4 Warn Weather

A Quick, Almost Wintry Hit for Halloween, but It Won’t Last Long

October 27th, 2014 at 9:26 pm by under 4 Warn Weather

After unseasonable warmth on Tuesday,  a cooler pattern will begin to take shape midweek. But the transition changes from cooler to Colder during Halloween into the weekend. A sharp disturbance will be able to tap in to the coldest air mass of the season. As this transition develops on Halloween into Halloween night, rain showers are likely to mix with snow and eventually turn to all snow by or during Friday evening, with some leftover snow showers around during Saturday. The chance for accumulating snow seems low near the Lakes, but a coating will be possible over higher terrain inland. One computer model has enough moisture for some modest accumulation over the interior, but another–the European–is less generous with the moisture accompanying the change to cold weather. This posting comes on a Monday night, so some change is still possible concerning snow chances. For historical perspective, it has snowed on 12 Halloweens in Buffalo, going back to 1871. The most recent significant snow was in 1993, when 2.8″ fell officially after rain during the day. While I’ve heard people’s selective memories picking out more frequent snowfalls on Halloween, actual data shows measurable snow is still a relatively rare event on October 31. Of those 12 Halloweens with observed snow for Buffalo, only 6 have been more than a trace (a trace means observed, but not enough to measure) and just 4 over 1″…and just 1 over 5″, in 1912 (6″).

As for this almost wintry hit Halloween night looks cold whether we have snow showers or mixed showers as a wind chill will increase; Saturday will be the coldest day of the season so far, with high temps only in the 30s, along with a nasty wind chill and some light snow or mixed showers. Sunday will be drier, and readings will edge back into the 40s. Temperatures are likely to go back above average much of next week, with some modest cooling possible late next week.


Some More Thoughts on the upcoming Winter…Complicated but Interesting (I hope)

October 14th, 2014 at 8:46 pm by under 4 Warn Weather

On Thursday of this week, NOAA will issue its annual Winter Outlook.  The third Thursday of all months is when the National Weather Service’s Climate Prediction Center issues a new 30 and 90 day outlook, with semi-experimental outlooks in 3 month groupings out to a year. My impression is NOAA management sees making this particular outlook as more newsworthy is a chance to garner needed public attention on the work NOAA and the NWS does for all of us, at reasonable costs.  My educated guess is that NOAA will continue to favor a milder than average winter over all of the northern states, with a weak 33% probability of milder than average temperatures in our region. The reasons for such an outlook are many and complex. A couple of models which forecast trends over several months in advance do weakly favor milder than average temperatures continuing from now through most of the winter. Here is a link to the last November-January outlook issued back on September 18th:

/products/predictions/long_range/lead02/off02_temp.gif

There is an estimated 60-65% probability of el nino conditions developing between now and November. El nino occurs when warm equatorial waters normally found in the western Pacific oscillate farther east, changing the path of the subtropical and polar jet streams, which steer our air masses and storm systems. Since that probability still exists in the newest el nino (El Nino Southern Oscillation) forecast, my guess is that NOAA will stick fairly close to their September outlook for November-January outlook.

BUT there are other variables which may come into play that could change this mild trend. First, el nino is expected to be weak. While a strong el nino IS correlated with warmer and often drier conditions for our region, a weak el nino is NOT correlated with thse milder conditions. In fact, National Weather Service Buffalo Meteorologist Robert Hamilton has done some extensive statistical research on this. He has found that 18 out of the 20 coldest (not necessarily snowiest, but coldest) winters in WNY since 1950 have occurred either with a weak el nino (which is what is forecast) or neutral southern oscillation conditions (which is the current condition). That doesn’t mean there is a high confidence forecast for a colder winter. It means there is a chance that the national NOAA outlook may paint with too broad a brush. MAY.

