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(NOTE: I am writing this thread for casual interest readers as well as more intensely interested fellow “weather geeks.” )
Many of you have already seen a couple of outlooks on the web, in social media and a Buffalo News article last week suggesting signs are somewhat ominous for this coming winter. The News article even included an AccuWeather prediction that the dreaded “Polar Vortex” would make an appearance sometime later in September, ahead of a wintrier than average winter.
Some of these predictions may pan out, some may not, some are from educated meteorologists, some are from uneducated friendly fakes whose work is much akin to astrologers (the Farmers Almanacs, whose methodology is based largely on nonsense), and some are from teenage children on social media who have learned just enough about weather to be dangerous.
Know this: seasonal outlooks are markedly different from 1 to 7 day weather forecasts. They operate on different timescales, they necessarily filter out the noise of quick moving fair weather systems and low pressure storm systems, and they paint a much more generalized picture of expected patterns. Their verification rates/track records are far less impressive than the accuracy of near term weather forecasts, and that is to be expected. Much of the time, the signals from nature are weak and poorly defined. Making a summer outlook, which gets less notice, can be even less successful because signals are even weaker as the warm weather season approaches.
One noteworthy exception in making a winter outlook would be the likely development of a truly Strong el nino, as was the case prior to the winter of 1997-98. That was a “super” el nino, and el ninos of that magnitude do correlate with warmer than average conditions across the northern tier of the U.S. and in much of the east. If such an el nino was expected this year, I would have some confidence in predicting a warmer than average winter for our region. But we are NOT expecting a strong el nino. Most models which deal with el nino and la nina are forecasting a weak el nino, with a small chance of a moderate el nino. Weak el ninos are not known to correlate with a warmer winter in the east in general and in our region in particular. So, THAT signal from nature is not as helpful a predictor as one might hope. No 2 el ninos are identical and neither are their impacts. There are many variables/changeable elements which can impact the strength and location of an el nino. As of this posting there is a high (65%) but shrinking probability that el nino conditions will develop by late summer/fall.
There are other variables which have predictability only out to 2 weeks, such as 2 oscillating patterns over the NW Atlantic out to Greenland and Iceland. These Atlantic oscillations can have a huge impact on weather in the east and in our region. But if we cannot confidently predict their status much beyond 2 weeks in advance, that makes winter outlooks even more uncertain. And other variables can impact the status of those variables–even something as obscure as how much snow falls in Siberia in the month of October may affect what position the polar jet stream takes during the winter, as well as the factor of how much arctic sea ice melts in the summer months.
I can go on with the enormous list of uncertain variables, but I’ll slow down here. Winter outlooks are difficult enough even in late October and early November, let alone in early August. In my lengthy experience (and that of other meteorologists), winter outlooks made during the summer months simply don’t work well. IF I were to lean toward one direction or the other, I’d reluctantly say that at this point I don’t see current signs which would lead to a much milder than average winter in our region. But that leaning can easily change by mid Autumn, and I wouldn’t make any plans based on it.
BOTTOM LINE: Any winter outlook you’re seeing now should probably be taken not just with a grain of salt, but probably the whole salt mine.
This week begins with a few rounds of showers & tshowers crossing parts of the region. As we head into later Wednesday evening, though, all roads seem to lead to a dry stretch lasting more than 1 or 2 days. Will you settle for 4 or 5? It’s been a while since we had that many rainfree days in a row. Following Monday evening’s showers closer to Lake Ontario, another round of scattered showers crossing the region during Tuesday, and a third round probably focusing on the southern tier during Wednesday, a ridge of high pressure/a fair weather system should set up shop close enough to us to keep us dry through the weekend. This is, in fact, the first Monday in at least 4 weeks in which showers were not already showing up up computer models for the upcoming weekend. Temperatures will be slightly below average in this drier air on Thursday, but begin edging back up on Friday and moving above average by Sunday-Monday next week. Another cold front will cross our region around Tue-Wed next week, ushering in some below average temperatures again (but not by too much) for a few days. Extended range guidance suggest more seasonably mild temperatures returning by mid-August. Uncertainty that far out, however, is abundant.
There are no signs August will do a complete flip-flop into true summer heat through the 20th. But it appears this next weekend will be on the most solid footing we’ve seen for any weekend in the last month. On a Monday, I can’t say a 100% dry weekend is a “lock”, but at least the odds are looking more favorable at this early point in the week.
Even on Monday of this week, it was already becoming apparent this next weekend would again present a challenge to meteorologists in the forecasting process…more on that in a moment.
