OceanStWx

The HRRR definitely has traceable features that have associated wind maxes within the larger LLJ. So there will likely be some convective elements that get ingested into the system that will have locally higher wind potential.

No we don't. We are already paying for WeatherBell, we aren't going to get approval for WeatherModels too.

Your window is like 10 pm to 4 am or so I think. HREF is painting quite a bullish picture for QPF for the upslope in NH and VT. Even taking 60-80% of QPF is like 3-4".

Looks a little sting-y

In an ideal world the independent analysis will show that the first guess is within 10 knots 100% of the time (as the study I modeled this off of found). Hopefully it's even better than that.

The good news is it all makes sense. The higher your wind and lapse rates the higher the potential wind gust, and the higher the 925 depth the lower your potential wind gust (inverse relationship there).

Spits out 50 knots around 12z. I'm pretty happy my equation will actually produce HWW criteria. My first attempts really fell short on the high end events.

Euro also doesn't have 09z output to show what happens between there and Penobscot Bay. I think the LLJ maxes out somewhere around Cape Ann to PWM.

Well after grinding all night to finish (between actually doing the forecast) I've come up with a multiple regression equation that explains roughly 60% of the variance in wind gusts at PWM. 32 + (50% 925 wind) + (90% lapse rates sfc to 925) - (5% of sfc to 925 depth) Based on the 06z NAM bufkit for PWM, that gives me a first guess gust of 47.6 knots at PWM. I kind of like it. Still have to test this against some independent data, but results are promising.

Some, like Cape and Islands, but outside that is probably reach at this point.

We get plenty of stout LLJs in October, and they don't all produce widespread wind gusts. If SSTs drove our wind potential, we'd never get wind events in January and February. While it may have some influence, it's not very high up the list.

Just wait 6 hours

It's not out of the question. Even in NH I have a few bufkit locations showing flashes of isothermal above 1500 ft.

One interesting aspect of the ensembles is that just about every single member is a bomb (GEFS and EPS). So it's not like there are a bunch of clunkers dragging the mean down, it's location dragging the mean down. I think it highlights the ingredients are all there for a big system. While some of these runs are clearly dealing with latent heat release issues, the negatively tilting trof and favorable location within the upper jet structure are good positives to have on your side.

I'm working on some VERY preliminary research up here on stable/neutral wind events and unsurprisingly the best correlation is 925 mb wind speed followed by 925 mb to surface lapse rates. I'm still working out the regression equation but it's roughly 50% of the 925 mb and 80% of the lapse rates (positive is more unstable). But since lapse rates rarely are in excess of 10 C/km, that only "adds" at most 10 knots to the forecast gusts. So 925 wind speed does a lot of the work in my regression. Would suggest 30-35 knots is a fine place to start. That's using the GYX sounding and PWM gust (we don't track gusts here on the hourly). Overall I think my first pass is failing to capture the higher end events. So now I'm working on using the GYX upper air and PWM T/gust to see if that significantly changes things (lapse rates are often more unstable at PWM).

I’m pretty sure the 5SD is verifying, what’s not is location and thus getting it to the ground/forcing the QPF.

I’ll give you that if you showed people unlabeled 500 mb charts it might be tough to really tell the flow pattern apart, but that’s a bullet I’m saving for the real deal.

Verbatim maybe, but it’s also a failure of model interpretation. We as an enterprise need to do better to interrogate QPF fields. Scoots mentioned some red flags with dry air in the lift generating layers. But it’s easier to rip and read a QPF map than make your own.

I agree it's not a great look, but sometimes in the short term you just have to go with what you think is going to happen, it's in the best interest of your users. I stand by my 0.25" since it hasn't rained yet at ASH.

It better pound between now and 18z if the hi-res stuff is going to be right. Inch an hour for the next 4 hours?

I think one of the hardest things to do is pull the plug on your own forecast. And I know people I work with struggle to know when to take the forecast in a new direction (positive or negative busts) in the near term. Like it's fine to say gusts to 70 mph are possible on the Cape, but if that's the upper bound what's the lower bound? 48 hours out 30 mph might be just as likely as 70 mph, but we never hear the 30. That I'll totally agree with. The NWS is struggling with that mentality given all the social media-rologists out there. My opinion is I would rather the NWS be the right answer than the first answer. If nothing else maybe the HazSimp process will move us towards a more traffic light mentality. Have a yellow light/caution product that "gets the word out" without details, and when it's time to honk you have the red light/warning. As things currently stand we don't have a great product set for events we know will be below warning criteria but will still have impacts.

I think there is a tendency to get too specific too early. It's one thing when we talk about impacts here on the board, but when actual forecasts are going out that describe in detail how the storm will evolve 72+ hours in advance stretches beyond our capabilities. QPF is a great example, it's just a poorly forecast variable by the models and even over 48 hours it can change quite a bit. I know with my colleagues I see way too much trust in models, and especially the latest model run. The hill I'm prepared to die on this winter is holding onto watches longer. We shouldn't be crying wolf on 40% of them.

I gotta say, it feels good to be using ensemble sensitivity again.

There's nothing like a good Plains blizzard. We get the Atlantic moisture, but true blizzards are so hard to come by around here.

While the pattern may ultimately be a colder one, that FV3 cold bias is going to be a tough one to shake this winter. Because of the seasonal progression cold is easier to believe, but given the old GFS propensity to rush cold and the current version biased at long ranges it's probably better that cold shot expectations are tempered.