Wednesday, January 31, 2018

Get Ready for Six More Weeks of Winter: Frigid February Ahead

Bundle up for a chilly month of February ahead of us. Even Punxsutawney Phil will probably agree, as he will most likely see his shadow on Friday morning "signaling" six more weeks of winter. But even without Phil's help, meteorologists are fairly confident that the month of February will be a cold one, and possibly even a snowy one.

Image result for Punxsutawney Phil with shadow
The famous groundhog Punxsutawney Phil in 2016 - Credit: NJ.com
After a roller coaster of temperatures to wrap up the first month of 2018, it appears that at the turn of the calendar to the shortest month of the year, colder than average temperatures will settle in and dominate the eastern portion of the country, possibly throughout the entire month. This weather pattern will also set up the jet stream in the right configuration to allow for some winter storms to impact the Northeast, maybe even as soon as this weekend.

We've been lured into somewhat of a false sense of security with a relatively mild second half of January. The map below shows that temperatures in the northeast ranged from two to six degrees above what they should be for this time of year from mid-January until now.
Temperature departures for the second half of January - Credit: High Plains Regional Climate Center
But all of this will change within the next couple of days as the jet stream will take a dive in the eastern half of the United States, ushering in cold, Arctic air and plunging temperatures to below average. The average high for State College for this time of year is 32 degrees with the average low being around 18 degrees. NOAA's Climate Prediction Center is fairly confident that temperatures will be below average all the way into the middle of February, as illustrated by the maps below (blue indicates below average temperatures with the darker shades signifying a higher confidence in that forecast).

6-10 Day Temp. Forecast - Credit: Pivotal Weather
8-14 Day Temp. Forecast - Credit: Pivotal Weather
But how cold will it get? High temperatures in State College on Friday are going to struggle to hit twenty degrees with lows dropping into the teens most nights. But something else stands out in this new weather pattern: the potential for a big snowstorm (or two). While everyone is watching the Super Bowl indoors on Sunday night, snow may be falling outside across the Northeast. Both the American and European models suggest a large system developing over the weekend and moving over the Pennsylvania area throughout the afternoon and evening portions of Sunday. The exact track of the storm will determine who will receive rain, who will get snow, and who could see a wintry mix. The storm also isn't expected to get too intense and it will move rather quickly up the coast, preventing it from becoming a blockbuster Northeast snowstorm.

Widespread rain and snow will cover much of the Northeast Sunday night - Credit: The Weather Channel
No official forecasts are out for the potential snow totals, but my first estimate would be around two to four inches of snow in central Pennsylvania from this system. However, recent model runs have suggested that the center of the low-pressure will track closer to the coast meaning that the rain would spread further inland and dampen the snow totals. Keep updated with your weather forecasts as we get closer to Sunday to see if this storm will bring central Pennsylvania some snow. One thing does appear to be fairly certain though: if snow does fall on Sunday, it will stick around for a while as cold temperatures throughout February will limit any melting.

Comment below if you like the cold weather and increased chances of snow, or if you just want winter to be over and can't stand seeing any more snow or cold temperatures.

Wednesday, January 24, 2018

Can the Weather Just Decide What it Wants to Do?



Temperature graph for the month of January in State College, lighter lines are the average temperatures for this time of year. Credit: AccuWeather
Welcome to the Northeast. The weather can't seem to make up its mind over these past couple of weeks, fluctuating from being bitterly cold to being mild and above average. It's like mother nature got confused that we were still in winter. Just last week we got a few inches of snow on Tuesday, but it was gone by the weekend after warmer temperatures and rain washed it away. And I'm sure no one forgets the harsh cold temperatures that we experienced at the end of December and beginning of January (and, of course, the #BombCyclone). What causes these fluctuations in temperatures and keeps us all on our toes as to what we need to wear each day?

Strong low-pressure systems are the main culprit, each one having a warm front ahead of it that brings in a southerly flow and causes temperatures to rise well above average. But then the cold front hits, dropping temperatures like a rock and shifting winds to be out of the northwest. I'm sure many of us remember the drastic change in temperature over a few hours earlier this month on Friday, January 12. One hour it was above 60 degrees and then before you knew it the temperature was below freezing. As long as a high pressure is over us, temperatures will remain chilly or seasonable until the next low-pressure system comes through starting the cycle again.
Temperatures over the past 14 days showing the warming trend. Credit: High Plains Regional Climate Center.


























It should be noted that the past fourteen days of January have been around two degrees above average in the central Pennsylvania area, but much warmer than average in portions of New England (orange, yellow, and red signify above average temperatures in the map above). In case you were wondering, the average high temperature for this time of year in State College is around 35 degrees and the average low is at 19 degrees.

So these next couple of days will be fairly seasonable and average for this time of year before temperatures warm up again for the weekend into the upper 40s and lower 50s. This is, of course, accompanied by a weak cold front with some rain, which will drop out temperatures back down, a little further this time. The early portion of next week will be fairly chilly, with temperatures possibly not getting above freezing during a couple of those days. But don't worry, this cold snap will again be short lived as we get back up into the upper 40s by the end of the week and more rain possible. So fasten your seatbelts and get ready to ride the Northeast temperature roller coaster over these next couple of weeks.

Static NE Saturday
The milder temperatures associated with the weak cold front that will impact PA over the weekend. Credit: Accuweather.
We should also keep in mind that we are in a La NiƱa winter, and forecasts at the beginning of this winter were for us to have slightly above average temperatures throughout the winter. The prolonged periods of cold earlier this winter have kept our winter average for temperature below average, but there is still plenty of time left for that to change.

Let's take a look at a longer range forecast of temperatures on the maps below issued by NOAA's Climate Prediction Center. From January 30 to February 3, forecasters are fairly confident that temperatures will be above average. However, in the period from February 1-7, temperatures are forecasted to return to average, and some forecasters are saying that it may get to be below average during the early part of February with arctic air invading the Midweat and Northeast.

CPC 6-10 Day Temperature Outlook. Credit: NOAA
CPC 8-14 Day Temperature Outlook. Credit: NOAA
Static US February Week Two Harsh Cold Returns
Arctic air might make its way into the U.S. during the second week of February. Credit: AccuWeather.
However, these forecasts are a few weeks out and we should wait a few more days before confirming that these temperature trends will indeed happen. What we can be for sure is that it felt like April instead of January a few days ago, but now the winter jacket is needed once again over these past couple of days. Stay updated to see how these temperature patterns will actually play out and to see when more storms are on our way.

It looks more like April than January in PA with dark clouds and no snow on the ground. Credit: J.P. Tracey