Battle Royale

We are in for a crazy 5-day stretch, with wild temperature swings and gusty winds.

We have the winds now, actually, though this is just an appetizer for what’s to come. Expect strong south winds to keep things mild today and Friday, and then a cold front slowly sweeps thru Saturday. We’ll go from the 70s on Friday to upper 20s and low 30s Saturday night into Sunday morning. Sunday looks very windy to boot, especially across central and northern MD. Wouldn’t be surprised to see a replay of last Monday’s power outages out in these parts.

We follow this with a strong warm front for Monday, just in time for Opening Day. It’ll be windy, but temperatures on Monday will bounce back into the 60s and low 70s. But the potential idyllic baseball day could get ruined still. A strong cold front will sweep thru during the afternoon, setting the stage for afternoon and evening thunderstorms, and some of these could be severe. Hopefully we’ll get the game in.

As if that wasn’t enough fun, models show an even colder air mass blasting into the region Tuesday morning. The latest GFS forecast for Tuesday morning is a bit unsettling, with temperatures well down into the 20s just about everywhere:

GFS surface tempertures Tuesday morning, April 5th.

Tuesday night, the high settles overhead… and our winds are forecast to go calm, setting the stage for yet another hard freeze Wednesday morning. Guess I’ll put the potted hibiscussessesses back into the basement. Damn.

So, we’re talking a freeze Sunday morning, and then a hard freeze Tuesday and Wednesday morning.

Welcome to April!

I Think We’re Good

Good morning, and Happy Spring!

Inre to the Wx for today and the pending coastal low, I think we’re good… most of the heavy pcp will fall to our east and northeast, though we could see a repeat of yesterday with some rain and wet snow this afternoon and evening… enough to once again coat the ground. The only major model out there still offering a “huh” forecast is the UKMET, and that’s not one of the big hitters, so to speak.

If anything changes I’ll let you know.

Inre to our hard freezes… the Monday morning freeze looks less impressive, and we may not get below freezing at all due to lingering clouds and some wind. Tuesday morning will be the primary freeze target, with lows in the upper 20s in the Piedmont, lower 30s along and east of I95… not as cold as previously indicated, but still a hard freeze.

Warm up begins in earnest Wednesday, when 60-degree readings will return.
Talk to you all soon!

E

Keep an Eye On Sunday

Good afternoon,

Wet snow falling in the Piedmont as expected. Nothing too terribly exciting… pretty to look at.

I wanted to let folks know that some models are suddenly coming in with a disturbingly heavy snow event for Sunday and Sunday night as the coastal low develops and intensifies. I’m not ready to issue an “Oh Crap” advisory just yet, but I may end up having to send you all frantic updates this eve and tomorrow if by chance these outlier solutions begin to become the norm.

As it stands now, wet snow this afternoon and evening, accumulations of up to an inch or two on grassy surfaces. Periods of wet snow again tomorrow, but no significant accumulation expected. This may change if the coastal low does what some of the models depict.

E

Weekend – More Precip, But More rain

Looking over the latest forecast data, and a few things are apparent:

1) The pcp will start sooner — and as rain — by early to mid-afternoon on Saturday
2) Saturday night, when we’d have the best chance of seeing snow thx to diurnal cooling, the pcp subsides as the first batch of moisture keeps pushing north
3) A new coastal low develops Sunday and reinvigorates the pcp, which could be heavy at times, but again, the fact that it’s during the day in late March means even if it’s snow, it won’t add to much.

A bit more info…

There are other factors at play, the most notable: We look at the movement of features aloft, typically honing in on temperatures and pressure at a level called “850mb”, which is about ~5,000 feet up in these parts. As an FYI, where the low is located at the surface is not necessarily where it is aloft… and in this case, despite a surface low to our east, the main upper-air low is to our west, over eastern Ohio. That will act to pull in warmer air aloft, and make it even more difficult to get snow, especially during the day on Sunday.

