RU848789

A little ominous...SPC just issued a mesoscale discussion stating that severe weather watches are likely for our area for this afternoon/evening. Mesoscale Discussion 2042 NWS Storm Prediction Center Norman OK 1056 AM CDT Sat Sep 06 2025 Areas affected...Parts of New England into the northern Mid Atlantic Concerning...Severe potential...Watch likely Valid 061556Z - 061730Z Probability of Watch Issuance...80 percent SUMMARY...Strong to severe storm development is possible by early afternoon. Issuance of one or more watches is likely. DISCUSSION...Filtered heating is ongoing late this morning from parts of NJ/eastern PA into parts of New England, to the east of a substantial cloud shield and embedded weak convection. Morning soundings depict generally poor midlevel lapse rates, but relatively rich low-level moisture (with dewpoints in the 60s to near 70 F) and continued heating will result in MLCAPE increasing to the 1000-1500 J/kg range. Scattered surface-based storm development is expected as soon as early afternoon, as a cold front begins to impinge upon this destabilizing environment. Deep-layer shear is already rather strong across the region, and will continue to increase in response to a notable mid/upper-level shortwave trough approaching the lower Great Lakes region. Initial development may quickly evolve into a few supercells, though deep-layer flow/shear roughly parallel to the front may eventually result in a tendency toward storm clustering and possible QLCS development. Some increase in low-level shear/SRH with time could support a tornado threat with any discrete or embedded supercells, especially where surface winds remain locally backed near a weak surface wave that will traverse the front this afternoon. Isolated hail may also occur with any supercells. Otherwise, scattered damaging wind will become increasingly possible with time, as storm coverage increases and low-level lapse rates steepen. One or more watches will likely be issued by early afternoon in order to cover these threats. https://x.com/NWSSPC/status/1964357439077200126

Yeah, our key time, a few miles south of Philly is 4-5 pm when the outdoor ceremony was planned (after that it's all indoors) and while the HRRR is showing precip holding off down here (and for 95 up through CNJ) until about 6 pm, the 12Z NAM and RGEM, so far, are showing at least 0.1-0.2" from 2-5 pm (presumably mostly closer to 5 pm), which would be a mess for an outdoor wedding that ends at 5 pm. Tough call, but we've already decided to move the ceremony indoors, which has the bonus of getting a bunch of people over 55 out of the heat and humidity. Thanks, as always, for your expertise.

Most of the 0Z and 6Z models have 0.2-0.5" of rain from 2-8 pm today for most of the Philly-NJ-NYC region (when we're both interested for the RU game and my son's wedding), but many have lollipops of 1" or more, so as usual it all depends on where the heavy downpours hit - won't be everywhere, but they'll likely be fairly widespread. Most of the models also have 1/2" or more after 8 pm. Below is the WPC rainfall forecast through 7 am Sunday.

NWS has up to 1", but obviously this can vary depending on strength/location of storms. We're almost certainly going to move our son's wedding ceremony (4-5 pm roughly) indoors in SNJ (about 5 miles south of center city Philly), since we have to make that decision essentially now. NWS graphic below. The one thing that makes me wonder, though, is the HRRR is consistently not showing any rain in this area before about 6 pm, but the HRRR is often wrong. The rest of the models from 6Z are all showing some showers between 2-5 pm and after that too.

Well, as can happen, it's now looking like a 1-day heatwave on Saturday with highs in the Philly area in the upper 80s with dewpoints in the upper 60s, so definitely summery, plus potential showers and t-storms just in time for our son's 4:30 pm wedding ceremony, which is planned to be outdoors (there is an indoor fallback). Too bad he didn't pick Sunday like I recommended a year ago to avoid the conflict with the RU game on Saturday, lol. As expected 4 days out the models are all over the place with regard to timing/location of storms and the NWS just has the usual chance of showers due to instability surrounding the frontal progression. Might be one of those "watch the radar and the sky" afternoons. Any insights appreciated, thanks.

Walt (or others) - would be interested in your take on 9/6 in the SNJ area adjacent to Philly, as our son is getting married there that day and hoping to do an outdoor ceremony (it's at a working farm) followed by an "upscale barn" reception. Not too worried about rain, as there is an enclosed space next to the barn if it rains, but would love it to not be hot and humid. Right now the 6-10 day and 8-14 day CPC forecasts look like normal to maybe a bit below normal in temps, but normal to above normal in precip. Obviously, those aren't predictions for a specific day, but I am happy to see no major heatwaves on the horizon and the last few deterministic model runs (GFS/Euor/CMC at least) show some significant rainfall on 9/4-5 clearing out for 9/6 with seasonable or below temps, but 9 days out we all know that that timing can change, but all things being equal, I'll take it for now. TIA.

Wow, tsunami warnings are up for most of the "Ring of Fire" around the Pacific, from a magnitude 8.8 earthquake about an hour ago off the coast of Kamchatka, Russia. It is feared that this could generate tsunami waves of up to 10 feet in parts of nearby Japan and Russia and perhaps several feet in places like Hawaii and elsewhere - even the US West Coast and Alaska are under tsunami alerts. This was a very powerful earthquake and, unfortunately, tsunami predictions aren't particularly accurate. Back in 2004, people in Indonesia certainly didn't expect the 150 foot tsunami that killed hundreds of thousands from a 9.2 magnitude earthquake; similarly in 2011, parts of Japan didn't expect tsunami waves of 50-100+ feet from a 9.0 earthquake (including at the Fukushima nuclear reactor, where 50' waves inundated and destroyed the facility, leading to partial reactor meltdowns and release of radioactivity). Hopefully people at risk are taking this seriously. https://www.ksl.com/.../87-magnitude-earthquake-in...

Got about 3" in the first ~90 minutes and about 4" overall, here in Metuchen, despite the radar showing only 2.5-3.0".

We're hosting an event on Sunday afternoon June 1st that we hope can be outdoors in our backyard (but is small enough to move inside our house if the weather is bad, but outdoors would be nicer). Euro and Euro-AI show the period from Saturday night through Monday morning being dry, while the GFS shows it mostly dry with just a few spritzes possible on Sunday - I know it's a long way out, but it's at least nice to have the models largely on our side at this point. I rarely ever look at the weather beyond 7-8 days, outside of general patterns (CPC 8-14 day forecast shows generally normal temps and precip for the period around 6/1), since specific forecasts are usually pretty inaccurate that far out, but I'm following this one on a couple of the long range "forecasts" just out of curiosity. Was interesting to see both the AccuWeather and MyWeather forecasts were showing some rain on Sunday for the last several days, until yesterday, when both switched to mostly sunny/dry forecasts with seasonable temps (highs near 80F) - and today they still show that. I've tracked a few other events this far out and the forecasts and models flip-flopped a ton from 10-15 days out, but sometimes they'll show consistent solutions, especially from about 10-11 days in. Hoping this is one of those cases. Comments welcome.

Do people think this looks right? Seems overdone for me, especially at lower elevations...

It has some snow for areas mostly N of 80 on 4/8 in the map below; it also has some more snow on 4/12 for areas N of 84 and then even more on 4/18 for the Catskills/Berkshires and north. Assuming you want the first one that gives you a bit of snow.

Agree on all counts, hence my "lol." The only thing that gives at least a little credence that we could have a bit of snow in some places around then is the CPC's forecast for that period to be well below normal in temp.

Only 11 days out and it's not the GFS, lol...

Another virtual monster snowstorm on the 6Z GFS on 4/3. That's about 48" from the GFS over the last 2-3 weeks, lol. At least for this one the AIFS is showing 1-2" NW of 95, which could be plausible.