Our community blogs
For Saturday - November 17, 2018 !
Lowest Barometric Pressure : 30.14″ at 3, 4 p.m.
Highest Barometric Pressure : 30.22″ at 10 a.m.
Lowest Relative Humidity : 36% at 2 p.m.
Highest Relative Humidity : 100% at 4 a.m.
Lowest Dew Point Temperature : 29° at 7 a.m.
Highest Dew Point Temperature : 44º at 9 - 11 a.m.
Lowest Wind Speed Calm at 12 - 8 a.m., 5, 11:59 p.m.
Highest Wind Gust : SW – 17 m.p.h. at 1:20 p.m.
Lo : 30º
Normal : 38°
Record Warmest : 61º In 1958 !
Record Coldest : 17° In 1959 & 1997 !
Hi : 71°
Normal : 61°
Record Hottest : 83º In 2016 !
Record Coolest : 33º In 1959 !
Rainfall : 0.00 Daily Normal 0.17"
Record Wettest : 1.69" In 1980 !
Snowfall Record 2" , 0.04" melted in 2014 !
November`s Total To Date : 3.87" In Bemis, TN.
2018`s : Total to Date : 72.78"
November 17, 2017 : Lo : 36º : Hi : 71º : Rainfall : 0.00
November 17, 2016 : Lo : 44º : Hi : 83º** : Rainfall : 0.00
November 17, 2015 : Lo : 57º : Hi : 75º : Rainfall : 0.63"
November 17, 2014 : Lo : 21º : Hi : 36º : Rainfall : 0.04", 2" snow
November 17, 2013 : Lo : 50º : Hi : 75º : Rainfall : 1.18"
November 17, 2012 : Lo : 28º : Hi : 64º : Rainfall : 0.00
November 17, 2011 : Lo : 25º : Hi : 51º : Rainfall : 0.00
November 17, 2010 : Lo : 31° Hi : 62º : Rainfall : 0.02"
November 17, 2009 : Lo : 41º : Hi : 49º : Rainfall : 0.06"
November 17, 2008 : Lo : 31º : Hi : 51º : Rainfall : 0.00
West TN`s Coldest Lo 28º at Lexington & Union City, TN.
West TN`s Hottest Hi 71º at Bemis, TN
U. S. Highest Temperature for Saturday, November 17, 2018 84º at McAllen, TX U. S. Lowest Temperature for Saturday, November 17, 2018 -8º at Langdon, ND
- Read more...
- 0 comments
Recent EntriesLatest Entry
Results from the storm are preliminary and Maine may be off a bit since its still snowing lightly there today. We are using the NOHRSC interactive snow map which tallies up the snow reports and bases a map off of them.
Lets start with the Euro - not too much variation in the three methods. Cobb had the least in NJ, CT, NYC and LI.
Next the CMC
Then the FV3
I'm not even posting the GFS other than the 10:1 as it was atrocious. Every other version was less.
- Read more...
- 0 comments
Forecasting / General Post
Winter's Opening Salvo
November 15 2018 - 0200z
I have my work schedule arranged in such a way that I enjoy a few consecutive days off in the middle of the week. It gives me a chance to "catch up", physically and emotionally, as well as providing a block of time to work on writing and other such projects. There is a pizza place that I frequent on these off days; frequent a little too much, if my rough calculations about yearly spending there are anything to go by. What can I say; they make really good pizza. I left around 15z today to get lunch, and noticed that we finally seem to have turned the corner from one season to the other. There is a solid chill in the air, stemming from a cold air mass originating deep in arctic Canada, and a classic winter wind that I can still hear from time to time as I write this. Perhaps nothing signifies our concluding transition, however, as much as the start of the first significant region-wide wintry event drawing to less than a day away.
This is a true "mixed bag" event, that is, one that will, somewhere, drop every type of wintry precipitation. Many storms have unresolved uncertainties even within the H+24 to H+36 range; the classic question in so many winter nor'easters is the exact location and orientation of the "deformation band", which often yields the highest local snow totals of the storm. For this event, however, the most critical remaining uncertainties, in my opinion, pertain to local temperature profiles, rather than QPF maxima and minima. To explain, allow me to first break down how these temperature profiles relate to precipitation type ("p-type"), and how local microclimates can have major effects on said p-types. I will then provide a brief summary of my forecast thoughts for the storm, and conclude with a safety tip or two. Shall we begin?