And, then there is an even more complex scenario. A private sector scientist who has been affiliated with MIT, Dr. Judah Cohen, has found that in years where October snowfall in Siberia (of all places!) is above average, that can make for a colder, snowier winter in the east and in parts of Europe. Here’s how: When snow covers much of Siberia in October, beyond the normal snowfall, a large arctic ridge of high pressure forms in the Siberian basin. Because this arctic air cannot press far to the south due to tall mountain barriers, it pushes east as a dense air mass and sometimes spills over the polar region into North America (this is called cross-polar flow). This can force the polar jet to dive to the SE across parts of central and much of the eastern US. Another oscillating index, called the Arctic Oscillation (quite different from el nino, briefly described above) goes into a cold (negative) phase in this type of a pattern. The “snowmaggedon” winter of 2009-2010 in which Baltimore actually received a little more snow than Buffalo appears to be linked to this October Siberian surplus snowfall. Some meteorologists are paying early notice to what’s happened so far this month. Judah Cohen has developed what he calls a Snow Advance Index tied to Siberian snow in October. Here is what it showed as of the end of last week:

As of October 11, Siberian snowfall is ahead of where it was during the last 5 years, including the “snowmaggedon” year.

And here is the departure from normal as of yesterday from the widely used Rutgers Snow Lab (no, that lab didn’t exist when I was there…we were still using punchcards :) ):

The area in purple is where snowfall in Siberia is above average for the month. Remember, the cold air over that snowpack cannot cross the mountain barriers to the south.

The reason for all this verbiage is this: even if NOAA states Thursday warmer than average temperatures are still expected over much of the US this winter, my confidence is not that high. On their maps, EC stands for Equal Chances–that is, there is insufficient evidence to determine above or below average temperatures and/or precipitation. I personally see our region in more of an EC situation. If el nino becomes unexpectedly stronger, I will change my mind. If that snowfall in Siberia is no longer excessive at the end of October, I may change my mind. But in the latter case, there are still other variables which would allow colder outbreaks to develop at times.  The OTHER bottom line: no one really came close in predicting the brutal winter much of the midwest and east suffered last winter. So…keep your knees loose, gang! It’s really too soon to make such an outlook. I have the feeling the meteorologists at the CPC/Climate Prediction Center would prefer that NOAA doesn’t reveal their public hand with such fanfare in October.


A Cool Pattern Sets Up by Midweek into the Weekend; Some Warming Next Week

October 6th, 2014 at 9:52 pm by under 4 Warn Weather

After a mild & occasionally wet start to this week,  cooler temperatures will return for several days. On Wednesday, there will be an extra chill in the air from a gusty wind, but it will not be so raw as this past weekend. An area of low pressure later in the work week should stay far enough south for our region to escape its rainfall, but it will bear monitoring. It looks like a cool fair weather system will dominate our region this next weekend. However, one model (the European) does have an area of low pressure getting closer by Sunday night and Monday, so it may be premature to call a dry Sunday/Game Day a “lock.” As of this posting (Monday evening), it does appear we’ll have fine football weather.

Next week, a warming flow will move into the eastern U.S. for a few days, which would bring temperatures back to well above average. After that, there are signs of some limited cooling returning by the following weekend. There are no current signs of a return to an exceptionally chilly pattern in the 14-16 day time period.

There is still an estimated 60-65% chance of El Nino conditions developing this autumn into the winter. As of this past week, however, el nino has not developed, with slight cooling in the key nino region 3.4 over the last 2 weeks. Most ENSO (El Nino Southern Oscillation) models favor a weak el nino, rather than a moderate one. Buffalo National Weather Service Meteorologist Robert Hamilton has found that since 1950, 18 out of our 20 coldest winters occurred during weak el nino or neutral ENSO conditions. A strong el nino has been correlated with warmer than average winter temperatures, but a weak el nino or a neutral ENSO (which is what we have now) may be correlated with colder than average temperatures.

Confidence on any winter outlook or forecast at this time remains very low.


Back to Reality by the Weekend, preceded by almost-as-nice weather much of the Work Week

September 29th, 2014 at 1:34 pm by under 4 Warn Weather

We still have some warm weather to get through this week in this incredibly pleasant pattern we’ve been in for so many consecutive days. While this week will not be quite as flawless as last week ( a few showers develop Tuesday, more numerous showers develop Friday), high temperatures will remain well above the average of 66 into Friday. On Friday, though, a strong cold front will be advancing into WNY, with numerous showers & possible tstorms, along with gusty winds. Behind that front, readings will drop below average for the weekend and early next week. It will be much cooler during the weekend, but not anything we haven’t already experienced in the last few weeks. However, Saturday will be on the windy side, and there may be some lake effect showers over the hilly terrain (for the most part). Signs are strongly pointing to a Saturday with something of a raw feel in the air, as will be rather breezy as well. Sunday should bring a little more sunshine with afternoon temps in the upper 50s.

