weatherwiz

Developing split flow should make medium-range forecasting all the more fun coming up

Kinda touched upon this in a response to Steve but you gotta be careful with just looking at the chart. compare how the models handle the pattern around the time the AO drops...it’s more in relation to a transient ridge which moves across the southern-tier of the AO domain...the drop does not appear to be in relation to any change with the overall strength or structure of the PV. I haven’t checked what the models are forecasting in terms of temps in the stratosphere but I would assume they’re still going to be quite cold. if we wanted to relay on the Arctic for help we would need to (actually would have already needed to) start seeing changes occur within the stratosphere and to the PV now. Having this major increase in the AO will only further strengthen the PV...especially given how intense the westerlies are in the strat

oh of course not...however, the influences it is having on the pattern...nearly controlling the entire hemispheric pattern is just making that probability extremely low. Just look at how much trouble we've had. I think there have been instances this winter where the PAC was actually not bad at all but the Arctic was just so unfavorable.

Moreso just another indicator that we're headed towards spring. But I totally agree with your post...I'm not saying we won't see any more snow or snow events at all...hell we've had snow events into April before lol...but what I'm just saying is (which agrees with what you said) deep winter is not coming. If we are going to get snow events as we get into March we are likely going to have to rely on something crazy to happen (thread the needle type deal?...I certainly don't think we will get any pattern support for it. If the PV wasn't as potent and strong as it was I would argue against my thoughts...but we've seen before when the PV is this strong it just doesn't break down. It's signal is just too overwhelming too to have other teleconnections overpower it. Here's 50mb zonal winds since February 1...the westerlies are through the roof. It would take a great deal of time for these to weaken and even when that occurred there is typically a 2-4 week lag between the response on the PV

been reading tweets and posts about changes coming since the end of December...it's now mid-February. spring training has started...we're almost a month away from the equinox...we are now exiting peak climo and slowly hedging towards spring climo.

The index itself can change very quickly...absolutely, however, the implications of those changes don't happen as quickly. But sort of dissecting that AO drop it appears it's related to some ridging which slides through the southern sections of the AO domain and isn't necessarily related to the structural change of the AO...which is going to be the most important when wanting a full-scale long-duration pattern change. Even during that projected AO drop the PV still looks to stay relatively intact and strong.

Speaking of February 1990 as an analog...wasn't that spring a big tornado producing year out in the Plains??? That would bode well for me

I think it's b/c the strongest anomalies are a bit outside of the NAO domain...although it's possible that Hurrell's NAO method (which I believe has a larger domain) would reflect a much more positive value than the CPC

Winter is done...it's over. It's already mid-February. We aren't going to get any help from the Arctic whatsoever...by the time any changes take place we'll be into the spring season...should changes take place. Given how strongly positive the AO will become again the PV isn't just going to weaken and breakdown in a few days or even a few weeks. Even with a somewhat favorable Pacific the Arctic signal is just too strong.

The AO forecast is beyond ridiculous...+6 to +7SD....yikes

As long as it is extremely active when I go out to OK at the end of May I will take 40's and 50's into July...I would make that trade.

It's going to relax in time to give us a crappy April and May. 40's and 50's with drizzle and overcast

We are down to 79-days to go!!! Once the 0z GFS completes tonight..it will be into March (well technically still Feb 29 but 0z March 1st!!!) which means there would only be ONE full month left in the model world before May

Approaching mid-February! Is that pattern change still coming? Getting closer and closer to spring

I don't want to muck up the Feb thread anymore but going back to what Scott was saying earlier about the warming oceans this is pretty insane. Small sample size being used of course but here's a list of the three previous weak EL Nino's and three weak EL Nino's from the 1970's Here is moderate One thing to keep in mind though is not taking into account the phase of the PDO/AMO. IIRC the AMO was negative in the 1970's as was the PDO. AMO has been positive since the mid 1990's.

Who is Heat miser? Thought cold miser changed his name but they're new.

Today marks the first day of the SPC using PROBABILITIES for ALL SEVERE HAZARDS for the day 2 outlook!!!! Big step towards spring/summer folks. Very fitting too with severe wx in southern FL tomorrow

You know what's one thing I've never heard mention of this winter...is PDO. In fact, haven't heard much on PDO recently. I am out of the loop with it...although I am trying to get back into long-range aspects but is the PDO not really a tool used like it once was? I'm sure the PDO has had to have some type of influence on the pattern...

I've been reading on on some papers regarding ENSO (not necessarily newly published papers) but one thing I find intriguing regarding ENSO is how the ENSO event develops...and more specifically EL Ninio events. Obviously each event is different...different strengths, where the warmest anomalies are located, but this one paper I'm reading talks about HOW the event develops...I guess typically you would expect EL Nino's to develop as the easterlies weaken (or reverse in strong events) the WHWP spreads east...however, EL Nino events as of late have had a tendency to develop in the central Pacific.

WTF...NWS pages have been very odd lately

June 5, 2007. That was a fun day. It was a Tuesday. I was at work and this is where my memory is faded but I remember checking something...possibly on a phone but I didn't have a phone at the time but there were I think tornado warnings very nearby. I remember going home and getting onto the computer and there were supercells firing off...like classic supercells. The storm structures were amazing...never seen anything like it (up until that time). I think I may even have a picture of the satellite from that day. What I recall happening was llvl winds backed around the pre-frontal trough as it was coming through and the shear became highly favorable for supercells. Everything also started on the earlier side (late morning). I wonder if it held off a few hours longer if it would have been a bigger event.

That was pretty crazy.

WTH has been wrong with this page? It's been horrific the past several months https://www.nws.noaa.gov/mdl/synop/products/bullform.all.php#bottom Thank God for this https://leonardo.met.tamu.edu/Weather_Interface/index.php

95 days to go!!! Will be doing a countdown post every Monday morning. Will also be incorporating one or two or five posts per week dedicated to a previous convective event.

that's a good point...but yikes thats a bit of money