MGorse

Epic lake effect snow event! 

19 minutes ago, Hurricane Agnes said:

Mt. Holly confirmed an EF1 tornado in Blackwood, NJ this morning -

 

 

I think that might be the first for the season in the CWA.

After a low of 68 this morning, I made it up to 83 and with the frontal passage, the humidity has definitely dropped from earlier.  It's currently 79 and mostly cloudy with peaks of sun, and dp 59.

This was the third tornado this year. The first one was in Bucks County at the end of March, second one was in Monmouth County in May. The new tornado ally continues. 

8 minutes ago, The Iceman said:

for some reason, I don't believe there's going to be 5.6" in a hour in Burlington county tomorrow...

That looks to be just about over NWS Mount Holly, so I will let you know. 

30 minutes ago, ChescoWx said:

Who or what is Stella??

 

That is a Weather Channel naming thing. 

3 minutes ago, anthonyweather said:

I would assume. They normally are very conservative

Just curious. Thanks. 

2 hours ago, anthonyweather said:

WFMZ just said tonight and tomorrow is going to be a very very dangerous situation with possibly a half an inch of ice in the Poconos and a 3rd inch of ice down in the Lehigh valley. 
 

 

 

good to see the typically conservative news up here getting the word out 

That wording sounds like a Winter Storm or Ice Storm Warning should be issued for at least parts of that region. Maybe that is what they are implying? 

23 minutes ago, anthonyweather said:

Love it, already getting messages to my weather page asking why we were downgraded to advisories. Smh 

You can tell them it is actually an upgrade. Look at the coding (UPG)…

NJZ007-008-PAZ060>062-242200-
/O.UPG.KPHI.WS.A.0005.220225T0000Z-220225T1800Z/
/O.NEW.KPHI.WW.Y.0012.220225T0000Z-220225T1800Z/
Warren-Morris-Berks-Lehigh-Northampton-
Including the cities of Washington, Morristown, Reading,
Allentown, Bethlehem, and Easton
338 AM EST Thu Feb 24 2022

...WINTER WEATHER ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO 1 PM
EST FRIDAY...

54 minutes ago, Albedoman said:

thanks Mike. But the key here is the term "zones". Zones should be based on physical topographical delinations, not just by county lines or interstate highways. Since the late 80's - early 1990's the NWS started going from the airport offices and went to a regional based approached. I was one of the naysayers back then stated that regionalization of the NWS loses  a much needed  local perspective of topographical weather issues and places much more emphasis on computer modelogy and not the physical geography characteristics of the ridge and valley region of eastern PA, especially the LV. I really also  do not like the idea of a county Emergency Manager setting the storm criteria as the they have no control of the federal and state highway system, PADOT does. Rt 22, Rt 309, Rt 100,  Rt 33  and I-78 are  the lifeline for the entire  trucking industry and the LV residents in PA and I believe PADOT should have a say so at the table too. 

Cyrious, does each of the zones in Eastern PA  being defined by physical geography or just political boundaries? How are these zones formed and what is the basis of each of these zones when assigning criteria for warnings and watches?  That has never been really explained to me if you have the time?  

Again, Thank you for issuing the winter storm watch for Lehigh County by the way.

Zones overall match the county borders. There are some exceptions like Bucks, Montgomery and Chester counties which were split years ago to better define the more urban from the higher elevation areas. Splitting of counties/zones is a long process. 
 

Emergency Managers do no set the criteria. They review what is planned to be in place basically to provide feedback. The criteria is based in part on climatology. PennDOT is usually not involved because the criteria is not strictly for what accumulates on roads. That is very difficult to predict. Some adjustments for as least some areas to the warning/advisory criteria were made over the years. There is some wiggle room when it comes to winter storm warnings as combined impacts can be taken into account despite the individual snow and ice amounts being below warning criteria. 
 

Lastly, I had no hand in expanding the winter storm watch this afternoon. 

12 minutes ago, Hurricane Agnes said:

I think the front has been moving through now. The winds have picked up significantly in the last 30 minutes or so. So far I hit 68 for a high and am bopping between 67/68 but the dp has taken a big hit and is now down to 46.

Great observation! Dew points will be first to really drop with the frontal passage. Main cold air push is during tonight. 

6 minutes ago, Hurricane Agnes said:

I'm just amazed at the little flood warnings that will run right along the sides of a river, which can be a tiny area on a map compared to the Warning areas for other products.  That's probably about as hyper-local as I have seen.

Yeah those are different and based on known impacts tied to a river gage level. 

Just now, Hurricane Agnes said:

There is no way you can do "hyper-local" forecasting (at least with the tech that is available today) and even then, it would be TMI for the average person.

Keep up the good work!

Yup especially with watches, warnings and advisories. Appreciate it! 

10 minutes ago, anthonyweather said:

I wouldn’t be Surprised to see ice storm warnings for Lehigh and poconos, surely models are showing the criteria being met

Perhaps but a challenge given the recent warmth. I could see more sleet occurring over snow. 

