LRC Suggesting Storm by the 25th

I haven’t written about the LRC (Lezak’s Re-occurring Cycle) in a while, so I will address it here a little bit.  The LRC, established by Gary Lezak at KSHB in Kansas City, MO, is a theory stating that a unique weather pattern sets up every year between October 1st and November 10th.  The cycle typically falls apart by late summer. The longterm longwave troughs and ridges that setup every fall are different.  A cycle length is usually established by the beginning of the winter, depending upon the unique pattern that sets up, which is identified at the 500 mb level.  This year, Lezak has identified a cycle somewhere between 58-66 days.  Therefore, this year’s cycle is approximately 62 days long, give or take a few days.  Based on this idea, we would expect our next storm system to arrive around the 25th of January, 62 days after the storm that moved through the area on November 24th.  Here is a look at what things looked like with the November 24th storm at 500 mb:

(Click to Enlarge)

We would expect a similar setup with this storm. Keep in mind, however, that it is possible that this storm sets up slightly further south, given the fact that we are in January with an upper-level jet that is typically stronger and further south. In November, this storm produced rain, as cold air was limited.  In January, we would expect either snow, or perhaps freezing rain (given the extensive snowpack and frozen ground).  I would be leaning more towards the snowy solution with polar air more readily available.  We will see, but it does appear that a storm will move into the area around the 25th, if you believe the LRC.  February also appears to be very snowy, bringing snowfall totals close to if not beyond record territory for Omaha.

On a different subject, thanks for all those who are viewing the blog. We have had 1739 views since the blog started last year, 1077 of them occurring in the past 3.5 months.  It really seems to be catching on this year, which is great news! Hopefully we can keep this going in the future!

Have a good weekend!

Ross

Winter Storm Verification

This blog entry is written to show the following: Old school techniques are NOT outdated.  Using Gene Weber’s rule of the heaviest snow falling along and to the left of the 500mb height fall center track, 4″+ was forecasted for the Omaha metro. The rest of the snowfall forecast made below was a result of using the Garcia Method, where the snowfall amounts relate to the mixing ratios that are found on theta surfaces.  Using these 2 techniques, with some but not total reliance on model forecasted qpf, the following forecast was produced:

It is important to note that while model GFS qpf indicated a wide area of 2-6″  across the entire midwest with no concentrated area of 4″+ a few days before the storm, the forecasted HFC track indicated that a concentrated area of 4″+ would be located very close to the above forecast.  Thus, it is stressed that model qpf should NOT be soley relied upon for snowfall forecasts.  Other techniques should be used.  The forecast is only as good as the time and effort put in by the forecaster.  Here are actual snow totals:

The forecasted HFC track almost exactly showed where the 4″ cutoff would be.  And now a look at Iowa’s snow totals:

While model qpf suggested that heavy snow would extend into northeastern Iowa, the Garcia Method suggested that the 4″ cutoff would occur as forecasted.  This proves the value of this method.

There were some 2″ amounts in western Iowa, which was surprising.  This was not forecasted, but these amounts were also not consistent with the 4-7″ surrounding them.  This made these amounts hard to forecast. Some 8″ amounts were also reported over northwestern Iowa, which should have also been accounted for in the forecast.

Overall, however, I think that the forecast worked out very well.  Models did not do that bad about a day before the storm, but they could have definitely been approved upon by using various techniques.

Ross

Snowfall Tapering Off — Phase II on the Way

With between 3 and 4 inches of snow on the ground at 1:00 PM, I’m not expecting much more than an additional inch of accumulation through the rest of today and into this evening. This places Ross’s forecast of 4 to 5 inches right on the money.

As the snow ends, the second phase of this winter storm will take over as winds increase significantly later today and tonight. At 1:00 PM, winds were southeast at 3 mph at Eppley, northwest at 22 mph at Columbus, and northwest at 35 mph, gusting to 40 mph, at O’Neill. This is what we’ll be dealing with later this afternoon, tonight, and on Thursday. Several inches of powdery snow are on the ground now, so the winds will create a lot of blowing and drifting snow, and potential white out conditions in open areas.

Wind chills are the other big concern through the end of the week. Lows should bottom out in the teens below zero on Thursday Night and at around 20 below zero on Friday Night. Highs on Thursday and Friday will probably not exceed zero degrees. The gusty winds will produce wind chills as cold as 35 degrees below zero, especially Thursday Night and Friday Morning. Winds will die down on Friday Night, but it still won’t take much to produce wind chills of 30 degrees below zero again. Some moderation in temperatures should finally occur toward Sunday.

