OT: Winter Storm Sat Night/Sunday (2/17-18)?
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Did ok with my NWS prediction last night, as the NWS in Philly converted the watches to advisories for 3-5" of snow for the I-95 counties and NW of there (no warnings for Mt. Holly counties), i.e., for Chester/Montco/Bucks, Mercer, Middlesex, the Lehigh Valley, Poconos, Morris, Sussex, and Warren. And the NWS in NYC converted the watches to warnings for 4-7" of snow for Union, Essex, Hudson, Bergen, Passaic, Rockland, Westchester, Bronx, Manhattan, northern Queens, and northern Nassau/Suffolk. Interestingly, the NWS in NYC left watches up for SI, southern NYC and southern Nassau/Suffolk, as they are predicting 4-7" of snow there, but have less confidence in reaching those numbers than in the warning areas, due to mix/rain.
And Philly/Delaware and adjacent SNJ (Salem, Gloucester, Camden and NW Burlington and western Monmouth) all have advisories for roughly 2-3" of snow - these counties are most at risk of getting little to no snow due to mixing/rain and similarly the rain could also hold down accumulations even up to I-95, as some media outlets are predicting (but not the NWS). Still a very close call with marginal temps.
Also, timing moved up by 1-2 hours with precip starting around 5-6 pm, as rain for most, but quickly changing to snow for the areas under advisories/warnings, with evaporational cooling bringing temps from the mid-30s at the start to around 32F by early/mid evening. The bulk of the precip should be over by 1-2 am. Roads will have a tough time accumulating during the first few hours, where it's snowing due to temps in the 34-35F range (near/along 95), but once snowfall rates go up to 3/4" per hour or so (and temps drop to near 32F), snow will accumulate on roads. Maps are up.
Been pretty busy today, so first time I had a little time to review today's 12Z model runs. Pretty much every model is showing at least 3" from Philly to maybe Hazlet to southern LI and some of those models are showing 4-6" along that line. The conensus is also for 4-6" just inland of 95 to 30-40 miles NW of 95. Less consensus for SE of 95 where some models have a sharp cutoff to no snow and others have more gradual cutoffs, with a couple of inches down to the Monmouth/Ocean coast. Having said all that, bust potential is still high, as temps are marginal for snow and some tiny changes turn 4-5" of snow to 2-3" of snow and slop/rain.
Except the GFS, which is still only showing an inch or two for 95 (and 2-4" 15-30 miles NW of 95) and nothing towards the coast. The most bullish models are the Euro and NAM, with both showing 4-8" for the 95 corridor, with the largest amounts just NW of 95. Most of the high resolution mesoscale models are showing pretty good snows, except for the last run of the HRRR, which is only showing 2-3" for most - could just be a hiccup. It's just about time to stop looking at models, anyway, and looking at the radar and reports to our west. Radar is lit up pretty good and the Storm Prediction Center just issued a heavy snow alert for central PA - if that kind of expected performance contines eastward, we'll do well. Should see updated maps and discussions shortly from the NWS.
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Westward ho!Here's earthlight's map (he's John Homenuk) from NY Metro Weather and one of the driving forces behind 33andrain. He might be my favorite pro these days. Explains things very well and is very insightful. It's actually quite similar to the NWS map...
https://www.nymetroweather.com/2018...ted-northeast-tonight-moderate-accumulations/
Let’s hope he’s on the money.
Still pretty warm here in Lambertville...hovering just above 40.
wow the HRRR really cutting back from this mornings runs
Really? You only show the one run of the last 10 that shows reduced snowfall? The next version is just about back where it was before with 3-5" for all of the 95 corridor...
In Philly at a museum with the family. It's still 41 and partly sunny. Forecast to still be 35 at midnight .
Oh god yes. He is exactly that way in person.
Very approachable at the many live events the show does. Or the bars he enjoys at the Jersey shore. He is a natural on radio, solid guy!
I see him a few times a year. Always go to Monmouth Park's Classic Car Show and he is always there.
Well, the NWS-Philly retained all the advisories and warnings from earlier today and didn't change their snowfall map appreciably, with a general 3-5" for the advisory counties along 95 north of Philly and 2-3" amounts for advisory counties SE of 95. The 3" line is still roughly from Philly to Sandy Hook. Similarly, the NWS in NYC retained their advisories for SI/southern NYC/LI and warnings for NE NJ, northern NYC/LI, the lower Hudson Valley and CT and didn't change their snowfall maps appreciably either.
Full speed ahead with the forecasts as is. We'll see if they were being too bullish or not, soon. I think they're going to be pretty close. Could definitely be some sleet in the "battle zone" areas between snow and rain - sleet isn't as pretty as snow, but it's just as impactful. Freezing rain is supposed to be unlikely. Sticking with my 4.5" forecast for my house. Updated maps below. Time to watch the radar, as snow is as close as Allentown to Chester PA and a mix in far SNJ/DE - storm's been performing on target so far, but a big key will be where the best bands set up. Snowfall maps and the map of advisories (blue) and warnings (pink) below.
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So the temperature has been plummeting here: it's now down to 28°.
Yep, I love listening to him on 101.5 when they play music: living large!
This part I don't understand. If the system gets here before it cold enough for snow that should impact totals, no?
Anyway it' just starting to drizzle here. Winds are gusty too. It's 41 degrees.
