Rounding Out March

First off, a big thank you to those that have submitted the very quick survey that will help me decide the direction this blog will go and what I potentially will be doing in the not too distant future. If you haven't had a chance to complete the survey, the link is: https://www.surveymonkey.com/r/7ZSGTTG.  It is very brief and will take you less than a minute.

I think just about everyone will be pleased with how the March weather has turned out across the high plains.  Beneficial moisture (more or less),and relatively mild temperatures can summarize the month.  Yes, there was a major blizzard/snow storm across the western part of the high plains (especially the Palmer Divide and Front Range).  But a major blizzard spared the remainder of the high plains.  But, it was close!  The widespread and major late winter storm on the 13th and 14th was really close to slamming the entire area with a mind boggling blizzard.   East of the extremely heavy snow there was instead widespread rain, some very excessive.  I was travelling back from Omaha on the 14th and experienced an east wind of 50 to 60 MPH with heavy rain at 38 degrees!

For March, the Dodge City airport was sitting at the 5th wettest March on record and those records date back to 1875!  And for Ford County, where the airport resides, the monthly total is actually far less than some other reports!  Of course not everyone got excessive rainfall but just about all locations got at least enough to improve drought or near drought conditions.  

Here is the map of estimated precipitation since March 1st (through the 25th)...

This amount of precipitation has helped mitigate drought conditions.  As of the 23rd, this was the latest map....

With the March precipitation, the improvement across many areas was substantial!

For the short term the final in a series of weather systems was moving out into the plains.  As of early this Friday morning the center of the system was located across Arizona.  It was weakening as it was moving out.  A few sprinkles were noted across the high plains but because the boundary layer of the atmosphere had been scoured of moisture, the system just isn't strong enough to produce significant rain.  Farther east, later into Friday evening, there was enough moisture for scattered thunderstorms.

In several of the previous posts I had mentioned March 25-31 as potentially being "cold" or at least below normal.  The pattern is set but because of the northern branch of the westerlies (jet stream) being strongest across Canada, the really cold air has been held up north.  Good thing!  With the colder air being held north and with the configuration of the jetstream, the Arctic Oscillation has been really positive in magnitude, polar opposite to what it was back in February.

The index was headed south (less positive and inching towards a negative value). IF (a big if) the AO index does go negative, that could set us up for that April 25-May 2 possible cold that I had mentioned.  BTW, if you missed it I discussed dates with the highest potential for having significant weather.  If you didn't see it, click here.

After doing some more analysis, I have come up with 2 more periods of potentially significant weather.  One period is April 4-8 where I think there will be an increased opportunity for thunderstorms. Hopefully far enough west to benefit the area with drought conditions.  The second period is May 6-13.  This could be  a pretty active severe weather set up.  I still think that April 25-May 2 could be really interesting and potentially very impactful at least for parts of the area.  The potential for cold still is there but it could also lead to a battleground from west to east of cold to warm.  More on this later.

Finally, this next 7 days should see ups and downs on temperatures.  Warmer/milder through the weekend but then much colder Tuesday through Thursday with probably overnight lows below freezing.

Thanks again to those submitting the survey.  

Wild March Weather - 300th post!

The weather has certainly been interesting this past week!  From severe thunderstorms to a major spring snowfall.  In the previous post I gave some periods that I believe to have pin-pointed.  If you didn't read that post, click here.

In the previous posting, I provided a link to a very short and quick survey that will help me determine the future of this blog and posts.  If you have not filled out that survey (again it's very brief), please help me out and do so.  That survey link is: here 

To date I have posted 299 times, this one is my 300th!  The first one I did was on April 15, 2014!  Wow I can't believe it was that long ago!  For those of you not too familiar with this blog, I have done it on my own time unrelated with my employment with the National Weather Service.  If you want to read that very first blog post, click here.  I need to determine if I will continue.

In the previous posting, I discussed the active weather expected for the period of March 10-17, but especially March 15.  Well it certainly has been active with the highlight being the 13th/14th.   It looks like the storm coming in tonight and moving out tomorrow (16th-17th) will be the end of that active period.  But, there is more to come! 

BTW, here is the estimated precipitation that has fallen this past 7 days, ending this morning March 16.

Here was the upper air chart this morning...

The Storm (the red L across Arizona) for tonight and tomorrow will be very compact making details in the forecast (type of precipitation and specific amounts) extremely challenging for forecasters.   The exact track and mesoscale processes will determine the final outcome.  Here is the guestimate from the Weather Prediction Center for the next 7 days (with the majority of this falling with this first system)...

So, if you didn't go back to the post on the 5th, here is the outline I left you with....

These following periods are not the ONLY possible weather....they just have my attention.

1) March 10-17, but especially around March 15.  This should be the next active period but probably only 1 storm will impact the high plains and that would be around the 15th.  Before then it could be the eastern plains.  I wouldn't be surprised if there was a blizzard, especially for higher elevations of the high plains.

Instead of 1 storm for the high plains - make that 2 although much of the high plains north of Kansas will miss out on this one.

2) March 25-31 is a period of potentially much below normal temperatures.  That could be problematic as with this recent rain and the mild temperatures coming up, there may be some early breaking of dormancy of some vegetation.  Also, the b word comes to mind.  The last 10 days of March are actually the most active for blizzards, based on history.

