JULY 2012 Severe Weather /Convection Discussion

[SmokeEater]

I feel it was not...not everyone is a hobbiest.....and often when we get a tstorm watch or tornado watch its beaten to a drum on the local news ch...smokeeater was ur local fd put on stand by for storm?

Yup, we get texts whenever a warning is issued for my county, and usually get enough guys to get one or 2 trucks on the air as soon as dispatched. The 24-36 hours that followed was crazy. I'm still trying to catch up on sleep. And we are one of the lucky FD's. Even though we had just as much damage as the area's to my east, all of our residences regained power by 10am this morning.

[TheTrials]

Pretty nice sounding for 18z Wed.

[forkyfork]

saturday's potential is more impressive on the euro and it's ens mean vs the gfs/gfes

[blizzardof09]

Pretty nice sounding for 18z Wed.

we'll see as we get into tommorow how real this threat may be, not getting too excited just yet about

[forkyfork]

our best chances on wednesday are in the morning

[earthlight]

Well, the NAM still has some isolated stuff near the area despite the convection moving through Wednesday morning.

The vort is nice, the timing is bad. The shear isn't great either, but some of the SREF runs today have improved the look. We'll see.

http://www.meteo.psu.edu/~gadomski/NAMSFC4_18z/rad51.gif

[blizzardof09]

Well, the NAM still has some isolated stuff near the area despite the convection moving through Wednesday morning.

The vort is nice, the timing is bad. The shear isn't great either, but some of the SREF runs today have improved the look. We'll see.

http://www.meteo.psu...4_18z/rad51.gif

looks like just some cellular, scattered development and nothing really organized. things can change and have but i dunno just dont think were gonna have the best severe day wednesday.

[forkyfork]

Pretty nice sounding for 18z Wed.

i don't like the height of the lcl

[NickD2011]

Derechoes like last Friday's are climatologically only once in four years in our area. We got screwed for this one, so it's not likely we'll see another one for a while.

[Dsnowx53]

So far this year, it's ironic, depressing and funny to see all the severe cells affect NE NJ and the Hudson Valley then weaken as it approaches Brooklyn, The Bronx and Manhattan. However, once the cells continue east towards Long Island and off the coast of Brooklyn and Queens, they immediately flare up again. Is this pure coincidence and bad luck on my part here in Brooklyn or is there a viable meteorological justification for this? Is it because of seabreeze outflow boundaries or higher convergence mixing ratios on Long Island and off the coast? But at the same time, SST anomalies off the immediate coast around all of the boroughs are at least 3 degrees celsius higher than normal.

Here's part of your answer:

These surface OBS were taken a bit after the storms formed...LI was already getting crushed at this point, but it still illustrates the point. These were at 22z. (6pm)

You can see the sea breeze boundary. It set up over central and northern Queens and Nassau, because the winds were southWEST instead of southeast. When the sea breeze winds are southeast, they can press further west into NJ and converge with the westerly and northwesterly flow to help provide lift for a storm much further west. But since the winds were southwest, they converged with the northwest winds much further east and that was where the convection initiated. (also to note, some of the winds in LI ATTM were northerly, because of the storms that were already hitting. They were previously south or southwesterly almost everywhere near the shore, just like JFK still was at 22z)

Considering how steep the mid level lapse rates were and how warm the boundary layer was, the marine layer didn't really stabilize the atmosphere very much; 84/70 is still very favorable for convection. Also, with the southerly winds in Long Island, that helped provide some directional shear as opposed to just speed shear, helping the updrafts to rotate a bit and strengthen the storms. They then moved east and turned southeast as they strengthened.

SW Nassau and Brooklyn was too far west and southwest. It sucks because I was in Rockville Centre and was excited about the Long Island possibilities for once, compared to most of the tri state. Of course most of LI did cash in, except me.

[Dsnowx53]

Also, the winds in NE NJ were relatively strong out of the NW, which is the same direction that the upper level winds were. This meant that there was pretty little shear as those storms moved east, and thus they weakened when they approached NY and rained themselves out. Not enough separation between updrafts and downdrafts.

[Dsnowx53]

i don't like the height of the lcl

I wish we could somehow get our surface winds to be a bit more southerly for increased moisture and shear...seems like some of SNE might get that based on some of the data, but not us.

[Hailstorm]

Dxsnow: Much thanks to your very detailed analysis. I understand the synoptic setup on that day much better now.

I would also like to point out that Long Island's SBCAPE was at a marginal 1500-2000 KJ during the time the storms hit them. In contrast, NJ's was above 3000 KJ. Further, Long Island's lifted index was between -1 and -3*C prior to the storms, while NYC's was -5. I think that the factors you described above overcompensated for the lack of LI and CAPE.

