Mountain West Discussion

[Chinook]

summer rain totals

My house (estimation based off CoCoRAHS):  June 0.28", July 0.92", Aug 0.74", total 1.94"

Fort Collins-CSU: June 0.05", July 0.91", Aug 0.76", total 1.72" (average is 5.47")

Boulder (as listed on NWS NOWData) 4.04" (average is 5.83")

Centennial (near Mayjawintastawm): June 2.66" July 0.61"  Aug 1.74", total 5.01"

DIA: June 1.62"  July 1.07" Aug 0.22", total 2.91" (average is 5.83")

Colorado Springs: 6.51" (average is 8.68")

Pueblo: 3.15" (average is 5.74")

Cheyenne: 4.21" (below average... yet considerably more than Fort Collins) Summer was 2.0F above average

note: the driest Fort Collins summer in my time here was in 2006, 1.65". So, very close to the official value for this summer. Also note: In August-September 2012, Fort Collins was in a D3 drought. Despite some days of rain in July 2012, the soil moisture was the lowest that I've seen. In August-September 2006, Fort Collins was in a D2 to D3 drought, so, fairly similar to 2012.

[raindancewx]

PDO dropped to -0.66 in August according to NOAA - coincides well with the monsoon being fairly weak this year outside Northern AZ.

[Panes and Portlets]

Beartooth Pass closed again due to snowfall.

[Mercurial]

Lots of snow above 6,000 feet in general.  Big Sky resort received a good amount I think.  Used to live there, and winter was a year-round affair...  Also, I know some of the higher valleys/towns such as Butte, Anaconda, etc., were forecasted to get some snow.  Not sure if they actually received any or not.

[raindancewx]

These moisture surges ahead of hurricanes/hurricane remnants are a lot of fun down here - some of our mountains are going to get 2-6" rain. About half of Albuquerque had a flash flood today too.

[Chinook]

looks like some Newtonian moisture has been drawn from the area of the hurricane all the way into the Midwest, with pretty high PW values. The moisture from the Gulf is probably a contributor to high dew points in the Midwest. My area has clouds now. The forecasters at Boulder thought it would be clear overnight with fog for the Front Range cities . If it remains overcast, I don't think we will get radiation fog. Dew points are up to 56 around here. I can't wait for a real rainstorm and lower dew points. I mean, it hasn't really rained since May. And dew points around 30 feel amazing when it is 80.

[Chinook]

Hurricane Newton approaches the US border near Tucson at 10:30z (4:30AM). radar is from 12z (6AM)

 

 

[PennMan]

On 9/3/2016 at 7:51 PM, Chinook said:

summer rain totals

My house (estimation based off CoCoRAHS):  June 0.28", July 0.92", Aug 0.74", total 1.94"

Fort Collins-CSU: June 0.05", July 0.91", Aug 0.76", total 1.72" (average is 5.47")

Boulder (as listed on NWS NOWData) 4.04" (average is 5.83")

Centennial (near Mayjawintastawm): June 2.66" July 0.61"  Aug 1.74", total 5.01"

DIA: June 1.62"  July 1.07" Aug 0.22", total 2.91" (average is 5.83")

Colorado Springs: 6.51" (average is 8.68")

Pueblo: 3.15" (average is 5.74")

Cheyenne: 4.21" (below average... yet considerably more than Fort Collins) Summer was 2.0F above average

note: the driest Fort Collins summer in my time here was in 2006, 1.65". So, very close to the official value for this summer. Also note: In August-September 2012, Fort Collins was in a D3 drought. Despite some days of rain in July 2012, the soil moisture was the lowest that I've seen. In August-September 2006, Fort Collins was in a D2 to D3 drought, so, fairly similar to 2012.

There's a reliable cocorahs site just to my west (Broomfield/Boulder Co line), and we were about as dry as I thought. I think at the apartment we may have had even less, there were a couple of showers/storms where I could see the veil of heavier rain west of here but it never quite made it.

June: 1.32"  July: 0.42"  August: 0.66"

Total: 2.40"

[Chinook]

Here, we had high of 90, low of 52. The high of 90 was 1 degree below the record for this date. Six days ago, on Tuesday of last week, it was 50 with some drizzle in mid-day, and some rain on Tuesday morning, Tuesday evening, and Wednesday. I got 0.16" from Sep 13-14. If we keep having this kind of weather, October snowpack will be low in the mountains.

