wdrag Posted July 11, 2020 Share Posted July 11, 2020 Please see SPC, NWS discussions, any statements, and our own members. Leftover PWAT, relatively strong 500MB (30kt) wind field, modeled CAPE, lightning density, SPC HREF and WPC D1 QPF all suggest pretty decent convection this afternoon dying out by late evening. Combination of convection (expecting several 1.5 to as much as 3" amounts today) and past weeks rains, should more easily permit isolated flash flood. Wind damage, mostly associated with wind and maybe a couple of uproots because of somewhat softer ground. Hail not mentioned but I dont think primary in this leftover tropical environment. Eastern LI seems less likely for SVR/FF this event. 1 Link to comment Share on other sites More sharing options...
wdrag Posted July 11, 2020 Author Share Posted July 11, 2020 I may have been 2-3 hours too soon on this window... but 12z guidance both SPC-3KM NAM and HRRR continue. I may be out of communication until about 1230P. Link to comment Share on other sites More sharing options...
wdrag Posted July 11, 2020 Author Share Posted July 11, 2020 Looks sort of lame so far as far as severe goes... not sure if it will crank up? will check again at 330P. Should be east northeastward moving lines. Link to comment Share on other sites More sharing options...
EJ123 Posted July 11, 2020 Share Posted July 11, 2020 Hearing thunder in Bergenfield NJ. What's the main limiting factor today? Is this too early for initiation? Link to comment Share on other sites More sharing options...
Rtd208 Posted July 11, 2020 Share Posted July 11, 2020 Looks like a decent area of storms have developed in Union, Essex moving into southern Bergen County. Not seeing to much activity south/southwest of that right now though. Link to comment Share on other sites More sharing options...
wdrag Posted July 11, 2020 Author Share Posted July 11, 2020 You all saw this? Mesoscale Precipitation Discussion: #0470 (Issued at 205 PM EDT Sat Jul 11 2020 ) MPD Selection Mesoscale Precipitation Discussion 0470...Corrected NWS Weather Prediction Center College Park MD 205 PM EDT Sat Jul 11 2020 Corrected for end time and removing counties from image Areas affected...Eastern PA, Northern NJ, Southeast Upstate NY and NYC Concerning...Heavy rainfall...Flash flooding possible Valid 111800Z - 120000Z Summary...Showers and thunderstorms developing in a highly unstable environment will become more widespread through the afternoon. Rainfall rates will likely exceed 1"/hr, and may approach 2"/hr at times. Despite rapid storm motion, rainfall of 1-2" with isolated higher amounts is possible. This rain falling on top of saturated soils may produce flash flooding. Discussion...Showers and thunderstorms evident in reflectivity from KDIX WSR-88D are expanding in coverage this afternoon. This expansion is due to intensifying ascent in an increasingly favorable thermodynamic environment. GOES-16 WV imagery indicated a shortwave lifting northward from southern NJ, impinging upon a stationary front analyzed at 15Z extending from a surface low in NW Upstate New York southward to the Chesapeake Bay. Recent GPS observations measured TPW of 1.9-2.1 inches, around 1.5 standard deviations above the climo mean, while RAP analyzed MUCape had climbed to around 2000 J/kg east of the stationary front. As the afternoon progresses, ascent will expand into the moist and unstable environment as the shortwave and front lift east-northeast. This should lead to increasing areal coverage of thunderstorms. With PWs remaining around 2" and MUCape potentially approaching 3000 J/kg, rain rates of more than 1"/hr are likely as noted by high HREF neighborhood probabilities. The limiting factor to flash flooding will be the expected rapid storm motions to the NE as noted by 25-30 kts of 850-300mb mean flow. However, bulk shear of 25 kts and unidirectional shear parallel to the stationary front both pose a threat for some storm organization and short-term training. This suggests that despite the rapid cell motion, rain rates of 1-2"/hr occurring multiple times across the region could produce 1-2" of rainfall with isolated higher amounts, and this is reflected by CAMs simulated reflectivity and 6-hr QPF. FFG here is quite low due to saturated soils from recently departed T.S. Fay. Rainfall of 2-5" occurred Friday, producing compromised FFG that is as low as 0.25"/1hr, with widespread FFG less than 1"/1hr and 1.5"/3hrs. HREF 3-hrly exceedance probabilities climb to near 50%, and NWM streamflow anomalies show several areas of high flow. While flash flooding is not expected to be widespread, these excessive rates, especially if they occur in any urban areas or across the most sensitive FFG, could lead to flash flooding into this evening. Weiss 1 Link to comment Share on other sites More sharing options...
wdrag Posted July 11, 2020 Author Share Posted July 11, 2020 Looks like some sort of flooding will be occurring ne NJ soon. already digital STP .6" and I see some OHP of around 1.2"near Pearl River in extreme se NYS. When it rains, it pours. Link to comment Share on other sites More sharing options...
wdrag Posted July 11, 2020 Author Share Posted July 11, 2020 Here's the 1 hr COUNTY wide FFG. Also FFW posted ne NJ (not attached). Link to comment Share on other sites More sharing options...
