Spring is Slowly Coming: 5-Day Forecast

5-Day Forecast
Saturday: Sunny; highs around 60°
Sunday: Clouds and sun; showers late in the day, up to a quarter of an inch; highs around 60°
Monday: Partly cloudy; highs in the lower-60's
Tuesday: Clouds and sun; highs in the upper-40's
Wednesday: Partly cloudy; highs around 50°

Snow Totals from the 3/25 Snowfall

These are snow totals for the snowfall on 3/25/13 from the Mount Holly National Weather Service website...

 

Small Update to Snow Map

Here is the small update to my map with the chances for more snowfall in South Jersey and Philadelphia...

5-Day Forecast and 3/24-3/25 Snowstorm Threat

5-Day Forecast
Sunday: partly cloudy with rain/snow showers late; highs in the upper-40's
Monday: rain/snow, windy; highs in the mid to upper-30's
Tuesday: storm clears out, turning to sun and clouds; highs in the mid-40's
Wednesday: partly cloudy; highs in the upper-40's
Thursday: partly cloudy; highs around 50°

Snowstorm Threat
   Well, the GFS was right from my post several days ago...as of right now, all the main models agree on our area receiving at least a light snowfall event.  A low from the Midwest and one from the east coast will move through the area and phase, or merge, off the coast and intensify.  The timing for this would be an arrival late on Sunday night and an exit late Monday into Tuesday morning.  Late Sunday night will bring snow and rain showers, which will persist into Monday when it will turn to snow with snow showers tapering off west to east late Monday or early Tuesday morning.  With temperatures being so close to freezing and above, rain and sleet could mix in or change over throughout the day.
   As with any wintry event in March, there is great uncertainty and skepticism with snowfall, and this storm is no different, as temperatures are warmer at the surface and chances for a bust in snowfall are higher than in the winter.  Most accumulation would be on grassy surfaces with temperatures on paved surfaces being too high to support much in the way of snow accumulation.  There is also the possibility of this storm throwing snow bands back into the area after it is supposed to exit, just as the last storm in early-March did and gave NJ a decent amount of unexpected snow, just as a heads up.
   The coast will probably not see much of accumulating snow due to temperatures being too high with an onshore flow and rain/mixing, keeping any accumulation minimal, most likely.  The further west you go in South Jersey, the best chances for higher accumulations.   Models give the Philadelphia/South Jersey area around one inch of precipitation, but it is almost impossible to predict how much of that will attribute to accumulated snowfall until the storm is in progress, depending on ground temperatures, how much snow melts away on impact, and how much snow actually falls during the storm.
   Finally, for snow totals, most sources mainly give a couple inches to our area, but the possibility of no accumulation is, of course, there this late in March.  The GFS and EURO each give our area a couple inches of snow.  The NAM hammers us with a major snowstorm and gives us up to a foot of snow, but that is wishful thinking.  Right now, I believe that non-coastal New Jersey and Philadelphia will see accumulating snow but just some small accumulations.  I'll post a few snow total forecasts, then give my map...

NAM

Credit: http://www.americanwx.com/raleighwx/models.html

GFS

Credit: http://www.americanwx.com/raleighwx/models.html


My Snow Map

5-Day Forecast and Storm Threat Outlook

   Here is my forecast for the next five days that will take us to the end of my, and a lot of others', spring break...

Tuesday: lingering showers in the morning give way to sun and clouds in the afternoon, windy; highs around 50°

Wednesday: sunny; highs in the mid-40's

Thursday: chance of flurries and snow showers in the early morning, then partly cloudy; highs around 40°

Friday: partly cloudy; highs in the lower-40's

Saturday: partly cloudy; highs in the mid-40's

Outlook
   Spring arrives on March 20th with the vernal equinox, which is only one of two times a year where the sun is directly over the equator.  In Philadelphia, and the rest of the region, day is now longer than night, and the time of sunset is pushed back later everyday from here on out into June, which I love!  However, after looking at the models, it doesn't seem like spring-like temperatures will be arriving within the next two weeks.  Unfortunately, there is no tell-tale sign of higher temperatures, a ridge in the pressure heights map, on the horizon, and it seems like temperatures will not make it past the lower 50's within the next 10 days.

   Furthermore, looking down the road, I see two storm threats within the next couple of weeks: one on my birthday, March 25th, and the other on April 2nd.  The one for March 25th would be a cold, rainstorm as it looks now, if it hits us...maybe if it was a few moths ago, I'd be more enthusiastic for snow, but it's just too warm now, especially on ground surfaces for much in the way of snow to fall and accumulate.  The GFS gives our area a direct hit, but the EURO takes the storm a couple hundred miles south along the Virginia/North Carolina border.  We'll have to see which model caves in to the other, and it is usually the EURO that wins out.  