Another unseasonably cold area of low pressure near the Great Lakes is again bringing well below average temperatures to the Great Lakes and parts of the midwest. As the difference in temperature between the warm lake waters (and, during the day, the somewhat heated land) and the cold air about a mile up increases, the more unstable/”bubbly” the lower atmosphere will become. Water vapor will be lifted up into the cold air, condense, and produces showers and some thundershowers over the Great Lakes and parts of our region. Some tshowers may contain small hail, and this temperature lapse/dropoff rate will also make conditions more favorable for a few waterspouts by Wednesday. After an unsettled Thursday, the atmosphere should be settling down Thursday night into most of Friday, but not for long.
On Saturday, a poorly organized area of low pressure to our SW will begin to feed moisture up through Ohio & PA into our region. This will result in an increasing likelihood of at least a few showers & tshowers, with chances currently (Tuesday post) looking greater over the hills to the S & SE. Similar conditions may prevail again on Sunday. At this point, neither day is looking to be a washout. So, it’s still possible we could end up as fortunate as we were during this past weekend. However, virtually every computer model shows SOME convection/shower & tshower development getting to portions of WNY at times during the weekend. That means no meteorologist could objectively predict on this Tuesday that we WILL be mainly rainfree. Both you and I will have to be patient for the details to emerge, as the mechanism to make these showers will be somewhat weak and diffuse.
After we’re through with this spate of September-like weather through Thursday, temperatures will edge back up closer to average on Friday into early next week. Most extended range guidance suggests more seasonable temperatures more of the time as we move toward mid-August. But I also have to tell you that the ups-and-downs which will probably occur in that time range can not be foreseen this far in advance.
As many of you know, June was quite a bit warmer than average. The monthly average daily high temp was 3 degrees above normal, and we ended up with the 11th warmest June on record. As for July, the trend is opposite thus far. Through the 20th, we’ve had 9 days above average and 12 below average. While we’re in a warmer than average start to this week, cooler weather will be returning for Wednesday night and Thursday. The overall trend for next week will be for below average temperatures. Bottom line: July is quite likely to be cooler and, probably, wetter than average.
After the current warmup, a cold front will cross the region Wednesday. Behind it, Thursday’s high temperature will be 5-7 degrees below average. Readings will gradually moderate on Friday into a seasonable and pleasant Saturday. Most extended range guidance on this Monday evening point to an area of low pressure moving back into the Great Lakes during Sunday. That would mean the development of scattered showers & tshowers for a portion–probably the afternoon–of the day. The threat of some showers will continue into early next week, depending on the timing of another cold front or two. A dip/wave in the jet stream will allow Cool Canadian air to return to the Great Lakes by Tuesday next week, lasting through much of the week. (No, I’m NOT calling it a “Polar Vortex”!) Readings may moderate again by the final weekend in July, but there are no current signs of a big warmup. In the immediate future, the thunderstorm potential for Wednesday’s cold front doesn’t look all that impressive at the moment. It appears rainfall amounts and coverage will tend to be greater south & SE of the metro area during Wednesday afternoon. Parameters for strong to Severe tstorms look very marginal/very low probability.
From the Monday afternoon vantage point: With fairly moist air in place, an upper level disturbance will trigger spotty showers & tshowers, becoming more numerous later in the day. The best chance for this convection will be over the hilly terrain S & SE of the metro area. The atmosphere will remain somewhat unstable overnight, with the approach of the now infamous (polar/nonpolar) vortex, so a few more showers & tshowers may still pop up. On Tuesday, temperatures will run below average, as that vortex increases its influence. Some scattered showers & tshowers will pop up occasionally. The stiffening breeze will put a chill in the air. Most computer guidance shows drier air in place by the time of the Canalfest Parade. However, when you have a cold upper disturbance over warm lake water, I can’t rule out a few lake induced evening showers. The coldest air will be in place midweek. The difference in temperature between 72 degree Lake Erie and the atmosphere about a mile up will cause some lake effect clouds and showers to pop up, mainly over the interior, on Wednesday. Thursday should be mainly dry, and temperatures will begin to moderate more noticeably by Friday. There is considerable uncertainty about shower chances for coverage and timing on the weekend. At this point, there are no indicators of a complete washout on either day, but some showers & possible tshowers will probably push into WNY on Saturday from the south. The best chance for the most activity currently appears to be to the south of Buffalo. And early signs favor less activity–if any–on Sunday. Monday also currently looks to be dry. Temperatures should be closer to average Friday-Sunday, and may edge up to above average by Monday.