HeadInTheClouds Posted July 11, 2020 Share Posted July 11, 2020 Expecting more rain today and this evening up here in mid hudson valley than Fay. Only picked up .5 yesterday. 87/73 right now. Link to comment Share on other sites More sharing options...
Stormlover74 Posted July 11, 2020 Share Posted July 11, 2020 Decent looking storm moving from somerset into union and Middlesex 2 Link to comment Share on other sites More sharing options...
Allsnow Posted July 11, 2020 Share Posted July 11, 2020 16 minutes ago, Stormlover74 said: Decent looking storm moving from somerset into union and Middlesex Pouring here! Link to comment Share on other sites More sharing options...
Santa Claus Posted July 11, 2020 Share Posted July 11, 2020 Impressive cell over me in Piscataway, might've gusted to 50 at one point. The rain is heavier now than probably any point yesterday. Ponding all over the place, we might be at 0.75"? Few CTC rumblers too. 1 Link to comment Share on other sites More sharing options...
Stormlover74 Posted July 11, 2020 Share Posted July 11, 2020 3 minutes ago, Will - Rutgers said: Impressive cell over me in Piscataway, might've gusted to 50 at one point. The rain is heavier now than probably any point yesterday. Ponding all over the place, we might be at 0.75"? Few CTC rumblers too. Not too bad here. Heaviest went to my north and south Link to comment Share on other sites More sharing options...
Rtd208 Posted July 11, 2020 Share Posted July 11, 2020 Warning here for that cell. Link to comment Share on other sites More sharing options...
SI Mailman Posted July 11, 2020 Share Posted July 11, 2020 the deluge has made it to me 1 Link to comment Share on other sites More sharing options...
doncat Posted July 11, 2020 Share Posted July 11, 2020 Did pick up a quick 0.50" from those cells. Link to comment Share on other sites More sharing options...
nycwinter Posted July 11, 2020 Share Posted July 11, 2020 pouring in manhattan no lightning or thunder so far.. Link to comment Share on other sites More sharing options...
Snowlover11 Posted July 11, 2020 Share Posted July 11, 2020 pouring here in yonkers Link to comment Share on other sites More sharing options...
wdrag Posted July 11, 2020 Author Share Posted July 11, 2020 Well...this one is about over. Not a good day for warnable storms. many brief heavy sun showers w rainbows, isolated thunderstorms. Few below severe gusts. Wantage .24" around 545P w a gust 27MPH. A few power outages se NYS. Did not quite live up to marginal risk here in NY forum. Link to comment Share on other sites More sharing options...
Allsnow Posted July 11, 2020 Share Posted July 11, 2020 .54 total Link to comment Share on other sites More sharing options...
PB-99 Posted July 12, 2020 Share Posted July 12, 2020 A nice cell on radar headed towards me. 1 Link to comment Share on other sites More sharing options...
PB-99 Posted July 12, 2020 Share Posted July 12, 2020 Held together nicely. 1 Link to comment Share on other sites More sharing options...
winterwx21 Posted July 12, 2020 Share Posted July 12, 2020 2 hours ago, Will - Rutgers said: Impressive cell over me in Piscataway, might've gusted to 50 at one point. The rain is heavier now than probably any point yesterday. Ponding all over the place, we might be at 0.75"? Few CTC rumblers too. The heaviest part of that cell went a few miles to my south, but we still had a pretty heavy downpour and gusty winds (30 to 35mph). I got 0.44" from it. And another tiny cell came through a little while ago and dropped a quick 0.10". Really glad we finally broke our drought here in Piscataway! Over a half inch today and three quarters of an inch from a t-storm a few days ago, and of course the big 2 and half inches of rain from the tropical storm yesterday. Won't have to water for quite awhile. 3 Link to comment Share on other sites More sharing options...