I think there will be a few more opportunities for storms as March is closing out.  Any system that would bring much below normal temperatures is not showing up at this time.  But, I still think there is that chance.

3) April 17-20 could be interesting.  If the warm sector is far enough north/west then perhaps a severe weather outbreak?  Hopefully no blizzard but I wouldn't be surprised for areas of the high plains.

This still looks to be on track.

4) April 25-May 2 could potentially see much below normal temperatures.  If there is going to be a late frost or freeze, that would be the time period.

No change in the thought process for this period.

I will wait a bit more before venturing out on a summer outlook. 

Again if you didn't have a chance to fill out that brief survey, I would appreciate it greatly if you could help me out. 

March Update

This is going to be a long post since I haven't updated in a month.  For those longtime readers, you know that I've discussed the difficulty in finding time to update this blog.  The posts I make about the current weather trends and outlook are made on my own time and are my own thoughts and are not part of my employment at the National Weather Service.  I regret that I'm not able to update more often.  When I retire from the agency (not that far away) I would be able to update quite often - but of course it wouldn't be free. :-)

To give me an idea if this blog is even worth my time, I would like for you to take a very brief survey.  It will take you less than a minute and you will remain anonymous.   I would appreciate it.  If you would, please Click here for that quick data gathering survey.  Thank you.

So, there is a lot to discuss since I haven't updated since the post on February 5.

First, just as a refresher and perhaps the following will be new to some of you...

When fall arrives, the jet stream across the northern hemisphere starts to intensify (speeds increase) and areas of maximum and minimum speeds fluctuate as these areas move around.  A pattern of where the jet stream winds intensify/amplify meridionally or latitudinally becomes established.  This pattern has been known to repeat around the hemisphere on a periodicity that varies from one year to the next. I have found the repeating nature to be from 45 to 60 days, but it has been outside of that range.   What causes the jetstream to behave in the way it does (differently) from one year to the next are influences from oceans and land masses - and probably the sun.   Some influences are more dominant than others but those tend to change from year to year.  Even on an intra-seasonal time scale the influences can change.

Some of the changes that influence the jetstream can from the tropical oceans (Atlantic, Pacific, Indian Ocean), northern latitudes of oceans, landmass/ocean interactions, Arctic oscillations of surface pressure,  stratospheric warming, blocking of the jetstream across the higher latitudes, etc. 

You've heard of El Nino and La Nina (warming or cooling of the equatorial Pacific oceans).  Many people will give a seasonal outlook solely on these events as if THEY are the ONLY factors that influence the weather pattern.  There is plenty of data available to quantify weather based on these events and that data shows a different outcome from event to event.   Based on the current La Nina, here is an outlook from The Weather Channel that was valid for February:

Did they do pretty good?

What about from the Climate Prediction Center (NWS)?

Pretty good?  I'd say a lot better.  Now, granted, this was an updated forecast made Jan 31.  Their original outlook looked similar to The Weather Channel.  What I saw on Feb 5th was that the build-up of brutally cold air (causing the Arctic Oscillation to go strongly negative) was finally going to make a visit on "our" side of the hemisphere.  The two other negative events (not as negative) were unleashed upon Siberia and Europe.  Plus, there was strong evidence of a significant Madden Julian Oscillation (MJO) and that MJO became VERY significant and I think had the greatest impact on our February weather. 

The MJO was well established and influential. 

But now look what has happened to the Arctic Oscillation! 

That is a major shift to the positive side!  Even though we are currently seeing a dip, the AO is forecast to go strongly positive and potentially with a magnitude that I haven't witnessed.  Now my question is just what influence will this have on the pattern for the next few weeks.   Is the AO the main controlling factor on the jetstream?  Or could be be forcing from perhaps the western Pacific (not La Nina).  If the cooling on the equatorial Pacific is the main influence, then there probably wouldn't have been this storm we just had.   

Now there is evidence of a resurgence of another MJO, just not as strong as the February event.  Regardless, I think this developing MJO in the presence of the pattern that developed during the fall has given me confidence of several periods of active weather or changes.  I actually had these dates in mind back on the 20th of February (the last time I intended to update this blog).  I haven't changed my  mind since then.

These following periods are not the ONLY possible weather....they just have my attention.

1) March 10-17, but especially around March 15.  This should be the next active period but probably only 1 storm will impact the high plains and that would be around the 15th.  Before then it could be the eastern plains.  I wouldn't be surprised if there was a blizzard, especially for higher elevations of the high plains.

2) March 25-31 is a period of potentially much below normal temperatures.  That could be problematic as with this recent rain and the mild temperatures coming up, there may be some early breaking of dormancy of some vegetation.  Also, the b word comes to mind.  The last 10 days of March are actually the most active for blizzards, based on history.

3) April 17-20 could be interesting.  If the warm sector is far enough north/west then perhaps a severe weather outbreak?  Hopefully no blizzard but I wouldn't be surprised for areas of the high plains.

4) April 25-May 2 could potentially see much below normal temperatures.  If there is going to be a late frost or freeze, that would be the time period. 

I'm not ready to venture into an outlook for the summer.  For a while this winter I was seeing resemblance and similarities to 2011.  Ugh.  I'm not sold on that yet so don't panic.

Again, if you wouldn't mind doing the quick survey...it would help me to determine the direction I go from here.