The most effective way for meteorologists to look at atmospheric conditions as a function of altitude are through the use of atmospheric soundings. These are launched by the National Weather Service several times a day, with exact frequency depending on regional and/or special requirements (for example, special soundings may be launched prior to a severe weather event, or to gain data for model input in high-consequence situations such as an impending hurricane landfall). Soundings usually consist of a radiosonde delivered via a weather balloon; rockets are the most common alternative. NWS sounding data can be obtained on the Storm Prediction Center website, the NCAR, or from local NWS Weather Forecast Office pages. A typical sounding (in this case, the 12z or 7am sounding from Albany, NY) may look something like this:
This is a LOT of data. The bottom boxes, as well as the hodograph (wind strength and direction relative to altitude) and surrounding charts are most important for protection of severe weather, and as such, will be disregarded for this post. What I want to focus on here, out of all that, is the red line on the plot seen on the top left of the data display. The chart itself is called a Skew-T Log-P diagram; that is, the temperature lines are skewed at an angle, and the pressure lines are represented in logarithmic format. For more reading, you can access some helpful information here, here, and here. That line is a visual representation of the air temperature at different altitudes; the former measured in °C, and the latter in hPa/mb (a note of conversion: 1 hectopascal, or hPa, is equivalent to 1 millibar, or mb). Let's take a closer look, shall we?
Remember that the Skew in Skew-T Log-P denotes the "skewing" of temperature lines off to an angle. The pair of straight blue dotted lines above highlight 10°C and 0°C from left to right. The green line, for reference, measures the dewpoint. Altitude, as I mentioned above, is measured in terms of atmospheric pressure; 1000hPa roughly equates to the surface (in low-lying areas; in higher elevations, the "surface" pressure may be significantly lower). 850hPa is about 5,000 feet, and 700hPa is approximately 10,000 feet. In terms of the temperature profiles I am about to discuss, we are going to focus on the 700hPa-1000hPa range, which is the most important in determining p-types for a specific location. One should note that the exact "true" altitude of a certain hPa line changes in response to temperature; the higher the temperature, the higher the altitude, as illustrated in this graphic.
So, I promised a discussion about temperature profiles. Specifically, how different profiles affect p-types, and how microclimates factor into that affectation. Nearly all precipitation occurring during the colder months of the year starts out as snow, high above the earth where it forms. How it lands on the ground, however, is a factor of two different temperatures: air and ground. We will start with the former. Imagine a single snowflake falling through the atmosphere. As it descends, the temperature of each layer of air it passes through will determine the end p-type of the molecule. If the entire air column is below freezing, the snowflake will stay a snowflake; likewise, if the entire column is above freezing, the snowflake will melt and land as plain rain. Where things get a bit complicated are when there is a "warm nose" somewhere in the lower to mid atmosphere (commonly between 700 and 900 hPa). When this happens, the snowflake will melt and refreeze. If the warm air intrusion is relatively shallow, with a deeper layer of cold below, the molecule will fall as sleet. If the warm layer is deeper, with less cold air available near the surface, the molecule will fall as freezing rain. The chart below is a visual representation of these different temperature profiles.
Tropical Tidbits and Pivotal WX both have point-and-click forecast soundings for several models; you can also plug in an airport identifier (such as KJFK) in the viewer window to pull up a forecast sounding for that location. I encourage all of you to play around with these viewers. Compare them for your location from model to model, and draw your own conclusions.
In regards to rain versus freezing rain, ground temperature also comes into play. Rain falling onto a -5°C surface will freeze; rain falling onto a 5°C surface will not. In that regard, even if most of the layer is above freezing, a cold surface level with subfreezing ground temperatures can lead to "ice on contact". Microclimates come into play here; small, yet crucial, variations in local temperatures coinciding with elevation, local wind flow, bodies of water, etc. Different types of soil will warm and cool at different rates. The water table plays into these things. These minute variations in ground and surface air temperatures can lead to different p-types falling over very small distances. Such factors are important to consider when forecasting a storm like this, where the temperature profile is proved to be variable during the course of the storm, and outcomes may be influenced by rather small changes in temperature. Typically, each microclimate is best understood by those who live nearby. Think to yourselves; what is that one place in town that always gets an extra inch of snow?
Now, I said I'd make some predictions, and I suppose I should live up to that. Below are the forecast snow accumulation maps from the 18z 12km NAM, 3km NAM, RDPS (Canadian short range mesoscale model), and the 00z HRRR (through 8z Friday, some areas will see more after that time). These show ratios of 10:1 (that is, 10" of snow for every 1" of QPF), and exclude sleet and freezing rain.
