Friday, February 9, 2024

Storm 3 - could be the one! (spoiler, it was)

 2/9  Set up is an upper low over TX that heads northeast into TN valley and then transfers off the coast. At the upper levels, there's two systems to the north of the main one that come into play.  First one comes through and delivers some decent cold air. The second kicks the storm east instead of letting it continue north.  Now things would have been really interesting if that second piece was faster or dove in behind more instead of kicking it out.  Then that upper low wouldn't be in such a hurry.


At the surface it's similar but the surface low is in front of the upper low, until the upper low catches up and causes the surface low to deepen. You'll see as the low approaches WV, it transfers to the coast and then deepens pretty quickly.  

The deepening quickly and the arrival of some colder air makes it possible for it to snow. While it may be in the 50s today and tomorrow, there is some cold air coming in behind that first shortwave and it gets here just in time for the surface low.  You can even see the low generate some of its own cold air. As you follow it out of TX notices the west side of the low turns blue.  

As far as final outcomes, right now the five models that go out this far agree there's a storm.  Its strength and path isn't agreed upon though.  The GFS and Euro however, are pretty close, and both hit the Tristate and PA. Icon is further north, UKMET further south.  The Canadian has been bopping around too much, but is currently aligned with the Ukie.

Ensembles are similar.

This leads me to believe that we have a good chance at a 6+" snowfall coming up on Tuesday.

Saturday Feb 10th update

System is still a go for a snow day on Tuesday.  Timing is overnight Monday until about noon on Tuesday.  Here's the surface run from the GFS

The 18z run got the ULL down to 528 just south of LI




These are the latest snowfall maps.  The UKMET didn't update in pivotal but it did push a little north on the 12z.  It's pretty safe to say that if you are in NNJ, HV, CT, RI, MA that you are getting snow, likely over 6"


Uptons first snow map


Results - after a shift north in the models over the weekend, nearly taking CT out of the precip, the models reshifted south, again almost taking CT out of the precip.  


Upton didn't bite on the shift south.


And as seen on the euro loop, the snow line shifted south then very last minute, north.




The storm focused its attention on NEPA, NNJ, HV, and CT.  This was it's final outcome


Upper Fairfield County was in the 10-13" range. Farmington had reports of 13-15".  We had 11.1" officially.  



NY metro and NEPA totals 4-14"
Listing of totals from Uptons area can be found here

Monday, January 15, 2024

"Storm" 2 - NADS

1-15

 From an outcome standpoint, this storm isn't very interesting.  Should be widespread 1-3" across most of the tri-state with higher lolipops of 4-5" over PA and in other areas.  NNE and WV should see 6+.

What makes this notable, for me at least to blog it, is the path that we took to get here. 

Euro first caught our eyes over a week before.


950's for pressure was pretty eye catching


Then it began to shift south on the 11th


Meanwhile GFS was ignoring it, making it a frontal passage



Then as the Euro shifted ots, the GFS became a threat on the 10th, 11th and 12th
10th
11th
12th

Then poof. It was gone from the GFS.  All that was left between the two major models was some flurries from a jet streak or something. 
18z on the 12th

Will note here that the Canadian has had this the entire time, although sometimes too far inland. Timing issues on some of the frames may look like misses but all but one run, 0z on the 11th, was a hit. 



Will also note that the AI models mostly had this as storm around or inside the BM as well.

When the NAM got into range, it brought back our hopes. Every run from the NAM laid down some powder for the MA/NE, though sometimes it was also too far inland and brought rain.  


Low and behold, the 14th into the 15th, the GFS started backing the storm to the west as seen by the qpf maps. Last three frames especially.


Euro also came around. 

It's always interesting when the crazy uncle from up north is the best model. 








Monday, January 1, 2024

1-7 First snowstorm

 1-6 - Well it's snowing out.  Pretty much the way described below too.  Had a business conference 1-2 to 1-5 so didn't keep this up but really nothing changed.  There was some movement of the rain snow line and some differences in QPF but we did get our first snowfall.




