The Department of Meteorology and Atmospheric Science at Penn State.

This is Weather World.

Hello everyone, and welcome to Weather World on this Friday the 13th.

I'm Rob Lydick joined alongside by Marissa Ferger.

With the forecast tonight and some bad luck out there with winds eventually going to be whipping tonight.

Yeah, they're already whipping across western Pennsylvania and they'll move into eastern PA by the time we get to later this evening.

So it's going to be a rough night in terms of wind.

But tomorrow looking like a pretty decent day across the region.

Okay, we'll get the weekend forecast details in just a minute.

Also coming up on tonight's show, it's our Friday forecast frenzy.

So we'll have the extended forecast taking us through next week.

And then Giannis will go into the final full week of March in week two trends.

But first here's Marissa and those winds today bringing in some warmer air.

But this morning it certainly didn't feel like it if you stepped outside everywhere we were at or below freezing across the northern tier, dipping down into the teens, many places in the lower 20s.

But as we started having those southerly winds come into the region that really pumped in some warmer air, already getting into the 50s across parts of southwestern Pennsylvania, moving into the 30s and 40s across northeastern PA.

But we will cool off a little bit across parts of the region tomorrow, as we do have a weak cold front that's going to move through tonight, but it certainly won't be as cold as we saw yesterday.

Now, along with the warm front that moved through today, there were a few showers.

Many of these didn't hit the ground, but we had a few light snow showers across northeastern Pennsylvania.

And we have some showers now across northwestern PA.

And as those are moving through, it's actually bringing some very gusty winds to that region.

And we'll continue to see those move through this evening.

And then as we go through the overnight hours, we will begin to clear out, check out these winds.

There was a 64 mile per hour wind gust in Erie as that shower moved through.

We continue to see these very high winds, and we'll continue to see these as we go through the overnight hours.

And if we zoom out on a wider scale here, you can see that the winds were whipping very high.

Out in Ohio, there was an 84 mile per hour wind gusts reported earlier today in Muncie, Indiana.

So these winds mean business.

And they'll be whipping through tonight and into parts of tomorrow.

They're going to fade from west to east as we go throughout the day tomorrow.

But they are a southerly wind.

So that's ushering in warmer air.

So compared to this time yesterday, we're about 15 degrees warmer across western Pennsylvania and anywhere between 5 to 10 degrees warmer across central and eastern Pennsylvania.

So it is warming things up as that system moves through.

And it's doing so from Texas all the way into the Mid-Atlantic cooler air really funneling into the Northern Plains.

It won't get that cold here in Pennsylvania.

That's where temperatures right now are in the 20s and 30s.

We're sitting close to the 50s across the Ohio Valley.

And again, we're not going to tap into the really cold air as we go through this weekend.

Temperatures will actually be rather comfortable for this time of the year.

So here's this clipper system that's moving through.

And that's going to be ushering in the windy conditions as well.

And then we'll get a reprieve in the action as we go through the day tomorrow.

I'll explain that here on the surface maps.

Here's that clipper moving through the Great Lakes tonight.

Notice the tightly packed isobars.

That's what's causing all the strong winds.

And that will continue as we go through the overnight hours.

They will damper a little bit as we go through the day.

West to east tomorrow.

And then by tomorrow evening, a little break in the action.

But then here's this next system that you see here in the plains that's actually going to push into Pennsylvania by the time we get to Sunday evening.

And look at all these tightly packed isobars, more strong southerly winds moving into the region as we go into the day on Sunday, bringing precipitation late in the day.

So I think it will be a dry day on Sunday for most, but it will be quite windy once again and wind advisories are in effect for a big part of the state, at least central and eastern Pennsylvania.

Those go through early tomorrow morning and even into the latter part of the morning in parts of eastern Pennsylvania.

High wind warnings in effect this evening into early tomorrow morning across western Pennsylvania, where wind gusts could be over 60mph.

So very gusty night in store.

We're saying may the bad luck get blown away on this Friday the 13th.

So gusty across western Pennsylvania.