[raindancewx]

Someone posted the analogs Accuweather likes for the winter (although it isn't their forecast):

1958 

1959

1983 x2

1984 

1992 x2

1995 x2

2005 x2

2013

I have some conceptual problems with those years as analogs:

1) I think with 1983/1984/1992 the Atlantic is too cold

2) 1992/93 was heavily influenced by Pinatubo (big-time volcano, VEI = 5)

3) For NYC/Baltimore/Philly/DC/Richmond those years would mean four snowy winters in a row - that's very rare, so (to use Philly) the analogs above would give +30-40% snow (31" v. 22" mean). Don't really buy that.

That being said, if it was somehow right, some of those years are incredible in the SW - 1958/1959/1992 are all top ten winters for snow in Albuquerque. 2005 is a horrible winter for much of the west though.

I'm still waiting on some data (August PDO from JISAO, although NWS ABQ said it came in at 0.52 - I haven't seen it yet on the JISAO site), Sept mean highs for ABQ, and final monsoon rainfall totals, but I like 1931-32, 1932-33, 1937-38, 1943-44, 1948-49, 1959-60, 1960-61, 1981-82, 2000-01 for "ocean based" analogs (AMO+, PDO=, Modoki look where 3.4 is colder than 1.2, ONI in DJF from 0.0 to -1.0, and I threw in a bonus to years after a double El Nino: (1941, 1942, 1959, 1970, 1988) because I think some of normal transition in SSTA that would take place from an El Nino to a La Nina or a cold Neutral is probably slower if you had two El Ninos in a row to warm the oceans. For weather analogs based on Summer (objectively similar conditions in weather, with some weight to ENSO), I like 1942, 1954, 1973, 1978, 1981, 1983, 1989, 1993, 1995, 2007, 2011, pending a lot of rain or a dramatic cold-swing over the next ten days.

[mayjawintastawm]

I've been following 2012 weather with great interest, as it's my benchmark for hot/dry (since I moved to CO in 2010, but also a very hot and dry year going back a long way in Denver climatology). Sept 2012 had 7 of the first 11 days over 90, with little rain. After that, the daily DFN went from +10 to -11 in one day with almost an inch of rain; the rest of the month was quite wet, and there were no more 90 degree days the rest of the year.

This month we've had 6 90+ days at DEN with little rain. last two days were +13. Would be nice for 2012 to repeat about now...

[beavis1729]

On 9/20/2016 at 4:07 AM, raindancewx said:

Someone posted the analogs Accuweather likes for the winter (although it isn't their forecast):

1958 

1959

1983 x2

1984 

1992 x2

1995 x2

2005 x2

2013

I have some conceptual problems with those years as analogs:

1) I think with 1983/1984/1992 the Atlantic is too cold

2) 1992/93 was heavily influenced by Pinatubo (big-time volcano, VEI = 5)

3) For NYC/Baltimore/Philly/DC/Richmond those years would mean four snowy winters in a row - that's very rare, so (to use Philly) the analogs above would give +30-40% snow (31" v. 22" mean). Don't really buy that.

That being said, if it was somehow right, some of those years are incredible in the SW - 1958/1959/1992 are all top ten winters for snow in Albuquerque. 2005 is a horrible winter for much of the west though.

I'm still waiting on some data (August PDO from JISAO, although NWS ABQ said it came in at 0.52 - I haven't seen it yet on the JISAO site), Sept mean highs for ABQ, and final monsoon rainfall totals, but I like 1931-32, 1932-33, 1937-38, 1943-44, 1948-49, 1959-60, 1960-61, 1981-82, 2000-01 for "ocean based" analogs (AMO+, PDO=, Modoki look where 3.4 is colder than 1.2, ONI in DJF from 0.0 to -1.0, and I threw in a bonus to years after a double El Nino: (1941, 1942, 1959, 1970, 1988) because I think some of normal transition in SSTA that would take place from an El Nino to a La Nina or a cold Neutral is probably slower if you had two El Ninos in a row to warm the oceans. For weather analogs based on Summer (objectively similar conditions in weather, with some weight to ENSO), I like 1942, 1954, 1973, 1978, 1981, 1983, 1989, 1993, 1995, 2007, 2011, pending a lot of rain or a dramatic cold-swing over the next ten days.

While I generally appreciate the idea of forecasting long-range patterns using analogs and correlations, the bolded approach shouldn't be used.  Your statement implies that each year's snowfall is correlated to the following years snowfall, regardless of the background pattern in place.  It's analogous to saying that "if I flip a coin and it lands on heads 3 times in a row, the 4th flip probably won't be heads"...whereas we know that isn't true.  Each coin flip is independent of the prior outcomes.  If you get 11 heads in a row, the 12th flip is still 50/50 heads or tails.

[raindancewx]

I agree that everything resets each winter, I'm just saying a sequence of four in a row for something that occurs ~40% of the time historically should only happen 2-3 times in a century using the independent odds, and from the ten or so cities I've looked it, the data matches the theory. Since the three winters have already happened, it is back to 40%. But I'd still bet against a snowy winter for the coastal NE personally.

