September 2017 PNW Discussion Thread

[Front Ranger]

62 on weather app for sat. Is it joking

 

Weather apps are known for their keen sense of humor.

[Front Ranger]

Arguably even more so this month. You pulled the Vegas card!

 

OLM is only running +8.1 this month. NBD.

[BLI snowman]

OLM is only running +8.1 this month. NBD.

 

It sucks to see UHI ruining more and more stations.

[Front Ranger]

Irma is probably a category 5 again. Unflagged 142kt surface winds on that last dropsonde and 162kts at flight level. Close either way though.

 

Yeah, but the eye is about to hit land. Looks like a larger scrape than some people were thinking. Will probably weaken Irma further than last night did. I'm thinking at least 20 mph from where it's at now, but could easily be more. Then it's just a matter of how much it can strengthen in the brief trip across the Florida straits. 

[Front Ranger]

It sucks to see UHI ruining more and more stations.

 

No doubt. OLM has not seen nearly as many record warm months as PDX or SEA the past decade. Last month being the most recent example.

[Deweydog]

Yeah, but the eye is about to hit land. Looks like a larger scrape than some people were thinking. Will probably weaken Irma further than last night did. I'm thinking at least 20 mph from where it's at now, but could easily be more. Then it's just a matter of how much it can strengthen in the brief trip across the Florida straits.

Yeah, the current progs account for no weakening despite what appears to be an imminent landfall. Cuba's pretty bumpy.

[BLI snowman]

No doubt. OLM has not seen nearly as many record warm months as PDX or SEA the past decade. Last month being the most recent example.

 

Missed. Joke.

[TT-SEA]

Yeah, but the eye is about to hit land. Looks like a larger scrape than some people were thinking. Will probably weaken Irma further than last night did. I'm thinking at least 20 mph from where it's at now, but could easily be more. Then it's just a matter of how much it can strengthen in the brief trip across the Florida straits. 

 

I was thinking that this is much closer to Cuba than they were thinking.   And it almost seems to be turning a little WSW in the last few frames.

[BLI snowman]

Yeah, the current progs account for no weakening despite what appears to be an imminent landfall. Cuba's pretty bumpy.

 

It would actually going over a very flat part of Cuba, and a full landfall still looks pretty iffy. Really looks like more of a glancing blow for the barrier islands and low-lying coastline with part of the eyewall. 

[Deweydog]

It would actually going over a very flat part of Cuba, and a full landfall still looks pretty iffy. Really looks like more of a glancing blow for the barrier islands and low-lying coastline with part of the eyewall.

Looks like a full landfall to me. Seems like it could easily spend 12 hours over land if it maintains its current trajectory before the prominent northward turn.

[BLI snowman]

Looks like a full landfall to me. Seems like it could easily spend 12 hours over land if it maintains its current trajectory before the prominent northward turn.

 

I think the northern part of the eye could remain offshore the whole time. Either way, a flat and marshy stretch of coast like that probably won't weaken it too significantly but you never know.

[Front Ranger]

Missed. Joke.

Played. Along.

[Phil]

Yeah, but the eye is about to hit land. Looks like a larger scrape than some people were thinking. Will probably weaken Irma further than last night did. I'm thinking at least 20 mph from where it's at now, but could easily be more. Then it's just a matter of how much it can strengthen in the brief trip across the Florida straits.

Also, the farther west it goes near Cuba, the more time it will have over open water before impacting FL. So I guess it's a pick your poison type scenario. With 18hrs over 90*F water, Irma could easily gain another 30kts if the outer eyewall is dominant. Will be interesting to watch unfold either way.

[Jesse]

Yeah, 1967 was the old record.

Where did they top out?

[Phil]

I think the northern part of the eye could remain offshore the whole time. Either way, a flat and marshy stretch of coast like that probably won't weaken it too significantly but you never know.

If just the northern eyewall remains offshore, surface H^2O fluxes will be sufficient enough to preclude rapid weakening. Also the frictional torque tends to force an asymmetric wind field which can then preclude a full landfall.

 

So, it's a tough call. I think it weakens to around 130mph then restrengthens to between 150-160mph before landfalling in Florida.

[Phil]

The number one red flag, IMO, is that Irma will be departing the Cuban coastline tomorrow evening, right at the start of the diurnal maximum for convection over water. That could produce a rapid intensity jump, especially given those 90*F SSTs and poleward exhaust pipe that will develop tomorrow afternoon.

[Deweydog]

Just seems odd to me the experts would be so reactive to different aspects of the storm. They didn't account for the potential strengthening on approach of landfall until late today despite nearly every model indicating some manner of intensification just offshore. Now they seem to be discounting any potential weakening from a Cuba landfall. I can see a lot of Floridians, a place with an inordinately large moron population, seeing updates about a weakening storm early tomorrow and throwing caution to the wind.

[TT-SEA]

That spit of land that Irma is about ravage is home to numerous high end resorts.   

[TT-SEA]

12Z ECMWF showed that Irma is over land from now until 5 p.m. PDT tomorrow. That is a long time and it has to weaken considerably.

 

Then 18 hours later its approaching Naples. Does not seem like much time to strengthen significantly.

 

The previous ECMWF run had Irma missing Cuba entirely.

[Phil]

This is the latest NHC update. Color me skeptical, unless by "relevant" they're implying a 20-30mph decrease in intensity won't matter once it resumes a northward track.

 

"The environment is favorable for Irma to maintain its category 4 status, and only unpredictable eyewall replacement cycles could result in intensity fluctuations during the next 48 hours. The interaction of the hurricane's circulation with Cuba will probably not result in any relevant change in intensity."

