May 2026 Obs/Discussion

[weatherwiz]

Unfortunately, the prospects for any sustained temperatures above the seasonal average is quite low as we move into the month of May and we may even have to wait fairly deep into May to flip the script. Unseasonably strong late season blocking continues to be a dominant mode within the Arctic domain and Greenland resulting in troughniess and below average heights dominating from the northern Inter-mountain West region across the northern Plains, upper-Midwest, and Northeast. There are some hints on the GFS/Euro we could see this pattern breakdown a bit moving towards mid-May, however, it is very possible that is a bit too optimistic and it is just the weighting of climo towards the end of the run making it appear the pattern will breakdown. 

Hopefully towards the back end of the month we can introduce some heat, humidity, and severe weather chances. While May is the beginning of severe weather season, that doesn't mean we get flooded with threats right away. Just like how June 1 is the official beginning to the Atlantic hurricane season...we aren't flooded with hurricanes on June 2. Patience, patience, patience. 

[SouthCoastMA]

Well, Sunday looks ruined again. F

[H2Otown_WX]

We May '05:

[Torch Tiger]

May looks to start near normal temps. Acatt reeling after last weeks hopes and even outright (reckless) calls for two weeks of rhea

[CoastalWx]

Great call. Last two weeks have sucked. Early next week looks good.

[CoastalWx]

Looks like east of ORH-GON may get the western edge of the coastal Saturday night into Sunday morning.

[weatherwiz]

18 minutes ago, CoastalWx said:

Great call. Last two weeks have sucked. Early next week looks good.

Finally some signals we may turn the tables a bit after the first week.

[CoastalWx]

Monday and Tuesday looks awesome. Seems like one of those deals where warmest temps Southern New Hampshire to CEF or so given srly flow. 

[CoastalWx]

12Z EPS and Euro AIFS love to hang some cooler wx through mid month. They'll be milder days for sure...but kind of an overall cooler regime.

[SnoSki14]

1 hour ago, CoastalWx said:

12Z EPS and Euro AIFS love to hang some cooler wx through mid month. They'll be milder days for sure...but kind of an overall cooler regime.

May tends to be cooler during a developing strong Nino

[Damage In Tolland]

Big flip to warm after 15th

https://x.com/bigjoebastardi/status/2049969900672647418?s=46&t=dhcbvkjmRcyBVQtDxJ3lRg

[Damage In Tolland]

All the complaints and this is thru day 7 finally N Atlantic Boston Climo. I mean this is nice overall 

https://x.com/ericfisher/status/2050002212894449665?s=46&t=dhcbvkjmRcyBVQtDxJ3lRg

[Torch Tiger]

1 hour ago, Damage In Tolland said:

All the complaints and this is thru day 7 finally N Atlantic Boston Climo. I mean this is nice overall 

https://x.com/ericfisher/status/2050002212894449665?s=46&t=dhcbvkjmRcyBVQtDxJ3lRg

Horrible 

[CoastalWx]

1 hour ago, Damage In Tolland said:

All the complaints and this is thru day 7 finally N Atlantic Boston Climo. I mean this is nice overall 

https://x.com/ericfisher/status/2050002212894449665?s=46&t=dhcbvkjmRcyBVQtDxJ3lRg

Weekend meh. Monday and Tuesday we take. That might be optimistic beyond that 

[Torch Tiger]

1 hour ago, Damage In Tolland said:

All the complaints and this is thru day 7 finally N Atlantic Boston Climo. I mean this is nice overall 

https://x.com/ericfisher/status/2050002212894449665?s=46&t=dhcbvkjmRcyBVQtDxJ3lRg

looks decent, but a few drunks or hookah hitters say it looks May 2005 horrible

[dendrite]

AEMATT trying to take the rest of us down with them

 

[Torch Tiger]

1 hour ago, dendrite said:

AEMATT trying to take the rest of us down with them

 

much rather cad than coast

[CoastalWx]

Meh weekend but M-W (Wed more east) looks good. 

[The 4 Seasons]

Last call for any final season snowfall reports for SNE (if you didn't already msg me). I'll have all the final season snowfall maps out this week. If i don't hear from you ill do my best to add the 3 minor events from Mar 3-4, Mar 5-6 and Apr 7 to this map. The numbers on this map were ending on March 2nd (except the climate sites which i already changed).

[dendrite]

Beautiful morning. The grass really responded after the rain yesterday.

46° but full sun is always a win.

[Typhoon Tip]

On 4/27/2026 at 8:33 AM, weatherwiz said:

Unfortunately, the prospects for any sustained temperatures above the seasonal average is quite low as we move into the month of May and we may even have to wait fairly deep into May to flip the script. Unseasonably strong late season blocking continues to be a dominant mode within the Arctic domain and Greenland resulting in troughniess and below average heights dominating from the northern Inter-mountain West region across the northern Plains, upper-Midwest, and Northeast. There are some hints on the GFS/Euro we could see this pattern breakdown a bit moving towards mid-May, however, it is very possible that is a bit too optimistic and it is just the weighting of climo towards the end of the run making it appear the pattern will breakdown. 