Philly has had two sequences of >=22.2" (the 1931-2015 mean) four times in a row since 1931, once in the 1930s and once in the 1960s, which to me is consistent with (0.4^4)(85). But obviously the pattern could be unique, or this could be the "third" sequence for the century of 1931-2030. The winters following a sequence of three snowy winters in a row vary quite a bit, but they do average ~18.8" snow (based on six winters after the previous three were snowy), with a couple very snowy and others nearly snowless.

It's also entirely possible that they just miss, and get 21" or something. I do think another issue in the analog package above is that the Jan 1996/2016 blizzards were pretty similar - you tend to not get those very often in the NE, so I think the big storms are largely in a different spot this winter (West or South of the big NE Cities)

[Chinook]

NWS predicts some respectable snowfall for NW Wyoming, NE Utah with this upper level trough in the next 3 days.

[Chinook]

A strong jet stream is affecting the mountain west. 136kt near Las Vegas and 120kt at the CO/UT border as of 12z.

[Chinook]

A few trees are turning around here. This red color of a maple tree is somewhat rare around here. A lot of trees turn yellow in town.

[raindancewx]

Got down to 42F here this morning - didn't happen til Oct 22 last year. All time record low for ABQ in Sept is 35F, so 42F is pretty respectable, and about two weeks early against the mean first date of that temperature. 

[Chinook]

7-day precip in the Western states. This week Salt Lake City got heavy rain on a couple of days in a row. There was a tornado at South Ogden UT, and a tornado in SW Utah. Several severe thunderstorm wind reports in Utah. Some mountains in UT and WY got 1-6" of snow, I believe.

 

[Chinook]

Yesterday it got to 83.5 here, then we got a breezy cold front with temps quickly falling to the upper 60s. There was a bit of rain at 9-11PM. This morning it was in the 40's.

[Chinook]

some red leaves of an ash tree

 

[mayjawintastawm]

Bumping this thread up... it's been a few days. Beautiful weather now but still SO dry... long range past day 5 at least gets us cooler, hopefully we'll get a rainy (or even a bit snowy) day in there to break the loooong cycle.

[ValpoVike]

11 hours ago, mayjawintastawm said:

Bumping this thread up... it's been a few days. Beautiful weather now but still SO dry... long range past day 5 at least gets us cooler, hopefully we'll get a rainy (or even a bit snowy) day in there to break the loooong cycle.

P&C here shows some snow for Tuesday night.  We'll see, but it sure won't be long til the cold weather thread is needed.

 

[Chinook]

The 12z GFS predicts snow for most elevations here Thursday. It would be a little unusual to see snow at 18z (12PM) as the surface temps would normally be above freezing for low elevations. The 06z GFS has more limited snow, 7000ft plus.

[Chinook]

Hurricane Matthew smiling (Thurs. evening)

[mayjawintastawm]

From 7/3 through 10/2, DEN has had 0.81" of rain. I'll go see if I can find another 3-month period since we moved (8/2010) that is so dry. Still have the sprinklers on basically a summer schedule... don't want the vegetation to get freeze-dried again.

 

Edit: Easier than I thought I guess. 6/11-9/11/12= 0.64", when the drought was really bad. Go one or two days either side of that though and there was a soaking.

[raindancewx]

Actually think Denver could be pretty dry much of this fall/winter. Oct/Mar would be my best best for wetness up there.

[Chinook]

My area was +2.7F this month, with officially 0.19" of rain. My place got 0.26" of rain. The May 1st - September 30th precip at my place was 4.17". That averages to merely 0.845" per every 31 days, that is, 0.845= 4.17/(31+30+31+31+30)*31. The last few days of September were in the 70's or 80's with nearly perfect weather, which pumped up the average temperature for the month.

[mayjawintastawm]

22 hours ago, Chinook said:

Hurricane Matthew smiling (Thurs. evening)

Seems like Matthew has had a convective sidekick about 200 miles to his E for most of the last few days. There must be a name for that. Wonder why.

[Chinook]

thunderstorm in Tampa moved east to west over Tampa Stadium, and has delayed Broncos/Buccaneers game. I heard it will resume at 6MDT/8EDT. radar shows .50" of rain since the storm started.

[raindancewx]

Weatherbell's Joe D'aleo had something interesting posted today in discussing the West:

"the best matching SSTA from 45N to 45S are 1959-60, 1960-61, 1998-99, 2013-14, 2014-2015" for the West. Fair number of pretty big snowstorms in the West in some of those years. Not sure what he bases it on though, it didn't look like a super great match when I plotted in for Sept.