2 minutes ago, Ralph Wiggum said:

You guys at Mt Holly are tops in the biz... not even close. Probably the most diverse region in the US to forecast for. Majority of us truly appreciate what you folks do over at the NWS. Thank you!

Thank you for the kind words and understanding. 

The warning and advisory criteria is by zones not mountain ranges and such. The criteria is also run by each county Emergency Manager. We try to factor in many things when deciding where to issue a watch. We did not purposely leave out Lehigh County, but focused where the higher snow/sleet is forecast plus where the higher confidence was. We have to start somewhere. Look for additional forecast updates later this afternoon and again tonight. We try our best and we are certainly not perfect! 

Some of these comments…oh my. 

13 hours ago, RU848789 said:

For what it's worth, Lee Goldberg was just on and showing a futurecast that looked a lot like the GFS/NAM, i.e., a bit of snow (an inch or two for NYC), then a fair amount of sleet, then maybe a bit of ZR and then rain, but not rain until 8-9 am, which would mean a real mess on even NYC streets with temps around 32F and 1-2" of snow and 2-3" of sleet (which is 6-9" of snow equivalent) for 7-11" of snow equivalent, which makes sense as those two models are showing nearly 1" of LE by 7 am before any rain.  I don't think anyone is thinking this storm will be as impactful as the GFS/NAM are showing right now for the immediate NYC/NENJ/LI area (and maybe even down into CNJ north of the Raritan/202, which would include me).  Those Tidbits maps show a ton of sleet.  

And the CMC got "snowier" vs. 12Z, according to the Pivotal snow depth map, which I believe is mostly sleet and which I don't believe is at 3:1 ratios (maybe 5:1, since it's probably some snow and sleet); Tidbits doesn't show sleet as snow on the CMC. 

 

 

Hey @MGorse- you were very helpful answering my questions about how the NWS does take into account snow/liquid ratios in their snowfall forecasts a few weeks ago (as per internal calcs, not Kuchera), so thought I'd throw out another question.  Does the NWS ever put out sleet accumulation forecasts or are they just folded into the snowfall forecasts at maybe 3:1 sleet:liquid ratios?  I've never seen any, but maybe I've missed it.  IMO, sleet is greatly underestimated by most with regard to impact, as 3" of sleet is roughly the same frozen mass as 10" of snow, both of which have about the same impact on driving (apart from visibility impacts) and snow removal - so it would be nice to have sleet maps or somehow factored in better in the snow maps.  Thanks, in advance, for any insights.  

Sleet is included with snow regarding accumulations. Sleet can be messaged separately if significant but otherwise it is combined. 

Interesting event. I recall at least some of the model guidance showing pronounced 700 mb or 850 mb FGEN farther northwest of I-95 and closer to the I-78 corridor, yet some were showing less snow. It is like what the model was showing at the surface was playing catch-up to the dynamics aloft. Colder air deeper farther west which placed that lift much better into the favored dendritic snow growth zone.  

7 hours ago, RU848789 said:

I assume you meant Delaware County, which borders Philly, not New Castle, plus neighboring Camden Co. locations were all above 7", also making a 4" South Philly measurement unlikely, but particualrly the Philly measurements NW of South Philly, where one might think less snow fell as generally was the case from SE to NW in this storm.  Thanks.  

Edit for @MGorse- now I'm confused, as the NWS just put up a new PNS, re-adding all the deleted, incomplete reports for Philadelphia County and elsewhere.  Was that supposed to happen?  

Public Information Statement
 National Weather Service Mount Holly NJ
 1150 AM EST Sun Jan 30 2022

...Philadelphia County...
 1 W Belmont                  8.9 in    1230 PM 01/29   Trained Spotter      
 Philadelphia Internati       7.5 in    0100 PM 01/29   ASOS                 
 Rittenhouse Square           6.2 in    0924 AM 01/29   Public               
 Rockledge SE                 6.1 in    0730 AM 01/29   COCORAHS             
 Fox Chase                    6.1 in    0730 AM 01/29   Trained Spotter      
 Chestnut Hill                6.1 in    0207 PM 01/29   Public               
 1 SE Point Breeze            6.0 in    1000 AM 01/29   Trained Spotter      
 Philadelphia 4.7 NE          5.0 in    0730 AM 01/29   COCORAHS             
 Philadelphia                 5.0 in    0830 AM 01/29   Broadcast Media      
 Manayunk                     4.5 in    0820 AM 01/29   Public               
 South Philadelphia           4.5 in    1027 AM 01/29   Public               
 1 S Philadelphia             4.0 in    0730 AM 01/29   Trained Spotter      

No I referenced New Castle County because that is farther southwest and had 3-6 inches. The 4-5 inch reports in Philadelphia County seen too low. 
 

As for that PNS, I am not sure why those old reports were added back in. 

