Jim Nichols Weather Blog

Become a Weather Observer

Go cuckoo for CoCoRaHs! Do you have a passion for the weather and want to contribute to advancing the science of weather forecasting? Now you have the chance of joining a network of weather observers whose regular reporting will be integrated into the next generation of weather forecasts. Find out how you can join the National Weather Service, Penn State and Rutgers University build the region (and nation’s) most advanced weather observation network! Every drop of precipitation counts!

Find out how you can join:

http://www.erh.noaa.gov/phi/cocorahs.php

http://www.cocorahs.org/

This kind of action is long overdue, many accidents and injuries are caused by snow and ice flying off the back of cars and trucks (especially tractor trailers) on highways. Have you ever been behind a car or truck at 65MPH when chunks of ice are flying towards you? Not fun!

Here is the link: http://www.nj.com/southjersey/index.ssf/2008/01/nj_law
_would_require_ice_snow.html

Enjoy !

-Jim

Goodbye mild 2007 hello chilly 2008. That is, of course, being totally short-sided...but a look at the 7 day would have you believe it. A quick punch of precipitation is expected to arrive late tonight and last through the early morning. Once again we find ourselves in the great "precipitation type" debate. The evidence is there to support a wintry mix to start and last for the beginning of the Mummers parade. We'll see a few flakes mix in until about lunchtime when plain-old rain should end the storm out. To be honest, I am not 100% sold on the wintry mix for the Philadelphia metro. The models have been inconsistent in handling the warm air (like we saw New Years Eve) and have been biased cold. Because of that, confidence is lacking that the cold air will be here waiting when the storm arrives. Also I think a quick shot of air from the south and southeast will hamper a wintry scenario. With all that said, however, I am electing to keep the "wintry mix" wording in the morning forecast for now. I am confident that it won’t be too pretty when the mummers start up, but at least the weather will be improving as the day goes on.

Now, at the risk of piling on move issues...winds may be a problem. Winds are expected to get very gusty as some of the coldest air we've felt in a long time starts to arrive Wednesday and Thursday. Wind Chills are going to be nasty on the 2nd and 3rd...not a very welcoming start to 2008. But, don't get too upset! Temperatures are expected to bounce back rather quickly by the weekend, with 50s a real possibility by Sunday and Monday. It looks like the wild winter ride we're on for temperatures won't end with a simple change on the calendar.

So, for all the snow lovers out there...if I could make a new year's resolution to predict more snow...I'd do it. But merely predicting snow won't actually make it arrive! We'll keep the resolutions simple...working out, staying fit, blah blah blah. I am thinking about making a few resolutions I know I can keep. So I plan to watch more TV, gain a few more pounds (let's face it, I need to) and not win the lottery. Those are all more realistic resolutions I know I can keep! What are yours?

Here's to wishing all of you a happy, healthy, safe and prosperous 2008 and beyond.

-Jim

Well, in response to what I've heard on the street and a few of the blogger comments...I have to agree...the constant cloud cover is a bit annoying. The problem? We are in the Jet Stream's path. The jet continues to "catch" these weak storm systems and deliver them right through the region. The heaviest of which will be Friday night into Saturday morning. The latest information has shifted this system further west, which will now allow for a later arrival time. Expect clouds to be on the increase Friday afternoon before the rain showers arrive after midnight. The heaviest of rain will move through between 2 and 4 AM on Saturday, with a few lingering showers when you wake up Saturday morning.

In keeping with this pattern, another storm system is set to arrive on Sunday, albeit a much weaker one. This may cause a wet start to New Year's Eve and the Mummers Parade. My main concern is not so much the rain however, it's the wind and the effects it'll have on the parade route. At this point, I would certainly say "parade on", but it'll be an interesting thing to monitor none-the-less.

Enjoy!

A quick update: A few reports of slick spots in Northern Bucks and Montgomery counties as some localized areas have dipped below freezing. I am being a little pessimistic on sun chances tomorrow because of a westward Low feeding our cloud cover. As of now, I think the extra cloud cover will keep temperatures a little cooler than anticipated and I have elected to forecast a high in the low 40s (vs. upper 40s). I think today's trend may be a good indicator of tomorrow, which provided more cloud cover than sun and thus...cooler temperatures. Another round of rain is set to arrive late Friday and last through early Saturday. At this point the models have been converging on this time-table and the track is consistent on bringing us rain.

Another shot of rain is expected on Monday with the possibility of a wintry mix; at this point confidence is low on the precipitation type. Temperatures are expected to be in the mid 40s before dropping off into the upper 30s midweek.

Enjoy!

