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Regarding Sunday the 16th: UK and EC model basically very little rain. The Ensembles from the wet 1"+ GFS, EC (less than 1/4") and NAEFS (showing big variability) have been added with also the WPC operational mesh of all the guidance. No topic for a big rainer, at least not yet. GFS has been shifting southward quite a bit the past several cycles (op and ensembles). 605A/14

Looks like the Friday morning segment JFK-I78 will not happen, at least not more than a few showers at worst. BUST on this last segment of the two day. Regarding Sunday, will post in the August topic since quite bit of uncertainty. 556A/14

GEFS is 1+ and increasing nw of I95, EPS about 0.3" and NAEFS 1/2"+ with lots of variability. Should rain sometime Sunday afternoon-night. Too early for me to get energized when this seemingly benign stuff is so challenging the next 12-15 hours.

Not completely done: I think i found one 4.1" two- day total in Manchester Township NJ, w of Toms River in Ocean County-via wx underground. It had 2.81 for two days but had to correct 1 day down because it baselined too high. Otherwise, I added a map of flood and heavy rain reports from this morning-midday. No overwhelming flooding but the short duration RW+ this morning into midday across the I95 corridor was significant for some of us. I anticipate pin head heavy showers along I95 tonight, but the bigger deal of spotty 1-3" rains should be developing between 2AM and Noon Friday near I78 or just south of I78. Am focused on vicinity JFK-Middlesex-Monmouth to maybe Somerset-Mercer counties for nearly stationary heavy showers developing overnight in a still moist unstable environment with very little steering aloft --driven by model anticipated low level convergence along the s coast of LI (subtle convergence between easterly flow directions into Raritan Bay. Showers probably will be concentrated at the nose of this possible convergence zone. Several models imply some sort of shower activity and knowing what has happened in this summer low top convective environment, it won't surprise me to see a bunch of heavy showers on-going somewhere between I78 and I195 when we get up tomorrow morning. All of this should subside midday Friday. So I could be wrong-my confidence on this occurring is around 60%. Am not planning to extend any heavy convective forecast beyond Noon Friday. 759P/13

Arghhh. activity extreme ne NJ into extreme se NYS and along LI Sound bordering coastal CT running a little north of where I thought there might be some problems from the past two days of posts. That in mind, heavy rains (possible new FFW over urban areas) will occur where they are now at 1135A and possibly advance northward between now and 130PM. Meanwhile, unsure on the remainder of the evolution over NJ/LI but seeing the Ches Bay complex activate south Jersey. How far north does it go? Modeling suggests to central NJ by 4P but uncertainty in a fairly potent heavy rain situation that lacks typical large scale cool season synoptic organization. Enjoy the processes and any reports of 4+ inch rainfall totals from the past 25 hours (started 1130A yesterday), please relay them here. Thanks. Walt 1140A/13

Seems to be calming down at 1030A. Don't know how this evolves this afternoon. Usually different areas of coverage if and where it refires. DCA-Ches Bay complex throwing lots of clouds northeast and that may minimize some of the potential refire up here mid afternoon. From my perspective... wherever it becomes obvious it can heat to 80+ with dew point more than 70 and surface wind convergence, are areas to monitor in NJ/LI. Max so far today seems to be 2.4 near Princeton. No more posts from me for a while til am sure of something. 1038A/13

HRDPS and HRRR 06z, 11z have no clue on what's going on this morning. NAM/RGEM have a sense but ~ 30 MI too far north (probably), UK has an idea but maybe a tough too far south. DIX radar seems to be underestimating rainfall as both digital STP from OKX/DIX.

8AM reports...~0.93 S Amboy earlier this morning and in the past hour many 1-2" reports Mercer County NJ east. Includes 2.24" in the vicinity of Princeton. Checked Rutgers and CoCORAHS. None capture the bigger amounts seen on Wxunderground and radar storm totals as well as NYC CLI sites. Attached early reports from CcCORAHS as of ~8A. These totals would be from 1130A yesterday to 8AM this morning.

Sunday or early Monday (16-17): GFS pretty wet with an organized low pressure system passing through the NYC forum coverage area. Other models much less organized with much less qpf. First we need to process today-Friday's rains.

