1/25/12

Strong Solar Storm Arrived Tuesday 1/24/2012...Auroral Forecast From NOAA

A strong solar storm arrived in the earth's atmosphere on Tuesday morning. An neat experimental web site from NOAA's Space Weather Prediction Center does an auroral forecast which displays where the Aurora Borealis (or northern lights) are expected based on solar wind and the interplanetary magnetic field /IMF/.

Also; check out these Aurora Borealis vidoes, courtesy of You Tube and The Inquisitor.

Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian

1/22/12

Mid-Winter 2011-12 Update...What Has Been Going On and What to Expect The Remainer of The Winter

             Written by: William R. Deedler, Weather Historian Southeast Lower Michigan
                                                                    1/22/2012

Well this has certainly been a difficult winter to initially forecast; then observe. Some of the main issues I stated in the Outlook and subsequent blog troublesome winter have unfortunately materialized. 

From the Outlook:

The Ever Elusive NAO/AO
The other main ingredient in this winter’s weather (like any other) is of course, 
the trend of the North Atlantic Oscillation/Arctic Oscillation throughout the winter. 
Of course, this is the biggest challenge to the forecast and potentially, has the 
biggest bust potential. While trends with La Ninas and El Ninos are seen (and 
these are not always consistent, either) the NAO is highly elusive and generally
trends are seen only a week or two out. The near term has been neutral to positive
reflecting the recent mild weather but what of the projected? Seems as though
the model ensembles are having a bit of trouble.

The first and utmost problem with this winter is one of the main issues every winter, the North Atlantic/Arctic Oscillation phase. Most forecasts this winter were counting on a negative or at least neutral average of the NAO like the past several winters but this surely has not been the case. The NAO/AO has been in positive mode (sometimes strongly) since last fall. Of course when the NAO/AO is in a positive mode or phase, the real Arctic cold air remains bottled up around the polar regions and other far northern latitudes; one of the reasons why Alaska has been so cold and stormy this winter. In the strongly positive NAO/AO phase, basically the Arctic Jet stream retracts northward somewhat as it circumnavigates around the North Pole. It has been only recently where the NAO/AO has been transitioning toward a neutral or occasionally, a negative phase. It is interesting to note that the projected phase of NAO/AO is mainly neutral-negative early, then becomes quite variable again but with a subtle trend downward as of 1/21/2012. One positive note in this recent transition is the fact it does reflect the Winter Outlook's analogue's call that the second half of the winter would contain the worst of the weather: being the coldest part of the winter and back-end loaded with snowfall. Of course the obvious question that arises; will the NAO/AO trend continue?






The second reason why much of the lower 48 and Southeast Lower Michigan have been mild is also the reason Alaska has been so stormy: the strong northern Pacific Jet Stream discussed in the Outlook and later in the Troublesome Winter. This part of our Winter Outlook equation is there, in spades. The jet has been so strong, occasionally it established a strong zonal flow into the US, ironically not unlike the jet seen in moderate to strong El Ninos; just further north. The analogue projected Pacific Jet "did it's part" to verify our expected winter jet pattern but it's partner, the Arctic Jet in which phasing or pardon the expression, "mating" was routinely expected but has occurred, infrequently. Therefore, much of the country has actually experienced in my opinion a "pseudo El Nino" winter with the strong Pacific jet bringing modified air into the country. In addition, many times this strong jet off the Pacific dug into the West and actually creating ridging into the center and eastern part of the country in the absence of the Arctic Jet.  This in turn; brought periods of above to well above normal temperatures. So much so, that up until recently Southeast Lower Michigan had experienced perpetually late fall-like temperatures with readings the first half of the winter averaging a good 5 degrees above normal!

Visualizing this further:
The Pacific Jet of the analogue's winter (Fig -1) upper wind pattern has been fairly accurate; while the Arctic Jet pattern has been focused further north across Alaska east into north and central Canada. It's interesting to note that between these patterns there was a notable absence of wind or "lighter wind path" west to east, across the center part of the country just north of sub-tropical jet. In the absence of the Arctic Jet, which has retreated north, one can visualize how the intense Pacific Jet would easily flood across the country in this basic analysis of the pattern (fig-2) (and remember to take into consideration the Arctic Jet being further north).