Now, here are my thoughts (north of the black dashed line has the best chance to stay all snow):
What, you wanted more? I will leave brief word on safety to conclude this message. Drive carefully, especially in areas with microclimate variations. Rain can turn to freezing rain when you drive up a hill, and road conditions can meteorite very quickly. Plan for extra travel time. Power outages may be more of a threat than with many comparable storms due to the saturated nature of the ground. Might not take much on a tree to knock it over.
Thank you for reading. Pass it on if you wish.
#1, 2 - Storm Prediction Center
#3 - National Weather Service
#4 - Wikipedia
#5, 6, 7, 8, - Pivotal Weather
#9 - Base Map from Free World Maps / Google Image Search
- Read more...
- 0 comments
Recent EntriesLatest Entry
"Call It Stormy Monday (But Tuesday Is Just As Bad)" Single by T-Bone Walker A-side "I Know Your Wig Has Gone" Released November 1947 Format 10-inch 78 rpm record Recorded Hollywood, California, September 13, 1947 Genre Blues Length 3:00 Label Black & White Songwriter(s) Aaron Walker a.k.a. T-Bone Walker Producer(s) Ralph Bass T-Bone Walker singles chronology "Bobby Sox Blues"
"Call It Stormy Monday (But Tuesday Is Just As Bad)"
"Long Skirt Baby Blues"
"Call It Stormy Monday (But Tuesday Is Just as Bad)" (commonly referred to as "Stormy Monday") is a song written and recorded by American blues electric guitar pioneer T-Bone Walker. It is a slow twelve-bar blues performed in the West Coast blues-style that features Walker's smooth, plaintive vocal and distinctive guitar work. As well as becoming a record chart hit in 1948, it inspired B.B. King and others to take up the electric guitar. "Stormy Monday" became Walker's best-known and most-recorded song.
...idee had a 'day' that was 'stormy'...the 'cause celebre' of the moment without even knowing about any of the 'controversy' until today...oh well...figured to start a place to rant, predict and generally talk weather...SF Bay Area (terrible smoke from fires in Paradise, CA) and such...
Paradise...lost... our thoughts and prayers go out to all the families and their loved ones who have been effected by the terrible fires...not just in Paradise, CA,... in Southern California and all other areas being damaged by nature's wrath...
Paradise Lost is an epic poem in blank verse by the 17th-century English poet John Milton (1608–1674).
If anyone is familiar with the LJS index they would be keenly looking upon Japan and waiting for snow to fall.
Well it looks to be occurring in or around the 20th.
The LJS index ignores all heights and troughs and ridges and strictly goes on precipitation type on or very near Aomori, Japan (a rough correlate to the 40 degree north US coast).
The LJS also utilizes a short lag correlate of only 6-8 days.
The index was created proprietarily over the years by following the east Asia rule. It’s been observed that when precipitation is forecasted as snow over Aomori that often times the US correlate also would be forecasted snow.
The proprietary calculations allow the index to not only predict a date of snowfall but also adjust accordingly for possible heavier snow and increasingly hazardous conditions.
Generally an index of +3.0 or higher means that snowfall can be expected over eastern PA and nearby regions.
An index of +6.0 or higher means that possible snowfall over a good portion of PA and NJ is possible.
Ultimately an index of +10.0 or higher means a multi-region wide multi day storm is possible. This rating is only reserved for the most detrimental snowstorms in central Japan.
I will be calculating the LJS index this year approximately 8-10days in advance of a correlative snowfall date.
Currently modeling shows the first + index rating for the US occurring around the 26-28th of November.
However, modeling in east Asia is extremely volatile so index calculations are usually never made until 2 days prior to a Japanese snowfall. Therefore even though modeling shows snow in Japan on a certain date the index will not be tripped until JMA forecasts are issued. Only at that time can the LJS index be truly calculated.
Cheers, take care and do stay tuned fir LJS index updates!
Noticing that the Blob is re-appearing. This patch of warm water in the Gulf of Alaska was predominant in the winter of 13-14 which was a cold and snowy one for the NE.
Also noticing on the gif of the daily anomalies for the last week, it may be dissipating. ERSL SST's
Others have noticed its return as well.
Should note that the ENSO signal for 13-14 was a weak La Nina to neutral, so not comparable to this year's weak Nino. 13-14 was cold in the East and I had 58" of snow
2013 -0.4 -0.3 -0.2 -0.2 -0.3 -0.3 -0.4 -0.4 -0.3 -0.2 -0.2 -0.3 2014 -0.4 -0.4 -0.2 0.1 0.3 0.2 0.1 0.0 0.2 0.4 0.6 0.7
Now before you get excited seeing the El nino conditions appearing in 2014, the blob had already spread out along the PAC coast by then. 2014 was also cold in the East and I again got 58" of snow. Note, my guesstimate for snow in my backyard for this year is 45-55" and leaning toward the 50-55" range.
