wdrag

Very good job way in advance nailing wetter than normal first week of August around here. Looks difficult to miss.

Failed forecast for the Max 3-4" range. Only verified about 2.5-2.75 in worst case, that I can find so far in a quick check. Think the rest did okay, timing, axis and glad LI got a pretty good rain. Note the DIX/OKX radar underestimated STP, imo, significantly per CoCoRAHS, RU CLIMATE stations and wx underground reports. Next events already in the other combined tropic. Should be an interesting few days ahead for some of us... water related. Northeast moving SVR a pretty big risk Sunday afternoon with stronger wind aloft, plenty of instability. This may show quite a few more damage reports than what we saw last night. Need to reevaluate with new guidance the next day or 2.

I worry when i put it out there, that some thing it WILL happen. Usually when i put it out there, I think odds are greater than 60% it will happen but have trapped myself too often with too strong a Categorical pontifications (near 100%). I do think we need to be aware of precursor rains, IF indeed Isaias does the coastal hugging as a TS. Bluewave posted on the UL jet anomaly which is a good idea of the potential contributions of the UL jet. Other on here noting the favorable upper air pattern (USA trough-WAR). Also for those using radar rains... I checked OKX and DIX estimates... they were too significantly too low in the east-west axis just below I78 last night. I its safe to say 3/4"-2.75" fell in that band last night (CoCoRAHS, WXUNDERGROUND and RU climate sites). It drains but soil remains a bit moist for whatever happens tomorrow night, then late Sunday svr risk, then the tropics, if its still on NHC track. Let's monitor and look for errors in the thinking. Not the end of the world but a player. Glad I'm not a cruise. 1119A/31

FFG is still high and River Flood ensembles are not amped. Still can see some problems develop if we get decent 1-3 total rains in NJ/se NYS Sunday and then followed by a coastal hugging Isaias track.

Good Friday morning everyone in our NYC forum, Little change from what was posted yesterday. Have used yesterdays as a starter with commented adjustments. It's likely we're going to see significant impact from Isaias. 1) Potential killer Rip Currents Monday-Wednesday for anyone who ventures into the waters s of LI. I'd be wary of swimming, especially non expert surfers/non expert swimmers. The significant undercurrent 1 feet 15 second swell may start arriving this weekend. These surprise swimmers with their energy and are sneaky dangerous. The higher surf just preceding and following the storm (within 18 hours) usually scares off most swimmers. 2) Rainfall as per multiple ensembles and WPC D4-5. Best multiple axis of 6-12 hr 4+ rainfall, to be determined. This on top of the amounts received Friday-Sunday will have to result in pockets of flooding. Where? Ensembles with the east turn (northern shutoff), now further north or non-existent implying less chance for OTS (i just learned that one yesterday). I'll add PRE info for comment in separate post but I think likely for a part of our NY forum Monday or Monday night, then it shifts north and northwest Tuesday as Isaias rolls northeastward. 3) Presuming the NHC 5AM Thursday track is reasonable, surge and wind field risks on the western side of ISAIAS are minimal but if the track shifts to where a portion of our area is on the eastern side of the TC, then those risks would significantly increase. I think eastern LI to the southeast New England coast are vulnerable for at least some of these stormier impacts. Not saying they will occur but my background preparation would include comments to that effect. 4) Isolated 7+" rainfall from the "necessary" combined events of Saturday nights WAA (warm frontal) event, Sunday afternoons probable fairly widespread severe storms, mainly nw NJ/se NYS westward into ne PA, and then finally either a PRE, or a direct impact of Isaias Monday-Tuesday. (maybe the slower 00z/31 EC is correct for early Wednesday but maintaining continuity with NHC). I'm more concerned today about a combined Predecessor Rainfall event and a possible direct ISAIAS impact in our forum. The 7+" rainfall in my estimation would probably have to occur west of the I95 corridor due to the ensembles probable combined Sat night-Sunday afternoon events depositing biggest amounts somewhere near the western edge of our forum coverage (~Sussex-Orange Counties?). If Sat night-Sunday does not occur (1-3" combined event band somewhere in that area), then a PRE or ISAIAS hit would have to do all the work by itself and at this time, this is too uncertain. So to get to 7+", it's a lot easier if we see sizable rainfall Sat night-Sunday. (There is still what I think is a diminishing chance not much happens here next Monday-Tuesday-it's in the envelope of possibilities). Let's see what happens. I'll be particularly interested in PRE comments. I'm adding PRE composites. Where this PRE occurs, IF it occurs, is unknown but my guess based on 00z/31 modeling is between I95 and Williamsport-Burlington Vermont. I'll add a link for the powerpoint. I'll also add modeling for the PRE which occurs in subtle convergence about 12-18 hours prior to the passage of the TC (usually east of the PRE so they don't necessarily overlap QPF events), and we need a decent RRQ of the UL jet (which is modeled to strengthen this coming week) and se inflow at 850MB, for a time. Plenty of PWAT and instability will be available. Looking for comments that this "possiblity" canNOT occur. I'm thinking it will but I don't know where. These 6-12 hour events can be easy 4-8" producers in 6-12 hours. I'm looking for narrow slices of darker or even brightly colored heavier QPF in the modeling 12-24 hours in advance of Isaias in the GFS/EC/GGEM. If we get to 36 hours and it's still possible, then we shift to the NAM and HRRR SPC HREF. I added EC ensemble 24 hr qpf simulation implied PRE in e PA/NJ well ahead of Isaias, and also the IR simulation. It's just a model and it can vanish in the future but this has my attention until it goes away. It's easy to say NO it wont happen but in these situations where it can be a flash flooder, we need to be alert for the possibility. 829A/31 https://www.wpc.ncep.noaa.gov/hmt/seminar_files/PRE_NWS_Teletraining.ppt