In case anyone didn’t notice, there is plenty of water vapor in the atmosphere this afternoon, and plenty more to come into Tuesday evening. The Storm Prediction Center has WNY & northern PA at Slight Risk for Severe Tstorms with damaging gusts. However, the abundant cloud cover has held down heating. That, combined with the stiff Lake Erie wind is keeping the atmosphere less unstable across the Niagara Frontier thus far. Any stronger storms which develop later today would be more likely Well S & SE, away from the lake’s influence. The humidity stays high tonight, with the best chance for scattered showers & TStorms in the early evening. On Tuesday, chances for showers & TStorms will be greater in the afternoon. SPC again has much of our region at Slight Risk for Severe Tstorms, but that risk appears mainly south and east of Buffalo, rather than closer to Lake Erie. Behind a cold front, humidity will drop back on Wednesday, even though a disturbance may yet kick off a few garden variety showers. A dry air mass will then stay in place Wednesday night into Saturday. Thursday will be seasonably cool, with readings edging up Friday & Saturday. By Saturday night or Sunday, an approaching disturbance will probably bring a few rounds of showers & tshowers across parts of the region. Timing and coverage remain quite uncertain at this point. Another cold front will be approaching late in the weekend, with readings dropping back early next week.
No extreme heat is in sight. The upper air pattern will favor troughing redeveloping over the Great Lakes from time to time, with the mean expressing that troughing. Currently, there are also no indications of extensive warm ridging near us in the next 16 days. However, there are no indications of lengthier cool and wet periods either. For agricultural purposes, precipitation should be sufficient to avoid frequent reliance on irrigation.
while they’re fresh in my mind:
Earlier estimates of a Strong or even Super El Nino appear to have been overdone and overblown. Newer model data suggests a Moderate or even Weak El Nino, which makes a difference. Every El Nino episode is different. In general, however, Moderate or Weak El Ninos taken by themselves have not been shown to necessarily correlate to a milder than average winter in our part of the country, while especially Strong El Ninos do appear to have such a correlation. So, it may take other variables in our atmosphere to produce a milder winter, none of which is predictable at this time (we had a number of experts in this field address us at the conference).
The danger of hyperthermia/heat stroke/death of children left in cars is even greater than you may have heard. Color of car makes no real difference, nor does “cracking a window”, and such deaths have been increasing even at more northerly latitudes. Here is the report from Jan Null, AMS Certified Consulting Meteorologist of San Francisco State University, written for laypeople: http://www.ggweather.com/heat/
-Beware of Alarmist Gibberish from unqualified Facebookers & other Social Media, presented by my scholarly friend Dan Satterfield: http://blogs.agu.org/wildwildscience/2014/01/31/the-great-facebook-blizzard/
-Future Weather Warnings may have more clarity, and less confusion…but it will take a while. The current list of color codes and warning/advisory criteria by the National Weather Service has become all but overwhelmingly confusing and difficult to digest on busy weather/severe weather days. The British Met Office has had great success with simplification by presenting Public Impact colors–just 3– ranging from Yellow (Be Aware) to Amber (Be Prepared) to Red (Take Action). While our weather is often more complex and severe than that of Great Britain, even Storm Prediction Center expert Greg Carbin has been impressed by these ideas from our friends across the sea. The watches, warnings, and advisories will still have to be fitted to individual threats, but the Public Impact color code is being examined by NOAA, the NWS, Emergency Manager organizations and others. The Met Office presentation was well received: http://www.metoffice.gov.uk/public/weather/warnings/#?regionName=uk&tab=map&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1403409600
There is some debate on the rate of current and future global warming, but evidence remains extremely strong that human activity is the primary forcing mechanism for the ongoing warming (which is currently focused more in the oceans than in the atmosphere, along with increasing rates of acidification–a danger to coral and many shellfish–due to increased amounts of carbon being absorbed by the oceans). Sea levels continue to rise, more than 90% of the earth’s glaciers are in retreat, and CO2 is at its highest level in at least 850,000 years, 400 parts per million, compared to 280 parts per million prior to the industrial revolution (up 40% from those levels). Due to continued industrial growth and building of coal fired power plants in nations such as China & India, CO2 emissions are likely to continue to rise rapidly. As I’ve frequently posted, one of the best sites for those who want to learn more about these topics is: http://climate.nasa.gov/
-It was a great conference, held in Squaw Valley CA, by Lake Tahoe…and a terrific learning experience. Thanks for WIVB/WNLO Lin Media for allowing me (and other LIN meteorologists) to take in this valuable continuing education.
The links in this text appear in usable form in the first comment below.
After Saturday’s crisp and comfortable conditions, warming will resume on Sunday and continue to build for a good part of the week of the 16th. An upper level ridge will strengthen in the east until later in the week. Around the periphery of this ridge, several short waves will cross the Great Lakes and bring several rounds of Showers & Tshowers. The humidity will begin to build noticeably on Monday and hold into at least midweek. There is relatively good agreement in the ensemble means that some degree of troughing will redevelop near the Great Lakes later in the week, allowing more comfortable conditions to return. At this point, this cooling doesn’t appear to be likely to bring below average temperatures for any extended period. More seasonable temperatures will prevail in the mean. It can’t be determined if this weaker troughing might continue a parade of occasional short waves or not. After the early ridging during the week of the 16th, the rest of the means either favor a zonal flow or a slight WNW flow with the weaker troughing, with no visible rebuilding of the eastern ridge.