                                                                              Fig -1


                                                                              Fig - 2

Ok, this is the past and present; what about the future?

While we have definitely seen a pattern change of late, the NAO/AO is still in a transitioning or "unstable" pattern which has been even more erratic than usual, which makes forecasting the second half of the winter just as troublesome (or difficult) as the first. But, if you know me by my years with NWS and my Southeast Lower Michigan Outlooks (and now Weather Historian Blog), I'm not going to let a "little" adversity get in the way. If I fall on my face, so be it...it wouldn't be the first time nor the last. And, using the famous pep-talk line; "Get up and put one foot in front of the other and get on with it!" ;-)

Temperatures:
Well, obviously taking into consideration the first half of the winter, my original call of 1 to 3 degrees below normal was much too cold. Therefore, adjusting for the exceptional warmth first half of the winter (with an average departure through mid January of +5.0) , I now expect the entire winter average temperature to range 2 to 4 degrees above normal. With these departures, one would expect the second half of the winter to be colder than the first half but I still look for it to average around 1 to 3 degrees above normal.

Snowfall: 
The snowfall issue was visualized and foreseen in the original Outlook:

"The ranges of snow each month (from the analogues) is extraordinary with some ranges two to nearly three feet. Just in February alone: Detroit ( 2.6" to 31.7" ), Flint (1.5" to 31.4") and Saginaw ( 3.7" to 34.2"). This handily shows this incredible range of snowfalls. Really, the only thing I can gather here is that these set of winter's seemed to be more back-end loaded with the worst of the winter coming the second half."

"If the storms ride further north than expected, this could also botch up the temperature forecast too with the upper level ridge holding stronger in the Southeast."

The second quoted line here has happened and mainly due to the positive NAO/AO and subsequent retreat of the Arctic Jet. My original snowfall call here was normal to above snowfall and thus far, most areas have seen around 6-10" below normal (and one decent storm would take care of that); whereas the Saginaw Valley region has had about normal snowfall.

Taking all this into account; I look for the majority of the region to still see close to normal snowfall (within 6") but with a few areas above that mark and a few below.

Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian

1/18/12

Third Wave of Arctic Air Reinforcement to Arrive Thursday...Most Snow of the Season Thus Far Arrives Friday /Update on Actual Snowfall/

1/21/2012-
The system produced generally just 1 - 3" snowfalls across much of the region. The heavier band of snow ended up falling just south of the region across northern Indiana and Ohio where I saw heavier reports of 5 -  8" as the bulk of the moisture stayed south of our region.  Another related problem here was snowflake size which was very small with the very cold air in place prior to the event. My forecast of generally 2 - 4" with areas of 3 - 5" was a bit too aggressive in this Saturday morning quarterbacking review with a 1 - 3" call better suiting the event. 

Snowfall reports from NWS White Lake Mi
----------------------------------------------------------------------------------------------------------
 Original Post

A quick third shot of Arctic air will plow through Southeast Lower Michigan Thursday. This reinforcing blast of Arctic air will be accompanied by gusty winds, snow showers and flurries. While accumulations of snow will be around an inch or less, falling temperatures and blustery winds will make for an uncomfortable January day for sure.

The better snow maker will move into Southeast Lower Michigan quickly on heels of the Thursday system during the day Friday. Our extended and now short term models have been fairly consistent with this system with its broad area of moisture, good forcing and lift which will squeeze out any available, layered moisture. While the center of the actual low pressure will be far south over the lower Ohio Valley, moisture will be flung far to the north over the Southern Great Lakes. Even though the moisture and precipitation amounts are not high with the system; they will be more than sufficient, given the dynamics of this system, to give much of the region its best snowfall of the season (considering the previous light amounts). I'm generally looking for at least 2 - 4"  of snow but with higher areas of 3 - 5" possible in the heaver snow. Even scattered pockets of 6" amounts are not unreasonable given the cold air mass in place and resultant high snow to water ratios of the system. The snow to water equivalent ratios should generally fall in the 15-20 to 1. This means for every .10" of precipitation (or melted water equivalent), snowfall should range in the 1.5" to 2.0" (possibly even as high as 2.5"). There's even a slight risk of some freezing rain near the Ohio border if the warmer moist layer is flung far enough north to clip that region. This system will have to be watched for any type of path change as some of the models are beginning to hint a bit further north with the core moisture. Any updates will be issued if needed in my blog.