3 minutes ago, Violentweatherfan said:

Thanks, no interview from me. I have brought this up many times when I see someone post "energy transfer" and mention there is no transfer and the term is incorrect.

I just wanted to be sure, thanks.

Thanks for asking. 

2 minutes ago, RU848789 said:

Also, thanks for confirming what I thought on the PNS reports on snowfall and how the final ones are determined and for the info on the measurements being done at the airport now.  As an aside, would you think a 4" report from South Philly would likely be wrong?  Seems like it would be or maybe a measurement error given blowing/drifting.  Thanks again!!

There were several 3-6 inch reports in New Castle County, DE. Given that and some other reports in Philly, I would say 4 inches in south Philly is too low. 

36 minutes ago, Violentweatherfan said:

Question for @MGorse. During a Miller B storm is there really no transfer of energy to the coast for redevelopment.

It's actually not a transfer of energy. That terminology is incorrectly used many times. What happens is that the primary low is becoming more vertically stacked, and thus losing upper level support (differential vorticity and temperature advections). The best upper level dynamics are now out ahead of the primary low, and as it reaches the coast where a natural baroclinic zone is present between the warm ocean and cold land, a secondary low develops.

First of all in no way am I referencing yesterday's storm, just Miller B's in general and do you agree with the above.

 

I feel like I am being interviewed. Lol. That statement sums it up well. Many times this is being said incorrectly because the energy is not being transferred. New coastal low develops due to incoming upper level support (results in surface pressure falls) while the inland low weakens then dissipates as the upper level support leaves it behind. 

20 minutes ago, RU848789 said:

Apart from being just a tad low in the northern 2/3 of Somerset and eastern Morris, I thought the NWS did a superb job on this forecast with the vast majority of people being within their forecast ranges or very close to them (and people on the edge of a forecast swath shouldn't be surprised if they end up on the adjacent swath), as per the final forecast map, below vs. the actual above.  

On another note, if any Philly folks are reading this, any reports from Center City/South Philly?  A guy I know is claiming he only got 4" in South Philly and that the forecast for Philly was a bust, despite reports from the airport, Fairmount Park and Chestnut Hill showing 6"+.  There had been a preliminary report of 4.5" from South Phillly before the storm was over, but no final report from there or Center City.  

Again, @MGorse- if you weigh in on the above post, maybe you could here, too.  Also always wondered whether the preliminary reports don't end up in the final PNS because somebody simply didn't update their report after the storm was over or do you guys weed out reports you think might not be credible?  

If we do not receive an updated report or final report then that is removed from the PNS. This is because it then becomes less representative. We do our best to quality control all reports but there are times when some slip through. If we catch it later then it is removed. We usually get tons of reports for snow events (overwhelming at times). Also, keep in mind that the airports that measure snow (PHL, ABE, ILG and ACY in our area) continue to measure and report every 6 hours. 

11 hours ago, RU848789 said:

MGorse in the house, thanks!!  Are you still at Mt. Holly?  Had been wondering if the NWS wasn't allowing employees to post on social media or something, since it's been a long time since I saw any NWS mets posting (or maybe I'm not paying enough attention).  

Two other questions if you don't mind.  First, @JERSEYSNOWROBin a thread on this on 33 said he had been told that the ASOS station is at the airport, like you confirmed, but that the snowfall measurements for "Philadelphia Int'l Airport" are taken across the river in National Park NJ.  Is that correct?  

Finally, yesterday, a met showed me how to find the forecast snow/liquid ratio in the point forecast matrices (which list QPF and snowfall, so one can easily do the math for snow ratios).  For yesterday, it was showing 13.8:1 for NYC, while Kuchera was 15:1.  Do you guys have some in-house ratio calculation and more importantly, do the NWS snowfall maps include a correction for ratios (vs. being 10:1 ratio maps)?  Would love to know the answers to these questions.  Thanks!!

I continue to post here from time to time, and yes I am still at NWS Mount Holly. The PHL measurement has not been taken in National Park, NJ in years. It is done at the airport. Airport’s are not the best places to measure snow but they do their best. 

As for snow ratios, we have in-house tools where we can blend different models to get the values desired. WPC also provides guidance on the ratios. Lots of internal collaboration occurs especially with big events like yesterday. We then use tools that take the forecast QPF and apply the selected ratios to give snowfall amounts. This can also account for temperatures as well. So in short, our forecast snowfall does account for ratios. 

6 hours ago, RU848789 said:

Question: I know that Philadelphia International Airport is the climate site of record for Philadelphia County, but I also know that part of the airport is in Philadelphia County and part is in Delaware County - does anyone know if the actual weather station is in Philadelphia County or not?  TIA. 

It is technically in Delaware County. We list it as in Philadelphia County though for continuity plus it represents Philadelphia. 

1 hour ago, RedSky said:

Family member keeps informing me Adam Joseph has 3" for Philly and that's what it will be 

According to his Facebook post a few hours ago, 6ABC has Philly in the 6-12 inch range (highest east into interior south NJ).