phlwx Posted September 4, 2011 Share Posted September 4, 2011 Guys, I cannot stress this enough. Root for the NAM. Root for the NAM with all your might. It must have a sleet pellet in there somewhere. Link to comment Share on other sites More sharing options...
Rib Posted September 4, 2011 Share Posted September 4, 2011 It must have a sleet pellet in there somewhere. You really think it's because of sleet? Okay, the cooler air behind the front on the NAM slightly increases chances from 0% to .000000000000000001%. Link to comment Share on other sites More sharing options...
Grothar Posted September 4, 2011 Share Posted September 4, 2011 You really think that this will be as bad as Agnes? Or was it more sensationalizing the situation? I say this because NWS in BGM, CTP, and PHL don't really talk about the type of catastrophic flooding you are talking about. First of all, I do not think this storm is the day after tomorrow event. I believe this storm mimics Agnes for several reasons 1. The month of August and Irene have brought record amounts of rain to the watersheds that I have mentioned. This happened in May and June for Agnes. The ground continues to be saturated, plain and simple. 2. The current projected storm path of Lee will bring it right over central PA setting up the same type of storm flooding as with Agnes 3. Even though the Qpf indicates less than 7 inches, the soil is much more saturated than with Agnes and the rivers and streams are currently running high. With these conditions, the likelihood of a flood at 7 inches is just as strong at 15 inches as was evident in Agnes in the Pottsville area 4. Lastly, there is one hell of a lot more impervious surface now than was evident in the 1970's. This is a big difference that is not looked at by the hydrologists in our area. They look at the soil conditions and the height of the rivers and streams when determining flood warnings. 5. Storm water control has been lax in all the counties except Lehigh Northampton, Chester, Bucks and Montgomery in PA. The storm water laws and regulations were initiated because of Agnes. The same areas that were affected by Agnes are subjected again to disaster if the floods occur. I am not crier of all doom, just warning the posters that weather history plays a big part in determining what will actually happen. I was around when Agnes hit and believe me it was not pretty. I have seen many disasters in this country and want to use my personal experience to enable those who read my posts to better predict the weather. Link to comment Share on other sites More sharing options...
ptb127 Posted September 4, 2011 Share Posted September 4, 2011 Not all the same areas.. for example, Wilkes Barre is not protected by a levee to 41 feet that would be sufficient to sustain a Agnes 40.71" foot flood. I don't know you from other posters on here only to say that anytime someone brings up a flood that destroyed an entire city almost, it makes me stop and think a second, especially when no other people anywhere are saying it. I appreciate your posts though. First of all, I do not think this storm is the day after tomorrow event. I believe this storm mimics Agnes for several reasons 1. The month of August and Irene have brought record amounts of rain to the watersheds that I have mentioned. This happened in May and June for Agnes. The ground continues to be saturated, plain and simple. 2. The current projected storm path of Lee will bring it right over central PA setting up the same type of storm flooding as with Agnes 3. Even though the Qpf indicates less than 7 inches, the soil is much more saturated than with Agnes and the rivers and streams are currently running high. With these conditions, the likelihood of a flood at 7 inches is just as strong at 15 inches as was evident in Agnes in the Pottsville area 4. Lastly, there is one hell of a lot more impervious surface now than was evident in the 1970's. This is a big difference that is not looked at by the hydrologists in our area. They look at the soil conditions and the height of the rivers and streams when determining flood warnings. 5. Storm water control has been lax in all the counties except Lehigh Northampton, Chester, Bucks and Montgomery in PA. The storm water laws and regulations were initiated because of Agnes. The same areas that were affected by Agnes are subjected again to disaster if the floods occur. I am not crier of all doom, just warning the posters that weather history plays a big part in determining what will actually happen. I was around when Agnes hit and believe me it was not pretty. I have seen many disasters in this country and want to use my personal experience to enable those who read my posts to better predict the weather. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted September 4, 2011 Share Posted September 4, 2011 I don't agree with using a historical storm if the current one is not anything like it in setup. Behavior therefore is likely to end up much different. For example, this is Agnes' path and precip shield: Lee's angle to PA and the time expected to be in the region and synoptic setup are FAR different than Agnes. Agnes was a five day deluge caused by a loop and stall over New York State. I know, I was there in the thick of it in central PA. Just because it has rained here in the last couple weeks and the ground is saturated doesn't make it a good analogy to Agnes. Hell, I can think of several situations that were similar. Link to comment Share on other sites More sharing options...
Harbourton Posted September 4, 2011 Share Posted September 4, 2011 The 0Z Euro has thrown a new wrinkle into the mix by building a small high pressure over us that would deflect most of Lee's moisture away as it connects with the Bermuda High. However, It also sends Katia close to NC and scares the bejesus out of the people vacationing on the Outer Banks. Stay tuned. Link to comment Share on other sites More sharing options...
Voyager Posted September 4, 2011 Share Posted September 4, 2011 Lee's angle to PA and the time expected to be in the region and synoptic setup are FAR different than Agnes. Agnes was a five day deluge caused by a loop and stall over New York State. I know, I was there in the thick of it in central PA. Just because it has rained here in the last couple weeks and the ground is saturated doesn't make it a good analogy to Agnes. Hell, I can think of several situations that were similar. June 2006. Most of the eastern half of PA received over 5", but the Tamaqua area was hardest hit with an 16" deluge that spanned 5 days. The town was evacuated due to fears that the Tuscarora Dam would fail, numerous smaller streams (in the local area) had some pretty epic flooding, and PA 54 from Nesquehoning to Hometown was mess, littered with mud and rocks that washed off the hillside in various spots. Reading back through the history, the lower Susquehanna also had some record stages during that event. With the evacuations (and brief fears of another Johnstown) I didn't really pay attention to other areas, but I'm sure some of the members can relate their stories from that event. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted September 4, 2011 Share Posted September 4, 2011 June 2006. Most of Eastern PA received over 5", but the Tamaqua area was hardest hit with an 16" deluge that spanned 5 days. The town was evacuated due to fears that the Tuscarora Dam would fail, numerous smaller streams (in the local area) had some pretty epic flooding, and PA 54 from Nesquehoning to Hometown was mess, littered with mud and rocks that washed off the hillside in various spots. Reading back through the history, the lower Susquehanna also had some record stages during that event. With the evacuations (and brief fears of another Johnstown) I didn't really pay attention to other areas, but I'm sure some of the members can relate their stories from that event. I remember that. I believe USEDTOBE the Met schooled us on heavy synoptic rain events with that one. I didn't remember that you guys got that much rain. That's a scary amount in Tamaqua given the terrain. Link to comment Share on other sites More sharing options...
Mahantango Posted September 4, 2011 Share Posted September 4, 2011 Yes I remember that well garden destroyed by 2' of creek water nothing surived. June 2006. Most of the eastern half of PA received over 5", but the Tamaqua area was hardest hit with an 16" deluge that spanned 5 days. The town was evacuated due to fears that the Tuscarora Dam would fail, numerous smaller streams (in the local area) had some pretty epic flooding, and PA 54 from Nesquehoning to Hometown was mess, littered with mud and rocks that washed off the hillside in various spots. Reading back through the history, the lower Susquehanna also had some record stages during that event. With the evacuations (and brief fears of another Johnstown) I didn't really pay attention to other areas, but I'm sure some of the members can relate their stories from that event. Link to comment Share on other sites More sharing options...
phlwx Posted September 4, 2011 Share Posted September 4, 2011 The 0Z Euro has thrown a new wrinkle into the mix by building a small high pressure over us that would deflect most of Lee's moisture away as it connects with the Bermuda High. However, It also sends Katia close to NC and scares the bejesus out of the people vacationing on the Outer Banks. Stay tuned. The front still taps into Lee's moisture on the Euro and we get soggy as the front crosses. Lee's lingering surface/500 low is held behind on the Euro as the high is quick to build in. However, the models are in pretty good agreement about a rather rainy Monday PM-Tuesday AM locally...some 2" amounts are possible nearby. Link to comment Share on other sites More sharing options...
