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Mountain West Discussion


Chinook

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Not a great match by intensity, but June 2017 looks like 1957 (x3), 1994 (x2), 1997 (x3), 2002 (x2), 2006 (x2). 

Was actually a pretty hard match, but a lot of cities in north Florida had a top-ten coldest June, so I threw in 1957/1997 to make the SE cold. 2002/1994/2006 get most of the US warm/

 

June 2017 National Map.png

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The HRRR runs today are pretty aggressive in predicting moderate-strength rain showers and thunderstorms in Colorado, with 500-1000 J/kg of CAPE over the mountains and plains. It will be unlikely to get 0-6km shear values over 25 kt. Other convection-allowing models have some scattered showers. Perhaps some impact for Denver.

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I was looking through the Jamstec monthly Modoki data (it goes back to 1870!) and I couldn't help but notice that "negative" Modoki values are more common historically in weaker solar cycles. That's a good sign for the winter, less likely to have a strong Modoki signature. For Dec-Feb from 1931-32 to 2016-17, the DJF Modoki value correlates at about 0.05 R^2 to July-June solar activity. That's actually fairly amazing given the length of time involved.

http://www.jamstec.go.jp/frcgc/research/d1/iod/DATA/emi.monthly.txt

Their Modoki definition is different from the one I tend to use for the SW, they do:

Box A SSTA = 165E to 140W, 10N to 10S

Box B SSTA = 110W to 70W, 15S to 5N

Box C SSTA = 10S to 20N, 125E to 145E

Modoki Value = (Box A)-(0.5*Box B)-(0.5*Box C)

 

Biggest "modoki" El Ninos for DJF come out to 1957, 1968, 2009. Biggest "east based" El Ninos are of course 1997, 1982, but 1976 is third.

 

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Yesterday night and this morning, my area may have gotten 0.07" total, plus some thick clouds in the daytime. Right now, there is some long-lasting stratiform rain that goes from Denver to Goodland - an unusual situation in a time of the year when there is normally convective rain.

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Rainfall continues to tease Denver. Right now there is a 5940m upper level low over Denver, and that's about the highest upper level low I've ever seen-- that is, it is a low pressure within a 5940m+ ridge. As for my area, dew points have been 55 or slightly higher for some of the last few days.

XnnXTbN.png

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Pending any rain today (unlikely) this is one of the driest July 1-July 15 periods on record for Albuquerque. Only 0.01" at the airport. It's interesting because the rains have been pretty decent this month just south and east of the city, but not much at all for the city. The HRRR has a line moving through the city after midnight.

It's also a bit cooler than last year, despite the dryness. When the July mean high here is over 94F it tends to not snow much, or at all, in December in the city, so nice to see it slowly trending below 94F.

 

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The summer rainfall, including our North American Monsoon contribution, has been mainly a failure for many of the years I lived here. I moved here in 2006 at the height of the D3 drought. I used the U.S. Drought Monitor archives to find drought designations in past years. Many summers have been warmer than normal.

hEL5XJy.png

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We should have some temps up around 96 for some of us tomorrow, with 101 in southwest Nebraska. This GFS 21-hr forecast should be 5-9 degrees too warm for the Front Range corridor here, and perhaps some 5 degrees too warm in other locations. I don't know why this is happening. The GFS temp profiles are super-adiabatic for too much of the lower atmosphere near Denver.  The weird part is that the GFS has been too moist and too cool with some of the Midwest in various times this summer-- seemingly the opposite boundary-layer problem. The GFS should be a perfectly fine short-range model when cool thunderstorms are not dominating the temperature.

NCEP keeps making the GFS better, right? Of course. In fact, the government says there will be a new NCEP global model created in 2018, that will be better than the GFS. My $5 bet is that the new model will be delayed by a year. In fact, I bet another $5 that when the new global model is operational, the U.S. will still be trying to catch up with the ECMWF modeling systems for a long time.

tANxMUV.png

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22 hours ago, Chinook said:

The summer rainfall, including our North American Monsoon contribution, has been mainly a failure for many of the years I lived here. I moved here in 2006 at the height of the D3 drought. I used the U.S. Drought Monitor archives to find drought designations in past years. Many summers have been warmer than normal.

hEL5XJy.png

Nice. We moved here in 2010 so have never experienced a "normal" summer. It seems like the Plains high dominates every year. The monsoon happens, it just doesn't get east of the Divide in northeast CO, or north of CO Springs. If it doesn't squeeze another 100 miles east this week, it might be a nonsoon, again.

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The Rockies have swept the Padres and scores 36 runs in the last 3 games. The ball really flies when there is low density, like when it is hot in Denver! Also, the Rockies are hitting very well, and they have a lot of motivation to beat the Diamondbacks in the Wild Card race.

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WPC seems to think we get some big time rains over the next week.

Have you guys looked into the AMO/PDO impacts on the monsoon in CO? I know in NM, the monsoon (usually) peaks in Aug when the AMO is cold, and peaks in Jul when the AMO is warm. PDO tends to enhance it when it is positive. Using 1931-2016, the PDO, the sun, and precip in the prior Nov-Apr are the best predictors (still very weak) for total monsoon rainfall Jun 15 - Sept 30.

I'd kill for >=2" rain in ABQ in August, hasn't happened here since 2006, seems to be the longest >=10 year break between >=2" in Aug since at least 1892.