1-1 - Starting coverage on this developing system that will affect the MA/NE (mid atl/northeast) around the 7th. We started seeing this on the 29th over at Wxsphere.com and it became more serious when we had 3 runs of the GFS in a row AND the Euro AND the Canadian all showing snow in the area on the 30th.




The setup is actually pretty straightforward.  Low crashes into California on the 3rd, exits out NJ on the 7th.  There's a confluence zone to our north which will keep it from cutting. The main concern would be that the storm gets suppressed. The confluence does break right as it goes by, but that would be a major shift.  I'm putting this at a 10% chance it tracks too far north for snow, 60% that it brings snow to the Boston to DC and 30% that it only affects NY south.  

 

Latest run of the Euro does demonstrate why there's still 10% chance that it goes too far north for the MA. Confluence to the north is a little too far ahead and there is some energy behind that can dig in.



Still a little concerned on the track of the low and the cold air which is not around.  It's cold enough for now though. The purple area next to the green is mix.  The purple areas surrounded by blue is heavy snow.

Even with the track being close and the slightly further north jog in the 500mb, we still get a decent amount of snow in the area. 



Sunday, December 17, 2023

12-18 wind rain storm

 Setup for this next storm is very interesting and involves 4, sometimes 5 parts. 



1 is a weird tropical like system. 3 will drop into 2 and merge.  3/2 will then grab 1. 4 is the steering mechanism. We've been waiting to see where 4 will be or if it further combines with the now 321 storm.



At this time, 4 seems to be separate. Maybe that forms another low once the cold air is in place and we can see a little snow. Surfacewise, it looks like this.


With a semi tropical system coming from the Gulf getting enhanced by another upper level system, there will be a lot of moisture and wind. 

Rainfall totals in the tristate likely exceed 3" and may get to 5"

6z GFS

6Z NAM

6z Euro on NY




Wind is also going to be a concern.  The last storm did produce 50+ mph gusts, though it was not widespread and focused on coastal locations. Due to different wind alignments, more mixing down of the winds may happen this storm and wind advisories and high wind warnings are up for the tristate and New England. Winds will be the highest from the Jersey Shore and Hudson river on east. NAM/GFS/Euro all in agreement with gusts in the 50kt range.

Euro gusts CT/LI/RI

NAM Gusts SNE

GFS gusts

This is the official map from Upton, but only goes to 7am Monday.

Coastal flooding is also an issue, though the moon was a crescent last night. This is a busy page from the NWS but at 3' above flood stage, it's pretty serious.  12-16' breakers on oceanfacing beaches. 3-6' breakers on the CT coast. Surge of 3.5 to 5ft possible. A lot depends on timing of the windshift either before or after low tide.  In addition, there's a lot of rain coming down the rivers still from last week, plus another 3+" of rain before the high tide will really bear watching along rivers.


HRRR trying to pinpoint those higher gusts. 75mph over central LI and 65mph over Newtown.


Officially widespread 50+ gusts reported 
with some 60's in RI/SEMA and unofficially in LI/CT on Wunderground stations


Locally I had 2.8" of rain as of 8am, but it is still raining, and Oxford airport reported gusts in the 50s. Two trees uprooted, no power outage.  Danbury had 4.43, Oakland NJ had 5.24, Verona had 4.83, Ringwood had 5.1", Cornwall on the Hudson had 5.03".It was still raining at all these sites. 

Power outages were widespread with 83k in CT, 148k in Mass and over 100k in Maine so far. NH also has 40k but didn't make the top five.  Other states in the mid atlantic saw 10-20k in outages. 

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Storm 3 - could be the one! (spoiler, it was)

 2/9  Set up is an upper low over TX that heads northeast into TN valley and then transfers off the coast. At the upper levels, there's ...