I really thought that southern Brooklyn and Queens was going to get slammed from that severe cell in NE NJ that was drifting southeast. That NE NJ cell had a 2.0" hail marker with an updraft over 40,000 feet. I also assumed that the seabreeze boundary winds would intensify the storm even more when it approached my area. However, when I saw that cell fizzle out into thin air, I almost got enraged. I haven't seen a severe storm (outside of Tropical Storm Irene) in my area for about 3 years.

And to add insult to my injury, the SPC just poo poo'd on our supposed severe threat on July 4, more or less. Look at their Day 2 outlook.

I apologize if it seems as if I'm rooting for destruction, but I am really not. I am just a fan of all kinds of extreme weather, even -50*F extreme cold! It just makes me envious to see the Mid-Atlantic and Southeast garnering two seperate instances of 1000+ severe reports in just three days while NYC proper only received two this entire summer so far. And both of those were on Staten Island.

[SmokeEater]

Much thanks to your very detailed analysis. I understand the synoptic setup on that day much better now. :)I would also like to point out that Long Island's SBCAPE was at a marginal 1500-2000 KJ during the time the storms hit them. In contrast, NJ's was above 3000 KJ. Further, Long Island's lifted index was between -1 and -3*C prior to the storms, while NYC's was -5. I think that the factors you described above overcompensated for the lack of LI and CAPE. I really thought that southern Brooklyn and Queens was going to get slammed from that severe cell in NE NJ that was drifting southeast. That NE NJ cell had a 2.0" hail marker with an updraft over 40,000 feet. I also assumed that the seabreeze bounday winds would intensify the storm even more when it approached my area. However, when I saw that cell fizzle out into thin air, I almost got enraged. I haven't seen a severe storm (outside of Tropical Storm Irene) in my area for about 3 years. :(And to add insult to my injury, the SPC just poo poo'd on our supposed severe threat on July 4, more or less. Look at their Day 2 outlook. :axe:I apologize if it seems as if I'm rooting for destruction, but I am really not. I am just a fan of all kinds of extreme weather, even -50*F extreme cold! It just makes me envious to see the Mid-Atlantic and Southeast garnering two seperate instances of 1000+ severe reports in just three days while NYC proper only received two this entire summer so far.

[Hailstorm]

Yeah, I admit that I do have a bit of that character in me now. However, I know the hardships you endured this week and I emphasize with you on that note. I hope that no severe t-storm that has any resemblance to the destruction your area received earlier ever happens again in your area.

On the other hand, I just simply want to witness a 74 MPH wind gust or 2-inch size hail that does no damage to my area. I will be satisfied and never complain about the lack of severe storms in my area again if I can have at least one of those weather events this year.

Edit: This post was directed at SmokeEater, to clear up any confusion.

[NEG NAO]

On the other hand, I just simply want to witness a 74 MPH wind gust or 2-inch size hail that does no damage to my area. I will be satisfied and never complain about the lack of severe storms in my area again if I can have at least one of those weather events this year.

Edit: This post was directed at SmokeEater, to clear up any confusion.

We won't be seeing that tomorrow although winds could be gusty - hail is always a wild card and difficult to predict in advance - July 4th is going to be another one of those events similar to what we have seen in the last couple of weeks where we have early showers and storms and then a break and depending on how much cloud cover vs. sunshine we get will determine the amount of convection and the level of severity later in the afternoon and evening - BUT fireworks scheduled for tomorrow evening have a very good chance IMO of going off in most areas because most of the action should be done by about 9 - 9:30 when they start firing them off..............although you will probably hear of some being cancelled in advance - south jersey and long island has the greatest chance of that happening because the second batch should be a line of storms traveling southeast bound with the front.......

[Weathergun]

Dxsnow: Much thanks to your very detailed analysis. I understand the synoptic setup on that day much better now.

I would also like to point out that Long Island's SBCAPE was at a marginal 1500-2000 KJ during the time the storms hit them. In contrast, NJ's was above 3000 KJ. Further, Long Island's lifted index was between -1 and -3*C prior to the storms, while NYC's was -5. I think that the factors you described above overcompensated for the lack of LI and CAPE.

I really thought that southern Brooklyn and Queens was going to get slammed from that severe cell in NE NJ that was drifting southeast. That NE NJ cell had a 2.0" hail marker with an updraft over 40,000 feet. I also assumed that the seabreeze boundary winds would intensify the storm even more when it approached my area. However, when I saw that cell fizzle out into thin air, I almost got enraged. I haven't seen a severe storm (outside of Tropical Storm Irene) in my area for about 3 years.