My analogs for the Summer had July 25 - Aug 1 as the most likely wet period, in terms of frequency of days w/ >=0.1" precip, so it's nice to see the coming days looking active.

late July 2017.gif

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On 7/19/2017 at 11:09 PM, raindancewx said:

WPC seems to think we get some big time rains over the next week.

Have you guys looked into the AMO/PDO impacts on the monsoon in CO? I know in NM, the monsoon (usually) peaks in Aug when the AMO is cold, and peaks in Jul when the AMO is warm. PDO tends to enhance it when it is positive. Using 1931-2016, the PDO, the sun, and precip in the prior Nov-Apr are the best predictors (still very weak) for total monsoon rainfall Jun 15 - Sept 30.

I'd kill for >=2" rain in ABQ in August, hasn't happened here since 2006, seems to be the longest >=10 year break between >=2" in Aug since at least 1892.

My analogs for the Summer had July 25 - Aug 1 as the most likely wet period, in terms of frequency of days w/ >=0.1" precip, so it's nice to see the coming days looking active.

late July 2017.gif

 

This should be your chance.  They Death ridge is sliding into Texas next week, along with the heat.  More return flow on the backside of the ridge for NM, CO.  However, around the beginning of August it appears the ridge may slide back to the Four Corners.

 

 

Hoping for one last shot of rain, and it is your turn next week.  One man's ceiling is another man's floor...

 

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My analogs for Summer had a pretty warm July nationally with some kind of ~cool area by the four corners and somewhere in the Midwest, looks pretty decent. Analogs certainly had the heat over Montana which has been pretty incredible this month. The cool in the East is NW of where I had it, and the cool in the West is Southeast of where I had it so far. Seems like my analogs produce "clockwise" spatial errors which I don't get. Have to see if it corrects in the remainder of the month.

It's nice having a relatively normal July in ABQ - 93F through 23 days is much better than 96F through 23 days.

Last July had:

29 Days that were 90F or hotter...

22 Days that were 95F or hotter...

10 Days that were 98F or hotter...

3 Days that were 100F or hotter...

July 2017 (1-23) has had:

<=28 Days 90F or hotter (likely under 28 w/ rains)

6 Days 95F or hotter (may go up by 1-2 for the end of the month)

2 Days 98F or hotter

0 Days 100F or hotter

July 1-23 2017 Temp Anomalies.png

July 2017 Temp Anomalies.PNG

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Asked Nate Mantua for the PDO value earlier, he updated it. Down to 0.79 in June, from 0.88 in May. Way down y/y too.

It's impossible to do an accurate winter forecast this early, but the PDO and AMO values both look lower than last year, with the Modoki status also flipping. The Modoki status from the Jamstec has flipped to -0.5 for winter to +0.15 in June. Solar is similar but lower. Suspect it will be drier/colder for much of the SW this winter, whether this ends up as an El Nino or Neutral. Lower PDO/Sun/AMO should all lower moisture availability.

Based on latest index values through June, I like something like this for my 'ocean/solar' automated analog system:

ONI: +0.8C   (ONI value, DJF)

PDO: +0.4    (Nov-Apr value)

AMO: +0.175 (Nov-Apr value)

ONIp: -0.4C  (previous ONI winter value)

SUN: +18     (annualized July-June)

MOD: +0.25  (from Jamstec monthly EMI table, east based Ninos have -Modoki values, extremely positive values are over 0.4 or so)

MONS: +3.75" (use this to make sure observed weather lines up with climate background)

 

A blend of 1943(x5), 1951(x1), 1953(x7), 1986(x4), 2006(x1), 2009(x2) works well at re-creating the conditions above. Out of the total range for each scale, the produced values are all within 5%. Would be a pretty warm winter nationally, but cold in the SW, and much of the West in Dec. The Modoki value is the hardest to predict, but it is almost always positive in El Ninos. The Midwest / South / Southwest seem like they'd be stuck in a semi-permanent rex-block which would fry the middle of the country but keep the SW cold.

If you all give me the seven values, can output the best matches from my auto-analog model.

 

Possible Blend for Winter.PNG

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We had some decent rains this morning as well, but only 0.05 - 0.20" in the city. Part of the issue this month is the Monsoon has been slamming Arizona over and over again while largely missing New Mexico. 

Should note that when Albuquerque gets 1 inch of rain or less in July, we do (more frequently) see bigger rain in August. City hasn't more than 1.6 inches in August (+10%) since 2006, and historically it "should" happen every three years or so. Would kill for 2 inches of rain or more in August - it tends to cool off Sept and fall more quickly since the sun is back to late April levels of light by late August.

July Precipitation Anomaly.png

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Canadian Model updated today. Has a cool August for much of NM/CO. Also has much of the West wet - but I think it is off.

The big change is the model now shows a (flat) Neutral winter instead of a moderate El Nino. This makes sense given Nino 3.4 has cooled rapidly since July 24th.

 

7.31.17 Canadian Outlook for Aug 2017 (4).png

7.31.17 Canadian Outlook for Aug 2017 (3).png

7.31.17 Canadian Outlook for Aug 2017 (2).png

7.31.17 Canadian Outlook for Aug 2017.png

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53 minutes ago, mayjawintastawm said:

We woke to some good bangs about the same time (actually one of my dogs woke us up) and got about 0.3". The COCORAHS data from your picture really shows the NW-SE progression of the core of the storm nicely.

That NW-SE zone was from the late afternoon storms

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