Good Friday morning, First glance a little disappointed in max rainfall. So far I find only 2.5" but need further eval. Anyone with more than 2.5" last night, please post. Thanks for adding all those comments on the overnight storms, and the radar imagery. Looks like the modeled R+ and potential SVR track was very good, especially HREF. Looks like general 1/2-2" in that slot, inclusive of LI I78-I195 corridor---definitely a little less than forecast but not all the reports are in yet. Added svr report info. More to post ~845A. 728A/31

Did anyone notice how HOT it may be/feel in NJ Monday if the slower EC is correct? Unsure of whether EC slowness on Isaias is correct? Posting more by 845A

Agreed100%. will update by 830A.

I think we're very close to seeing a rapid increase in convection and subsequent east-northeast development - training near I78. Winds turning nw and soon north, to the north of I78, while hot and humid upper 80s with TD low-mid 70s south of I78 (non marine). A good sign is the remaining pings of small but heavy showers the PA entering se NYS at 745P. In the meantime, not sure what will happen to all that DELMARVA activity, maybe it's own separate entity into the night? This may be pretty interesting between midnight -10AM in the southern part of our NYC forum area-at least for R+/TR+. (I78-LI southward). 750P/30 and possibly my last of the night.

Have seen .88" in ne Sussex County NJ near where digital STP is 1.8", which could have occurred in reality unless hail contaminated?

I think this will occur, big time. look for development between PHL-ABE* around 11-11P and toward NYC from there. All sorts of high dew point air moving northward from the Delmarva along with pressure falls. We've had two or three thunder episodes here. 215P, around 330 and about 520P. Dog barks when outside. Can't see what he hears. Wantage 0.07 so far. Added severe weather so far today in our area... the report in south central CT is a 47MPH wind gust at about 440P.