There’s enough against this that I think for most of us, this will be a cold rain and novelty wet nighttime snow event, with maybe a coating to perhaps an inch or two in the Piedmont, but even this only on grassy and elevated surfaces.

There are a few outlier models that show the precip intensifying earlier on Sunday, getting ramped back up during the pre-dawn hours. If this were to happen, then we’d be chatting about 2-4″ of snow on grassy/elevated surfaces before the daylight made snow accumulations virtually impossible. If this were January, I’d be all sorts of pumped; the liquid equivalent in the models is averaging a solid 0.5-1.0″, locally more,,, and that’d be a solid 5-10″ snow in the dead of winter. It’s March… and those snowfall ratios don’t apply.

I’ll keep you updated in case anything changes.

Main Event: GFS v EC

Good morning,

Lots of chatter about snow this weekend… but I’ haven’t been able to do any real looks until this morning, with work and issues outside of work needing my full attention.

As for the weekend, we appear stuck in a pattern where we have record-setting warmth while we are at work/school, and then cold, windy, unsettled weather arrives for the weekend. This weekend will be no different.

Short version: A good bet of cold rain or perhaps wet snow — the latter most likely in the Piedmont and western mountains — Sunday into Sunday night. We could see a coating or so on grassy surfaces, but this is still 3 days away and a low-confidence forecast. There is the potential snow could be heavier (The European), or that we could get just light cold rain (the GFS). It’s too early to pin it down, so if that’s all you need for now, I’d stop there.

Long version: We’ve got all the ingredients for a snow storm, except it’s entering the 3rd week of March. The NAO (North Atlantic Oscillation (a measure of whether or not we have the requisite blocking high over the northern Atlantic (if we have a blocking high, it’s “negative”))) is as negative as it has been since our blizzard… supporting the idea that we’ll have a high to our north and a coastal low this weekend. But the blocking high is not going to stick around… it’s more a transient feature… so the models are handling this weekend’s weather vastly different. If the blocking north Atlantic high were to sit tight for a week, then I’d issue at the very least a Fat Free Milk Advisory, or perhaps even upgrade this to a Toilet Paper Watch. But it’s not… and again, the models are all over the place with how this plays out.

First bowl of porridge, the U.S. GFS model: According to the GFS, it’s a non-event. The blocking high breaks down (not like a nervous break down), and the coastal low scoots out to sea. It’s faster too, with the pcp – cold rain — arriving late Saturday and lingering into Sunday morning. The GFS’ gut-check models, the tweaks and reruns known as Ensembles”, all agree, to the point where it’s hard to just toss the GFS forecast out the window.

Second bowl of porridge, the European: This model, called the “EC” (for “European Community” Model (or the “Burning Bush”, tongue-in-cheek by yours truly)) and the GFS are the two big hitters in medium range (3-5 day) forecasting. And the EC is all about a negative NAO/blocking high and a subsequent strengthening coastal low… and yes, a rare late-March snowstorm… like 4-8″, Sunday afternoon into Sunday night.

Second Bowl, side of cinnamon… the UKMET model: Hard for me to separate this from the EC, as these often say sort of the same things being essentially from the same folks… even though this one is run solely by the UK Met Office. The UKMET model says if you put your snow blower away, get it back out. It’s got the Toilet Paper Watch and a SOB Advisory in effect (Stock up On Booze). Snow, potentially heavy, Sunday evening.

Third bowl, the Canadian model: The CMC usually doesn’t see a potential snowstorm it doesn’t like. That’s why it’s handling of this event is a bit surprising. It’s literally like the 3rd bowl of porridge… not a lot of snow, but not none either (how’s THAT for a double negative!)… it has wet snow in the Piedmont Sunday afternoon and evening, but not a snowstorm. Probably enough to whiten the ground and non-paved surfaces.

Desperate times call for…

The Navy NAVGEM (formerly NOGAPS): We joke that if you are really desperate for input, look at the NAVGEM/NOGAPS. This model is famous for having ominous looking storms that miraculously produce no pcp. But the NAVGEM/NOGAPS is all-in on a snow storm Sunday evening. Esp the latest run (the 06z). Huh.