Those wind gusts over 40mph in eastern Pennsylvania where we'll clear late.

There could be a few raindrops or maybe even some snowflakes across the northern tier.

But we're not talking about a lot, and those will clear out by the time we get to the midnight hour tomorrow.

The winds will wane from west to east as we go throughout the daytime.

And I think it will be a relatively bright day for all.

So we're calling it a pie in the sky day, the pie being the sunshine on March 14th, which is Pi Day and clouds will increase across western Pennsylvania late in the day ahead of this next front.

That's going to move through on Sunday.

Ahead of it, though, very strong winds out of the south that will warm things up into the 40s and 50s a bit of a dull day as far as cloud cover goes, and some flakes early in the day across the northwest.

The extended forecast features more weather whiplash on the way for Pennsylvania, right as we begin next week.

On a mild note, we quickly transition back to some cooler conditions and even a transition in precipitation types as we have that clash of air masses right over the Keystone State.

More on that in just a moment.

First, we'll take a look at the last 48 hours on the water vapor.

Satellite imagery gives us a sense of the steering winds aloft.

We see this clipper system moving in and passing by.

Today.

Big Ridge is starting to take shape out the west, and that will eventually influence a record breaking heat wave for March standards.

As we go into the second half of next week.

On the upper air pattern here on the European model, you really can't miss this deepening trough across the Corn Belt to begin the day on Monday.

Just off to the east of the tight packing of isobars.

Here will be where we find our cold front at the surface.

Now, the timing of that front's passage in Pennsylvania, a bit of uncertainty there is how quickly that will move through on Monday, but I do expect we'll see rain and thunderstorms eventually as the boundary crosses.

That will transition things back over to some mix and snow as our temperatures rapidly fall with the passage of that boundary.

And that sets us up for some cooler days ahead, especially by the time we get to Saint Patrick's Day on Tuesday.

Not only a cold day, but also very breezy, I think both Monday and Tuesday looking very blustery here in Pennsylvania the second half of next week.

Not quite as exciting.

A few ripples of energy will be passing by just off to our north, and that will keep the chance for an isolated snow shower.

If it begins early enough in the day, or rain shower going into the afternoon.

But the big story as we go into the second half of next week will be this building ridge across the west that will sponsor some record breaking heat places like Phoenix that have never hit the century mark in the month of March could exceed that, maybe even go as high as 105 as we go into the second half of next week.

Even some parts of California seeing some record breaking heat likely there.

So that will be the big story we'll be talking about as we go into next week.

For us, just a few isolated chances for precipitation and still on the cool side before we moderate by the end of the week.

Precipitation tracker shows this robust storm system moving in for Monday.

Ahead of that, we'll see a southwest component to our flow temperatures soaring 60s to near 70 with rain and some thunderstorms, maybe even some severe weather there in the Mid-Atlantic.

As the boundary crosses, we'll see our temperatures rapidly fall, especially in the west, and that will change things over to some mix and snow, possibly lingering even into the first half of Tuesday.

High pressure then builds in, so I think we'll see just a few leftovers late Tuesday.

Otherwise for Wednesday, Thursday, Friday.

A few isolated chances for rain or snow showers.

The system skirt by to our north, but more uncertainty there.

If we do see any snow chances.

It doesn't look to be significant here in Pennsylvania with the ground being so warm as of recent.

So our extended forecast shows cloudy skies, blustery conditions on Monday, rain and thunderstorms.

Eventually, temperatures fall in the west.

We'll see rain and storms change to mix and snow going into Tuesday.

Temperatures really take a big tumble, so 60s to near 70 on Monday, many of us in the 20s or 30s for Tuesday, Saint Patrick's Day limited sunshine, then drier and brighter in the east on Wednesday.

Isolated rain and snow chances with moderation.

Late next week, John takes us out into the final full week of March in Week two.

Trends next.

Week two trends is part three of our Friday Forecast trilogy.

Here we go beyond the extended forecast into the 8 to 14 day period, which will actually take us into the first full week of spring.