wdrag Posted July 12, 2020 Author Share Posted July 12, 2020 Unsure what will be reported from the recent warning in se NYS...but thought it would be interesting to post OKX radar, a couple of wundermaps with large 2+ amounts (includes a slight amount of early this morning), verifying OKX radar (yellows 2+") and radarscope digital storm total and verifying the SPC HREF max qpf fcst for today (12z/10, 00z/11, 12z/11-you will see the init times I have reversed order but the idea is there just the same)) Note ne NJ and se NYS, and subsequent verification idea (purple is 1.5+ and red is 3+). This is why WPC and myself use this guidance quite a bit. 845P/11 1 Link to comment Share on other sites More sharing options...
gravitylover Posted July 12, 2020 Share Posted July 12, 2020 That last round of storms came through in a rather dramatic fashion and dropped an inch in a pretty short time. The wind was worse than yesterday, the rain was much heavier and w lost some big tree branches in addition to more garden damage. Uggh 1 Link to comment Share on other sites More sharing options...
JerseyWx Posted July 12, 2020 Share Posted July 12, 2020 Dropping in late, but had a couple of rounds that produced some really good downpours. Link to comment Share on other sites More sharing options...
wdrag Posted July 12, 2020 Author Share Posted July 12, 2020 7 hours ago, gravitylover said: That last round of storms came through in a rather dramatic fashion and dropped an inch in a pretty short time. The wind was worse than yesterday, the rain was much heavier and w lost some big tree branches in addition to more garden damage. Uggh These reports, akin to this, not sure if they're called into the NWS or sent in on a spotter line. This kind of documentation is valuable for NWS (and ourselves) self assessment. I can help get this connected to the right location for their consideration. Good report. Thanks. 1 Link to comment Share on other sites More sharing options...
BxEngine Posted July 12, 2020 Share Posted July 12, 2020 A few blocks near me had pretty impressive wind damage, tops of some trees ripped off, a few large ones completely uprooted which took out a gas main, very localized but wasnt just a run of the mill thunderstorm here. 1 2 1 Link to comment Share on other sites More sharing options...
gravitylover Posted July 12, 2020 Share Posted July 12, 2020 13 hours ago, wdrag said: These reports, akin to this, not sure if they're called into the NWS or sent in on a spotter line. This kind of documentation is valuable for NWS (and ourselves) self assessment. I can help get this connected to the right location for their consideration. Good report. Thanks. I've never called a report in. Since the turn of the century I've hoped that those that need to know follow the forums and the reports we post are seen and utilized. Is that too optimistic? Link to comment Share on other sites More sharing options...
wdrag Posted July 13, 2020 Author Share Posted July 13, 2020 Too optimistic... office's can be tied up in forecast processes, resolving communications difficulties, be it radar, computers etc, answering media, following twitter, messenger, automated data platforms (of which there are many). Now with COVID, not sure how many are in the office to assist (teleworking?). Here's a link which i didn't try, but presume works. You may want to include in the narrative your equipment, exposures for wind...if time and if you feel necessary. I liked to see credible data and sometimes NWS has to initially filter out data that at first glance looks suspect. Any problems, please let me know. Thanks for checking back on this. I recommend this for everyone. Just use the criteria that they give you (pasted below the link - used PHI since it's slightly more compact-note the SVR reports that SPC posts. A large branch can count. https://www.weather.gov/okx/SubmitStormReport Submit Storm Report Submit a Report! Send a Storm Report to NWS Mount Holly Privacy Policy Users can send storm reports via email to the following email address: [email protected] Please provide the following information: Name and/or Skywarn ID Phone number City, county, and state Latitude and longitude (if known) Date and time of the weather event Type and description of weather observed (see the table below) Photographs of measurement and/or damage, if possible The National Weather Service in Mount Holly NJ greatly appreciates the cooperation and dedication of all of our spotters and cooperative weather observers. Tornadoes Flooding Winter Weather Tornado Funnel cloud Wall cloud Persistent rotation Flooding that results in evacuations Water rescues: cars, roofs, or trees Water rapidly rising, or entering homes, not just basements Roads impassable or closed due to high water Small streams or rivers overflowing their banks Moderate coastal flooding, not just nuisance inundation 1”+ snow in 24 hours 1”+ snow in past hour Freezing rain/drizzle Any ice accumulation Thunderstorms Miscellaneous Tree uprooted or downed > 1 large limb downed Power lines downed Hail (any size) Rain > 1” in past hour Winds > 40 MPH Damage to structures Tsunami Any injuries or deaths that are weather related 1 Link to comment Share on other sites More sharing options...
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