm Prediction Center (SPC):
“INITIAL STORM DEVELOPMENT WILL BE DRIVEN LARGELY BY SFC HEATING AND
LOW-LVL UPLIFT…ALTHOUGH SOME DEGREE OF UPR-LVL FORCING MAY
ACCOMPANY LOW-AMPLITUDE DISTURBANCE MOVING E ACROSS NM. WARM SECTOR
MOISTURE WILL REMAIN COMPARATIVELY MODEST…WITH SFC DEWPOINTS
MAINLY AROUND 60 F AND PW OF 1.00-1.25 INCHES. NEVERTHELESS…GIVEN
500 MB TEMPS AOB MINUS 16C AND STRONG SFC HEATING…THIS SHOULD
YIELD 2000+ J/KG SBCAPE.
GIVEN THE DEGREE OF BUOYANCY…45-50 KT WSWLY MID-LVL FLOW ATOP 30+
KT SWLY 850 MB JET WILL BE MORE THAN ADEQUATE FOR STRONG SUPERCELLS
WITH VERY LARGE HAIL AND LOCALLY DMGG WIND. WHILE INCREASING DEGREE
OF LOW- AND MID-LVL FORCING SUGGEST THAT MUCH OF THE ACTIVITY WILL
FAIRLY QUICKLY EVOLVE INTO CLUSTERS/BROKEN LINES…SOME OPPORTUNITY
WILL EXIST FOR A FEW LONGER-LIVED DISCRETE STORMS…ESPECIALLY NE OF
SFC LOW AND NEAR DRY LINE/LOW INTERSECTION. THESE COULD YIELD A
COUPLE TORNADOES IN ADDITION TO VERY LARGE HAIL AND DMGG WIND.”
So, the risk of tornadoes is low, but the thunderstorms will likely produce strong rising motion and if there are a few strong Super Cell Thunderstorms that can separate from the clusters or lines a few tornadoes will be possible. Here is the tornado risk today:
This storm is similar to so many others we have had this season, but we getting the late March version of the storm system. This storm is like so many others that left KC in the wrong spot for activity during the winter. It is another positively tilted system:
In this March version we are getting the right conditions for severe weather with the surface responding to this early spring part of the cycling pattern:
We will be tracking the storm chasers later today as they will likely be heading into northeastern Oklahoma. Have a great day and be safe!
Good morning Weather2020 bloggers,
There are two storm systems we are tracking today. The lead storm system has an upper level center that can be seen if you look closely at today’s satellite pictures. It was located over Colorado as it was moving out over the Rocky Mountains as of 7 AM this morning. You can also see a small MCS, the first Mesoscale Convective System of the season, located over eastern Nebraska as indicated by the enhancement in the higher cloud tops.
There is a warm front located over southern Kansas, stretching southeast into southwestern Missouri and northeastern Arkansas. The air north of this front is mostly in the 40s and 30s, while the air south of the front (the warm sector of this developing storm) is warming into the 60s.
The Colorado storm system has not been modeled well by most of the computer models, and now that we can actually see it in Colorado, and the fact that it has some strength to it, we are now confident that it will take a track similar to this RUC model depiction of it tracking to near the Kansas/Missouri border by 7 PM. This track will likely keep the surface low well south of Kansas City. This will keep the KC metro area and north in the colder air all day long with a new area of rain and thunderstorms forming in a little comma head around that upper level storm. Where it interacts with the warmer and moist air from the Gulf of Mexico will be the most likely spot for severe thunderstorms today with large hail being the main threat.
The Storm Prediction Center has placed a slight risk of severe thunderstorms over this area near the surface low, warm front and warm sector.
The slight risk does not include the KC metro area. As the upper level disturbance approaches we can expect some potential for hail with thunderstorms that may form within the comma head later this afternoon or evening, but the bigger risk of severe weather is farther south. Let’s track these developments today. Here is the RUC surface forecast valid at 4 PM this afternoon. The surface low is forecast to be just west of Joplin, MO.
There is a second storm system that will strengthen and then move into the eastern states later this week with yet another impacting storm over the northeast. As this second system develops KC will again be on the edge of this developing system. The risk of severe weather on Wednesday is farther south, and there may be enough cold air for a few snowflakes later this week near Kansas City. Get the winter coats out today, and then again for later in the week.
Have a great Tuesday! I am back to work tonight on 41 Action News. You can always watch our newscasts streaming live on www.KSHB.com if you are not in the Kansas City area.
Good morning Weather2020 bloggers,
Welcome to the LRC Forecast Experience blog. The pattern continues to cycle according to the LRC and we have an interesting early spring set-up developing right now. Severe weather season has gotten off to a very quiet start, but there are risks showing up in the next three days:
The day 1 risk for today is posted above, and the risk for Tuesday and Wednesday are posted below:
The Storm Prediction Center has a new way of showing these risks this year. There are a couple of new risk areas that have been added to the mix of products they provide to inform everyone on the potential risks. There is a new “marginal risk area that is just below a slight risk, and there is a new enhanced slight risk, which is just below moderate risk. As you can see above there is a darker green risk area, the marginal risk area, around the general thunderstorm lighter shaded area. Here is the answer in the FAQ section on the Storm Prediction Center’s website: Marginal, Slight, Enhanced, Moderate, and High risks represent progressively larger threats for organized severe storm episodes. These risks, along with their numerical, abbreviated labels, and colors (1-MRGL-dark green, 2-SLGT-yellow, 3-ENH-orange, 4-MDT-red, 5-HIGH-magenta), are based directly on the numerical probabilities of severe weather that we provide with every outlook.
Let’s look at the set up for the next 24 to 36 hours:
There are various solutions that are out there from the computer models. Especially in the early severe weather season, cooler air can really limit the severe weather potential as the surface instability gets sacrificed by the amount of rain cooled air that can influence the pattern near the best area of severe weather potential. A strong warm front is now forecast to develop, as you can see above, near the Oklahoma/Kansas border east of a developing surface low west of Wichita, KS by early Tuesday morning. Conditions will become quite favorable for thunderstorms just north of this warm front boundary and a large area of rain cooled air will likely develop. Here is one rainfall forecast ending at 7 AM central time Tuesday:
On this next map you can see the rain cooled air that will likely significantly impact severe weather potential farther north, and this is why the Storm Prediction Center has not placed the slight risk farther north. There are other models that bring the warmer air a bit farther north, but at the moment, I favor the farther south placement given the time of the year.
Look at that temperature contrast from the 80s to the 30s. At the surface, the low pressure area is forecast to be anywhere from this farther south position to as far north as the Iowa/Missouri border. Again, due to the rain cooled air and the time of the year I am favoring this surface low placement:
The latest NAM model continues this trend. Kansas City would have a high in the lower to middle 50s on Tuesday and this would place any significant severe weather risk way to our south, somewhat like what the SPC is showing on their outlooks.
And, I am pretty sure you don’t want to hear this, but KC is once again trending into not being in the right spot again. What is happening? This storm system will likely have the surface low track north into the colder air. And, then the main, and larger storm system will begin evolving for Wednesday. Snow is even possible across Iowa.
Have a great start to the week! I am back in KC, but I do have the day off. I get back to work on Tuesday just in time for this storm to come together. We can discuss the new data as it comes in during the day. This set-up is still not etched in stone yet.