So I'm not really sure how much affect the blob has. It forms due to already existing atmospheric conditions and per linked sources, doesn't control the atmosphere, rather at that latitude, the atmosphere controls it. If the blob moves in the way it did in 2014-15, then combined with a weak nino, I could end up flipping to a colder forecast.
These are the final standings for most quotes making my weekly top 100. The first quote from the forums made my top 100 in January 2009, and the most recent quote made it in July of this year. Several quotes from the old forums are still on my top 100. Here is everybody who made my top 100 at least five times. A few people had fewer than five charted quotes but still made the top 10 once or twice. The person with the most charted quotes, surprisingly, never made the top 10. A few people have added to their totals since WXDisco opened. I will have an updated version of this list in a couple of months.
MAINE JAY 12
MDBLUE RIDGE 6
MILLER A 6
POCONO SNOW 5
Coming soon: Forum Members with Highest-charting Quotes
- Read more...
- 0 comments
Hello. I dont really want to post this on the main boards where 12 million people can see, but I thought I'd still post here so that the 'main people' on the board can get word... While I leave the weather stuff to the experts, I finally have something I can contribute - some footage from a couple of my cameras. I had storm surge up to my doors for Hurricane Hermine a couple years ago (I have an image gallery w/ some pix)... and if TS Michael takes a similar path, it could also make for some interesting camera shots, or worse (lol). I didn't have the cameras back then for Hermine. I definitely cant guarantee the feed will always be up for the entire next week (in fact it will prob go down often as I work and do various things) but I'll try to have it up at least for the interesting parts over the next few days, unless I end up with 12 million people watching, lol.
Happy storm chasing! Here's the feed:
[ Note to the 0.000001% thieves: I have ADT, firepower, neighbors and friends with firepower, and a whole separate NVR of more cameras besides this one which I choose to make public. Also - a 20 pound female schnauzer, lol. :) Also, despite what the twitch stream is, every camera is high resolution 4K with infra-red night vision. ]
- Read more...
- 0 comments
Hey all! Been a while since I added an entry. Hopefully I should be able to get back to regular posting before autumn starts to really ramp up.
So I was looking outside my window and did a double take - yellow leaves?! This is on a birch tree (Betula lenta / Black Birch).
Quite surprising! I did cherry-pick the most yellow branch, but this is not an isolated occurrence. Numerous birch trees are starting to "turn". Some may bring up the point of stress causing this rapid change, but considering the amount of trees that have started to "turn," and the fact that my location is at 85% of its monthly precipitation with 10 days left, I think that can be ruled out. From a bit of memory I do think that this is usual for the tree, but not 100% sure on it.
Let's see if any more harbingers of winter can surface during the upcoming cold wave!
On September 1, 1862 the Batlle of Ox Hill at Chantilly was fought during severe thunderstorms. It was one of the only battles of the Civil War known to be fought under stormy weather conditions. While our military troops currently view adverse weather and low visiblity environments to be advantageous, this was not the case for troops in the Civil War era. Military tactics at this time favored engagements between large numbers of troops, and so stealth was not usually a primary concern. Combat during the Civil War was always brutal beyond belief, but the weather conditions at this engagement led to even more confusion and difficult fighting conditions than usual.
Prior to the Battle of Chantilly, Union troops had been defeated at the second Battle of Manassas. Exhausted and battle weary, they were retreating toward Washington to regroup. The Confederate troops attempted to flank their movement and cut off their retreat. A small skirmish alerted the Union commanders to the Confederate movements and they responded by attacking the Confederate troops. This caught the Southern troops by surprise at Ox Hill. The Union army attempted to exploit the advantage of surprise by pressing the attack as the Confederate troops dug in at Ox Hill. Meanwhile, a very strong cold front was passing through the area, which led to the severe storms which were a decisive factor in the outcome of this battle. While technically a Confederate victory, the Southern troops did not accomplish their goals in this battle or its aftermath.
The weather on this day was notable due to an extremely strong early season cold front – the exact kind of cold front many are wishful for this year but we currently can find no sign of on the horizon. It was clearly strong and Canadian in origin, and being only September 1, was pushing into hot and humid summer conditions. This is a recipe for severe thunderstorms, and that matches perfectly with the accounts from the Battle of Ox Hill. Prior to the passage of the cold front, winds were observed out of the south. After the passage of the front, the winds had shifted to the northwest and became quite gusty. The storms produced very heavy rain, strong winds from the downbursts, and frequent cloud to ground lightning. Some of these storms passed directly over the battlefield.
