The Department of Meteorology and Atmospheric Science at Penn State.

This is Weather World.

Good evening and welcome to Weather World on this Thursday, April 2nd, 2026.

I'm your host, Matthew Carlson, joined alongside our forecaster Rob Lydick and Rob Pennsylvania.

Weather today.

Quite the flip flop.

Some areas with abnormally cold temperatures yesterday now have a record breaking warm temperatures today.

Yeah, we've actually seen a front kind of do a dance across the Commonwealth.

And so as you mentioned, we went from record warmth to almost feeling like winter in places in the East and a flip flop in the west and more unsettled weather on the way.

That's right.

Alright, looking forward to hearing more on your forecast, Rob.

Stick around on tonight's show as we've got a feature with Ben Reppert talking about weather and fly fishing.

But first, here's Rob at the wall and thanks very much, Matthew.

That boundary has been a key player for our weather pattern really throughout much of this week.

And it's been the difference maker, not just in terms of temperature, but also in terms of weather conditions.

You can actually see in our nine camera view today, where we had some sunshine and breaks in the clouds in the west, versus socked in with clouds and drizzle and misty conditions in the east.

And that's where our temperatures were really held back today.

This was the temperature map that Juliet showed on last night's show, a record high in Philadelphia yesterday.

Contrast that with only 36 degrees in northwest Pennsylvania.

And then as we put this into motion overnight, you can see when that front really began to meander its way westward.

So as we went into our afternoon today, temperatures struggled to make it out of the 40s in eastern areas, even upper 30s in Mount Pocono.

Contrast that with the west, where now they're seeing 80 degrees in Pittsburgh and Washington and kind of the dividing line right along the Central Mountains around 99, where temperatures held into the 50s there today.

I think we'll see that continuation of the clouds and drizzle in the east as we go through tonight.

But a different visual perspective of that 24 hour temperature change, anywhere from 30 degrees colder off towards the south and east, nearly 30 degrees warmer in the north and west.

So really, what a difference really that boundary can make that has also influenced our wind direction, pulling in some cooler air from the east.

Meanwhile, warmer air in the west, and we'll see some more sunshine in some of those areas in the west as well.

As we take a look at a wider perspective here.

You see where we've been socked in with the clouds.

It's been a drizzly and kind of drippy day in eastern Pennsylvania.

Not much in terms of rain making it to the ground.

Meanwhile, in the West, where we've had that southwesterly breeze, more breaks in the clouds allow for more sunshine there and temperatures really soaring, actually a bit of a humid feel.

The dew point temperatures there in the 50s and even lower 60s across portions of the Midwest.

This storm continues to get its act together, and it's actually producing some severe weather across the Corn Belt this evening.

As we take a look at that perspective there, we've actually got an enhanced risk for some severe weather in Chicagoland tonight.

Isolated tornadoes but damaging winds and hail.

Really the primary threats there.

I think that severe weather threat will continue there as we go into the end of our workweek tomorrow, we'll see this front kind of continue to do a dance across Pennsylvania over these next couple of days.

And you can actually really see where that boundary has been set up from the plains all the way into the northeast, where the cooler air has been kind of trapped to the north, 70s and 80s to the south.

But eventually that boundary will nudge northeastward tomorrow.

I think everybody should see temperatures make it into the 70s for daytime highs.

Here's a look at our surface setup for tonight.

We've got that boundary situated off towards the west.

It really won't be budging much tonight.

So I think these areas in the east will be held in with clouds tonight.

And also temperatures kind of on the mild for this time of year, but cooler compared to the west.

Temperatures there should stay in the 50s and 60s going into the day tomorrow that boundary moves off to the northeast.

Cold front is still situated to the northwest.

We're kind of in the warm sector tomorrow.

Isolated thundershowers possible mainly in the west.

And as we go into the beginning of the weekend, you see the storm system continue to organize a bit more.

Eventually, a warm front will be nudging northeastward through the state.