I'm staying off the EC for now (despite 2 of 3 similar runs the past 3 cycles), but do note a seeming trend to a more robust eastern seaboard-just off the coast solutions. Expert input sought... My guess is that despite cooling SST's as this storm moves north beyond NC, storm intensity may maintain due to pretty strong RRQ of the upper level jet and we should see an expansion of the tropical wind field. That's what I'm looking for. Let me know why this steady state intensity won't happen as the storm passes by LI. (how far east of?) Also: rains tonight, Sat night-Sunday afternoon-eve will be moistening up some of the areas with 3+" storms totals by daybreak Monday (i think). Then do we rely on ISAIAS direct left side heavy rain to douse us, or can ISAIAS pass by to the se of LI but a PRE occurs in the coastal plain with a big 6 hour dump Monday or Tuesday, 18 hrs before ISAIAS passes by?? The PRE is my interest... I still cant buy an eastern LI hit but updated ensembles the next several days can change my mind. For now, I'm hugging the NHC cone to embrace primary surge/wind/wave and primary ISAIAS rainfall. 450P/30

Just letting you know of near 40VIL developed just n part of Wantage NJ since 2PM... so far no warnings. Tha may not last too long. Haent had time to reevaluate but follow local statements and/or warnings. Thanks.

Quick update at 1053A: Too much cirrus today for much if any SVR... still need to monitor CT after 5P. However: Tonight seems destined for some warnings in NJ and possibly LI. FFW in the most vulnerable tracks of 3-4" within 6 hours and I still think 1 or 2 storms overnight with damaging wind and a possible super cell I78 southward. This latter supercell risk, I'll need to recheck at 4P. I've added 1 and 6 hr COUNTY wide threshold FFG for triggering a possible FFW, courtesy of NWS BGM. Do note that the NWS offices have sub basin triggers and can really hone in on specific areas, should the needed rainfall occur. You should be seeing-hearing lightning and dogs barking overnight in parts of NJ and LI with FFW potential late tonight-Friday morning primarily in any heavily paved communities where rainfall exceeds 3".I think that will be between I78-I195 in NJ and probably parts of LI.

Good Thursday morning, Decided to start a combined topic covering Saturday night, Sunday afternoon and the uncertain impact of ISAIAS this coming Monday-Tuesday. ISAIAS has track uncertainties until everything gets re-organized Friday. Thereafter, I think the EPS/GEFS should nail whether or not tropical storm conditions can impact the coasts. Follow NHC guidance and the contributions from American Weather tropical experts. One reason for uncertainty; I see multiple 00z/30 ensembles showing the northern bounds of heavy rainfall not too far north of our NYC forum which suggests, at this distant date, that a hard right turn of ISAIAS could yet occur that would spare us more than a dangerous rip current situation. In other words, we're on the gradient of substantial rainfall impact. Big forecast busts tend to occur in the ensemble gradients, buying in too early to one set of solutions or another. So dangerous rip currents are my first primary concern for Monday-Wednesday, especially Long Island. Southerly swells should gradually build over the western Atlantic into early next week. Presuming the NHC 5AM Thursday track is reasonable, surge and wind field risks on the western side of ISAIAS are minimal but if the track shifts to where a portion of our area is on the eastern side of the TC, then those risks would significantly increase. My secondary primary concern is isolated 7" rainfall from the necessary combined events of Saturday nights WAA (warm frontal) event, Sunday afternoons possible isolated severe nw NJ/se NYS westward into ne PA, and then finally either a PRE, or a direct impact of ISAIAS Monday-Tuesday. I'm more concerned about Predecessor Rainfall event rather than direct ISAIAS impact. The 7" rainfall in my estimation would probably have to occur west of the I95 corridor due to the ensembles probable combined Sat night-Sunday afternoon events depositing biggest amounts somewhere near the western edge of our forum coverage (~Sussex-Orange Counties?). If Sat night-Sunday does not occur (1-3" combined event band somewhere in that area), then a PRE or ISAIAS hit would have to do all the work by itself and at this time, this is far too uncertain. So to get to 7", it's a lot easier if we see sizable rainfall Sat night-Sunday. There is still a chance not much happens here next Monday-Tuesday-it's in the envelope of possibilities. (See the 06z/30 GFS run). Let's see what happens. I'll be particularly interested in PRE comments. 733A/30