And to add insult to my injury, the SPC just poo poo'd on our supposed severe threat on July 4, more or less. Look at their Day 2 outlook.

I apologize if it seems as if I'm rooting for destruction, but I am really not. I am just a fan of all kinds of extreme weather, even -50*F extreme cold! It just makes me envious to see the Mid-Atlantic and Southeast garnering two seperate instances of 1000+ severe reports in just three days while NYC proper only received two this entire summer so far. And both of those were on Staten Island.

On Sunday afternoon, I think we just area, between NE NJ and SW CT, where there just wasn't enough support for stronger t-storms. Best MLCAPE was to west. While best shear and convergence, along the sea-breeze front, was to our east.

[IsentropicLift]

I was up to 11 that night......watched and read through thread in mid atlantic region. When i retired for the evening radar showed no evidences of strong storms coming to snj......no watch out or media attention on that area....was shock to see when i woke up that a storm even effected them...not calling anyone out but it was poor nowcasting and crappy lead time....but it happens and thats weather....jakes argument of people being people is also correct...but if one wants to sit here and say forcast was great....thats so far from truth

The watch went out around 10-10:30 that night. I also thought we were too far north down in Atlantic County as the whole MCS appeared to be moving more SE than east, but a very large cell moved eastward from Maryland into DE and then eventually into southern NJ. That was the cell that got me. A band of storms also fired eastward of the main cell around 12:30 or so and that was when it began raining. That lasted about 15 minutes and wasn't too bad, but they did put out a warning at that time. Then we had about a 20 minute break before the main storm began, which was about 1:15-1:20. We lost power around 2:15 and when I went to bed at 3:00 it was still raning a long with a few flashes of lightning.

I have no problem with how Mt. Holly handeled the system, except that when it was very clear it was going to at least rain, they only went with 20% pops and the local forecast from NJ 101.5 FM called for mostly clear skies overnight.

[HM]

As to why people weren't expecting a storm of that magnitude, people will always be people. The warnings emphasized the strength of the storms and while I wasn't in the local area I'm sure there was media coverage. Regardless of the strength of the storm (or even hurricane or snowstorm, for the sake of the argument) you're always going to have people who either don't know it is coming, don't care it is coming, or have a mistrust of warnings/meteorologists.

I disagree. While the warning time was sufficient, I think the real issue is in the forecasting ahead of the time (before the warnings). Until this is better resolved and the information is conveyed appropriately, we cannot say whether or not that would have had an effect on the amount of casualties. But we should go on the assumption that it was a likely an issue, resulting in a percentage of the deaths. Overall, the forecasting Friday was a failure.

it doesn't take more than a half hour to prepare for severe weather

I usually laugh at your posts and see the sarcasm but I think you actually believe this statement. This isn't about preparation as much as it is about conveying properly the potential for something to the public. 13 deaths is a failure.

and for the campers, a watch was issued hours prior to the derecho's impact. why would you not have a wx radio and why wouldn't you put yourself in a safer position?

This is too idealistic. The forecasts that morning had no indication of that potential. Until the forecasts before "show time" improve, I don't think it is fair to say what you are saying here.

[Allsnow]

Thank you hm.....nice write up on it at the phl thread

[Allsnow]

The watch went out around 10-10:30 that night. I also thought we were too far north down in Atlantic County as the whole MCS appeared to be moving more SE than east, but a very large cell moved eastward from Maryland into DE and then eventually into southern NJ. That was the cell that got me. A band of storms also fired eastward of the main cell around 12:30 or so and that was when it began raining. That lasted about 15 minutes and wasn't too bad, but they did put out a warning at that time. Then we had about a 20 minute break before the main storm began, which was about 1:15-1:20. We lost power around 2:15 and when I went to bed at 3:00 it was still raning a long with a few flashes of lightning.

I have no problem with how Mt. Holly handeled the system, except that when it was very clear it was going to at least rain, they only went with 20% pops and the local forecast from NJ 101.5 FM called for mostly clear skies overnight.

Very good assessment...to many here have ties to the nws and will not admit it...yes warnings went out....but it was a equivalent to putting out a winter storm warning for 6-12 at 11pm....and no mention of a flake during the day...perhaps my stands did not come off well

[HM]

Thank you hm.....nice write up on it at the phl thread

I read through the report. I don't think changing the warnings is going to change these bad circumstances. I thought, for example, that Mt. Holly's warnings were exactly how they should be and that is not the issue here.