A storm system will track up the East coast but move out to sea on Wednesday, taking a bulk of the rain out towards the ocean. Right now, it looks like we're going to just get a "glancing blow" from this system with the best chances for rain down the shore. There is a chance that those rain showers could make it as far inland as Philadelphia and the northwest suburbs, so I have elected to put a "chance" for rain throughout the Delaware Valley tomorrow afternoon. We'll get a quick break before another round of showers moves in by the weekend. Temperatures will warm up as the storm approaches, with highs reaching into the 50s on Saturday. We'll continue to moderate slightly above average through the end of 2007.

Enjoy!

Merry Christmas! It appears the Northeast is the place to be for this holiday. Temperatures are mild and the sky is clear (well, except a few clouds). High pressure is in control and will stick around through the next few days. There will be an attempt to repeat Sunday's weather this weekend. However, this next system set to arrive is not as strong. The warm air will race in the upper levels, but the wind isn't strong enough to bring that warmth down to the surface. For the moment, I am going to keep highs in the mid 50s Saturday and low 50s Sunday. There is a potential to get temperatures higher, but right now I don't think the winds will be strong enough to support it.

Are you a fan of GPS? If you are, you have to check out the NORAD Santa Tracker. That's right, the men and women on our nation's missile defense are working for the big guy as he approaches North America. You can track Santa in real-time here: http://www.noradsanta.org/en/home.htm

High pressure off the New England coast is providing an easterly wind off the ocean. This will often lead to low clouds and a bit of drizzle, like what we saw Friday. Anticipate another day of this on Saturday. A new storm system will approach on Sunday, catapulting our temperatures to near 60 with very gusty winds and heavy rain Sunday night. Temperatures will even out just in time for Christmas with plenty of sunshine. At this time, it seems like a green (or brown) Christmas!

Enjoy!

-Jim

As the winds howled and power lines fell, many were left asking...why is it so windy?

Well…you can thank that mess of a storm we had over the weekend. As the center of that storm moved over the New England coast it quickly intensified. At the center of this storm is low pressure, which at the time of this writing was at 28.64" or 970mb in geek speak. Right now High pressure is trying to move into Philadelphia, providing today's sunshine. It is the difference in pressure between the High and the Low that is causing the wicked winds. The stronger the difference is between the High pressure and Low pressure, the stronger the winds. Right now, with the Low is at a pressure of 28.64" and the high is sitting at a pressure of 30.32", in the weather world this is considered to be a large difference, and therefore, the reason why we got such high wind gusts.

You see, Mother Nature likes to have everything in balance. In fact, one of this planet's basic uses for weather is to balance out the atmosphere with pressure, temperatures and moisture. Of course we never get a balance and therefore we always have some sort of weather. In order to balance out the pressure, nature tries to move energy from high pressure to low pressure. That movement is reflected in winds. Now, winds will typically flow in a counterclockwise direction around the Low and clockwise around the High. This is due to a myriad of reasons that physics and thermodynamics can explain. We're not going to do that here. But, expect as the low continues its trek away from Philadelphia that incoming High pressure will allow our winds to calm down a bit later tonight.

Gerald Kolpan reminded me the other day of a famous New Jersey radio station that used to feature "weather in a word." Well, if I were to sum up this storm for the weekend in just one word, it'd be: Everything.

That's right, we have a little bit of everything setting up for this weekend…rain, sleet, snow and perhaps a touch of freezing rain. The computer models did us a favor by coming to some sort of consensus, which is always helpful. I am a bit hesitant on the final call for this storm because 1.) The models have been forecasting way to warm recently, 2.) We are depending on a yet-to-form Low off the NC coast 3.) We are banking on the primary storm to phase into the coastal storm...which is always tricky. Anyone who follows coastal storms knows that where it forms and where it mergers a highly volatile.

However, you just can't ignore the very strong warm signals the data is providing. Upper level temperatures surge above freezing even through the Lehigh Valley. The storm's timing seems to have slowed a bit, with a nighttime arrival but on the heels of a day's worth of warm air. When faced with such factors, it is always important for a forecaster to rely on the data, run the most probable cause and eliminate any personal "want" or "desire" for either snow or rain. With that said, the best data supports a snow start in Philly and North and West with a quick changeover to rain Saturday night. A wintry mix is anticipated to be the "major" impact further north in the Lehigh Valley and significant snow is to be expected in Northern Pennsylvania and New York state. Any accumulations of the first snowfall locally (at the storm's onset) or at the end of this storm will be difficult to substantiate. The rain will most likely washout any snow to start and the ground will be well saturated and therefore, slower to cool as the snow showers arrive on the storms departure Sunday. With that said...a simple shift in the storm track can dramatically change all of this, but it seems now that rain will be the dominate factor for most of the area with icy conditions in the Northwest suburbs.

Once this storm moves out, cold, windy conditions set in. The sun will make an appearance on Monday and stick around through the end of the week.

Enjoy!