Uncertainty is considerable and confidence in any severe storm today is below average. Feel best chance 3P-10P and mainly southern CT. Much greater confidence for an event to monitor late tonight-Friday morning, especially midnight-Noon when the front stalls, surface convergence produces heavy showers and isolated strong thunderstorms in NJ-LI in high PWAT airmass, especially I78 south where 6 hour "isolated 3-4" rains could occur in Ocean, Monmouth or Mercer County. It is s of I78 where a storm may become severe after midnight and a little concerned about a supercell there early Friday. A fair amount of low level shear in a somewhat high CAPE environment is modeled down toward the Jersey shore s of Sandy Hook Friday morning. So not guaranteeing the second paragraph above but a number of models are heading in this direction as of 6AM/30. Meanwhile, some beneficial rainfall is seeming headed for parts of nw NJ, maybe even all of the forum area where storms missed last week.

Hi! I see a couple of showers formed along the NJ shore earlier this afternoon, even sw LI. Congestus looked pretty neat from the back side here in elevated Wantage of extreme nw NJ. I don't have much time to post today and so nothing new til tomorrow morning. Differences in GFS/EC for tomorrow night should iron out on the 00z/30 cycle. Am thinking continuity on this mornings post and mulling over how to topic the following.. Thu aftn-Fri morning SVR potential s CT/se NYS Thu afternoon-evening, then quite a bit of rain for at least e LI tomorrow night and Fri morning. Sat night-early Sunday: WAA slug of heavy showers. Sun afternoon: potential for svr into extreme nw NJ? Monday-Tuesday: Tropical rains and a possible PRE? Am thinking lump Thu-Sunday as one topic with potentially 4 different events... and Monday-Tuesday as the tropical topic locally featured unless there is a major change in 00z/30 EPS/GEFS and associated tracks of the as yet named storm (410P). Looks like an eastern seaboard pockets of excessive rainfall event. Didn't yet buy into the EC op gusts/850 winds for our area. Too-too much can wrong 5-6 days in advance. Modeling does underscore some of the potential, especially qpf. Back after 9P Walt 410P/20

Winter for me tends to be easier, with the R/S line. EC handles extra tropical cyclone development very well... in my opinion it lags the GFS in convection. For me, that means summer is more problematic-narrow channels of big stuff.

Modeling has improved dramatically since I was a kid (1950s). Still, there are times when vast differences occur. Easy out is no action-and probably more often than not, nothing much happens. I like your suggestion on the Euro. We should have a better feel by 3P. Did see the 12z HRRR is trying to develop e-w band of convection across se NYS-southern New England (SNE) by 18z Thursday. SPC seems to be onto something in their early morning D2 outlook.

Good observations and agree 100% on deep well...we also have a 400 footer...sooner or later that pump will die and pay the price, if we want to live. This event was a basic dud but at least I realized the uncertainty. The future event(s) of the next 7 days look more promising.