Willy

4-5″ of Snow Likely For Omaha Tue Night Through Wednesday Evening

We are looking at 4-5″ in the metro out of this system.. Snow will begin after midnight Tuesday night lasting till about 6 p.m. Wednesday.  The heaviest snowfall will be to the left of the 500mb HFC track.. This will produce a 4-6″ band from Sioux City southeastward towards Ottumwa, Iowa.. 2-4″ will surround this band, with 3-4″ in Lincoln. Keep posted!

Ross

12-16″ Snow Likely

Snow is likely this afternoon through Saturday until about noon.. the snow really begins to pick up in the metro around 2 p.m… Frontogenetical forcing will cause snow to develop up and down the missouri river tonight.. I am expecting 12-16″ in the metro.. This is a very good bet.. Near blizzard conditions will also occur tonight as sustained winds are between 30-35 mph.. We may be just under blizzard criteria.

10-15″ Snow Thursday/Friday/Saturday

The metro is looking at 10-15″ of snow from Thursday through Saturday… There could be some 16″ amounts between Valley and Columbus, NE.  These amounts do not count what will fall today to our west.

Another Update

As Willy mentioned, things continue to trend westward.  That being said, here is a look at the latest timeline:

3 p.m. Tuesday – 9 a.m. Wednesday –> Freezing Drizzle

9 a.m. – 12 p.m. Wednesday –> Drizzle

12 p.m. Wednesday -  6 a.m. Thursday –> Rain

6 a.m. Thursday – 9 a.m. Thursday –> Cloudy

9 a.m. Thursday – 4 p.m. Thursday –> Rain

4 p.m. Thursday – Friday –> Snow

Now, there are some possible complications as we go towards Thursday evening and Friday night… The latest 00Z ECMWF is not favorable for area in getting very much snow once it switches over… However, I have some problems with this model run, as I believe it is too weak with the southern vort max…

We will see what tomorrow’s runs hold.

Ross

Winter Storm Update

This is just a quick update on the winter storm that will impact the area this week. It still looks like two waves of more organized precipitation will affect the area — one on Wednesday as a lead disturbance moves through, and another on Thursday into Friday as the main storm strengthens and lifts into the area. The overall trend I’m seeing with the new December 22nd 00z computer model data is for a track farther to the west, which will result in warmer temperatures, at least initially. This could mean more rain than freezing rain on Wednesday for Omaha, as well as a later switch to all snow on Thursday. In addition, if this tracks much farther west, the surface low could move almost directly over Omaha, placing the heaviest snow off to our west. Regardless of the track, the models still deepen this storm pretty significantly, so the snow that does fall will be blown around on very strong winds.

Obviously, there are still a lot of details to be worked out. Hopefully the next 12 to 24 hours of model data will help answer some questions.

Willy

Major Storm Possible Christmas Eve/Day

Traveling is going to be a nightmare Christmas Eve/Day across the middle part of the country.  It still appears that a very strong storm system will lift into our area by Christmas Eve.

Based off the October pattern, in which this upcoming storm tended to phase over our area, I would not see any reason for the same thing not to occur in December.  In my opinion, the GFS is too far south.  Regardless, the ECMWF and GFS both showing accumulating snow for us Christmas eve. However, the latest 00Z ECMWF cuts further north, which is very interesting.  In fact, the latest run is forecasting a 980 mb sfc low over extreme northwestern Missouri.  Holy cow, that is an intense blizzard!

What is interesting about the ECMWF solution is that it continues to trend westward. We will see if this trend continues.  IF it does, areas just to our west may get into the brunt of the snow.  These strong storms almost always will make a more abrupt turn to the left after bottoming out.  This would put the surface low near Omaha if the 00Z ECMWF run was exactly right (which is doubtful).. That would put a dent in snowfall amounts here.. We will see what models do over the next few days.. Still a lot of time.  However, it does appear certain that a big storm will affect somewhere in the midwest by Christmas Eve..Keep posted!

Ross

Unsettled Weather Pattern

Slightly unsettled weather is expected over the next day or two, but no significant impacts are anticipated for eastern Nebraska and western Iowa. A weak weather disturbance will bring a light mix of flurries and freezing drizzle on Friday, with some flurries possibly lingering into Saturday. Right now, snow and ice accumulations are expected to be quite minimal.

A much more interesting situation is possible next week as a stronger storm system moves across the central plains. Like usual, the track of the storm is all over the place, but there is certainly the potential for accumulating snow in the area. The timing right now looks like Tuesday Night through Wednesday Night.

For once, a white Christmas looks like a guarantee. Even if the midweek storm does not materialize, I don’t imagine that our current snowpack is going to go anywhere anytime soon!

Willy