These Civil War troops were battle hardened veterans. They were accustomed to the intense fighting conditions of Civil War battlefields, including close proximity to rifle and cannon fire as well as hand to hand combat. Dealing with those conditions while also enduring severe thunderstorms was a challenge to even the most experienced of these men. A firsthand account from one Private Greely in the Union army is indicative of this: ”The roll of musketry and the roar of cannon left all of us unmoved, but the crash of thunder and the vividness of the lightning, whose blinding flashes seemed to be in our very midst, caused the uneasiness and disturbance among some of the bravest men.”
Early on in the battle, General Isaac Stevens of the Union army was killed as the storms were just getting underway. Having seen his son felled by enemy fire, he led the Union charge while holding the battle flag. This made him an obvious target for the enemy and he was subsequently shot and killed. He was not the only Union general to die by enemy fire on this day. Union General Philip Kearny led the Northern reinforcements that arrived on the battlefield later that afternoon. Arriving during the height of a thunderstorm, he became disoriented by the limited visibility and rode directly into the Confederate lines. Once he realized his error, he turned and tried to ride away but was shot down before he could retreat to his own lines.
The torrential rainfall caused issues with the rifle ammunition. Unable to keep their powder dry, both sides affixed bayonets and resorted to hand to hand combat. This 19th century battlefield had turned medieval, with a huge group of soldiers fighting with blades and clubs in a brutal fight for survival. Estimated casualty figures from this battle are over 2000. While the Battle of Ox Hill is not one of the more famous Civil War engagements, there was a lot at stake here; the outcome was dictated in large part by the weather conditions. After hours of fighting in terrible conditions, the battle slowly came to an end as the sun went down. The men on both sides were very tired and very cold. They had been fighting tooth and nail for hours in the lightning, thunder, and windblown rain. The cold front had now passed and temperatures dropped to fall like conditions.
The results of this battle appeared to favor the South at first glance. The Union had lost two of its most respected and popular generals. The Union troops were the ones who retreated from the battlefield with the setting of the sun on this day, leaving the Confederates in possession of Ox Hill. Upon closer examination, the outcome was not what General Lee had in mind. The Union troops were not stopped from retreating and the defeat was not as crushing as what was originally envisioned. General Lee’s orignal plan was to incapacitate this group, and then turn his attention toward an attack towards Washington. Going in to the battle, the Confederates had superior numbers and a tactical advantage. But when the North was able to begin the battle preemptively, they were able to gain an advantage due to the element of surprise. Added to this, the confusion and chaos caused by the thunderstorms prevented the Confederate army from carrying out its battle plan effectively. In the end, the Northern troops were able to escape and the Southern troops were unable to launch an attack on Washington. The thunderstorms on September 1, 1862 played a huge role in the war, even though this particular battle is not usually listed among the more significant battles of the Civil War.
And we sure hope it has no notion of (ever) leaving (though we know that nothing is forever).
The old pattern is dead (for now) and may it remain in the dust bin of history (for at least a while). Let's let NWS speak to just how.
Great news for local hot spots that rely on less than soaked conditions (e.g. - golf course, ice cream vendors, local fundraiser fairs).
I'm going to keep this entry short - not even look into the next pattern change (not that it will be bad) just so we can focus on simply enjoying the next 5-7 days of sunny Summer delight. 🙂
- Read more...
- 0 comments
Plenty of harmony in the pattern analysis over the past month. Interesting to note the uptick in correlation between RRWT projected and observed 500mb hPa anomaly. Attached is the 46-50d outlook verification from 6/29 for 8/14-18. More verification maps here; http://www.consonantchaos.com/a-all.html
If there are any questions, comments, or suggestions on the material presented please let me know. Thank you for reading.
- Read more...
- 0 comments
Recent EntriesLatest Entry
The Dog Days of Summer are here!
Since the end of July we have been in the soup here on Long Island. Very muggy, tropical haze and down right hot to boot. Not often see 90 here at the shore but this August has made that a daily thing.
While those just inland have gotten torrential rains and cooling thunderstorms at the expense of flooding we have gotten very little. I have been going full steam with the sprinklers for the past two weeks just to keep the brown lawn!
Pattern looks to continue for at least the remainder of this week. Keeping cool thinking of those valley snows!
Recently Browsing 0 members
No registered users viewing this page.