Needless to say driving beginning Friday afternoon into Saturday morning will become slippery and dangerous and all cautions should be exercised. 


Making weather fun while we all learn,
Bill Deedler - SEMI_WeatherHistorian

 

1/12/12

And The Battle Is On! Round One...And Now Round Two /Update 1/15/2012/

Overall, the first wave of cold air behaved well in regards to expectations of snowfall and temperatures in my most recent blog. Generally, "one to three inches of snow"  was forecast across the region Thursday night into Friday with some locally higher amounts possible. As one can see by this snow map through the 13th (courtesy of the NWS) actual snowfall pretty well fit the bill. 

In addition, more snow fell behind the system on Saturday, converging in and around Wayne county with an inch or two of additional snow (and I must say; it was a beautiful scene as the nice size flakes of snow fell while walking in the local snow covered woods). So now it at least looks and feels like winter with temperatures falling off into the teens and some single figures (Sunday Jan 15th) as some breaks in the clouds allowed over the freshly snow covered landscape.
 
I ended the blog by writing:  A second wave of Arctic air will already be charging south for round two of this winter onslaught early next week. Stay Tuned.... 

I also briefly stated in that blog, this next in the series of cold shots of air will be proceeded by a mild surge of air early this week with temperatures shooting back up above freezing. Latest indications are as this wave of cold air approaches late Monday night and Tuesday, some energy aloft sliding up along the cold front should enhance the rain and snow associated with it. This energy should help focus in the development of a low pressure system nearby as the front slides southeast down into our neck of the woods. In response to the upper level support, the low will deepen somewhat as it moves off  to the east out over the eastern Great Lakes. Therefore, the timing of the colder air flooding into Southeast Lower Michigan behind the low on overnight Monday into Tuesday and its subsequent deepening and moisture supply will determine when the rain changes to snow scenario along with how much snow falls. At this time, it does look like some of the area will see some light measurable snow with this system with the preferred area over the Saginaw Valley and Thumb Region. Temperatures under this next Arctic air mass should be at least as cold, if not a bit colder than over the weekend.

If things change appreciably with snow expectations or temperatures, I'll make note of it in my bog.


Now, reflecting back to the upper air plots I posted projected by the NCEP ensemble members last week I stated the following:

"As the two jets align and merge next week, a strong zonal flow is expected to evolve mid month over southern Canada and the northern US. Occasional ridging in the west is also projected to develop and thus, help divert and phase the Pacific air northeast into the Arctic jet over Canada. This would then create a strong west-northwest jet stream across the northern and eastern part of the country".

It is said a picture (or two) is worth a thousand words: Take a look at the GFS projected upper wind pattern at about 39,000 FT /200 MB/ and at 18,000 Ft /500 MB/ for roughly mid week. It is easy to see the jet core here over the Northern Plains with a wind jet max of around 150 knots. The second map shows the strong Pacific and Arctic jet at the "jet stream" level of 18,000 feet /500 MB/.
                                                                           


Another wider western view of the same time period shows this strong phasing nicely, initially over the Gulf of Alaska and additionally over North America!   






Coming in the next week or so: The Mid-Winter Outlook Update

Making weather fun while we all learn,
Bill Deedler - SEMI_WeatherHistorian


____________________________________________________________
Initial Blog of January 12th

In my previous post, I displayed and discussed the NCEP model ensembles regarding the up and coming changes I expected by mid January.  I gave details of these changes and the likelihood of the alignment of the jet cores in the swiftly moving Arctic and northern Pacific jet streams by next week. This, in turn would set up an ongoing battle into next week of the milder air we've become accustom to and the Arctic air hovering over Canada.

Well, the first onslaught in a series of Arctic blasts is slated to surge through the region by Friday /good 'ole Friday the 13th - so don't temp fate, watch you driving ;-)/.  This "Arctic air" (and I use the word loosely since at this time of the year, it could be a lot worse) will settle in as a weekend guest. This abrupt change in air mass will be accompanied by snow showers and squalls, surely enough to leave untreated roads icy & dicey through Friday. This won't be a big system as far as snow amounts for Southeast Lower Michigan still; the system should deposit one to three inches of snow (but locally higher amounts are possible if she wraps up a bit better and is aided by Lake Huron). Much worse lake effect snow squalls are expected on the west side of the state downwind of Lake Michigan into Northern Indiana so motorists heading that-a-way should also be advised.