   Also, the latest EURO run stops just short of modeling the April 2nd storm, but it definitely shows a coastal storm developing.  The GFS models the storm as giving our area a good dousing of rain, but it, of course, is very far out at 14 days, so I'll just keep an eye on it.  

   Anyway, enjoy the next several sunny days, and hopefully higher temperatures begin to show up sooner than later!

Early Spring Break Outlook and 5-Day Forecast

Spring Break Outlook
   With spring break at Rutgers (March 16-24), and many other schools, starting in a couple days, I wanted to post an outlook for what the weather will be like for our days at home.  Unfortunately, it doesn't seem like spring break will exactly have spring-like temperatures, but it looks like it will have spring-like precipitation for our area.  For the outlook, I used a combination of the GFS and EURO, with a bias toward the EURO, of course, since it is the best weather model, but the GFS goes out further.  For reference, the average highs, for mid-March in Philadelphia, are in the lower-50's, and March is Philadelphia's second-wettest month, according to weather.com.

Saturday: showers, about a tenth of an inch of rain; highs in the upper-40's
Sunday: cloudy with some sun; rain and snow showers at night, highs in the lower-40's
Monday: rain, up to an inch of rains; highs in the mid-40's
Tuesday: system exits, showers in the morning; highs in the upper-40's
Wednesday: clouds and sun; highs in the lower 40's
Thursday: showers moving in toward the night; highs in the mid-40's
Friday: rain; highs in the 50's
Saturday: rain; highs in the upper-50's
Sunday: wet weather clears out; highs in the 40's

   About the system on Tuesday...a few days ago, the euro was modeling it as a major snowstorm for our area and the rest of the northeast.  That is no longer true.  The possibility is not completely gone, but a bunch of factors work against  a high-accumulation snowstorm in March due to the high sun angle and warmer ground surfaces.  Furthermore, the GFS never jumped on-board with the euro for a snowstorm, and the euro has now modeled a mainly rainstorm for the past few runs, now.  It is still around a week away, so anything can still happen, though.  As of now, it looks like a lot of rain for Monday/Tuesday.    

5-Day Forecast
Thursday: partly cloudy, windy; highs around 40
Friday: mostly cloudy; highs in the mid-40's
Saturday: showers, around a tenth of an inch of rain; highs in the upper 40's
Sunday: clouds with some sun, giving way to snow and rain showers toward nightfall; highs in the lower-40's
Monday: rain, up to an inch; highs in the mid-40's

3/7-3/8 Snow Totals and Upcoming Forecast

 Storm Snow Totals

   Well, the snowstorm that wasn't ended up turning into the snowstorm that was.  After the low pressure system stayed to our south and didn't give our area much precipitation, except for the shore points, it moved offshore and drifted northeastward, only to stall.  It was due to this stalling that snow bands were able to wrap around the low and come into New Jersey and Philadelphia from the northeast.  This was actually modeled to happen, except to a lesser extent as accumulations ended up at least doubling or tripling predictions in a lot of places.  Here are snow accumulation totals from southeast Pennsylvania and South/Central New Jersey from the National Weather Service...note that a lot of these are from the morning before the snow ended, as the times of the measurements are listed next to each town:

Snow Total Prediction   

   Before I get to a very nice weekend forecast for the area, I want to explain how I come up with predicted snow totals and why snow accumulation can be so hard to predict.  Models like the EURO, GFS, and NAM all have runs where precipitation amounts are outputs that are displayed on a map using different colors for different ranges of values.  This output of precipitation values is called QPF, or quantitative precipitation forecast, which is the amount of liquid water precipitation that an area is projected to receive.

   Once you get the QPF, you use a snow conversion table where liquid water amount, in inches, can be converted to snow amount, in inches.  However, this is dependent on air temperature.  The higher the temperature, the denser the snow, and the more it will compact together on the surface, causing a smaller snow accumulation than at colder temperatures.  Conversely, the colder the temperature, the fluffier the snow, and the accumulation on the ground will be greater because the snow pack on the ground is less dense and compacted.  Heavy, wet snow is good for snowballs, and fluffy snow is easier to shovel but not good for snowball-making.  Here is a liquid water to snow ratio chart:

   This is not the end of predicting snow accumulation, though.  Several factors go into predicting totals.  First, you need to know the QPF and liquid to snow ratio, along with the air temperature during snowfall.  Second, you need to know where the rain/snow line will set up and move during the storm, as rain, sleet, and freezing rain dampen snow accumulations quickly.  Third, you must know the ground temperatures, because if they are above-freezing, then it will take heavy snowfall or take time for cold air to cool the surface and get snow to stick to the ground.  Fourth, the track of the storm is quite an obvious one that you must know.  Then, finally, the set up of heavy snow bands within the snowstorm can cause 'jackpot' areas of localized, heavier accumulations relative to surrounding areas.  These are main factors in predicting snow accumulations, and some of these caused problems with forecasting Wednesday's storm.