Good Wednesday morning, Some of our forum participants have had enough of recharge by Wednesday afternoon August 5. Lot's of possibilities ahead, but which will produce? HEAT WAVE to continue 2 more days non-marine influenced regions..lower Hudson Valley and near NYC, and especially our non hilly NJ coverage area (Wantage only 87 yesterday). Today-tonight: No topic even if an isolated svr thunderstorm slides and dies out into se NYS/w CT portion of the forum at night. Saw some modeling for afternoon showers LI with minor CAPE today. Thursday night Friday morning: Terribly different modeling between the EC GFS---CAPE about 2000J different. EC with 3000+J of CAPE on LI 06z Friday. No wonder it's yielding hefty rains portions of the forum inclusive of LI/S CT. Also noted a substantial westerly jet core to our ne near or just s of Nova Scotia. UK is starting to throw some small bullseyes up here and even the GGEM has a hint. I may let this slide as a topic unless I see 4" potential and/or svr. Big CAPE can be dangerous. SPC has a MARGINAL Risk for a portion of the forum Thursday. PWAT per the EC is quite substantial so worthy of monitoring but no topic for now...uncertainty but am pretty sure it rains and some spots it rains hard (LI/CT best for now). Saturday night Sunday morning: WAA and it looks like potential for some pretty big shower/thunderstorm producers...this might be more NYC west across NJ/se NYS. Finally whatever any tropical connection...still looks like a favorable situation for increased moisture from the tropical system and a favorable jet structure to permit a band of excessive rainfall. Will future modeling hold for an as yet named storm? WPC has 1.5-3" up here Monday-Tuesday if I read their early morning guidance correctly. Summarizing: no new topics from me this morning. Eyeing Thursday night-Friday, and then a combined Sat night-Monday-Tuesday dual event topic. Need more time to see if it's worthy. 652A/29

Yes...we here in Wantage of nw NJ have been pretty dry since ~Fay. Past two weeks 1/4". Bummer. Misses with big rain last week (2.5" around Port Jervis) and between I80-I78 in NJ-PA. Today wasn't looking too good for the past couple of days, especially se NYS. Lot's of target watering and having to be careful with the well pump.

Agreed on done for the front end aft-early eve, probably the back end too except maybe e LI. Walt

Good Tuesday morning everyone, Posted a topic for today-tonight but only as a cover... just not an ideal SVR day. However, looking beyond, I see the possibilities for more topics-but wont start them til closer. In particular...Thursday afternoon-night-early Friday looks of interest to me with much much greater CAPE nearby (LI southward), decent flow aloft, a front and some pretty good KI. This could be isolated SVR, but from my view...a bigger chance for a FF event somewhere in our area...particularly, as of this writing, CT/LI. Just need to get to Wednesday for a reevaluation. Sunday-Monday: Already large QPF by WPC. Modeling has been consistent for several days on a ne USA event but location varies. No thoughts yet on most likely scenarios. Thereafter, the tropics for Tue-Wed, and whatever connection. That too looks of interest to me, not for any direct hit by any storm that may develop, but influence on a secondary inland band (a 6-12 hour band of heavy convection), in part associated with marginal inflow from the tropics/a surface convergence zone and clearly a RRQ quad of a strengthening upper level jet over New England/se Canada and adjacent waters. Whether this comes to pass, is very uncertain but it's what I've been seeing in some of the MODELED suggestions including QPF bands and wind fields aloft. This could fold if nothing forms in the Atlantic Basin the next couple of days, which would mean jet structures would change and be less favorable. Just need to wait it out. 90+... may break se NYS-nw NJ-CT today due to clouds/showers, but resume Wednesday-Thursday, while parts of NJ/NYC area have a decent chance of continuing 90+ today, Wednesday-Thursday. HI may be greatest today on LI and I80 south of 100-104 before cloud cover/showers. 626A/28

Topic posted as a cover for the possibilities but this, as of 611AM Tuesday does not look like w widespread SVR or FF event. Please see SPC D1 Marginal Risk and followup's, as well as local NWS discussions, statements and any warnings plus our own American Weather interpretations and observations of any significant storms. Enough CAPE/KI/marginal wind aloft for a couple of clusters of strong storms. Don't like the 850 westerly flow for lots of svr, and the trough appears too close for too much SVR organization. Best chance for se NYS-nw NJ, 1P-7P. Best for s CT/LI/NYC, ne NJ and s of I80 later...3P-9P, then again midnight-5AM. This secondary late night increase is when it may be most favorable for an outbreak of heavy convection and several hours of training with embedded isolated SVR/FF and estimating best location IF this is to occur, would be anywhere on Long Island overnight. (noting several models with much increased convections overnight but mostly s NJ eastward. Could be more interesting up here on LI near the leftover boundary). I wont be updating anything on this topic between 8A-330P. Hope this produces something of interest.