July 2016 Observation and Model Discussion for the Pacific Northwest

[ShawniganLake]

Not for down here. That was in response to Matt and myself agreeing that best dynamics would be up north.

I see.  I guess I missed that part.  Didn't realize the discussion was specifically for the Portland area. 

[ShawniganLake]

Sunny but windy here this morning, still gusting to 25mph.  Warm night here.  Low of only 61F

[Jesse]

I see.  I guess I missed that part.  Didn't realize the discussion was specifically for the Portland area. 

 

Yeah, once the NW wind started blowing and it started clouding up/cooling off around 7-8pm things just didn't feel right for the Portland metro.

 

Glad you guys got something though. At very least we got some decent rains down here this morning.

[seattleweatherguy]

The new 06z GFS brings the heat in a big way next Friday and Saturday. Approaching all time record highs if it verifies.

 

http://maps1.pivotalweather.com/maps/models/gfs/2016072206/186/sfct.us_nw.png

http://maps1.pivotalweather.com/maps/models/gfs/2016072206/210/sfct.us_nw.png

If that verifies seattle hits 95?

[snow maniac]

Not a drop of rain overnight.

[TT-SEA]

Looks like a short ridge crashing event to start August on the 12Z GFS.   

[GobBluth]

Looks like a short ridge crashing event to start August on the 12Z GFS.   

the crashing may commence on the 31st.

[BLI snowman]

Not for down here. That was in response to Matt and myself agreeing that best dynamics would be up north.

 

The ULL didn't quite track right for folks south of Cowlitz County to score overnight convection, but that doesn't change the physical dynamics of it   The marine air wasn't the issue.

 

There were showers and storms as far south as Castle Rock around 2-3am. 

[Jesse]

Sunbreaks here now. Today will probably once again get warmer than predicted.

 

It is a shame we haven't had more to show for the consistent shots of cool 850mb temps this month (they are dropping down to +6, nearly 10 degrees below average, today).

 

Jim made a pretty good point last night about the surface temp anomalies not really reflecting how persistently cool 850s have been regionally in July so far, at least on the west side.

 

All comes down to pattern details. Ironically a month with lots of marine intrusions and warmer upper level temps overall (July 2010) has a much easier time putting up big negative anomalies this time of year.

[Jesse]

The ULL didn't quite track right for folks south of Cowlitz County to score overnight convection, but that doesn't change the physical dynamics of it 

 

There were showers and storms as far south as Castle Rock around 2-3am. 

 

Indeed it does not. 

 

But I would argue that location in space-time is an important aspect of physical dynamics.

[GobBluth]

Sunbreaks here now. Today will probably once again get warmer than predicted.

 

It is a shame we haven't had more to show for the consistent shots of cool 850mb temps this month (they are dropping down to +6, nearly 10 degrees below average, today).

 

Jim made a pretty good point last night about the surface temp anomalies not really reflecting how persistently cool 850s have been regionally in July so far, at least on the west side.

 

All comes down to pattern details. Ironically a month with lots of marine intrusions and warmer upper level temps overall (July 2010) has a much easier time putting up big negative anomalies this time of year.

It does seem bizarre the surface temps haven't given us the goods of the low 850s. Lingering effects of the above average SSTs right off the coast? 

[BLI snowman]

Indeed it does not. 

 

But I would argue that location in space-time is an important aspect of physical dynamics.

 

The contention that the presence of stable marine air at the surface was the ultimate hindrance is the incorrect part, which is what I pointed out. Just a bit of summer convection 101 for you. 

 

We had a window for overnight thunderstorm activity in the late night and missed it by about 30 miles. Not a huge deal. The timing (and morning rain) was a pretty straightforward forecast. 

[GobBluth]

12z cmc reduces it to a 2 day hot spell, if that.

[Jesse]

It does seem bizarre the surface temps haven't given us the goods of the low 850s. Lingering effects of the above average SSTs right off the coast? 

 

I doubt that has had much of an effect, if any. Could be wrong, but I can't see the relationship being that linear.

 

More something along the lines of lower 850s causing more mixing and destabilizing the marine layer. Hard to stay much cooler than low 70s in July down here when there are any afternoon sun breaks.

[GobBluth]

I doubt that has had much of an effect, if any. Could be wrong, but I can't see the relationship being that linear.

 

More something along the lines of lower 850s causing more mixing and destabilizing the marine layer. Hard to stay much cooler than low 70s in July down here when there are any afternoon sun breaks.

that sounds more likely.