On the matter of El Nino, there continues to be some disagreement between the more conservative forecast offered by CPC on the amplitude of the event, compared to the NASA link we’d posted earlier, and some other projections. At the current time, the positive sea temp anomalies have some similarities to those observed in June 1997. However, there has also been Kelvin wave activity which has produced some of this warming. Owing to the ENSO ensemble members I’ve seen, there are only a couple of the many members which bring amplitude beyond 1.5 degrees positive anomaly. That is, most members project a Moderate El Nino. The correlation between a Moderate amplitude and WNY winter positive temperature anomalies is much less so than in the case of a Strong el nino. The hopelessly tired cliche “time will tell” applies here. We’ll have to continue to monitor the ENSO ensemble over the next several weeks to see if the trend changes.
As we’re now into the warm weather season, the surface features on the weather map tend to be flatter and weaker, as do many of the mid-level features aloft. In other words, timing weaker more subtle systems makes for some challenging forecasting. That doesn’t mean ALL systems are weak and poorly defined. In fact, as I type this post conditions look favorable for a rather major Severe Weather Outbreak on Tuesday the 3rd over portions of Iowa, Minnesota, Nebraska, NE Kansas and west central Illinois. But in the mean, defining troughs and ridges in the 500 mb flow, properly placing them, and properly determining their strength/amplitude becomes tougher. That’s because the mean tends to produce more of a zonal look. That’s in contrast to the blocky, high amplitude pattern we had so often until recently.
And remember, this mean is often the smoothed mean of many ensemble members in the global models which have a lot of spread between one another. The mean can be a best choice by default. But it is not necessarily the most reliable choice.
There will be a cooldown with reduced humidity returning toward Wednesday morning. Almost immediately afterward, there is already low confidence as to when any showers associated with an area of low pressure going by to our south might arrive in parts of WNY, with 2 operational models bringing those showers back in by mid or late Wednesday afternoon. Odds do favor much of the rain with that system staying farther south. The GFS is blindingly fast with onset and exit times, and viewed with suspicion on that speed. After lovely and dry days on Friday and Saturday, during Sunday another area of low pressure will be approaching, probably bringing some convection in by later in the day, with a few more rounds into Monday AM. There are no signs of prolonged heat and humidity, nor are there signs of prolonged cool weather. So, at this point, much of this next weekend looks pleasant. But unlike the last 2 weekends, the finish to the weekend is in doubt.
There are no changes to the ENSO forecast this week. The so-called key Nino Region 3.4 has a +.6 degree positive SST anomaly. Generally, an el nino is not considered as such unless there are 3 consecutive months of el nino conditions. A couple of weeks doesn’t cut it, partially due to the rising and ebbing warming/cooling caused by Kelvin waves traversing the Pacific. I’m still seeing only a handful of ENSO models projecting a truly strong el nino. Many, including the mean of the CFSv2, lean toward a moderate el nino.
At mid-latitudes, we are still in something of a “blocky” pattern. A warmer ridge of high pressure will briefly peak aloft on Tue-Wed, followed by a large upper level low forming well to our NE by later in the week. That almost-cutoff low will usher in a return to below average temps for Thursday-Friday. However, it will gradually relax its grip during Saturday, allowing milder temperatures and dry air to move in for Sunday and Memorial Day. The overall 500 mb flow in the ensemble means favors above average temps much of the time next week, with an uncertainty concerning precipitation potential.
Even this week, as we draw closer to the long advertised rounds of scattered convection which arrive late Tuesday into Wednesday, precipitation potential has uncertainty. The amount of precipitable water in the lower atmosphere will be high, but the triggers for organization don’t look impressive. There may be a couple of isolated downpours. In addition, a couple of models suggest a convective complex could come riding down on a NW flow into NW PA toward Wednesday AM, which would pose a risk of heavier rainfall close to Chautauqua County, and stronger winds. Our in-house models don’t see this potential as of this posting (Monday evening). Even during our Tue-Wed moderating sfc flow, local Lake Erie shoreline/waterfront temps will remain below average–so this isn’t much of a warmup. After a Thur-Fri with high temps in just the low 60s, and a few leftover light showers possible, Saturday should bring high temps in the upper 60s inland with only a small chance of a couple of deep interior light showers. Sunday and Memorial Day look spending, with Monday being the warmest of the 3 days.
Odds for El Nino will continue to increase by early summer, and will approach 80% by autumn in CPC’s newest perusal of ENSO models from around the globe. As I’ve already mentioned in the previous thread, a summertime el nino has little if any effect on our regional weather. And, as most of you know, its impact on our cold weather months seems to be keyed to the amplitude/strength of el nino. Some researchers are suggesting evidence is growing for a strong el nino. Model ensemble members are more of a mixed bag on strength. In my judgment, uncertainty on strength remains fairly high.