OK. I’ll keep you posted…. but I’m gonna be touch and go with work and things outside of work.

Take care.
E

Wavelength All Wrong…

Enough of the model data has rolled in… the snow is trending toward the low end…. but there’s still a good shot at a coating to an inch, maybe 2 on grassy surfaces. The lack of a decent snowfall is pointing back to the lack of a western U.S. ridge, which in turn makes and East Coast trof a no-go… which in turn makes snow a no-go, or nearly a no-go. The CONUS is about 1 full wavelength wide atmospherically, so we typically get a ying and yang setup: a ridge/warm over the west and a trof/cold over the east, or vice versa. But with our current pattern, there’s no ridge, so now downstream trof. Fascinating, huh? Aren’t you glad you’re on this list?! If your friends or family tell you we’re going to get 3″ of snow tonight, you can look them right in the eye and say “The wavelength is all wrong. Duhhh….” and roll your eyes and walk away (or duck).

Interestingly, the Saturday clipper has become the more interesting of the two in terms of snow potential, but as with most clippers it’ll not a big or widespread snowfall. Currently appears to be targeting the northern half of MD and srn PA with a coating to a couple inches. Will sort this one out a bit later.

March Snow, But Not a Big Deal

Haven’t been saying much about this pending early-March snow, despite some models at times getting surprisingly jiggy with it. I think wet snow is a good bet this eve, but I will hold to my gut of a coating to an inch or two, primarily on grassy surfaces… with perhaps — if everything breaks just right — some local amounts up to 3″. But I think the vast majority of us will see an inch, maybe less. Curious to see how the morning models play out… and if anything changes I’ll pass it along.

The main thing working against this snow… well, two things, actually… the first being the time of year. But on top of the time of year, the storm is primarily taking a west-to-east storm track, which doesn’t allow it the opportunity to tap into Gulf and Atlantic moisture until it has passed us by. In addition, models show this storm rapidly intensifying as it gets to our east off the coast, which will serve in this case to cause the snow to consolidate offshore, which in turn will cause the pcp to basically shut off in these parts by mid-day. Still could be some commuting issues for early risers tomorrow morning, but by mid-day things should be fine. As a side note, BCPS are already a 1/2-day… so I’m a bit worried they may just pull the plug all together on the kids. Obviously, a delayed opening is not in the cards for BCPS.

For folks that follow this a bit more closely, another little tidbit. Another factor working against a heavy snow is the jet stream “upstream”… to our west. It’s relatively flat, meaning there’s no big northward rise (a ridge)… which in turn keeps it also oriented more or less flat (west-to east) here as well. Our big storms usually involve a jet stream that has a pronounced southward dip (a trof) over the eastern U.S., but in order to get a deep trof you usually need an equally strong ridge in the jet stream over the western U.S. Without that western ridge, it’s a tall order to get a big Nor’easter to form and move up the East Coast.

OK… on top of that, we have a clipper coming through Saturday night. And this may actually end up producing a bit more snow than Thursday night’s event. Still not a big deal… and inch or two, but I’m half expecting the Saturday night snow to end up being more noteworthy, if merely for the reason that it will be hitting at night.

BTW, our parting taste of winter this weekend will be replace by spring-like warmth just in time for the work week!

About this week…

Drought Monitor shift is over… let the drought detox begin…though it really wasn’t too bad this go around. We’ve all got spring fever… so naturally, winter’s not going to let go easily. Models have actually been teasing a snow for this week for quite some time, but given the March sun angle and general overall warmth in the lower 48, I adopted a wait-and-see attitude. I’ve waited and seed it long enough. We may be dealing with a late-season snow event for the end of the week.

I’m not going to get too crazy with the email. Strong cold front will come through on Wednesday, and then… well… it will get colder. Go figure! Hopefully all the stink bugs will bust out of hibernation just in time to get zapped. Anyways, after the cold air settles over the eastern U>S., models show an area of low pressure tracking from the Mississippi Delta to the Virginia/Carolina Coast Thrs night into Friday. How far north/south this thing tracks will — like always — determine what we get and how much.