Good Thursday morning everyone with interest in Heavy Rain, several FF warnings and isolated SVR's for NJ I78 southward and LI. No guarantees. Subtle areas of surface lift will be the drivers the next day or two. Small groups of heavy showers have popped near EWR and se CT since 130 AM. These are along what I see as somewhat defined boundary of drier dew points in extreme nw NJ (Wantage dew point 63 at dawn), se NYS and n CT. This boundary is probably the focus this morning-midday. I expect heavy showers and thunderstorms to become more numerous by 10AM across parts of LI and in NJ I78 region southward into Monmouth County. We'll see how this goes. Plenty of instability is available along this dry-moist boundary along with PWAT 2". Won't take much for intense short duration rainfall. This afternoon, wind shifts further south down in Ocean County to Mercer County will focus heavy convection there where a FF Watch is posted. By the time activity dies out around 9PM this evening 'isolated' 4" rainfall should have occurred. The worst this morning is probably LI with the concentration of heavy convection shifting to mostly central NJ s of I78 during mid afternoon. Friday: Renewed activity is expected by Noon in NJ-LI, but PWAT should be 4 tenths of an inch less so the chance of 4" rainfall diminishes tho is not completely zero. Will try to reevaluate at times today as convection-modeling unfolds. 559A/13

552PM update: reports attached for our area. Once the convection subsides by 10PM, it should retire, in potentially heavier manner between 4AM and Noon Thursday...again mostly NJ/LI but can't rule out brief development into se NYS/CT. IF for some reason this is erroneous, then afternoon convection will occur. It's one or the other but from what I can tell, a significant Thursday morning event is coming. The greatest threat for tiny areas of excessive 4+ inch rain Thursday appears to be the southern edge of the forum up to I78 in NJ and include LI. No surprises if several FFW's are needed for this area and even isolated SVR's. Frontal boundary, WAA in the lower layers with weak wsw steering current and PWAT near 2" leads me to thinking we've a busy Thursday ahead. 558P/12

W LI... Wundermap storm totals... a few if you can read the towns they're near. 320P/12

So far as of 115PM I've found at least two 1+" storm total reports near I195, rainfall RATES of 3-5"/hr (digital and WXUNDERGROUND). I discounted one 4+ report...needs another detailed surroundings check. Offline til 245P. NO SVR verification posted as far as I know as of 110P. 121P/12

Shower activity began developing NYC-PHL (I95 corridor) around 1130-1145A. Wind north in Wantage with dew point 72. 1151A/12

Doesn't look too good to me for se NYS, even Sussex County in extreme nw NJ and most of interior CT. Maybe storms will end up further north? For now, I'd plan on watering vulnerable flowers late today, Thursday, Friday, Saturday before we get our next area wide chance of 1/4 to 2" rain late Sunday-Monday. (parts of our NYC forum had rain early this morning but that's about done til sometime between Noon-3P today).

Since PHI issued a FF watch for much of its area yesterday, and then OKX followed suit this morning for parts of NY metro; have started this topic. Yes, potential exists for Flash Flooding and a few small areas of 4+ inch rains by Noon Friday, but model guidance is not overwhelmingly favorable for our NYC forum area. Northeast NJ, because of its infrastructure, and previous soil moisture condition is most vulnerable. But, best convergence for heavy convection appears to favor I78 southward for the entire period (south of more vulnerable ne NJ), with heavy convection possible further north to FWN-HPN-BDR up there only this afternoon. (for now, it seems se NYS and much of interior CT will miss the big stuff these next several days - keep watering the flowers from time to time). More than adequate CAPE and PWAT exist for heavy rainfall, KI are not pooled excessively in our area so far, but enough exists with a frontal boundary in a fairly light wind flow aloft. SVR: Since winds aloft are light, SVR if any, should be very limited, and probably only the I78 region southward-subject to modeling change. In summary: There should be organization for 1-3, short duration episodes of very heavy rain the next several days, especially in NJ. It seems most of this will be in the southern part of our NY forum area and even though the FF guidance is not as vulnerable in Monmouth, Ocean, Mercer counties--- that may be where the predominant threat for excessive rain is greatest-per WPC's morning excessive rain outlook for today-tonight. 610A/12

fwiw..have seen the 18zNAM with 8+ on e LI by Fri night. Will rereview late tonight and Wed morning and add in the 00z/12 NAEFS qpf which is increasing through Fri. No action at this time on my part. Walt 523P/11

Good Tuesday afternoon everyone, I saw the 1 SVR for the ne NJ coast. Won't surprise at a nice line of vigorous convection drifting into the NYC forum coverage area after midnight and dying out vicinity NYC-LI at dawn Wednesday per the midday HRRR Thereafter, new convection late Wednesday along the front with uncertainty on amounts-placement late Wed-Sat. The very wet GFS op of near 8" here by Monday seems to be far too wet as compared to the 12z/11 UK, GGEM, EC op runs. The GEFS/EPS ensembles are generally ~1" NYC. So, showers and storms are coming, a little bit today, late tonight and more late Wed-Fri or Sat. How much?? For now no topic. I see the heat wave may not make it, even for EWR?? 348P/11

