April 2021 Discussion

[ORH_wxman]

6 minutes ago, RUNNAWAYICEBERG said:

That would be the money shot out here if this was 30 days earlier. 

Yeah, even 2-3 weeks earlier would matter a lot I think.

[CT Rain]

1 minute ago, ORH_wxman said:

I think most of interior SNE would get accumulating snow if it played out like that. Prob significant snows for at least the Catskills/Berkshires, NW CT and prob N ORH county/Monads.....the details would determine if bigger impact snows hit the rest of the interior. Those details won't become clearer for a couple more days. The ULL could trend north or south....or weaker or stronger.

That is a really perfect mid April evolution on the EPS. 

[Typhoon Tip]

HO boy .. I just saw the Euro and EPS

Uh... 

That looks like it's trying to evolve a system analog to 1997 -

I looked up the CIPs ...but that's based upon the 00z GFS and is not even right. I compared the 00z to the CIPs and I am not sure what in f they are comparing because the 00z GFS did not look like the CIPs 500 mb at the same hour: 120 so... I don't trust that I am using that product correctly ?  whatever -

Anyway, those heights deepening AS IT IS CURLING UNDER LI is precisely what turned a D5 interesting look into a historical juggernaut back whence, and believe me 24" in metro west was a bit of an over performer to put it lightly. And while I would not ever forecast that in a mid range, on or after an April 12th run... fact of the matter is, in 1977 21" fell in N-central Mass.

I'd say we are around 50% for ... +1 SD snow result, which for D4.5/5 is pretty damn bright - ... Just a hair cooler and that's +2 .. +2.5 at 75%, only limited by strength. Just ball-parking

[ORH_wxman]

1 minute ago, CT Rain said:

That is a really perfect mid April evolution on the EPS. 

Yeah it has the rapid deepening of the upper low as it slides by our longitude and that track is optimal down between 40 and 41N. We'll definitely need that if we want the good rates/dynamics to overcome the marginal temps.

If we're nitpicking, maybe we could use a bit more of a defined high up in the CAR region, but even the current depiction has that higher pressure isobars nosing down to provide the drier air for evap cooling.

[CoastalWx]

EPS looks sweet for a lot of the higher elevated areas. Maybe ORH north is best if one judges mid level low placement/RH...but even as it pulls away, a change to snow probably in interior lower elevated spots towards Saturday morning. 

[Typhoon Tip]

UKMET has a classic evolution, too - ... not very strong, but spatially inured to the same playout

[HoarfrostHubb]

Where was this in January or March?

[tamarack]

35 minutes ago, ORH_wxman said:

I think most of interior SNE would get accumulating snow if it played out like that. Prob significant snows for at least the Catskills/Berkshires, NW CT and prob N ORH county/Monads.....the details would determine if bigger impact snows hit the rest of the interior. Those details won't become clearer for a couple more days. The ULL could trend north or south....or weaker or stronger.

 5 days out and GFS's unreliable qpf, but ORH/AFN shows 1-1.2" while RUM/AUG has <0.1".  As expected.

[ORH_wxman]

6 minutes ago, tamarack said:

 5 days out and GFS's unreliable qpf, but ORH/AFN shows 1-1.2" while RUM/AUG has <0.1".  As expected.

Yeah this would have to shift northward quite a bit to hit your 'hood hard. That block forces the ULL underneath as it approaches from the lakes. Though I wouldn't rule out snow up there beyond this threat, as the pattern continues to look pretty ripe for late season snow threats up north. A lot of troughiness over the east and cold intrusions.

[SJonesWX]

1 hour ago, George001 said:

I just checked the models and based on what I am seeing it appears a low is going to be developing underneath Long Island and undergo rapid cyclogenesis, developing into a monster ocean low reminiscent of April 1st 1997. It is later in April, but the low appears to strengthen so drastically on the Euro and Navy that it dynamically cools the atmosphere and changes the rain over to heavy snow and blizzard conditions. The models aren’t showing it with the snow map algorithms, but based on the upper levels of the atmosphere as well as the strength of the low, the models support mostly snow after starting as rain. The upper levels are well below freezing with a low rapidly strengthening after transferring under LI, which screams blizzard not only in the berkshires but right down to the south shore and possibly even the cape. Based on the Canadian, which is the lower envelope of guidance in terms of snow potential, approximately .5 of liquid falls as rain before the upper levels dynamically cool enough to support snow, and from that point to the end of the storm approximately 1 in of qpf falls, which translates to roughly 6-8 inches in the lower elevations with 12+ in the higher elevations (due to ratios). This is the LOW end. If you look at the navy or euro, the low develops earlier, strengthens more, and brings in more cold air which lead to not only increased QPF but higher ratios, so it supports 30+ in the higher terrain with 18-24+ right down to the south shore. In this type of early spring nor’easter threat, the snow map algorithms are useless. The upper levels and dynamics tell a different story than the 10:1 snow maps as well as the surface maps. My official forecast is a blend of the euro, navy and Canadian:

Worcester Hills and Berkshires: 20-30 inches, iso 40

I95 corridor: 15-25 inches, iso 30

south shore: 8-16 inches, iso 20

cape: 6-12 inches, iso 15

if inside I95/128 gets >12", I will allow you to impregnate me. which, since I am a man, is just as likely to happen as anything you stated in your post.

[Hoth]

1 hour ago, ORH_wxman said:

12z EPS has a pretty impressive evolution.