[Jesse]

The contention that the presence of stable marine air at the surface was the ultimate hindrance is the incorrect part, which is what I pointed out. Just a bit of summer convection 101 for you. 

 

We had a window for overnight thunderstorm activity in the late night and missed it by about 30 miles. Not a huge deal. The timing (and morning rain) was a pretty straightforward forecast. 

 

It was a SWrly push. Thunderstorms generally formed in areas further north where the marine layer either hadn't moved in yet or was in the process of moving in when the ULL was in a prime position. Areas further south stabilized more quickly. The marine push cut things off before the best dynamics were present from Cowlitz county south.

[Jesse]

12z cmc reduces it to a 2 day hot spell, if that.

 

Good. Hope the trend keeps up.

[BLI snowman]

It was a SWrly push. Thunderstorms generally formed in areas further north where the marine layer either hand't moved in yet or was in the process of moving in when the ULL was in a prime position. Areas further south stabilized more quickly. The marine push cut things off before the best dynamics were present from Cowlitz county south.

 

The instability was rooted well aloft and none of the valley convection was surface based, so the low level marine push wound up being fairly irrelevant since it didn't synch with the main push of the trough. It was entirely driven by the tracking of the upper level trough, which appeared to track in over the NW OR coast. The best instability is generally going to be on the east and NE side of that. 

[Jesse]

The instability was rooted well aloft and none of the valley convection was surface based, so the low level marine push wound up being fairly irrelevant since it didn't synch with the main push of the trough. It was entirely driven by the tracking of the upper level trough, which appeared to track in over the NW OR coast. The best instability is generally going to be on the east and NE side of that. 

 

Fair enough. Although if the marine push was irrelevant I can't understand why we were all in agreement that it would serve as a good trigger just yesterday?

 

Whatever the reason, it didn't feel right for convection in the Portland area last evening, and we ended up not seeing any. Just one of those things.

[BLI snowman]

Fair enough. Although if the marine push was irrelevant I can't understand why we were all in agreement that it would serve as a good trigger just yesterday?

 

Whatever the reason, it didn't feel right for convection in the Portland area last evening, and we ended up not seeing any. Just one of those things.

 

It comes down to timing and strength mostly i.e. synching it up with the best mid and upper level dynamics, which occur with the passage of the trough. Our best summer thunderstorms also occur with a prominent gradient reversal and strong "sea breeze front". In yesterday's case we never had much hot air or moist, offshore flow ahead of the marine push to begin with. Low level moisture was rather weak.

[Jesse]

12z GFS ensembles seem to be in pretty good agreement with the operational regarding a quick break down of the ridge.

[Geos]

Had about 0.35" of rain here this morning. Hovering around 64°. Clouds slowing brightening up from the south.

 

Looks like a couple hot days coming up.

[Deweydog]

Fair enough. Although if the marine push was irrelevant I can't understand why we were all in agreement that it would serve as a good trigger just yesterday?

 

Whatever the reason, it didn't feel right for convection in the Portland area last evening, and we ended up not seeing any. Just one of those things.

 

Justin's right, the marine push was irrelevant when it came to last night's elevated stuff.  But the models were pretty consistent in keeping that activity to the north and our best opportunity was with the marine push as a trigger.  We had the one little storm form around Scappoose or so when the push initiated, but that was about it.  

[TT-SEA]

12Z ECMWF is all crashy too... hopefully a quick rebound afterwards.  I doubt there will be long-term troughing at any point until the middle of September at the earliest.  

 

http://stream.ecmwf.int/data/atls00/data/data01/scratch/ps2png-atls00-95e2cf679cd58ee9b4db4dd119a05a8d-n8dkzP.png

[Jesse]

Justin's right, the marine push was irrelevant when it came to last night's elevated stuff. But the models were pretty consistent in keeping that activity to the north and our best opportunity was with the marine push as a trigger. We had the one little storm form around Scappoose or so when the push initiated, but that was about it.

It was actually my observation of the cell near Scappoose blowing up then fizzling out with the onset of marine air that prompted my call for a no-go in PDX last night. Nothing was firing to the south at that point, where marine air had already become established, and the fact that the short-lived Scappoose cell was the most we could muster with our push was a harbinger of the rest of the evening.

 

The upper level based stuff that occurred later is neither here nor there, since modeling showed that staying mostly to our north all along.

[Jesse]

Let crash-tracking '16 commence!

 

My guess is that there will be some VERY meaningful runs that water it down the next several days, as well as others that don't.