5-Day Forecast

   Finally, we get to the forecast for the next week...After a messy and cold couple of days, we'll be rewarded with a sunny weekend for Saturday and Sunday, with highs in the mid to upper-50's.  On Monday, clouds will move in, accompanied by a high of around 60.  Showers on Tuesday, modeled to bring around a quarter of an inch of rain, with highs in the mid-50's.  Then, it will clear out for Wednesday, leaving behind a nice day with highs in the lower-50's.

Yet Another Snowfall Disappointment

   In a winter full of disappointment for snow in New Jersey and Philadelphia, we have yet another bust for snow, or at least as much of a bust as you can have when there was so much uncertainty.  Contrary to the models and what was expected, the storm and main bulk of precipitation stayed south and moved east, rather than northeast.  This meant that a constant onshore, warm flow kept any precipitation as rain until late last night when the storm finally moved northeastward and rain showers changed to snow showers.  By the time this happened, it was too late for any snow accumulations, and we woke up to some snow showers and flurries scattered around our area.

  

   I believe that Cecily Tynan, of 6 ABC, summed up the thoughts of all meteorologists yesterday in her Facebook post about frustrations with forecasting this storm:

"Ok, I am waving the white flag & throwing out any snow maps completely! The track of this storm (more south and moving east , not northeast) is a RAIN and WIND storm, not a snowstorm. It is not out of the question that a few areas could see a BRIEF changeover to snow, but we are quickly running out of time for this to happen. Man, this has been a headache of a storm since last week! Bring on spring. I am done with this frustrating winter!"

   If you want to see how tough it was to forecast this storm and visualize the uncertainty among news stations in the northeast, here is a photo that somebody posted of snow total maps on the Rutgers Meteorology Facebook group...

   Although snowfall totals busted, the other aspects of this storm that were forecasted came to fruition.  Coastal flooding was a big problem along the shore points of NJ, especially from pictures I saw of Wildwood and many other photos that I saw of the ocean making its way up toward the boardwalks of several towns.  Furthermore, winds were also a huge issue all across our area, with the most impressive wind gusts naturally coming from the coast.  Here are some of the highest wind gusts recorded during the storm:

Harvey Cedars-64mph

Sea Girt-61mph

Atlantic City Marina-60mph

West Cape May-56mph

Philadelphia-46mph

Flooding Pictures from the "Jersey Shore Hurricane News" Facebook page:

Long Beach Island

Cape May County

Ocean City

North Wildwood

   The system will still affect our area today and into tomorrow, as some bands wrap around the low off the coast, bringing some snow and rain showers throughout the day and overnight tonight.  Any accumulations would be very light, the best chance for seeing snow on the ground in anyway would be as you head north in New Jersey.  The good news, though, is that this weekend is going to be beautiful with plenty of sunshine and highs in the upper 50's!

Snow Totals Revision

   Hey everybody, after looking at the latest models and giving it more thought, I have decided to revise my snow totals map a tad bit.  It is very hard to predict totals with this storm because it is unknown how much snow tonight will stick to the ground because of how warm surface temperatures are.  Also, as the storm strengthens along the coast, a stronger onshore flow of warm, marine air will affect the coast. It is uncertain how much this will affect snowfall later on tonight.  Therefore, be prepared to possibly wake up tomorrow to the potential of not really having much snow on the ground.  Regardless, temperatures over the next few days, especially this weekend, will be well-above freezing, so any accumulations will quickly melt away. 

 

Final Thoughts on the 3/6-3/7 Storm

Sorry if this is kind of brief, but I've had a busy night and haven't been near a computer.  

   I only have one change to mention about the snowstorm, and that is that it will start earlier and end earlier.  The moisture should move in within the next few hours and end in the morning on Thursday.  I am sticking with my earlier thoughts on snowfall amounts: coating to 2" along the shore, then a general 2-6" for inland New Jersey and Philadelphia, with the interior of New Jersey receiving the most.  I believe that a few localized areas will receive more than 6 inches, but regardless, this storm should not be too bad snow-wise.
 
   Although the snowfall will not be crippling, and should be mostly confined to grassy areas, other aspects of this storm may cause dangerous conditions.  Since the snow will be a very dense and heavy snow due to near-freezing temperatures, it could cause power lines and tree limbs to come down as it accumulates on them.  Also, winds will also add to the potential danger of downed power lines and tree limbs, as they will be in excess of 20mph and gust even higher than that.  Finally, the shore points will see the threat of flooding due to the counterclockwise, onshore flow of winds around the low-pressure center, which will help to push the ocean waters inland.

