High Temperatures today and tomorrow.

Warming up ahead of the next Winter blast.  

Highs for days 3-7:

The next  blast of cold in the NorthCentral  US will head east. Starts receding towards the end of the week....except for the far north.

How do these days 3-7 temperatures compare to average at this time of year?

 
Not as cold as recent cold with the Cold blue anomalies. Warm red anomalies increasing this week to the west

Low Temperature Departures:

Surface features for the same 3-7 day period:

After the Big WINTER storm  passes the next 24 hours,   Canadian High pressure for several days.....then the next storm towards the end of the week.

  Pattern

The latest liquid equivalent precip forecasts for the next week are below.

This storm passes then mostly quiet midweek.

New storm late week. HEAVY Widespread precip! Almost of it should be rain.

Day 1 below:

http://www.wpc.ncep.noaa.gov/qpf/fill_94qwbg.gif?1526306199054

Day 2 below:

http://www.wpc.ncep.noaa.gov/qpf/fill_98qwbg.gif?1528293750112

Day 3 below

http://www.wpc.ncep.noaa.gov/qpf/fill_99qwbg.gif?1528293842764

Days 4-5 below:

http://www.wpc.ncep.noaa.gov/qpf/95ep48iwbg_fill.gif?1526306162

 Days 6-7 below:

http://www.wpc.ncep.noaa.gov/qpf/97ep48iwbg_fill.gif?1526306162

7 Day Total precipitation below:

http://www.wpc.ncep.noaa.govcdx /qpf/p168i.gif?1530796126

Current Dew Points

Latest radar loop

http://www.nws.noaa.gov/radar_tab.php

Go to: Most Recent Image

Precipitation the past 24 hours

You can go to this link to see precipitation totals from recent time periods:

https://water.weather.gov/precip/

                              Go to precipitation, then scroll down to pick a time frame. Hit states to get the borders to see locations better. Under products, you can hit "observed" or "Percent of normal"      

+++++++++++++++++++++++++++++++++++++++++++++++

     Soil moisture anomaly:

Still  wet on this particular metric in an enormous area.

+++++++++++++++++++++++++++++++++++++

Precipitation compared to average for the last 7, 14, 30 and 60 days. 

Been pretty dry the last few weeks.............that will change late this week.

Usually not updated for previous day until late the next day.

https://www.atmos.illinois.edu/~snodgrss/Ag_Wx.html

The top map is the Canadian ensemble average, the maps below are the individual members that make up the average

End of week 2....................0Z ensembles from SUNDAY:

From Friday:  Big disparity still. Some are very cold with northern stream a major player. Along with that, is the risk that part of the polar vortex will take another excursion unusually far south. This would replenish the frigid weather reservoir to Canada, that gets depleted leading up to this period.

 Some have mild/zonal flow that cuts off the cold. 

Saturday: Big change, actually huge change. The vast majority now are milder. Very few show the threat for the polar vortex to shift south
.

Sunday:  The average, deceptively looks zonal. Numerous members look colder than yesterday, with some now back to featuring the polar vortex shifting south again. However, the disparity is huge. I am very low confidence for this time frame. It could be mild or morph back to extreme cold.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Each member is like the parent, Canadian model operational model.......with a slight tweek/variation in parameters. Since we know the equations to represent the physics of the atmosphere in the models are not perfect, its useful to vary some of the equations that are uncertain(can make a difference) to see if it effects the outcome and how.

The average of all these variations(ensembles) often yields a better tool for forecasting. It's always more consistent. The individual operational model, like each individual ensemble member can vary greatly from run to run.........and represent an extreme end of the spectrum at times. The ensemble average of all the members, because it averages the extremes.............from opposite ends of the spectrum.........changes much less from run to run.

360h GZ 500 forecast valid on Dec 10, 2018 00 UTC

0Z GFS Ensembles

Friday: A great deal of uncertainty at this time frame but still leaning strongly to cold for this model! Threat for polar vortex to start moving south again is elevated today.

Upper level trough somewhere.

Saturday: This model hasn't changed that much since Friday(but less threat for polar vortex shifting south). Looks like alot of  widespread precip with an upper level trough and coldest temps west(possibly milder east of the Upper trough)

Sunday: This model has done best for week 2 recently. It looks even a bit colder in the East now. It also looks MUCH drier, with the northern stream dominating and southern stream out of the picture.