This "weekend guest"  (or maybe it should be "pest") of snow and cold will bring the first interval of notably below normal temperatures this season, quite atypical by this time. Temperatures across Southeast Lower Michigan during the period will be mainly in the teens and 20s with some overnight lows possibly dipping into the single figures (especially with the snow cover and partial clearing). Therefore, it truly will be a shocking reminder to the inhabitants of Southeast Lower Michigan what season this truly is...winter. On the brighter side, it should give the winter weather enthusiast (of which I am one) something to talk about and the winter weather sport persons, something in which to be out and about.

However, as I mentioned above, she'll (after all, La Nina is running the show this winter ;-)) just be a weekend guest and will quickly scurry off to the east later Sunday and be replaced by a sharp moderating trend, in time for Martin Luther King Day.

A second wave of Arctic air will already be charging south for round two of this winter onslaught early next week. Stay Tuned....

Making weather fun while we all learn,
Bill Deedler - SEMI_WeatherHistorian

1/9/12

Bitter Arctic Air to Pool Over Canada Mid January

NCEP ensemble model members continue to advertise a change in the upper air pattern across the northern hemisphere in mid January. The some of the coldest air of the season is projected to relocate or "drain" from Siberia, Alaska and the Polar regions and settle east southeast over northern Canada over the weekend into next week (14th-21st). This in turn will "recharge the freezer" so to speak up in northern Canada. To check on the evolution of this projected ensemble model pattern, click here.

In addition, this air is expected to migrate south at times into the US. How far south this air is able to infiltrate the US is questionable since the northern Pacific La Nina jet stream has been strong and has acted as a door, shuting off much of the true Arctic air this season. 




 
As the two jets align and merge next week, a strong zonal flow is expected to evolve mid month over southern Canada and the northern US. Occasional ridging in the west is also projected to develop and thus, help divert and phase the Pacific air northeast into the Arctic jet over Canada. This would then create a strong west-northwest jet stream across the northern and eastern part of the country. It is way too early to tell how much of this true Arctic air projected to pool over northern Canada will be caught up in this strong west-northwest flow and make it into Southeast Michigan. Stay Tuned... 

Making weather fun while we all learn,
Bill Deedler - SEMI_WeatherHistorian

1/8/12

Oh Winter Where Art Thou??

The way things are going, pretty soon the Winter of 2011-12 will become to be known as the year without a winter. A bit exaggerated I know but the winter thus far has not only been exceptionally mild, it's been exceptionally BORING! In the first five weeks of "winter", temperatures across Southeast Michigan have averaged in the lower to mid 30s...not the highs...the averages or means. Our normal highs this time of year are generally in the lower 30s, so this is pretty much where our temperature averages have been. In the past five weeks, the high temperatures across the region have averaged around 40 degrees...give or take a degree. So, if you've thought the weather has been behaving and feeling like a "perpetual late fall", then you are right on the money. Average high temperatures across Southeast Lower Michigan late fall, say around Thanksgiving, are generally in the lower 40s.

So what gives? Did mother nature suddenly become senile lately and just forget what season we are supposed to be in? Did she fail to read the Winter Outlook and behave accordingly?  You'd think so ;-).  But seriously, the reasons I discussed on why we have been so mild into Christmas Day, have more or less persisted into early January.  However, in that same discussion I also reasoned and explained why I expected a pattern change to commence in January. This explanation also jived well with the mild analogue Novembers I researched and posted along with the difficult winter to forecast ahead! 

However, I'm not blind to the fact that the mild and lack of snow beginning of the winter will obviously affect the outcome of the winter 2011-12 statistics! Therefore, in that same vein, I will be updating my Winter Outlook within the next few weeks to account for the exceptionally mild and boring beginning. Oh, I'm not giving up on winter just yet and I believe the notable change I talked about at Christmas time is now happening, albeit slowly.


Summarizing...Mother Nature has become a pain in the Butt!

Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian