RobbTC Posted May 18, 2011 Share Posted May 18, 2011 From NWS: PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 513 PM EDT WED MAY 18 2011 ...TORNADO CONFIRMED IN NORTHEAST PHILADELPHIA... LOCATION...NEAR THE INTERSECTION OF RED LION ROAD AND NORTHEAST AVENUE IN NORTHEAST PHILADELPHIA, PENNSYLVANIA. DATE...MAY 18, 2011 ESTIMATED TIME...150 PM EDT MAXIMUM EF-SCALE RATING...EF0 ESTIMATED MAXIMUM WIND SPEED...75 MPH MAXIMUM PATH WIDTH...100 FEET PATH LENGTH...300 FEET * FATALITIES...0 * INJURIES...2 * THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO CHANGE PENDING FINAL REVIEW OF THE EVENT(S) AND PUBLICATION IN NWS STORM DATA. ...SUMMARY... THE NATIONAL WEATHER SERVICE HAS CONFIRMED A TORNADO IN NORTHEAST PHILADELPHIA. THIS INFORMATION CAN ALSO BE FOUND ON OUR WEBSITE AT WEATHER.GOV/PHI. FOR REFERENCE...THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE FOLLOWING CATEGORIES: EF0...WIND SPEEDS 65 TO 85 MPH. EF1...WIND SPEEDS 86 TO 110 MPH. EF2...WIND SPEEDS 111 TO 135 MPH. EF3...WIND SPEEDS 136 TO 165 MPH. EF4...WIND SPEEDS 166 TO 200 MPH. EF5...WIND SPEEDS GREATER THAN 200 MPH. Link to comment Share on other sites More sharing options...
RobbTC Posted May 18, 2011 Author Share Posted May 18, 2011 Updated: THE LAST CONFIRMED TORNADO IN PHILADELPHIA OCCURRED LATE IN THE AFTERNOON ON JANUARY 18, 1999. IT WAS AN F0 TORNADO (OLD SCALE) AND IT STRUCK AT MARCONI PLAZA IN SOUTH PHILADELPHIA. A TOTAL OF 18 PEOPLE WERE INJURED. Link to comment Share on other sites More sharing options...
mike2010 Posted May 19, 2011 Share Posted May 19, 2011 Is everybody asleep ? I can't believe this doesn't have a 100 replies yet. maybe another thread ? Link to comment Share on other sites More sharing options...
Engine2211 Posted May 19, 2011 Share Posted May 19, 2011 I was quite shocked when I heard the news this evening. Last think I expected today. But it was so muggy outside this morning I knew thunderstorms were a possibility. Has anyone else noticed that whenever we get that on-shore flow from the southeast like we've had these types of nasty problems pop up. September 2008 tropical storm remnants make their way to the Northeast with an on shore flow and some gusty winds along the coast. In a squall similar to today's Allentown, PA gets hit with a tornado. Back in 2005 (I believe) weak remnants of a tropical depression out in the atlantic come close enough where our area is hit with some scattered showers and storms. An F-0 tornado severely damages the discovery museum in Cherry Hill, NJ. Again, very much like today. Is there something to this? Link to comment Share on other sites More sharing options...
phlwx Posted May 19, 2011 Share Posted May 19, 2011 Is everybody asleep ? I can't believe this doesn't have a 100 replies yet. maybe another thread ? It's not snow. Link to comment Share on other sites More sharing options...
phlwx Posted May 19, 2011 Share Posted May 19, 2011 I was quite shocked when I heard the news this evening. Last think I expected today. But it was so muggy outside this morning I knew thunderstorms were a possibility. Has anyone else noticed that whenever we get that on-shore flow from the southeast like we've had these types of nasty problems pop up. September 2008 tropical storm remnants make their way to the Northeast with an on shore flow and some gusty winds along the coast. In a squall similar to today's Allentown, PA gets hit with a tornado. Back in 2005 (I believe) weak remnants of a tropical depression out in the atlantic come close enough where our area is hit with some scattered showers and storms. An F-0 tornado severely damages the discovery museum in Cherry Hill, NJ. Again, very much like today. Is there something to this? Upper level lows, tropical systems have a bit more "spin" in them...the mid level winds come in at one direction while the surface flow may be different...this can result in a weak twisters spinning up. If you looked at the radar yesterday you had a spiral band moving in and moving NW...almost like a tropical system in that the spiral band is rotating around the low center...the spiral bands can have some weak rotation in them from time to time and tornadoes can spin up quickly within them... The Philly tornado yesterday traveled just 100 yards. Not to trivialize or downplay it but it's almost like a swirling version of a downburst in terms of localized impact and strength...the damage was incredibly localized and nowhere on the scale of the EF-3's that paraded across the South last month. Damage is damage no matter how you slice it though... Link to comment Share on other sites More sharing options...
HurricaneJosh Posted May 19, 2011 Share Posted May 19, 2011 Upper level lows, tropical systems have a bit more "spin" in them...the mid level winds come in at one direction while the surface flow may be different...this can result in a weak twisters spinning up. If you looked at the radar yesterday you had a spiral band moving in and moving NW...almost like a tropical system in that the spiral band is rotating around the low center...the spiral bands can have some weak rotation in them from time to time and tornadoes can spin up quickly within them... The Philly tornado yesterday traveled just 100 yards. Not to trivialize or downplay it but it's almost like a swirling version of a downburst in terms of localized impact and strength...the damage was incredibly localized and nowhere on the scale of the EF-3's that paraded across the South last month. Damage is damage no matter how you slice it though... Yeah, that is about as small-scale as you can get with a tornado, in terms of track length and wind speed. (That's not to take away form it, as it's always interesting when a tornado occurs in a large city.) Did anyone actually see a funnel, by the way? It can't have lasted more than about a minute or so. Link to comment Share on other sites More sharing options...
NaoPos Posted May 19, 2011 Share Posted May 19, 2011 Just surprised at the lack of warning on behalf the NWS, Although it seems to have been rather quick, and thankfully, non lethal. Radar bv's and srv's weren't too impressive yesterday at the time, but i do believe this cell was warned as it got near NE montgo. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted May 19, 2011 Share Posted May 19, 2011 Just surprised at the lack of warning on behalf the NWS, Although it seems to have been rather quick, and thankfully, non lethal. Radar bv's and srv's weren't too impressive yesterday at the time, but i do believe this cell was warned as it got near NE montgo. I'd think it would be exceedingly difficult to formally warn residents Re: such a small, localized event that probably lasted less than a minute. Link to comment Share on other sites More sharing options...
gakmsg Posted May 19, 2011 Share Posted May 19, 2011 Just surprised at the lack of warning on behalf the NWS, Although it seems to have been rather quick, and thankfully, non lethal. Radar bv's and srv's weren't too impressive yesterday at the time, but i do believe this cell was warned as it got near NE montgo. There was a warning when it was still well south of the turnpike.... I called some friends to warn them. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted May 19, 2011 Share Posted May 19, 2011 Just surprised at the lack of warning on behalf the NWS, Although it seems to have been rather quick, and thankfully, non lethal. Radar bv's and srv's weren't too impressive yesterday at the time, but i do believe this cell was warned as it got near NE montgo. A key problem with tornadoes in this part of the country is how fast they form and die, such as this one. The NWS reacted quickly to the velocity scans and did a great job in placing the polygon. I'd think it would be exceedingly difficult to formally warn residents Re: such a small, localized event that probably lasted less than a minute. Yup Link to comment Share on other sites More sharing options...
NaoPos Posted May 19, 2011 Share Posted May 19, 2011 I'd think it would be exceedingly difficult to formally warn residents Re: such a small, localized event that probably lasted less than a minute. I understand that. It's just accountability that I'm pointing out. No mentioning of tornados unless you looked at the spc tor risk (2%) for that day, no one was alert. Granted, I understand a watch may have been overdone, I don't believe I saw any wording in a special wx statement with the possibility of a tor. The poly and wording went up, but after the cell/ line segment produced in a highly populated area. No matter how big or small it was. Bot bashing the nws, I know the occurrence was a rare event. However, I'm sure it's not unprecedented. No one heard a tornado warning, which caught people off gaurd. Is no warning / watch better than having just 1 occurrence? Link to comment Share on other sites More sharing options...
HurricaneJosh Posted May 19, 2011 Share Posted May 19, 2011 I understand that. It's just accountability that I'm pointing out. No mentioning of tornados unless you looked at the spc tor risk (2%) for that day, no one was alert. Granted, I understand a watch may have been overdone, I don't believe I saw any wording in a special wx statement with the possibility of a tor. The poly and wording went up, but after the cell/ line segment produced in a highly populated area. No matter how big or small it was. Bot bashing the nws, I know the occurrence was a rare event. However, I'm sure it's not unprecedented. No one heard a tornado warning, which caught people off gaurd. Is no warning / watch better than having just 1 occurrence? Really tiny, localized tornadoes (like this one) can happen pretty randomly-- so I don't know that it's always possible to see the potential in advance. If a swarm of long-tracking EF3s hit the Philly Metro area with no warning, I could see really questioning what happened and wanting an explanation from the NWS. But for a 60-second eddy like this? Nah. P.S. There are implications to over-warning-- especially warnings with the word "tornado" in them. Link to comment Share on other sites More sharing options...
Quakertown needs snow Posted May 19, 2011 Share Posted May 19, 2011 Saw some folks on the news interviewed that said they saw the tornado. From my captures, 2 from just after and one animation from about 1:43pm... Link to comment Share on other sites More sharing options...
MGorse Posted May 19, 2011 Share Posted May 19, 2011 Just surprised at the lack of warning on behalf the NWS, Although it seems to have been rather quick, and thankfully, non lethal. Radar bv's and srv's weren't too impressive yesterday at the time, but i do believe this cell was warned as it got near NE montgo. I understand that. It's just accountability that I'm pointing out. No mentioning of tornados unless you looked at the spc tor risk (2%) for that day, no one was alert. Granted, I understand a watch may have been overdone, I don't believe I saw any wording in a special wx statement with the possibility of a tor. The poly and wording went up, but after the cell/ line segment produced in a highly populated area. No matter how big or small it was. Bot bashing the nws, I know the occurrence was a rare event. However, I'm sure it's not unprecedented. No one heard a tornado warning, which caught people off gaurd. Is no warning / watch better than having just 1 occurrence? Your second post comes across like you are bashing the NWS. We should chat then after you are in the warning seat. Since I was the warning forecaster yesterday I would like to address your comments. Any tornado that was able to form in yesterday's environment would be rather brief given the wind field (they typically are brief spin-ups in this part of the country). There was a Special Weather Statement issued for that storm however typically one will not mention tornadoes in it. This was a very isolated and brief tornado (weak). I was using the Philadelphia International Airport Terminal Doppler Radar as the beam height at the location of the tornado was between 400-500 feet above the ground, compared to around 2,000 feet above the ground on the NWS Doppler Radar. Also, the terminal radar elevation scans update every minute compared to about 3 minutes on the NWS radar. The NWS radar showed rotation but it was weaker and not gate to gate as the beam height was higher up.This storm was being closely monitored given its reflectivity signature, then it started to develop rotation aloft. The terminal doppler showed the velocity tightening for about 3 scans but only one scan had about 25 knots of gate to gate shear. I saw that and immediately issued the warning. The warning included parts of Northeast Philadelphia, however by this time the touch down already occurred. Again, this all happened in a matter of about one minute. From a warning standpoint, these are very difficult because they develop and then dissipate very quickly. Looking back now, I wish I had issued the warning 3-5 minutes earlier. Link to comment Share on other sites More sharing options...
NaoPos Posted May 19, 2011 Share Posted May 19, 2011 Your second post comes across like you are bashing the NWS. We should chat then after you are in the warning seat. Since I was the warning forecaster yesterday I would like to address your comments. Any tornado that was able to form in yesterday's environment would be rather brief given the wind field (they typically are brief spin-ups in this part of the country). There was a Special Weather Statement issued for that storm however typically one will not mention tornadoes in it. This was a very isolated and brief tornado (weak). I was using the Philadelphia International Airport Terminal Doppler Radar as the beam height at the location of the tornado was between 400-500 feet above the ground, compared to around 2,000 feet above the ground on the NWS Doppler Radar. Also, the terminal radar elevation scans update every minute compared to about 3 minutes on the NWS radar. The NWS radar showed rotation but it was weaker and not gate to gate as the beam height was higher up.This storm was being closely monitored given its reflectivity signature, then it started to develop rotation aloft. The terminal doppler showed the velocity tightening for about 3 scans but only one scan had about 25 knots of gate to gate shear. I saw that and immediately issued the warning. The warning included parts of Northeast Philadelphia, however by this time the touch down already occurred. Again, this all happened in a matter of about one minute. From a warning standpoint, these are very difficult because they develop and then dissipate very quickly. Looking back now, I wish I had issued the warning 3-5 minutes earlier. I apologize if it seems like i was bashing your office. You guys do a superb job. All warnings and outlooks by you and your fellow workers are some of the best in the country. I knew the scans were gonna be a pain to pick up any evidence of circulation. I wasn't questioning the way's in which the warning was issued. I was just wondering why there wasn't the mention of tornado possibility in the SWS ? It would seem reasonable, no matter how unlikely, yet possible, the chance was. Is there anyway reason why tornados, such as these types,aren't mentioned in the wording? Like i had said, i completely understand it was extremely brief and weak. I'm not telling you how to do your job. Your the met here. I'm just asking a question, reviewing the event. Please don't take it as a bash, but more of a learning oppurtunity for me. Link to comment Share on other sites More sharing options...
MGorse Posted May 19, 2011 Share Posted May 19, 2011 I apologize if it seems like i was bashing your office. You guys do a superb job. All warnings and outlooks by you and your fellow workers are some of the best in the country. I knew the scans were gonna be a pain to pick up any evidence of circulation. I wasn't questioning the way's in which the warning was issued. I was just wondering why there wasn't the mention of tornado possibility in the SWS ? It would seem reasonable, no matter how unlikely, yet possible, the chance was. Is there anyway reason why tornados, such as these types,aren't mentioned in the wording? Like i had said, i completely understand it was extremely brief and weak. I'm not telling you how to do your job. Your the met here. I'm just asking a question, reviewing the event. Please don't take it as a bash, but more of a learning oppurtunity for me. If a mention of a tornado possibililty is in a Special Weather Statement (SPS) regarding an ongoing thunderstorm, then technically a tornado warning should be issued. There is a difference between the two products. The majority of times in this part of the country, tornado warnings are doppler radar indicated which means a tornado potential is increasing but no confirmation. I have seen a tornado mention in an SPS as an outlook when the potential is greater and more certain and generally prior to thunderstorms developing. What happened yesterday was tough as it was a very very brief spin-up. Link to comment Share on other sites More sharing options...
phlwx Posted May 19, 2011 Share Posted May 19, 2011 I understand that. It's just accountability that I'm pointing out. No mentioning of tornados unless you looked at the spc tor risk (2%) for that day, no one was alert. Granted, I understand a watch may have been overdone, I don't believe I saw any wording in a special wx statement with the possibility of a tor. The poly and wording went up, but after the cell/ line segment produced in a highly populated area. No matter how big or small it was. Bot bashing the nws, I know the occurrence was a rare event. However, I'm sure it's not unprecedented. No one heard a tornado warning, which caught people off gaurd. Is no warning / watch better than having just 1 occurrence? If this were straight line winds we probably wouldn't be having this thread. This is essentially a microburst/straight line type event in terms of strength and localized impact but because it was cyclonic the "t" word gets tossed around. In these scenarios tornadoes can spin up and drop quickly...and then pop back up into the clouds as quickly as they dropped. A football field length tornado is no different. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted May 20, 2011 Share Posted May 20, 2011 If this were straight line winds we probably wouldn't be having this thread. This is essentially a microburst/straight line type event in terms of strength and localized impact but because it was cyclonic the "t" word gets tossed around. In these scenarios tornadoes can spin up and drop quickly...and then pop back up into the clouds as quickly as they dropped. A football field length tornado is no different. Bingo. This thing was the cheapest, crappiest little tornado-- an event so localized and short-lived it barely deserves the T-word-- essentially a 45-second eddy that lasted long enough to cross a city intersection. How on earth can any agency be expected to warn for random atmospheric junk like that without consistently over-warning in the long-term? I mean, c'mon. Link to comment Share on other sites More sharing options...
Grothar Posted May 20, 2011 Share Posted May 20, 2011 Mike- what is unusual with this tornado is that it is eerily similar to the Allentown Dieruff High School tornado in many ways. With squalls lines from the Atlantic pushing west to the very nature of how tight the damage page path was would make a good case study for any met student. Anyway, I am glad you made the call when you did. Thanks Link to comment Share on other sites More sharing options...
CoastalWx Posted May 20, 2011 Share Posted May 20, 2011 Cool video shown on TWC of this little guy, as it went through. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted May 20, 2011 Share Posted May 20, 2011 Cool video shown on TWC of this little guy, as it went through. You mean those security-cam shots? Yeah, pretty cool-- although I'm not sure I would have guessed it was a tornado. P.S. You going to the conference? Link to comment Share on other sites More sharing options...