Canada's supply of frigid air will be replenished so cold fronts could pack some punch.

Latest, updated graph/forecast for AO and NAO here, including an explanation of how to interpret them. 

Last Sunday's comment: For late week 2 here on Sunday. Huge disparity and change from recent solutions.

The  AO was in uncharted low territory for awhile last week.........with extreme cold indicated but now is shown to just temporarily spike down(not quite as extreme) and bouncing back towards zero but still negative and decent cold indicator.

The NAO was also strongly negative last week and is showing the same tendency, a spike lower but bouncing back towards zero...........still  remaining a bit negative at the end of week 2, suggesting cold.

The day to day changes are big enough to generate low confidence.

Monday: 2nd day in a row that shows the same thing. Negative AO and NAO are recovering at the end of the period.........reducing the threat of extreme cold for early December. 

Tuesday: The trend towards a reduction in the magnitude of the negative AO and NAO continues. It morphs towards zero at the end of the period, lessening the risks for extreme cold in early December. 

Wednesday: AO and NAO diving into solid negatives then rebounding. AO STAYS negative, more so then Tuesday. NAO keeps rebounding to near zero at the end of 2 weeks. Huge spread and uncertainty.

Thursday: AO and NAO show the dive to negative being shorter lived than previous bouncing back closer to, if not all the way back to zero at the end of 2 weeks. This reduces cold risks in December. 

Friday: Huge change late in the period. Negative AO and NAO, after bouncing back, on all members crash to extremely low values and the end of 2 weeks...............on a slight majority, while on a minority, keep going higher and even poke above zero.The spread/disparity is "off the charts" especially with the AO but the average is MUCH colder than yesterday/Thursday.

Saturday: Not nearly as cold as Friday. AO and NAO still negative but closer to 0 as week 2 goes on(especially the NAO). 

NAO close to 0 vs strongly negative reduces cold risks in the East. 

Sunday: Similar to Saturday. Both the AO and NAO increase to just sub zero at the end of 2 weeks. Massive disparity on the AO with a few strongly positive now for the first time in awhile, while others are solidly negative.The average is often not the best indicator in this case because there are too many that disagree with the average. Great uncertainty with the potential for either extreme almost as high as something in the middle.

https://www.marketforum.com/forum/topic/15793/

National Weather Service 6-10 day, 8-14 day outlooks.

 Updated early this afternoon.

Sunday am take: The forecast maps don't look as wet or mild to me as the Saturday NWS automated forecast.  In other words, I'm colder and drier than Saturdays NWS forecast.

PM Update: I'm good with there huge cold changes in the 8-14 day forecast below.  If the latest models are correct, much colder changes will be needed in the East too.

On precip, in the 6-10 day period, there will probably still be lots of widespread precip, especially early in that period, especially heavy in the east.

In the 8-14 day, I think the Northwestern half of the belt and Plains may end up much drier than the map below.

Temperature Probability

Precipitation Probability

the 8-14 day outlooks ArchivesAnalogsLines-Only FormatGIS Data

Temperature Probability

revious discussion:

                By WxFollower - Nov. 20, 2018, 4:34 p.m.            

            Mike,

 Have you noticed that the average anomaly for US highs has been much colder than that for the lows, especially in recent weeks? Is that related to global warming and the very warm oceans? I know the SW Atlantic just off the SE US remains quite warm anomalywise though it is starting to cool some.

++++++++++++++++++++++++++++++++++++                

                By metmike - Nov. 20, 2018, 7:44 p.m.            

Yes Larry, great observation!

Actually this has been going on  for 2 decades.

It's been causing highs to be lower and lows to be higher. This has done several things.

It's decreased the diurnal temperature spread.

It's causing record warm minimums to exceed record warm maximums.

Related to that, its reducing record warm maximums vs where they would be and reducing record cold minimums.

It's been warming the coldest places on the planet the most, especially during the coldest times of year.

It's reduced extreme highs in the Summer vs where they would be without this going on.