Now, areas in the Poconos and in the mountains, they may see their temperatures held back a bit as we begin the day, but I think that will continue its northeastward trajectory.

Everyone sees some warmer conditions before that boundary crosses Saturday night, and that produces a round of some heavy rain and some gusty thunderstorms going into our Easter Sunday.

So for tonight, we'll call it the contrast that continues in the Commonwealth.

Temperatures held back in the 40s with clouds, fog, mist and drizzle in the east.

Meanwhile in the west, a few breaks in those clouds, but some spotty thundershowers possible after midnight.

Still on the warm side there.

Temperatures mid 60s in the Pittsburgh metro on Friday.

Our boundary will be nudging northeastward so everyone should see a warmer day, especially in those cooler areas to the east.

So temperatures in the 70s a bit more humid as well.

Morning fog though I think in the east will eventually give way to more afternoon sunshine.

Some pop up thunderstorms in the west, but not a widespread rain event.

And then a warm night for all going into Saturday.

On Saturday, we could be talking about record challenging warmth, temperatures, flirting with 80 across the Capital Region, scattered thunder showers possible, some of those gusty in the west, but our best chance for a round of heavy rain comes in on Saturday night.

Back in a moment with more.

Saturday kicks off a new fishing season in all 67 Pennsylvania counties.

But before you go and hang out with the trout, it's a good idea to become familiar with recent and current weather.

Your safety and success on the stream could depend on it.

Penn State has been a leader in fly fishing education for just shy of a century.

The program was originally developed by the legendary George Harvey in 1930.

It has evolved over the last nine decades, now falling under the direction of George Daniel is.

This is just a kind of a lifelong dream, being able to come here to Penn State and and teach a historic program.

Ideal fly fishing conditions are largely impacted by the weather, not only how the weather impacts the streams and the fish, but especially the insects.

Fly fishing revolves around the imitation of insects to bait trout, making successful fly fishermen the anglers that are most aware of what is happening on a stream.

Long story short, when you have insect activity, you have trout activity.

Trout are just masters of efficiency.

They are not going to be moving during periods where there are not really many insects that are essentially drifting.

So what I'm saying here is that so many of our insects, like the types of insects that are aquatic, that eventually emerge to become winged adults, many of them are light sensitive.

So often these insects hatch during like low light periods, maybe cloudier periods, maybe rain drizzle.

This also creates a big misconception when it comes to the ideal fishing conditions.

When people think about fly fishing and just, you know, when you walk along the stream or you drive along the stream, when you have these beautiful bluebird sky days in clear water, I mean, this is a beautiful day to be out, but it's not always the best day to be fishing.

In most situations when you have lower light periods and you have right ideal water temperatures, you often get some of the best fishing opportunities.

And those high dew point days with oppressive humidity, those are good too.

But when you have moisture, it takes a lot longer for these adult insects to dry their wings and fly away from the water.

So basically it keeps them on the water and trout know that it just basically elongates the time period that these fish, these insects are struggling on the water where you compare it.

Like you, you go out west to places like Colorado and where basically you may have warmer days in some situations, but you have less humidity.

A lot of times those insects can dry off their wings.

In a split second.

They can basically break through the surface and pop off, not really creating much of an opportunity to catch fish to maximize the fishing experience.

All of these other conditions need to team up with ideal water temperatures for trout.

Those range from the mid 50s to the low 60s.

It's an important threshold for anglers to keep in mind, especially as we get into the hotter summer months.

If you have water temperatures that are 67 or greater and that fish is pushed under stress if you hook it, and that fish is basically, um, under some degree of stress, it's fighting for its life, it's more probable that it will die.

Luckily, a majority of Pennsylvania streams are spring fed.

So dangerously high water temperatures are rather rare.

It is like a giant, almost like AC unit where the water is coming under the ground.

It's fairly regulated compared to streams that are influenced from like rainwater or from the mountains, where those water temperatures will fluctuate greatly.

Our streams are fairly regulated.