[Kayla]

Tracking the consecutive 75+ max record at PDX.

 

Be sure to keep us posted on the amount of smokiness in Bozeman in the mean time!

 

Nah, I think Tim has got that well covered. 

[Phil]

12Z ECMWF showed that Irma is over land from now until 5 p.m. PDT tomorrow. That is a long time and it has to weaken considerably.

 

Then 18 hours later its approaching Napes. Does not seem like much time to strengthen significantly.

 

The previous ECMWF run had Irma missing Cuba entirely.

Let's hope your take here is better than your Jose call.

 

It only loses 25mph/^20mb on the 12z ECMWF due to favorable upper level conditions. I think a weakening to 130mph or so is reasonable. Not sure why NHC wants to keep it at 155mph.

[TT-SEA]

Nah, I think Tim has got that well covered.

I actually think its been smoky in the Flathead Valley and the panhandle of ID for most of the last 6 weeks.

[Kayla]

I actually think its been smoky in the Flathead Valley and the panhandle of ID for most of the last 6 weeks.

 

Yeah no doubt. When we broke out of it early this week, Missoula and Flathead Valley were still socked in. Have definitely benefited being east of the divide this season in that aspect. But now we're back in it again as well, it's been a rough fire season all-around. Wednesday can't come soon enough!

[Jesse]

Pretty hard to imagine PDX falling below 60 tomorrow morning. That would make 8 consecutive 60+ lows. That's got to be close to a September record.

[Front Ranger]

Pretty hard to imagine PDX falling below 60 tomorrow morning. That would make 8 consecutive 60+ lows. That's got to be close to a September record.

I think they have a good shot at it.

[BLI snowman]

Where did they top out?

June 23 to September 10 that year.

[Jesse]

I think they have a good shot at it.

 

They've been holding at 72, DP 59 for the last hour with heavy overcast. Not looking likely.

 

Actually managing to fall below the old monthly record min for the first time in four nights would be an accomplishment in and of itself.

[Phil]

Well, I guess Irma doesn't care about Cuba. Once again a category 5 with winds of 160mph, gusts to 195mph. Hurricanes have a notorious history in those torchy waters so I guess it's not too surprising.

[Front Ranger]

Well, I guess Irma doesn't care about Cuba. Once again a category 5 with winds of 160mph, gusts to 195mph. Hurricanes have a notorious history in those torchy waters so I guess it's not too surprising.

Too soon to say.

[TT-SEA]

Well, I guess Irma doesn't care about Cuba. Once again a category 5 with winds of 160mph, gusts to 195mph. Hurricanes have a notorious history in those torchy waters so I guess it's not too surprising.

 

Its just touching Cuba now...we will see what it looks like tomorrow morning.

 

I think Miami is looking better and better.   The next big story is going to be the people pissed off that there was a massive evacuation which may have actually put some people more squarely in the path on the west side of the state.

[crf450ish]

Just seems odd to me the experts would be so reactive to different aspects of the storm. They didn't account for the potential strengthening on approach of landfall until late today despite nearly every model indicating some manner of intensification just offshore. Now they seem to be discounting any potential weakening from a Cuba landfall. I can see a lot of Floridians, a place with an inordinately large moron population, seeing updates about a weakening storm early tomorrow and throwing caution to the wind.

#itllhappenyouwatchtheydontcallIitfloriduhfornothing

[Phil]

Frictional torque doing its dirty work now. Irma's center is now undergoing vacillations and bouncing off the coast.

 

Speed up this animation and it's like it just hit a wall. What a beautiful demonstration of fluid dynamics, in such intricate detail.

 

http://weather.cod.edu/satrad/exper/?parms=meso1-10-96-1-10

[TT-SEA]

00Z GFS still shows crazy strengthening tomorrow night into Sunday morning... it initialized Irma at 00Z at 934 mb.  

 

[Phil]

Winds starting to increase at the pines and palms resort on Islamorada Key.

 

http://pinesandpalms.com/index.php/webcam/?utm_source=Fla-Keys.com&utm_medium=WebcamLink&utm_campaign=StreamingLink#.WbNmDUEpCaM

[Phil]

The "southernmost beach resort". Gonna go nuts here.

 

https://www.youtube.com/watch?app=desktop&persist_app=1&noapp=1&v=QHjVJt8MARA

[snow_wizard]

Let's hope your take here is better than your Jose call.

 

It only loses 25mph/^20mb on the 12z ECMWF due to favorable upper level conditions. I think a weakening to 130mph or so is reasonable. Not sure why NHC wants to keep it at 155mph.

 

I just saw an interview with Bastardi and he says the upper level conditions above Irma will become the most favorable yet in the coming hours.  He also emphasized the storm will be in a strengthening phase when it makes landfall.  Always a bad thing.

[Front Ranger]

I just saw an interview with Bastardi and he says the upper level conditions above Irma will become the most favorable yet in the coming hours. He also emphasized the storm will be in a strengthening phase when it makes landfall. Always a bad thing.

And that guy never hypes anything.

 

He was also calling for an East coast landfall earlier.

[snow_wizard]

The GFS is slightly further east than the 18z.  Very bad track.

[Phil]

And that guy never hypes anything.

 

He was also calling for an East coast landfall earlier.

Bastardi will be Bastardi, but poleward exhaust will improve markedly over the next 24hrs, while shear decreases by another 5kts. So I do think Irma will intensify after she makes the right turn tomorrow evening, after weakening maybe 25mph tonight and tomorrow. There's just too much history of RI cycles over those waters to deny it, IMO.