I think the increase in H2O in the air can be part of it but the increase in CO2,  causing the "greenhouse" effect  could explain most of it by itself. This effect would be greatest in the coldest places and at night(Polar latitudes have night time conditions all Winter long), when long wave radiation dominates the heating signal......CO2 plays a key role with the long wave radiation...........more of it, means more heat stays in the atmosphere. 

So higher minimums.

 During the day solar, short wave radiation dominates the heating signal, so greenhouse gas warming from more  weaker, long wave radiation is not as important. So not as many higher maximums because the intensity of the sun(TSI) has not changed much.

           +++++++++++++++++++++++++++

                By metmike - Nov. 20, 2018, 7:51 p.m.            

           This was a good article on it:

http://www.climatecentral.org/blogs/record-warm-nighttime-temperatures-a-closer-look

But looking at these four types of records, it appears that nights have warmed even more: the average month recorded 10 percent more record high minimum temperatures than record high maximums. The record low temperatures tell an even more compelling story: it was much more likely for the daytime temperature to be colder than average than it was for the nighttime ones. There were only 1,235 record low minimum temperatures set per month, while there were 1,697 record low maximum temperatures set per month. By this measure, a record cold day was 40 percent more likely than a record cold night.

Interestingly, when I looked at different months of the year, I found that the nighttime warming was even greater during the summer. During June, July and August, record high minimum temperatures outnumbered record low minimum temperatures by about three to one.

More cloudiness could also explain part of it, as clouds trap heat from escaping at night and block heat from getting in during the day. 

+++++++++++++++++++++++++++

                     By metmike - Nov. 21, 2018, 9:50 p.m.            

See comments in the natural gas thread about the polar vortex and this being the coldest Thanksgiving in the last century in the East/Northeast:

https://www.marketforum.com/forum/topic/17783/

                             Re: Weather Saturday            

                By WxFollower - Nov. 24, 2018, 7:29 p.m.            

Why does anyone believe anything the GFS says past about day 7 and especially past day 10? (not just talking about this latest very cold 18Z run). Look at how cold it now is vs the SE warmth that was shown just a couple of days ago on most runs. It clearly has had the warmest bias of any of the major models. So, those warm runs turning colder is not a surprise. But it tends to vary so much from one run to the next past about day 10.

 Fortunately, the NG market (among others) has learned to not react as much as it used to (years back) post day 10 of the GFS since the market realized that it should be taken with a grain.

 For that matter, any details about storms, etc., past about day 7 on most runs of operational models should be taken with a grain. But the GFS has been extra horrible recently. That's where the ensemble means become more valuable as a forecasting source. Week #2 in general is much less unreliable on the ensembles vs the operationals.

++++++++++++++++++++++++++

                By metmike - Nov. 24, 2018, 7:38 p.m.            

Great points Larry.

Here is the latest 18z GFS operational model run for day 10, then day 15.........Siberian Express!!!

++++++++++++++++++++++++++++++++++++++++++++++++     

                By metmike - Nov. 24, 2018, 7:53 p.m.            

Here are the same time frames for the GFS ensemble average-18z (a bunch of GFS solutions with slight variations in different parameters to yield  different solutions-some extreme some not but the average of them stays consistent/doesn't change as much from run to run)

The maps below are 500 mb heights........around halfway up in the atmosphere. The upper level winds tend to flow in the direction of the lines, almost parallel to them. Think of the lines as being channels for air flow, like the banks for a river of air.

The day 10 map, which has gotten quite a bit colder in recent runs, actually doesn't look that much different than the operational model for the same time frame. At day 15(360 hours) one of the biggest reasons that it loses the extreme nature of the flow/pattern is because some of the ensembles have the opposite pattern, a much milder pattern, with Pacific flow undercutting the strong northern stream that was in control at day 10. When averaged in with the very cold members, we get something in between.

++++++++++++++++++++++++++++++++++++

                By metmike - Nov. 24, 2018, 8:05 p.m.            

Looking closer at the 18z ensemble, for an ensemble run, its quite a bit colder during week 2 than the previous runs, especially late in that period. 

Here are the 850 mb temperatures(around 1 mile up in the atmosphere). 

Last nights 0z ensemble average had an 850 mb temp of -3 deg C in Chicago. For the same time frame on this latest run, the 850 mb temp is -10 deg. C.