Early look at the models… the latest Canadian has an impressive snowstorm for the Mid-Atlantic, with notable accumulations extending well into southern PA and “jackpot” in srn MD/nrn VA/DC. The GFS is much lighter… albeit still with accumulations, and it too has a swatch of heavier snow across south-central VA and srn MD. The European (from last night) keeps most of this to our south, with little significant snow accumulation.

I’ll add we are getting to the time of year where in order to get accumulating snow, you almost have to get the snow to fall at night… since the sun still manages to burn thru clouds to some extent and warm the ground. The Canadian has most of the snow falling during the day Friday, while the GFS is a bit faster, with the snow falling Thrs night.

Curse of the Drought Monitor

Been wicked busy with week 1 of the US Drought Monitor (USDM) in the books, and have 1 more week to go. The first week of my USDM shift featured unexpectedly heavy snow (4-9″) south of DC on Monday, and a slow-to-let-go ice event (and subsequent Winter Storm Warning) Tuesday morning over much of the area. On top of that, had the nation-wide Comcast outage on Monday. So, naturally, with me doing the USDM, what else could happen?!

Well, models are teasing up a late-season winter storm for next week. While I’d normally go on and on about this, I’m trying to get some things done to allot me the needed time for USDM work next week. So this’ll be short (and from a tall guy, that’s saying something).

A cold front will come thru Sunday… and while cold air won’t blast in behind it, temperatures will drop steadily during the afternoon and particularly Sunday night.

Monday, the action appears likely to remain to our south along the front as it stalls, though I have some concerns that the pcp may be slow to let go as the front pushes south, or worse yet, may be quick to return as everything turns around and heads back north.

Tuesday and Wednesday… all sorts of craziness in the models, with no 2 solutions the same. The European Model (I am not worthy…) has been remarkably consistent, however, with a coastal low that brings rain and snow back into the region Tuesday afternoon and Tuesday night. It shows the storm transitioning to all-snow Tuesday night into Wednesday.

This is still a-ways off, and I really haven’t had the time to devote to this. Will update you tomorrow, and try and get some more concrete ideas over the upcoming weekend.

Northern Ice

Good morning,

In an “everything evens out” twist, appears the heaviest snow will be south of Baltimore with this one as cold, very dry air over nrn MD has cut into the pcp shield and caused the snow that was falling up this way to dissipate for now. If we had a high to our north, it would be irrelevant (like the blizzard), cos eventually the pcp would get up to nrn MD and probably even intensify. But with no high to our north, by the time the moisture eventually gets here our temperatures aloft will be above freezing, setting the stage for a very unpleasant and potentially hazardous afternoon.

So, in the south, with very cold air and very high snow to liquid ratios, 4 to 8″ a good bet well south of Baltimore. Already got a report of 5″ in Fredericksburg, VA south of DC. Impressive.

As you head north, snow will be less… 2 to 4″ still a good bet in the immediate Baltimore metro before changing to freezing rain in the early afternoon, though it’ll change to plain rain along and east of I-95. Driving will be tricky and ill advised in the afternoon when the freezing rain kicks in.

In nrn MD, I’ll trim back snowfall expectations to 1-3″, with 3″ being a bit of a long shot. What sucks up here is the new look of an extended period of freezing rain. Freezing rain during the late afternoon and continuing until about midnight, when temperatures will finally get above freezing. Driving in the north where there’s been a solid snowpack for a week will be hazardous during the afternoon and evening.

Man, this sucks.

Hopefully this will be it. Seriously. Never thought I’d write that, but I’m ready for spring, I really hate freezing rain. Like more than I hate stinkbugs. Speaking of stinkbugs, it’s been especially gratifying to catch the ones around the house over the past 3 days and toss them out into the frigid cold and onto the snow… Die, you little bastards, Die! Wooo ha ha ha!