 

 

Wtf couldn't we get that like three weeks ago? infuriating.

[Modfan2]

Looks like a surprise Birch bender for some.

 

[Chrisrotary12]

2 hours ago, George001 said:

I just checked the models and based on what I am seeing it appears a low is going to be developing underneath Long Island and undergo rapid cyclogenesis, developing into a monster ocean low reminiscent of April 1st 1997. It is later in April, but the low appears to strengthen so drastically on the Euro and Navy that it dynamically cools the atmosphere and changes the rain over to heavy snow and blizzard conditions. The models aren’t showing it with the snow map algorithms, but based on the upper levels of the atmosphere as well as the strength of the low, the models support mostly snow after starting as rain. The upper levels are well below freezing with a low rapidly strengthening after transferring under LI, which screams blizzard not only in the berkshires but right down to the south shore and possibly even the cape. Based on the Canadian, which is the lower envelope of guidance in terms of snow potential, approximately .5 of liquid falls as rain before the upper levels dynamically cool enough to support snow, and from that point to the end of the storm approximately 1 in of qpf falls, which translates to roughly 6-8 inches in the lower elevations with 12+ in the higher elevations (due to ratios). This is the LOW end. If you look at the navy or euro, the low develops earlier, strengthens more, and brings in more cold air which lead to not only increased QPF but higher ratios, so it supports 30+ in the higher terrain with 18-24+ right down to the south shore. In this type of early spring nor’easter threat, the snow map algorithms are useless. The upper levels and dynamics tell a different story than the 10:1 snow maps as well as the surface maps. My official forecast is a blend of the euro, navy and Canadian:

Worcester Hills and Berkshires: 20-30 inches, iso 40

I95 corridor: 15-25 inches, iso 30

south shore: 8-16 inches, iso 20

cape: 6-12 inches, iso 15

In my history of being on this weather forum I do believe that this post has the honor of being the first I have given the hot dog and bun symbol to. Congratulations.

[WinterWolf]

2 minutes ago, Chrisrotary12 said:

In my history of being on this weather forum I do believe that this post has the honor of being the first I have given the hot dog and bun symbol to. Congratulations.

Lol..yup he’s cooked. What a fantasizing Mega weenie. 

[dendrite]

1 hour ago, Damage In Tolland said:

Where would a solution like that bring accumulating snow?

Too bad Stein is camping out in your backyard. Could’ve been a special one otherwise. 

[CoastalWx]

47 minutes ago, HoarfrostHubb said:

Where was this in January or March?

Another thing I noticed on the euro op, is that it CAA from the NE at 925. That's a lot better than waiting for it to dynamically flip and then have to wait for winds to back a bit and drag colder and drier air south. 

[Ginx snewx]

Classic slow mover. Basically cut off from 200 and 300 jet. 

[Damage In Tolland]

11 minutes ago, dendrite said:

Too bad Stein is camping out in your backyard. Could’ve been a special one otherwise. 

Don’t think there’s any chance of snow here . Just hoping it doesn’t sink south with qpf 

[powderfreak]

Finally something interesting synoptically, even if it has no impacts up this way. Be fun to watch this evolve.  Those 300mb winds backed out of the east that Ginxy just posted looks textbook.

[Ginx snewx]

Para Euro 

[CoastalWx]

NAM was about to weenie out. That's a tug of cold air coming in from Maine.

[HoarfrostHubb]

EPS probability maps look healthy for mid April

[CoastalWx]

2 minutes ago, HoarfrostHubb said:

EPS probability maps look healthy for mid April

Congrats again.

[tamarack]

1 hour ago, ORH_wxman said:

Yeah this would have to shift northward quite a bit to hit your 'hood hard. That block forces the ULL underneath as it approaches from the lakes. Though I wouldn't rule out snow up there beyond this threat, as the pattern continues to look pretty ripe for late season snow threats up north. A lot of troughiness over the east and cold intrusions.

Would be fine by me, slowing plant phenomena to avoid a late frost kill.  Farmington co-op has had only traces since Feb 27.  Their lowest for Mar-Apr in their 128-yr POR is 1.0" in 1966 (then 3" on 5/9/66) and lowest Mar 1st forward is 2.0" in 1915.  I'd rather not set a new record.

[Damage In Tolland]

15 minutes ago, CoastalWx said:

Congrats again.

Wish we lived where there’s a chance 

[ORH_wxman]

28 minutes ago, CoastalWx said:

NAM was about to weenie out. That's a tug of cold air coming in from Maine.

Yeah it was already pounding over the far interior near ORH and westward. Another panel and it’s probably choking aggregates in metrowest BOS. 

[George001]

when the upper levels are all below freezing and you have a slow moving bomb rotting underneath LI that screams overperformer. I can understand why many of you doubt my forecast (my forecasts haven’t been the best during the winter), but the signs are there. Hopefully my first spring forecast is better.

[MJO812]

[powderfreak]

Clown map with a 20-spot in northern Berks lol.

[Typhoon Tip]

1 hour ago, CoastalWx said:

NAM was about to weenie out. That's a tug of cold air coming in from Maine.

That's the key element ... I've been discussing that, how some of the historical inference/paradigms for spring anomalies seem to all carry that in common - a key inject of cold at a critical phase of development. It's interesting that the Euro/EPS and NAM are trying to hit on that ... 

oh boy ...this is happening shit