Harbourton Posted September 4, 2011 Share Posted September 4, 2011 The front still taps into Lee's moisture on the Euro and we get soggy as the front crosses. Lee's lingering surface/500 low is held behind on the Euro as the high is quick to build in. However, the models are in pretty good agreement about a rather rainy Monday PM-Tuesday AM locally...some 2" amounts are possible nearby. Thanks for the interpretation, but I'll take the two inches and run at this point - better than 5-7" although some models are showing another gulf storm behind Lee that could present a problem down the road. Link to comment Share on other sites More sharing options...
phlwx Posted September 4, 2011 Share Posted September 4, 2011 Thanks for the interpretation, but I'll take the two inches and run at this point - better than 5-7" although some models are showing another gulf storm behind Lee that could present a problem down the road. The 5-7" in one shot went out the window on Friday night when the models shifted to nudge the front south of the region for a time on Tuesday night...this is looking like two punch hit if the GFS is right. The one thing I am somewhat curious about with the Euro placement of Lee is the typical "holding back" bias it has...I wouldn't be surprised if the Euro shifts that 500 energy a bit east and thereby nudges Katia a bit farther out to sea. Link to comment Share on other sites More sharing options...
phlwx Posted September 4, 2011 Share Posted September 4, 2011 For sh*ts and giggles....12z NAM is rolling in and the axis of rain is generally over I-95 for Monday night/Tuesday AM. Storms fire up just north/west in PM...Lee's remnants slug through overnight. Run is only out to 45 so I don't know how much rain but it looks like 2"-3"+ locally if things extrap as they look they do. Link to comment Share on other sites More sharing options...
Rainshadow Posted September 4, 2011 Share Posted September 4, 2011 I don't agree with using a historical storm if the current one is not anything like it in setup. Behavior therefore is likely to end up much different. For example, this is Agnes' path and precip shield: Lee's angle to PA and the time expected to be in the region and synoptic setup are FAR different than Agnes. Agnes was a five day deluge caused by a loop and stall over New York State. I know, I was there in the thick of it in central PA. Just because it has rained here in the last couple weeks and the ground is saturated doesn't make it a good analogy to Agnes. Hell, I can think of several situations that were similar. If we're talking about central PA, the Susquehanna Valley, they were not hit that hard with Irene's rainfall and their flash flood and headwater guidance is in better shape than our's. http://www.erh.noaa.gov/marfc/Events/ That said, the models are still too flippy with the midweek solution, the ones that stalled the front over PA would obviously be more dangerous, but the other solution of a two shot deal because the front clears the area around Tuesday would be easier to handle. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted September 4, 2011 Share Posted September 4, 2011 That said, the models are still too flippy with the midweek solution, the ones that stalled the front over PA would obviously be more dangerous, but the other solution of a two shot deal because the front clears the area around Tuesday would be easier to handle. Tony, What about the models possibly suggesting that Lee's remnants are suppressed south due to a building high over NE? So, a one shot deal as the front heads off the coast, but that one shot deal isn't so bad as only some of Lee gets involved. Link to comment Share on other sites More sharing options...
phlwx Posted September 4, 2011 Share Posted September 4, 2011 NAM in lolland suggests round 2 stays south/east but it finally keeps Lee from going completely back into the Gulf. At least it's no longer fully on crack...just on bath salts. FWIW, I think we'll some "north trend" kick in on the NAM round two starting with the 0z tonight. Link to comment Share on other sites More sharing options...
IsentropicLift Posted September 4, 2011 Share Posted September 4, 2011 The 12z NAM got much much wetter for NJ Link to comment Share on other sites More sharing options...
ptb127 Posted September 4, 2011 Share Posted September 4, 2011 http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=indexℑ=&page=Param&cycle=09%2F04%2F2011+06UTC&rname=PRECIP+PARMS&pname=precip_ptot&pdesc=&model=GFS&area=NAMER&cat=MODEL+GUIDANCE&fcast=6+Day+Loop&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=M 6z GFS total rainfall at 5"+ for E PA. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted September 4, 2011 Share Posted September 4, 2011 http://mag.ncep.noaa...el=&imageSize=M 6z GFS total rainfall at 5"+ for E PA. HPC is shifting south and east for round two Link to comment Share on other sites More sharing options...
Voyager Posted September 4, 2011 Share Posted September 4, 2011 http://mag.ncep.noaa...el=&imageSize=M 6z GFS total rainfall at 5"+ for E PA. Cool map. Anyway, that shows our region getting 5-10 inches of rain. While it probably wouldn't be catastrophic, it would cause some serious to major problems if it were to verify verbatim. Link to comment Share on other sites More sharing options...