[Deweydog]

It was actually my observation of the cell near Scappoose blowing up then fizzling out with the onset of marine air that prompted my call for a no-go in PDX last night. Nothing was firing to the south at that point, where marine air had already become established, and the fact that the short-lived Scappoose cell was the most we could muster with our push was a harbinger of the rest of the evening.

 

The upper level based stuff that occurred later is neither here nor there, since modeling showed that staying mostly to our north all along.

 

I agree.  But Justin has a point the elevated stuff is a tough call and history tells us it can be pretty random.  I could have shifted south 50 miles fairly easily, even with what at that point down here was a well-entrenched, drizzly stratus deck.  Might not have even seen the lightning...

[BLI snowman]

I agree.  But Justin has a point the elevated stuff is a tough call and history tells us it can be pretty random.  I could have shifted south 50 miles fairly easily, even with what at that point down here was a well-entrenched, drizzly stratus deck.  Might not have even seen the lightning...

 

Like I said earlier, the Portland metro really hasn't seen a good setup for surface based, warm-core convection since August 12, 2014. That's an unusually long time and it feels like something has to give soon. 

[Deweydog]

Like I said earlier, the Portland metro really hasn't seen a good setup for surface based, warm-core convection since August 12, 2014. That's an unusually long time and it feels like something has to give soon. 

 

It's been a decent drought.  Consistently missed, primarily on the south end of things even going back to the convection-a-palooza of September 2013.  

[Front Ranger]

I doubt that has had much of an effect, if any. Could be wrong, but I can't see the relationship being that linear.

 

More something along the lines of lower 850s causing more mixing and destabilizing the marine layer. Hard to stay much cooler than low 70s in July down here when there are any afternoon sun breaks.

Too much afternoon sunshine, night time cloudiness.

 

And honestly, Tim was right about the only substantial troughing being in the first 10-12 days of the month. Since then, it's been either weak troughing or weak ridging.

[Phil]

12Z ECMWF is all crashy too... hopefully a quick rebound afterwards. I doubt there will be long-term troughing at any point until the middle of September at the earliest.

 

http://stream.ecmwf.int/data/atls00/data/data01/scratch/ps2png-atls00-95e2cf679cd58ee9b4db4dd119a05a8d-n8dkzP.png

Willing to wager on that?

[GobBluth]

Let crash-tracking '16 commence!

 

My guess is that there will be some VERY meaningful runs that water it down the next several days, as well as others that don't.

water down the heat?

[Jesse]

water down the heat?

Maybe the heat, maybe the crash. Maybe both.

[Phil]

Not that it matters, but I'm more confident in a significant troughy period in August than I was for prolonged troughing in July. I'd say there's a 70% chance that SEA, OLM, PDX, and EUG all finish below average for the month, perhaps significantly.

[Jesse]

The coming heatwave looks like just a Thursday/Friday deal on the Euro ensembles.

[TT-SEA]

Willing to wager on that?

Not sure... local history using your analogs suggests you are being too pessimistic about August. Much like you were with July.

[TT-SEA]

GFS ensemble mean is warmer than the operational run with the cool down.   Just getting down to normal at the 850mb level before starting to climb again.

 

http://old.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

[Phil]

Not sure... local history using your analogs suggests you are being too pessimistic about August. Much like you were with July.

What? July turned out almost exactly how I thought it would, minus some timing differences. So did April-June.

 

The August analog aggregate is even cooler w/ a more stable NPAC ridge/-AAM versus July, stronger signal for Maritime forcing/EPAC subsidence, too. September is another story, uncertainty there mid/late month.

[TT-SEA]

July turned out almost exactly how I thought it would, minus some timing differences. So did April-June.

 

The August analog aggregate is cooler w/ a more stable NPAC ridge/-AAM versus July, stronger signal. September is another story, uncertainty there.

 

July was the reverse of what you thought really.

 

July turned out like I was thinking in terms of timing and I might have been too cold for the Seattle area with my monthly forecast. Local history suggests that August will not be dominated by troughing and cool weather... only for maybe a week or so.

 

I would not bet on SEA being below normal for August. I am pretty sure I will end up too cold for SEA in the contest again.

[Phil]

July was the reverse of what you thought really.

 

July turned out like I was thinking in terms of timing and I might have been too cold for the Seattle area with my monthly forecast. Local history suggests that August will not be be dominated by troughing and cool weather... only for maybe a week or so.

 

I would not bet on SEA being below normal for August. I am pretty sure I will end up too cold for SEA in the contest again.

What are you smoking?

 

Your July forecast busted magnificently, I called for a troughy month, you didn't. You even had to publicly "concede" to me after throwing a temper tantrum for weeks on end.

 

Everyone here saw what happened.