That's alot of an ensemble mean change in 18 hours. Considering that the models have underestimated cold for the past month, this is something to pay close attention too.

What makes this especially interesting is that the European and Canadian models are almost completely opposite.........showing very mild temperatures spreading across the country. 

++++++++++++++++++++++++++++++++++++++++++++++++

                By metmike - Nov. 24, 2018, 8:18 p.m.            

This was the last 12z run for the Canadian ensembles with the average at the top. 

Much different than the GFS Ensembles. One should also note the huge spread in the AO at 14 days that reflects this huge difference. Some members are strongly negative with the risk of frigid weather, some members are near zero, low risk of frigid weather.

Lots of conflicting signals. The recent pattern has favored very strong cold........but the Pacific is supposed to be morphing into an El Nino which favor warmth.

The Madden Julian oscillation, I think is moving towards increasing odds of cold. This and models not being cold enough recently has me leaning towards the GFS right now(though the European model ensembles has a slightly better track record) 

Actually, I just checked how each of the models have been doing recently and the GFS ensembles have been clearly outperforming the other models in the extended range. It's #1 in the 6-10 day period and is mopping the floor with the other models in the 11-15 day period(which have been doing horrible-too warm). This has me leaning strongly towards the colder solution. 

   By WxFollower - Nov. 24, 2018, 10:59 p.m.            

            Mike,

 Per history, with El Niño likely not getting any stronger than low end moderate, that is actually often a cold rather than warm signal for at least much of the eastern half of the US. I wasn’t sure if you realized this. Many of the coldest winters in the E US were actually weak to low end moderate El Niño’s: 1884-5, 1885-6, 1904-5. 1911-12, 1939-40, 1963-4. 1968-9, 1969-70, 1976-7, and 1977-8.

 Then again, we still have -AAM, which is most often associated with La Nina and usually not as cold for much of the E US. Having the -AAM in combo with El Nino is quite unusual from what I learned from Radiant though I wonder if it will hang on through winter.

Does anyone have a link to an historical monthly AAM table?

Good points on the weak El Nino correlating with more colder than average Winters in the East.

Maybe it's because the southern stream generated from El Nino was not strong enough to have an impact far enough downstream to deflect the northern stream, so the northern stream dominated:

https://www.climate.gov/news-features/featured-images/us-winter-temperatures-every-el-ni%C3%B1o-1950

With regards to El Nino Winters from more than 70 years ago, I don't put alot of stock in the accuracy of the magnitude since there were no widespread accurate  measurements from that time frame.

No doubt they had trade winds recorded and barometric pressures (and differences) at some locations that would be useful in getting a ball park type figure, maybe even a guess but the actual sea surface temp data needed to assess this metric was not there. 

"Then again, we still have -AAM, which is most often associated with La Nina and usually not as cold for much of the E US."

My first thought was that La Nina's are cold in the East and memory tells me that some very strong La Nina's have featured extreme cold in the Midwest and East, however I checked and what you stated, not as cold in the East seems to be what's out there on the internet. I am skeptical. 

To me, this flow diagram does not make sense meteorologically..........unless you shifted  the weather to the east/right several hundred miles. 

A high pressure ridge to Alaska and Western Canada will feature mild Winter conditions there, not cold.

The blue cold, would be escorted south, much farther east INTO the deep trough from the Midwest to the East Coast. 

I don't have any AAM historical data and have not studied this a great deal.

Thanks for bringing this up though Larry so that I can learn more about it. 

1. I just found out I was wrong about there still being -AAM. It was that way in Sep. but it turned to +AAM in Oct  and has become strongly +AAM this month. So, disregard my concern about how El Nino tends to be with -AAM.

2.  Looking at records, the SE US and Mid Atlantic (I think to at least NYC) has averaged colder during weak to moderate El Nino than all La Nina's averaged out. I think the upper Midwest and most of the plains has averaged colder in La Nina. I'm not sure about the lower Midwest though I lean toward warmer in La Nina for Cincinatti.

3. IMO, there is plenty of data to suggest what years were El Nino and what were La Nina including SOI and various SST data. I've been using this for ~15 years.