Good Tuesday morning all, No topic from me this morning. Will re-evaluate late this afternoon and beyond but for now... I see isolated strong northeastward moving storms, from I95 northwestward, 2P-10P, some with tiny areas of 1-2" rain, and even one or 2 that might produce a severe weather report but not a widespread event, as far as I can tell. There should be pretty decent band of thunderstorms across central NYS this evening that may die out in se NYS, w CT and extreme nw NJ overnight? Wednesday-Thursday and now via the 06z/11 GFS include Friday into early Saturday. Not enough model consistency for me to as yet, if ever, target topic 4"+ rains and/or more than 2 severe reports. However, not out of the question for parts of the I95 corridor northwestward, but just too early for me to express any confidence. Modeling has become a little timid in it's 00z/11 model cycle (06z/11 GFS differs considerably wetter). Even the SPC HREF, noted for more easily identifying big rainfall, is relatively modest through Wednesday afternoon. I'll probably be off line 8A-2P. 736A/11

Wantage NJ 740'MSL MAX 89 7P 87/73. Maybe we'll get lucky and get the dying remnants of the showers and storms in se NYS and ne PA? Watching these for Ct but expecting all to diminish and end by 10 or 11P. Considering a broad topic of heavy rainers and iso svr/FF Tue aft-FRi but nothing hot right now. UKMET has quite a bit of qpf, as does WPC D1-3. I do see 18z HRDPS seems to have a pretty good handle on what's going on right now (23z/10)...much much better than the HRRR and NAM 3K. Probably my last post of the evening. Rereviewing Tuesday. Walt

89/72 Wantage, dying thunderstorm west of us in PA and 30VIL probably just n of Lords Valley in ne PA near I84 heading for Port Jervis? 355P/10 50Vil n of MPO.has to have hail in it and could be a pretty good gust for no flow. ET under 38K. 410P/10

Few decent sized CU distant e-s of Wantage. Otherwise, no sign of buildups near Wantage - different here than yesterday but maybe something isolated will happen toward the NJ coast later this afternoon? Fwiw...posted on tropical forum and RTD transferred over a loop from Eric Blake using Levi's Trop Tidbits... animation of Atlantic Basin shear changes with MJO passage ~ 8/20. It's modeling and so maybe timing is off slightly but activity changes appear on the way for Atlantic Basin. Normally the Atlantic Basin TC season gets active about that time. 146P/10

Did anyone notice a very recent tweet from Eric Blake? I can't access this on trop tidbits, but credit goes to Eric Blake, also apparently just promoted to Senior Hurricane Forecaster there. After August 20 a big change in shear across the Atlantic Basin. It's an excellent hint at changes to come around the normal time of basin increase. I can delete this post if you wish. Just caught my attention on trop tidbits. I can't move the loop over to this forum but credit Trop Tidbits-Levi and Eric Blake. Really nice illustration of before and after the Madden-Julian Oscillation passage in the Atlantic from the GEFS-parallel. Note the initial high shear (red) in the deep tropics, then the late Aug transition to lower shear (blue) through the first part of Sep @TropicalTidbits @EricBlake12 · 40m Really nice illustration of before and after the Madden-Julian Oscillation passage in the Atlantic from the GEFS-parallel. Note the initial GIF

Good Monday morning, August 10, almost a week after Isaias. Still quite a few in our forum area that are without power-6 days later (attached). I share a tech memo by expert world known research developers (Stan Benjamin and Ed Szoke) with those interested in use of the publicly available HRRRX wind forecast guidance (posts made Tue morning 8/4), especially inside 24 hours. I didn't seek their permission but think they would appreciate spreading their knowledge of this valuable guidance. --from the author's below-- Ed Szoke was also a pretty central author of a NOAA Tech Memo we published a couple of months ago https://rapidrefresh.noaa.gov/Diag-vars-NOAA-TechMemo.pdf On pages 13-14, we described the wind gust potential diagnostic used for the RAP and HRRR models. Ed also added a nice comparison of 4 different fields related to max winds, all of which we see used in different situations. Note: We consider the diagnostic called 'wind gust' is really a 'wind gust potential'. It's NOT a best estimate of an instantaneous wind gust, but instead is an estimate of what may occur. There are lots of users who want to know what might happen with wind gusts. So that variable needs a special asymmetric kind of verification. As Ed wrote in the caption for Fig. 8, for many situations, the 80m wind speed, a clean prognostic variable, is an excellent estimate also for 10m wind gust 'potential' and maybe the best one. Hope some of you will find the Tech Memo useful. 603A/10

Especially NYC, at least for snow, per a private NYS TV met study years ago. Makes sense... If you don't have Dec, you have along days to go to make up. Boston January-March 2015 was an anomaly.