Let's start by improving our forecasting ahead of time because that is what sucked.

The SPC products on Friday were not sufficient. My post from yesterday:

http://www.americanwx.com/bb/index.php/topic/35100-late-june-2012-storms/page__view__findpost__p__1622471

[LocoAko]

Very good assessment...to many here have ties to the nws and will not admit it...yes warnings went out....but it was a equivalent to putting out a winter storm warning for 6-12 at 11pm....and no mention of a flake during the day...perhaps my stands did not come off well

Who here has secret ties to the NWS?

I don't disagree with HM's post -- the forecast earlier in the day did not properly emphasize the severe weather risk. For the second time, my initial issue was with psv's claim that there was "no time" to prepare. Not "less than ideal", but "no time", which I consider to be histrionics.

[HM]

Who here has secret ties to the NWS?

I don't disagree with HM's post -- the forecast earlier in the day did not properly emphasize the severe weather risk. For the second time, my initial issue was with psv's claim that there was "no time" to prepare. Not "less than ideal", but "no time", which I consider to be histrionics.

Oh okay then it seems like we are on the same page. We can't possibly fault the public, despite our excellent warnings, given the circumstances.

My belief is that we would have increased the percentage of people checking back later in the day had we had some indication earlier in the day for the potential of extreme weather...possibly saving more lives / preventing injuries. For example, if I am going on a camping trip and saw the forecasts Fri AM, I would have thought nothing more after I left that afternoon.

[LocoAko]

And to add insult to my injury, the SPC just poo poo'd on our supposed severe threat on July 4, more or less. Look at their Day 2 outlook.

I apologize if it seems as if I'm rooting for destruction, but I am really not. I am just a fan of all kinds of extreme weather, even -50*F extreme cold! It just makes me envious to see the Mid-Atlantic and Southeast garnering two seperate instances of 1000+ severe reports in just three days while NYC proper only received two this entire summer so far. And both of those were on Staten Island.

I find life is much more enjoyable when you never get excited about severe weather when you live on the water until it on your doorstep. Low expectations breed happiness.

[TheTrials]

important to realize John and Jane Doe along with Suzie and Sam Q dont log onto AmericanWX, nws, etc 10 times a day watching the weather. They get up, eat their coco puffs, watch the morning weather, and a large majority of the time plan their day on what they see hear or read about in the A.M. Maybe they check back in at lunch or catch something on the radio, but even still, from what I am reading, that wouldn't have helped here since the severity and magnitude of the threat really wasn't being called out publicly in lamans terms till much later in the day.

[blizzardof09]

Could not agree with you more trials. The general public takea there generic news stations morning weather reports as pretty much gospel. Your right they dont check NOAA for local hazardous weather updates for there area through the day on whatever source of internet access they can get. The general public just doesnt take threatening weather seriously unless its a hurricane or bigger weather story, not severe weather. If everyone twice a day in there spare time checked there local NOAA hazardous weather outlook there would be a better warning for an impending weather event IMO. Sadly though its just not going to happen with most people.

[Allsnow]

important to realize John and Jane Doe along with Suzie and Sam Q dont log onto AmericanWX, nws, etc 10 times a day watching the weather. They get up, eat their coco puffs, watch the morning weather, and a large majority of the time plan their day on what they see hear or read about in the A.M. Maybe they check back in at lunch or catch something on the radio, but even still, from what I am reading, that wouldn't have helped here since the severity and magnitude of the threat really wasn't being called out publicly in lamans terms till much later in the day.

+1

[mcwx]

I read through the report. I don't think changing the warnings is going to change these bad circumstances. I thought, for example, that Mt. Holly's warnings were exactly how they should be and that is not the issue here.

Let's start by improving our forecasting ahead of time because that is what sucked.

The SPC products on Friday were not sufficient. My post from yesterday:

http://www.americanw...ost__p__1622471

You said that 13 deaths is a failure, I'm not sure how you would convince an 80-year old woman crushed by a tree while sleeping that these weren't what she would think of as run of the mill thunderstorms and that she shouldn't go to sleep at the time she normally would go to sleep. Would stronger language in a warning change her behaviour?

[IsentropicLift]

For those that don't know, NJ 101.5 is a radio station based in NJ and serves mostly central and southern NJ only. At 9:30PM that night the forecast was for mostly clear skies overnight. No mention of rain or thunder at all. Mt. Holly even did a zone update around 11 after the watch had already been in place and they sill went with 20% pops. I think they all believed until the last possible minute that the cells were going to miss to the south. They recorded an 81 MPH gust in Tuckerton, which is in Burlington County. That County wasn't even included in the watch.