Beginning of the storm was always supposed to be in the mid/upper 30s and probably rain at least from 95 and SE (36F and cloudy here). The reason why start time doesn't matter much is that the cooling that's expected is actually generated by the storm itself, so that cooling will occur when the storm arrives, whether it's 5 pm or 7 pm. The cooling is a result of evaporational cooling of the column from falling snowflakes that melt and evaporate (saturating and cooling the column).
That cooling will likely get most locations to the mid-30s whether they started at 38 or 40F - and then additional cooling will occur as the storm cranks up and heavier snow falls - as it falls it can dynamically cool the column by bringing some colder air down from aloft, although surface temps may never get below 32F, but that's immaterial as long as snowfall rates are high enough. Sure, for locations pretty far south, initial temps in the mid-40s are going to be hard to overcome, which is why those locations are likely to get all rain.
The evaporational cooling only occurs until the column is saturated and then it stops. The dynamic cooling occurs off and on during the storm as a function of intensity. The third factor in cooling should be when the storm strenghens as it passes to our east, it should produce NE winds, bringing in slightly cooler air. None of these is a guarantee for snow everywhere, though. Philly is right at the battlground as are places along the Delaware to Bordentown and then probably along the SE border of Mercer and Middlesex Counties to about Keyport (that's a bit of a guess, but the battlground between snow and rain will likely not be too far from that line).
My guess is a bigger question may be how much precip we get. If we only get 0.4" vs. 0.7" of liquid equivalent that'll be the difference betwen 3" and 5-6", even if it's all/mostly snow. This is the fun part, where nobody, really, knows exactly what's going to happen - I'll enjoy it no matter what though, as I know we're getting some snow, at least, in the middle of crazy warm days, which is kind of a miracle itself.
I ran into him a couple times at the Culinary Classic Benefit for the Food Bank. Seemed like a friendly guy.
Snowing in Hillsborough. Not sticking to the roads or sidewalks. Heavy snow bands with big flakes reported in a swath in Bridgewater per Channel 4.
22zHRRR was better for i78 and north...would have this wrapping up between 11PM-12AM for most
Same (5:30pm) here on SI.
Haven’t seen anything special in my inbox with regard to this so guess the City thinks it won’t be a big deal.
P-type on radar is displaying as all snow except for the Toms River / Brick areas of Ocean County. That said, it also appears to be largely virga at this time.
all snow here in southern Middlesex. Monroe, near Englishtown, coming down heavy, but not sticking yet.
Mt Holly disco....lets see how far that rain/snow line drifts north later tonight cutting into totals in philly to central jersey
Mid level short wave energy moving up the Ohio River Valley
this afternoon will enhance precipitation rates this evening. A
relatively brief period of moderate to heavy snow is expected
with amounts in much of eastern Pennsylvania, far northeastern
Maryland, northern Delaware and central and northern New Jersey
ranging from 2 to 5 inches. The far upper Delmarva, extreme
southeastern Pennsylvania and the southern part of central New
Jersey should favor the low end of those values.
The guidance has trended a bit warmer with the system than in
previous runs. As we get into the late evening hours, the
rain/snow line may advance well into the Philadelphia
metropolitan area and central New Jersey. We will indicate a
change to rain before the precipitation ends. The rain will cut
into snowfall amounts in parts of those areas.
Due to the expected location of the rain/snow line, our lowest
area of confidence in our snowfall forecast extends from the
upper Delmarva and extreme southeastern Pennsylvania into parts
of southern and central New Jersey.
A mid level short wave trough located over Iowa and vicinity
this afternoon will progress to the east and it should pass
overhead late tonight. The feature will kick the last of the
precipitation out to sea. It appears as though most of the rain
and snow in our region will end by 2 or 3 o`clock in the
morning.
Mid level short wave energy moving up the Ohio River Valley
this afternoon will enhance precipitation rates this evening. A
relatively brief period of moderate to heavy snow is expected
with amounts in much of eastern Pennsylvania, far northeastern
Maryland, northern Delaware and central and northern New Jersey
ranging from 2 to 5 inches. The far upper Delmarva, extreme
southeastern Pennsylvania and the southern part of central New
Jersey should favor the low end of those values.
The guidance has trended a bit warmer with the system than in
previous runs. As we get into the late evening hours, the
rain/snow line may advance well into the Philadelphia
metropolitan area and central New Jersey. We will indicate a
change to rain before the precipitation ends. The rain will cut
into snowfall amounts in parts of those areas.
Due to the expected location of the rain/snow line, our lowest
area of confidence in our snowfall forecast extends from the
upper Delmarva and extreme southeastern Pennsylvania into parts
of southern and central New Jersey.
A mid level short wave trough located over Iowa and vicinity
this afternoon will progress to the east and it should pass
overhead late tonight. The feature will kick the last of the
precipitation out to sea. It appears as though most of the rain
and snow in our region will end by 2 or 3 o`clock in the
morning.
I'm seeing snow now, as well. I ducked out back for a few minutes and it's actually a mix of snow and light rain. The only thing it's sticking to is the pool cover.
Just ripping here and it dropped from 35 to 33F in the last 15 minutes of mod/heavy snow. About 3/8" on the ground in the last 15-20 minutes, easily enough for snow to start accumulating on paved surfaces on our street, as expected.
Roads completely covered now in Metuchen - heavy snow continues with about 1/4 mile visibility. Might have to tape the hoops game to watch this. Yes, I did say that on a sports board, lol. Don't get snow this heavy that often and we can lose on the road anytime.
We used to bust his chops about working on a cookbook. With good reason. He had the last laugh when it sold out in less than 8 months. Proceeds went to the Food Bank.
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