The weather will be turning chilly for a few days, as I described above. But as of this posting (Monday afternoon) there are no signs of a drastic, long-lasting pattern change to unseasonably cold weather.


Autumn Begins on the Calendar, but Not in terms of the Weather Pattern

September 22nd, 2014 at 9:43 pm by under 4 Warn Weather

An enormous ridge of high pressure—a fair weather system–will take shape during this week, and dominate our weather into early next week. It’s not often I can make such a statement so far in advance with confidence (actually, I began talking about this pattern in the middle of last week), but this time around will be the exceptional case.  “High pressure” means greater density, and greater weight to the air mass. That means more sinking motion in the lower atmosphere, and THAT means the downward motion will tend to “squish the clouds.” Nightime temperatures will be comfortable, and daytime highs will move above the average of 68-69 degrees into the low-mid 70s…all with virtually no chance of rain in WNY. This ridge may give way just a bit around next Monday-Tuesday to a weak cold front dropping down from Quebec into northern NY, bringing some clouds as temperatures which may be just a very few degrees cooler, but still a little above average. There may be a chance of some showers returning by next Tuesday or Wednesday. However, even that chance is beyond the useful range of computer models to predict precipitation.

As of this Monday night (the 22nd) posting, there are no signs of a drastic pattern shift back to chilly weather within the 16 day range of extended global models.

And, this is from my Facebook page: To counter all the Fake Forecasts on FB, I thought I’d post a real one, from the National Weather Service’s Climate Prediction Ctr. They are currently projecting a weak tendency toward above average temperatures across all of the northern US, including our region, no clear tendency on precip–for the period of November thru January. CAVEAT: Winter outlooks issued this far in advance do not demonstrate high forecast skill in most years, and CPC’s winter outlook last October fared poorly in the midwest and eastern U.S.
http://www.cpc.ncep.noaa.gov/products/predictions/long_range/seasonal.php?lead=2


On the Cool side this week, especially Thursday; Brief Wknd Warming, Shaky Sunday

September 15th, 2014 at 9:14 pm by under 4 Warn Weather

Daytime high temperatures will run below average this work week, particularly on Thursday. But a brief though noticeable warmup will develop for the weekend. After the Monday night rain, little measurable rainfall is likely (as of this Monday night posting) during the week and into Saturday. A cold front crossing the region Wednesday night may set off a few sprinkles, and temperatures will bottom on Thursday–which will be cooler than the rest of the week. A storm system approaching the northern Great Lakes on Saturday will pump up some genuine warmth on a SSW flow, with Saturday’s high temperature heading well into the 70s (average high is now down to 72). By Sunday, this storm’s system’s trailing cold front will be approaching, and triggering a period of showers & possible tshowers for a portion of Sunday. Temperatures should still be mild ahead of the cold front, most of Sunday. As opposed to the Miami game weather conditions, wind may be more of a factor this time around for the San Diego game, along with that period of showers. Behind that cold front, below average temperatures will return for the following week, especially Monday-Wednesday.

Elsewhere, abundant moisture from the remnants of Hurricane Odile may cause flash flooding problems in parts of the SW later this week.


Gather Ye Warmth While Ye May

September 8th, 2014 at 9:58 pm by under 4 Warn Weather

There’s a tortured title if ever I’ve come up with one! In fact, much cooler weather will arrive in a few days. And, I’m confident we’re done with the mid and upper 80s we had last Friday. But that doesn’t mean we’re headed into a permanently chilly pattern just yet. The air mass which arrives for Saturday looks like the coldest one so far for this season, but it won’t be a record breaker or all that extraordinary for this time of the year. It appears most days next week will bring below average temperatures to the Great Lakes as well. Even then, however, there will be some ups and downs within that pattern. After Saturday’s chill, signs are pointing to beautiful, cool conditions for the home opener with the Dolphins (Maul the Mammals! :D )

The average high for the day as of this posting is down to 74. So, high temperatures in the 60s should not be looked upon as anything very unusual. After next week, there are some hints in our most extended range model guidance of a return to more of a west-to-east flow, allowing more Pacific air to replace Canadian air. If that verifies, temperatures would be more nearly average.