As far as storms are concerned, we are "in the zone" so to speak. The mid-level jet stream is poised over Philadelphia, where cold and warm air battle for dominance while weak storms pass right through. We are going to continue the rain/snow/sleet dance through the weekend before the warm air finally wins Monday. A bowling ball of a storm is expected to barrel in late Monday, Tuesday and Wednesday. The track of this storm will bring in a lot of warm weather ahead of it, which will be a nice change from the 30s we've dealt with recently.

There is a bit of good news...the latest guidance data provides the chance for a little sunshine late Saturday afternoon. As it stands now, this might be our only window to see sun for a few days.

Enjoy!

-Jim

I'll use the word "wicked" for the weather ahead, and no it has nothing to do with witches or a never-before-known Boston accent. I say “wicked” because of the mix it brings of both snow and rain together. We are in the "target zone" for storms the next few days. These aren't expected to be of much significance, but will prove to be quite annoying by the middle of next week. As the mid-level jet stream aligns right over Philadelphia, the epic battle between warm air and cold air will play out right over us. We get the benefit of being stuck in the middle.

Clouds will make themselves comfortable around here the next few days as the first in a long line of weakling fronts arrives tomorrow. We could see a spritz around the region tomorrow afternoon, with some seeing flurries, others raindrops. Another line of showers will arrive and pose the "precipitation type" test on Sunday before a much larger storm arrives on Monday providing rain showers into Tuesday. It does appear the larger Monday storm will be all rain at this point. If you're a fan of sunshine, you'll just have to hold out hope for late Wednesday and Thursday.

Despite your want for cold or warmth, just remember to take it easy of the roads and sidewalks. Some spots can still be icy.

From the 70's Thursday to struggling 40s today, at the risk of sounding utterly cliché...what a difference a day makes. High pressure is in control tonight...with a clear sky and calm winds, expect temperatures to p-l-u-m-m-e-t. It's going to get cold...the extra-blanket on the bed; dog doesn't want to go outside kind of cold tonight. A few people will reach down into the teens (I'm looking at you Mount Pocono!) while the rest of us remain in the low 20s. Sure, we haven't felt this kind of cold in a while...but hey...many of the bloggers here like the cold stuff anyway.

A cold front will arrive on Monday providing a good deal of rain showers Monday afternoon and Tuesday morning. As was proven on Thanksgiving...timing for the front is everything. There is a potential for the temperature to rocket into the 60s but for now I'm going to shoot for the mid-to-low 50s. Expect it to be windy...which is one of the reasons why it's *possible* to reach higher. Expect to lose your trashcan lids if you have collection on Monday.

Temperatures are set to level off by the end of the week as we are waiting the arrival of a pattern change next week. It appears that the Jet Stream is poised to ride right over Philly in the beginning of December. At this point, all the cold air that the jet is bottling up over the Midwest plains (the Dakotas) will shift our way. For those that want the really cold stuff...this could be your December gift. There is not a lot of indication on how long this will last, as the models become way too unreliable past this point. However, the models have been consistent in advertising this the last few days and it appears to be convinced that a decent cold shot with some storm possibilities will arrive the first few days of December.

Enjoy!

Temperatures are expected to warm nicely over the next few days. Today we had to contend with an irritatingly slow "clipper" system which was a delight to ski lovers and snow lovers far north...but provided nothing but a cold, damp, clammy Monday for the rest of us.

Temperatures are expected to edge out the 50s and 60s by midweek. The debate is just how warm we are able to get. I have decided to go on the cool side of the computer guidance. It has been apparent that the models have been forecasting way to warm recently. For instance the ensemble mean computer model forecast was 47 for Monday, compared to what we actually hit for a high...42. Because of this trend (and I do say trend because it has been doing this for this entire pattern) I have kept this week’s temperatures on the cool side. The clouds will be stubborn to break and the southerly flow will be inconsistent at low levels, which leads me to forecast a lower daily temperature. This will probably last until the pattern breaks...which looks to be in early December. At that point...it looks like we'll be transitioning to a much colder setup.

Enjoy!

Hello All!

Our weather this weekend hinges on an approaching clipper now in the Midwest. The center of the storm is expected to track south of Philly, but will provide a good deal of cloud cover Saturday afternoon. A few light showers can be expected with a few flakes mixed in far north and in the higher elevations. At this point, this system looks to be a minor problem this weekend, with the most notable issue being cloud cover. High pressure arrives Monday and provides beautiful travel weather.

The problem? Thanksgiving. A cold front will make an attempt to move through by the end of the week. The computer models keep flip-flopping this between Wednesday and Thursday. As of now, I am going to put the rain on Thanksgiving given the evidence currently on the table. But, since this timing has been so inconsistent, I have little confidence that rain on Thursday will actually happen. There is still plenty of time for this system to change its timing and because of that, confidence is low on precipitation on Wednesday and Thursday. We should have a better handle on this situation Monday.

Thanks for reading! Enjoy!

-Jim