That being said, if we get into a prolonged period of hot, dry weather in the heart of summer, it wouldn't hurt to bring a thermometer.

And if you start seeing temperatures in the 60s, high 60s, close to 70, that's where you just stop fishing because fish can still survive.

But if you catch them and you play them, you're you could potentially be giving them their death sentence by doing so.

These important fly fishing principles are just a sample of the things that George makes sure to cover in the classroom.

These students, I mean, they're getting ready to get into the real world, and they're going to be dealing with high levels of stresses within their professional and personal lives.

And one of the things that we all need is some way of decompressing and any more these days, it's so difficult to basically become unplugged.

You know, we're just stressed.

We're on our phones all the time, but there's great activities, including like fly time, fly fishing, where activities where whether you want to think of it as a meditative state or whatever, but basically where you just focus on this, basically the moment of now and you're not worried about the past, you're not worried about the future.

You're kind of just focused on the task at hand.

And there's something very therapeutic, uh, and very rewarding about being able to perform these very simple tasks, simple tasks for a fun hobby with important implications down the road with the future prospect of development, clean water, uh, natural resources, these are all things that are going to be kind of at risk or going to be continued to be at greater risk down the future.

So we need stewards to basically be able to protect.

And the only way someone's going to want to protect these resources is if they have some sort of vested interest in the in what better way?

Again, someone interested in the resource and an activity that connects them to that resource, like fly fishing.

So with all of that groundwork laid in the eyes of a very accomplished angler, what is the perfect fly fishing day weather wise?

I would say like late April, early May, uh, you have a number of insects that are hatching all at the same time.

Uh, you have ideal water temperatures.

That's that high 50, low 60 degree temperature range is kind of like a peak, like an optimal temperature.

That's when the trout are the most active, maybe an air temperature that's maybe in the, you know, low to mid 60s.

But you have like drizzle, like a light rain.

Uh, that is like, that is like magic.

And if you want to become an amateur angler as prime time approaches, George recommends a couple of great resources.

One's called the bug book.

The other one is called The Pocket Guide to Pennsylvania Hatches.

These are like two very simple books that basically explain because, like I said, trout become active when insects are active.

So it's really plays in your best hand as a fisher to understand the time of the year, the types of insects that are hatching during that time of the year.

And usually when those insects hatch, it just it's advantageous to actually just understand and have a book that is basically understands that like a second grade level, which is where I read, uh, that basically lays out that information in very simple terms as it relates to fly imitation and being a better angler for weather world.

I'm Ben Reppert.

Well, the temperature swings will continue in Pennsylvania over the next couple of days.

We'll see clouds, fog, mist and drizzle continue in the east tonight.

Temperatures held back in the 40s with a few isolated showers.

Better chance for some spotty thundershowers will be in the west, where they'll be warmer to temperatures 50s and 60s overnight there on Friday.

Eventually, that boundary will nudge northeastward.

Everyone should see a warmer day.

Temperatures topping off in the 70s.

A bit more humid as well.

Some breaks in the clouds after some morning fog and cloud cover to start in the east, and winds become a bit more gusty in the afternoon.

Some pop up thundershowers possible in western Pennsylvania, but not a widespread rain event, and Saturday looks mainly dry as well.

Just some pop up thunder showers during the afternoon.

Some of those could be gusty at times, especially in the west.

I think the big story Saturday some record challenging warmth, especially in central and southeastern Pennsylvania before a cold front crosses that will bring a round of some heavy rain and thunderstorms as we go into Saturday night, and probably a soggy start to our Easter Sunday morning in some places.

To Matthew.

That's right.

Even though I might be dodging some showers this holiday weekend, I am looking forward to spending some time outside enjoying those warm conditions, hoping to do some hiking.

I can't wait to hear about it.

Awesome.

Well, come back tomorrow for the week two trends taking you through the holiday weekend and beyond.

Of course.

Thank you from everybody here at weather and have a great night.