RobbTC Posted May 20, 2011 Author Share Posted May 20, 2011 Another nearby one. PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1008 AM EDT FRI MAY 20 2011 ...TORNADO CONFIRMED NEAR CHURCH HILL IN QUEEN ANNES COUNTY MARYLAND... LOCATION...CHURCH HILL IN QUEEN ANNES COUNTY MARYLAND DATE...MAY 19, 2011 ESTIMATED TIME...1215 PM EDT MAXIMUM EF-SCALE RATING...EF0 ESTIMATED MAXIMUM WIND SPEED...65 MPH MAXIMUM PATH WIDTH...50 FEET PATH LENGTH...3 MILES BEGINNING LAT/LON...39.16N 76.06W ENDING LAT/LON...39.18N 76.00W * FATALITIES...0 * INJURIES...0 * THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO CHANGE PENDING FINAL REVIEW OF THE EVENT(S) AND PUBLICATION IN NWS STORM DATA. ...SUMMARY... THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS CONFIRMED A TORNADO NEAR CHURCH HILL IN QUEEN ANNES COUNTY MARYLAND ON MAY 19, 2011. THIS TORNADO BEGAN AS A WATERSPOUT IN THE CHESTER RIVER AND THEN MOVED ONSHORE NEAR RALPHS WHARF. IT CONTINUED MOVING IN A NORTHEASTERLY DIRECTION, CROSSING ROUTE 213 AND THEN LIFTED AROUND 1235 PM, BEFORE CROSSING ROUTE 544. DAMAGE WAS MINOR AND INTERMITTENT WITH THE MOST DAMAGE OCCURRING ON UNION CHURCH ROAD. WEE WOULD LIKE TO THANK THE QUEEN ANNES COUNTY AND KENT COUNTY OFFICES OF EMERGENCY MANAGEMENT FOR THEIR HELP AND ASSISTANCE DURING AND AFTER THIS EVENT. THIS INFORMATION CAN ALSO BE FOUND ON OUR WEBSITE AT WEATHER.GOV/PHI. FOR REFERENCE...THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE FOLLOWING CATEGORIES: EF0...WIND SPEEDS 65 TO 85 MPH. EF1...WIND SPEEDS 86 TO 110 MPH. EF2...WIND SPEEDS 111 TO 135 MPH. EF3...WIND SPEEDS 136 TO 165 MPH. EF4...WIND SPEEDS 166 TO 200 MPH. EF5...WIND SPEEDS GREATER THAN 200 MPH. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted May 20, 2011 Share Posted May 20, 2011 50 ft wide with winds of 65 mph. I would have run up to it! Link to comment Share on other sites More sharing options...
Thunder Road Posted May 20, 2011 Share Posted May 20, 2011 Is there a limit on how small one of these guys can get? I mean how small can a vortex get before it's not even a vortex anymore? Link to comment Share on other sites More sharing options...
Hoosier Posted May 20, 2011 Share Posted May 20, 2011 You mean those security-cam shots? Yeah, pretty cool-- although I'm not sure I would have guessed it was a tornado. P.S. You going to the conference? I only saw the video once but it seemed like there was some swirling motion to the debris. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted May 20, 2011 Share Posted May 20, 2011 I only saw the video once but it seemed like there was some swirling motion to the debris. I saw that, too, but it looked like the kind of swirling that you see at busy city intersections on very windy days. I'm not dissing the tornado, but 65-mph winds rotating over a 50-ft wide area is about as minimal as you can get. Link to comment Share on other sites More sharing options...
MGorse Posted May 21, 2011 Share Posted May 21, 2011 I saw that, too, but it looked like the kind of swirling that you see at busy city intersections on very windy days. I'm not dissing the tornado, but 65-mph winds rotating over a 50-ft wide area is about as minimal as you can get. Well, usually these are the type of tornadoes we get in this area. Link to comment Share on other sites More sharing options...
NaoPos Posted May 21, 2011 Share Posted May 21, 2011 I saw that, too, but it looked like the kind of swirling that you see at busy city intersections on very windy days. I'm not dissing the tornado, but 65-mph winds rotating over a 50-ft wide area is about as minimal as you can get. haha make sure you video it so people can see it and think it' safe to do! ( kind of like that guy that drove his kids into the "non violent" small tornado) Link to comment Share on other sites More sharing options...
SouthernNJ Posted May 22, 2011 Share Posted May 22, 2011 I remember just one occasion when Mt. Holly used a Special Weather Statement mentioning the possibility of a tornado. It was back in May 2002 when a Supercell was moving out of Baltimore and onto the Chesapeake Bay. I was listening to my NOAA Weather Radio when an SPS came up and said "Tornadic thunderstorm heading toward Cecil County". About ten minutes later, a Tornado Warning went up for Cecil County, mentioning that this was "a life-threatening storm". 19 minutes later, a pair of upper-echelon F-1's touched down simultaneously near Earleville and caused damage to numerous structures. In this rare case, the certainty of a tornado was fairly high for around here, so that is why the SPS was used mentioning the possibility of one. I believe Tony Gigi was the one who issued this particular warning, so it was good foresight on his part. Link to comment Share on other sites More sharing options...
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