Hopefully towards the back end of the month we can introduce some heat, humidity, and severe weather chances. While May is the beginning of severe weather season, that doesn't mean we get flooded with threats right away. Just like how June 1 is the official beginning to the Atlantic hurricane season...we aren't flooded with hurricanes on June 2. Patience, patience, patience. 

10th-14th is a transition period suggested by the numerical trajectories ...albeit recently emergent.  However, it was at least vaguely hinted starting 5 or so days back. As of a last night's computation from all three major source, GEFs, EPS, GEPs, there's movement toward a neutral EPO, -PNA state.  That's basically shutting down BN.  Adding to that presumption, the AO and NAO are flat-lined, perhaps seasonally too. 

That tells me that the op. Euro's extended warm surge into the latitudes of the lower Lakes ( huge swarm outbreak in the Euro 300 hours btw -), with 80s to southern Ontario may not be dependable per se, but at least the principle of a bigger flip is well founded.   We'll see where it goes.  Personally lean to this having legs tho.

That's the broad orbital perspective.  

At a bit more of a discrete level, ...Tuesday and Wednesday next week are precariously close to going excessively above normal.  A typical result in this latter leg of CC; when the environment "allows" a warm departure, the result is disproportionately warmer than normal compared to when the environment is pushing cool departures.   Scott and I have an ongoing interesting observation about this...  if you look at just about any month's climate records since last autumn when this cold hemispheric look became dominate, despite that being the case those months will host something like 3 or 4 days stretches with +15 to +20, separated by 10 or so days of -3.  So that month ends up either near normal or even decimals above normal, while having successfully cheated everyone that enjoys warmth from being able to subjectively feel like that was ever the case. HAHA.  It's been a total liar journey for months now.  We used to have a saying back in the day, "Statistics lie".   The irony being that they don't... but they do at times belie the daily experience. You'll formulate your impression over 10 days of -3 much more so than 2 or 3 days of 70s.

[jbenedet]

Nova Scotia wet snow bomb incoming

[Typhoon Tip]

On 4/28/2026 at 11:36 AM, Torch Tiger said:

May looks to start near normal temps. Acatt reeling after last weeks hopes and even outright (reckless) calls for two weeks of rhea

Today's a sneaky mild naper.  In fact, with May sun potency now lasing the land and man, might even subjectively argue it gets warm out there mid afternoon for an hour or two.   (altho hold on.  One caveat:  not sure if we pancake destruct this, which would cap temp rise....)

Sunday morning?   there may be wet snow falling around the top and tuck towns of the Worcester Hills.  That sure is fuck won't be normal - it would objectively be well below normal actually... 

However,  (today's sneak warm) + ( Sunday morning cold butt pump)/2 = typical bullshit godless NE spring climate by average so yeah...I guess that argues near normal in the aggregate

It's a matter of magnitude.   Does the cold anomaly on Sunday out weigh today's warmth?   It might be a fun 4 min comparison on Tuesday morning for nerds that like to crunch those numbers.  

Tuesday and Wednesday are going to be close to bigger warmth.  It's going to depend on whether the warm boundary that is more and less defined among the models, ...actually gets through here.  Climo says it doesn't and gets shunted some how, some way.  Even when there is no physics to shunt, Earth seemingly comes up with physics ( like interdimensional weather) in order to get what it wants:  pumping NE spring enthusiast bum.    Seriously though, if we can get S of the perceived boundary, we surge from Sunday local era nadir to AN for those two days.  That'll prooobably seal the first 7-day's worth of the month as +

[Typhoon Tip]

29 minutes ago, jbenedet said:

Nova Scotia wet snow bomb incoming

It might zygote as cat paws or even some mangled bow-tie pastas if the cold infant CCB head gets this far NW Sunday morning, too.  

Kind of an interesting day.  12z could have some cold rain mixing in if the CCB head gets as far W as Worcester to SE NH, then is sharply clears by 10 or 11am as the back edge rolls out with that fast moving developing coastal.  It's not a big system. Compact actually... those tend to have a sharper back edge on rad and sat.   So you're sitting there in misery, and then least expecting a brilliant sun bursts forth through the S windows.  

That backside environment appears to only be weakly CAA mixing as there's not a steep vertical delta-T...while also being down slope. That might allow the temperature to get near 50.   I was looking at the 700 and 500 mb level RH and the %ages are < 50.  Some DVM may offset the pancake destruction. 

Point being, going from Labradorian nut sack to at least a C+ afternoon is an interesting sensible flip.

[Typhoon Tip]

This looks like a terrific opportunity for Brian to end up under one of those stationary diurnal cloud streets while it's sunny a mi E and W of his immediate neighborhood ?

[CoastalWx]

2 hours ago, The 4 Seasons said:

Last call for any final season snowfall reports for SNE (if you didn't already msg me). I'll have all the final season snowfall maps out this week. If i don't hear from you ill do my best to add the 3 minor events from Mar 3-4, Mar 5-6 and Apr 7 to this map. The numbers on this map were ending on March 2nd (except the climate sites which i already changed).

Did I let you know? I honestly forget. I think it was 72.7.