   In the days following the winter storm, I will post about post-storm snow totals, upcoming forecasts, any possible threats in the coming week or two, and an early outlook for spring break at Rutgers, March 16th-24th.

Winter Storm Watches Posted

   The National Weather Service in Mt. Holly has posted winter storm watches for the southern New Jersey counties and Philadelphia.  A winter storm watch is posted when there is potential for significant winter weather within the next 36 hours.  This watch includes Gloucester, Camden, northwestern and southeastern Burlington, Ocean, Atlantic, and Philadelphia counties.  Also, coastal flood and high wind warnings have been posted for the NJ coastline.  The National Weather Service has forecasted 3-5 inches of snow for our area tomorrow night into Thursday.



Credit: http://www.weather.gov/phi/

First Guess at Snowfall Totals (3/6-3/7 Storm)

   This is an extremely complicated system that is even stumping the hardiest of meteorologists.  Everything about it is complex: what the exact track will actually be, the location of the rain/snow line, the amount of snowfall that will actually stick due to the ground temperatures and rain, and where heavy snow bands will set up.  Of course, some of these are problems in most winter storms.  Therefore, it may take until tonight to come up with a final call that I will feel confident in. 

   Regardless, there has been a major change to this storm.  The NAM and GFS both give our area a hit for snowfall.  The 0Z EURO model run from last night still keeps the main bulk of precipitation to the south but did take a step to the north, though.  However, I’m going to go with the short-range model, NAM, and the GFS and say that New Jersey and Philly will see some decent snowfall.

   As of now, I believe that rain/mix will begin on Wednesday in the early afternoon, with scattered showers possibly starting earlier. This will then turn over completely to a heavy, wet snow around nightfall and last into Thursday morning.  The NJ coastline should expect more in the way of rain with some snow due to the onshore flow of warmer, marine air from the winds that will flow westward around the low. 

Here is what the 12Z NAM run says for snowfall totals in our area...

Credit: http://raleighwx.americanwx.com/models/nam/12znamsnow_NE048.gif

   

   Snowfall accumulations are very difficult to pinpoint with this storm at this point.  Due to the air temperature hovering around freezing, the snow will be a very heavy and wet snow that accumulates slower than the fluffy, powdery snow that falls in colder temperatures.  Coastlines shouldn’t see much of an accumulation, maybe an inch or two at most.  Interior NJ and Philly should see a widespread area of 3-6 inches, but depending on the exact track and heavy snow banding, I believe that 6+” totals could occur in random pockets of interior NJ.  I think that the best chances for higher snow accumulations in the South Jersey/Philly area will be southwestern New Jersey. 

Here is my first guess at what tomorrow's storm should bring us in terms of snowfall totals...

   

   Due to the great uncertainty surrounding this storm, my snowfall map may change later today as more information becomes available. 

Initial Thoughts on 3/6-3/7 Snowstorm

   This week's storm will be another that disappoints snow-lovers and will delight those that loathe the snow. For several days now, the best model, the EURO, has kept Wednesday/Thursday's snowstorm south of us into northern North Carolina, Virginia, and Maryland.  Another factor that keeps the disappointment for snow-lovers coming is the approaching spring.  This means that we are in March...the sun angle is changing, cold air is becoming less available, and ground temperatures are gradually warming up, especially thanks to the past week or two.  Regardless, the NAM, a short-range weather model, is now in play and also keeps a lot of the moisture to the south of New Jersey.

   

   The timetable for this storm is that rain should begin by Wednesday afternoon, turn to a wet, heavy snow at night, and end on Thursday as some lingering rain and snow showers.  We're on the outer fringes of the storm, leaving precipitation with this storm in New Jersey and Philadelphia at a premium.  The surface temperatures for us will be in the 30's and 40's, leaving us on the ugly, rainy side of the rain/snow line for much of this storm, which has been the case for most of the snow events this winter.  

   

   Snow amounts will be at a minimal with this storm due to the rain and warm ground temperatures.  The immediate NJ coastline will see temperatures too warm to support much in the way of snow accumulations, while the farther south you go in Jersey, the more of a chance you have at any accumulation.  My early thoughts would be a general coating to a few inches of snow for South Jersey and Philly, if there is accumulation at all.  However, the American GFS model does have us receiving more snow than the other models, so the potential is still there for some higher accumulations.  Disregarding precipitation, it will be windy, no matter what, as the low intensifies on its approach to the Atlantic coast: winds at 20-25mph, potentially gusting to 30+mph with higher winds along the coast.

This is the NAM's latest accumulated snow map(12Z) from today that shows accumulated snow through Thursday morning.  I agree with this map, as of now, as it gives most of our area an inch or two, at most.

Credit: http://raleighwx.americanwx.com/models/nam/12znamsnow_NE072.gif