What I see is a pattern that does not favor a long stretch of warmer than average weather will kind of be on the edge of warmth, but I don't think we'll really dip our toes into it.

It's also a pattern that I think starts out relatively dry and then maybe turns wetter later in the week too.

Period.

Here are the average highs and lows during the middle of that week two period.

These numbers continue to go up at the rate of 2 to 3 degrees per week.

As we near the beginning of astronomical spring, which will come next Friday.

Um, keep these numbers in mind as we assess the risk of temperatures being above or below average.

They're changing so quickly, you kind of need to recalibrate every week.

But a day when the high gets to 50 in central Pennsylvania by this time will actually be right around average.

To assess the risk of temperatures being above or below average, the risk of getting getting any significant precipitation.

We look at an ensemble of forecasts, about 30 different runs of the in this case, the European model.

These are pressure lines up around 20,000ft.

The winds tend to follow these lines from west to east, where they're closer together.

The wind is blowing faster at high altitudes in a very fast flow across the lower 48 states right now.

Ushered in the big change in the weather yesterday and kind of chilly today.

As we go forward in time, notice that the colored lines begin to separate.

The white line, by the way, is the average of the nearby colored lines.

That's a sign of the growing uncertainty in the forecast.

Now, by that time, we're going to see the dominant pattern start to take over.

Big bulge in the jet stream in the west, dip in the east.

Some record heat on the way for the for the southwest and the Rockies during this period.

By the beginning of my forecast period, we're still in a northwest flow.

That's a generally dry flow.

It's not necessarily a warm flow.

There may be a weak disturbance or two in there, but I'm going to keep it dry.

Initially during the week two period.

Eventually another disturbance will come along in that northwest flow and I think knock us back a bit.

Temperature wise.

I'm just averaging all the solutions together here.

Now this is day ten.

So this would be Monday of week two.

The warmth is in orange.

The chill is in blue and purple.

And you can see we're in that battleground right in the middle.

And this kind of pattern favors an area of high pressure developing over New England, which means our winds will start to come in from the east, and an easterly wind this time of year is not a warm wind in Pennsylvania, and I think that will dominate the beginning of week two.

Eventually, though, somewhat warmer air will head our way later in the week.

And I think as that warm air tries to come back, that will bring us a chance of a significant storm later in week two.

So here's how this looks on our checkerboard.

Generally dry to begin.

There may be a weak storm or two in here, but not a lot of precipitation.

Perhaps a more significant storm later in week two as the warm air tries to come in three days with below average temperatures, though.

Sunday, Monday.

Tuesday of Week two.

This is not a pattern that's favorable for above average temperatures.

As we begin spring officially.

That's it for week two.

Back in a moment with more.

The winds are already whipping across the state, and they'll continue to do so as we go throughout the overnight hours.

Could gust up to 60mph in the west, over 40mph in the east.

We will have a chance for some drops and flakes across the northern tier this evening, but then we'll clear out.

We'll also clear out in southeastern Pennsylvania, where it's still on the cloudy side, then a much warmer night than we had last night.

We're going to blow away that.

Any bad luck on this Friday the 13th?

Tomorrow for Pi Day.

The pie in the sky is going to be the sunshine.

A bit of a reprieve as the winds wane from west to east throughout the daytime hours.

High temperatures getting into the mid 30s across the northwest.

We've got that wind coming off the chilly lake and then getting down or up into the lower 50s across southeastern Pennsylvania.

But today is the quiet of the days of the weekend.

As we go into Sunday, the winds start whipping again out of the south, bringing in some warmer air.

But it's going to be a bit of a cloudy day.

Filtered sunshine with high clouds moving in, maybe a few flakes before sunrise in the northwest, and then late Sunday night the showers move in and I think that front on Monday we've got to stay weather aware on Monday looks like a day that could be stormy.

And then eventually, as I mentioned, the extended some big changes.

Another blast of cold air coming in.

That's right.

Thank you very much for the forecast Marissa.

And thank you for tuning in.

We will see you back here next week.

On Monday, we'll have hashtag headlines and more features as the week goes on.

Have a good weekend.