Rainshadow Posted September 4, 2011 Share Posted September 4, 2011 Tony, What about the models possibly suggesting that Lee's remnants are suppressed south due to a building high over NE? So, a one shot deal as the front heads off the coast, but that one shot deal isn't so bad as only some of Lee gets involved. I don't know, the medium range modeling has been pretty muddled and inconsistent. My feeling is we (the entire PHI CWA) won't be able to escape round two. Link to comment Share on other sites More sharing options...
Rtd208 Posted September 4, 2011 Share Posted September 4, 2011 Talk about the 12z NAM and GFS being on opposite sides of the planet, the NAM shows 3-5" of rain while the GFS shows 0.75-2.00", quite a difference. Link to comment Share on other sites More sharing options...
Voyager Posted September 4, 2011 Share Posted September 4, 2011 Talk about the 12z NAM and GFS being on opposite sides of the planet, the NAM shows 3-5" of rain while the GFS shows 0.75-2.00", quite a difference. Yup. And the 12z GFS lost most of the high qpf totals northeast of Harrisburg and into New England. Link to comment Share on other sites More sharing options...
tombo82685 Posted September 4, 2011 Author Share Posted September 4, 2011 12z candian is not good, 2 rounds of heavy rain...then we get some affects from katia or katis pushing the front back west and we get another rd later on Link to comment Share on other sites More sharing options...
tombo82685 Posted September 4, 2011 Author Share Posted September 4, 2011 The 12z NAM got much much wetter for NJ it will get wetter to post 84 hrs. Sim radar has another batch of hvy rain coming in Link to comment Share on other sites More sharing options...
tombo82685 Posted September 4, 2011 Author Share Posted September 4, 2011 Talk about the 12z NAM and GFS being on opposite sides of the planet, the NAM shows 3-5" of rain while the GFS shows 0.75-2.00", quite a difference. the nam is going to have big swings between each model run do to the grid its run on, i think its like hydrostatic or something like that. Basically the model is very detailed and can pick up on big changes from run to run. While the gfs is a static model? Tony can correct me on this or one of the nws guys, but the gfs smoothes it out more so that it changes progressively instead of wildly like the nam. Link to comment Share on other sites More sharing options...
Rainshadow Posted September 4, 2011 Share Posted September 4, 2011 the nam is going to have big swings between each model run do to the grid its run on, i think its like hydrostatic or something like that. Basically the model is very detailed and can pick up on big changes from run to run. While the gfs is a static model? Tony can correct me on this or one of the nws guys, but the gfs smoothes it out more so that it changes progressively instead of wildly like the nam. Just reading some of the Lee posts, it looks like the nam is forecasting too much bogus convection around Lee and that has been sending it on a downward spiral rather quickly. Link to comment Share on other sites More sharing options...
mike2010 Posted September 4, 2011 Share Posted September 4, 2011 If we were to nitpick, 18z NAM didn't even pick up the convection near Wilkes Barre / Scranton, PA right now.. 12z GFS kind of did. Talk about the 12z NAM and GFS being on opposite sides of the planet, the NAM shows 3-5" of rain while the GFS shows 0.75-2.00", quite a difference. Regardless, PW values will be high, so the 2.00 QPF from the GFS doesn't really mean much. Many areas will get twice as much this upcoming week. Link to comment Share on other sites More sharing options...
famartin Posted September 4, 2011 Share Posted September 4, 2011 If we were to nitpick, 18z NAM didn't even pick up the convection near Wilkes Barre / Scranton, PA right now.. 18z GFS kind of did. Regardless, PW values will be high, so the 2.00 QPF from the GFS doesn't really mean much. Many areas will get twice as much this upcoming week. You're talking about yesterday's 18Z GFS yes? Today's hasn't started yet. Link to comment Share on other sites More sharing options...
mike2010 Posted September 4, 2011 Share Posted September 4, 2011 You're talking about yesterday's 18Z GFS yes? Today's hasn't started yet. lol, corrected post just before u posted this. (12z I meant) And now after re-checking, the 6 hour 18z NAM actually does show convection...even though 9 hour doesn't. 0-2 in one post.. not good. Link to comment Share on other sites More sharing options...
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