So, if you’re seeing doom and gloom on social media, especially Facebook, you’re not getting it from me or 4Warn Weather. While I have no reason at this early point to believe we may have a very mild winter, I can also say I have little confidence as to how this winter may be headed. There is so much hype at this time of the year on FB (and it gets worse every year), I would only ask that you BE SKEPTICAL! If you don’t know the source, don’t believe it! A little of the hype comes from professionals who should know better, but most of it comes from charlatans, high school kids, hobbyists who enormously overestimate their understanding of weather and interpretation of data, and a few keyboard sociopaths.

Let the reader beware.


After a nearly Hot Finish to the week, a Cooler Weekend Arrives–but No “Polar Vortex”

September 2nd, 2014 at 11:03 pm by under 4 Warn Weather

Aside from the Farmers Almanac and a certain private forecasting company’s hype, along with a newspaper article or 2, there is still no sign of any lengthy period of prematurely chilly weather through the 17th of September. I chose that date because that is the limit of the time range (as of this posting) of more reliable global models for forecasting temperature patterns which are of some use, with some reliability. By Thursday and Friday this week, summery temperatures will be back. Readings will be well above average for that time period. Following passage of a cold front Friday night, weekend temperatures will fall back to several degrees below average. In fact, the average high in early September is around 76, so we won’t be too far off the mark. During a near sultry Friday, another cold front will be crossing the Great Lakes and may trigger some scattered showers & tstorms in the afternoon. This activity will become more likely in the late afternoon and evening, and we’ll have to monitor some of those tstorms for intensity. Lingering showers behind the cold front may mar a portion of Saturday. There is uncertainty how long the showers will hang around before drier air pushes in from the west during the afternoon…they’re more likely to linger longer south & east of the metro area. Sunday is more of a sure bet, with dry & seasonably cool air in place, and abundant sunshine likely. Temperatures will slowly edge up during early and mid week, next week. Readings should again be above average by Wed-Thursday, when shower chances will increase again. Somewhat cooler (but NOT cold) air may return by the following weekend.

As for “what’s shakin’” with el nino (this section is for more technically oriented bloggers), key nino region 3.4 has seen an increase to 0.4 degrees above average over the last 2 weeks, which is still .1 degree shy of an earlier peak of 0.5 degrees for an SST anomaly. In any case, ENSO is still neutral at this time–that is, there is no el nino threshold being passed, aside from the necessary 3 months duration of 0.5 degrees above average for el nino conditions to be accepted as ongoing. Probabilities are still at 65% for el nino conditions to develop by early autumn into early winter, down from earlier modeled estimates of greater than 70%. Most ensemble members favor a weak el nino when it develops, but a moderate el nino remains possible (and a relatively small minority of model members show this).

All that aside, much of the warming over the last few weeks is due to the downwelling/warm phase of a Kelvin wave which–eventually–will be followed by some degree of an upwelling/cool phase of that wave. Now, back to general interest for any readers, not just the technically-oriented.

I found it unfortunate that our best and only daily local newspaper chose to publish more nonsense about an utterly unscientific Farmers Almanac winter forecast which I saw while I was on vacation. We may end up having another colder than average winter in the east, but no one has shown reasonable forecasting skill in this time range, under these conditions, to make a scientifically based winter outlook. As silly as the Almanac forecast is, it is even sillier this year, showing cold to colder than average temperatures across the entire lower 48 states. Owing to the ridges and troughs (undulations in the polar jet stream) such near uniformity in cold temperatures across the entire country is all but physically impossible. That’s just not the way the jet stream sets up over any extended period. Personally, I even found some of the rebuttals to this junk hype to be overly tepid, including some remarks from some NOAA people that the Farmers Almanac “might be wrong.” That’s giving them entirely undeserved credibility. Like blind choices in a multiple choice exam, when the F.A. is right, they’re right for the wrong reasons. And they’re wrong, they’re wrong for the wrong reasons. Junk, period.


Now, About All These Winter Outlooks Popping Up in Print and on the Web….

August 11th, 2014 at 9:42 pm by under 4 Warn Weather

(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.


Are We Turning a Corner? Probably not, but a Dry Stretch is Enroute

August 4th, 2014 at 8:58 pm by under 4 Warn Weather

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.