Saturday, March 23, 2013

11 comments:
So, What's The Deal? 
(with this storm...)


9:25 PM EDT 3/23/13 (Winter Stormcast Team) If you're like Forecaster Christy-- and wondering what to expect for the upcoming "winter-like" storm moving across the country, here are some questions our team is investigating:
  • Will this storm be a "repeat bust" of the March 5th storm?
  • Even though it may be cold right now, will it be cold enough by Sunday night in which did see snow last time?
  • If the metro areas from Philadelphia to Washington remain in a northeasterly flow, will temperatures cool sufficiently before moisture is pulled away from the coast as the storm intensifies?
  • Is it possible for areas expecting rain Sunday afternoon and evening, with temperatures in the 40's, to receive accumulating snow overnight with lows in the lower 30's?
  • Could rapid intensification near the coast produce additional high impacts in areas that currently are not expecting significant effects?
Pennsylvania Team: 
Forecasters Andrew Barney, Zach Fasnacht, Christy Reuille, Amber Liggett
Maryland Team: 
Forecasters Mike Natoli, Advisor Rich Foot

Friday, March 22, 2013

17 comments:
The Winter That Wasn't...Won't Leave

9:45 PM EDT 3/22 (Forecaster Mike & Winter Stormcast Team) The calendar may have flipped to spring, but the weather is stuck in winter. With highly unusual cold for this time of year, across  much of the U.S., all it takes is a storm to form and rare spring snows may start. As a result of this chill and wintry pattern, there may be another winter storm in the works at the end of spring’s first weekend to impact the Mid-Atlantic Sunday night into Monday. The good news? We currently do not expect a major, high impact snowstorm is at this point, but some inland areas are likely to receive accumulating snow. 
(Photo credit: Fusion Photographer Emily R., Carroll County MD)

WHY SO COLD? - This excessive cold pattern of late has been caused in part by a near record low value of the Arctic Oscillation (AO). When the AO goes so negative like it is currently (shown by the sharply decreases on the graphic to the right)  it creates an upper level “block” in the atmosphere at high latitudes, and this displaces the cold air. In response, the cold air has nowhere to go, so it floods southward into the United States. 

We have limited the possibilities down to two scenarios that we believe are most likely. At this point, we think that Scenario A is the more likely of the two, but we cannot eliminate Scenario B just yet. 

CURRENT SNOWFALL PROBABILITIES FOR 4 OR MORE INCHES, SUNDAY NIGHT - MONDAY 

Source: NOAA Weather Prediction Center
  • SCENARIO A Most Probable: "The Warmer Storm" In this scenario, the low pressure center would take a more northerly track, and flood warm air in off the ocean. Since the storm has access to only marginal cold air, it would be forced to create its own, but due to low precipitation rates, more rain would dominate. 
POSSIBLE RESULTS?  Coastal areas of the Mid-Atlantic would be all rain. For those along the I-95 Corridor, this scenario would bring rain, with snow mixed in at times, but little accumulation. In this case most of the snow would be confined well NW of I-95, and at higher elevations. 

  • SCENARIO BLess Probable: "The Colder StormIn this scenario, we would have the storm staying a little further south. Instead of pulling warm air off the ocean, it may have access so some cold air being fed from the north, but the set up is marginal for that as well. 
POSSIBLE RESULTS? With more cold air available for the storm to work with, we would be looking at snow reaching the I-95 corridor and the major cities. Accumulations would NOT be extreme, but given the time of year, even light accumulations are noteworthy. For the coast, this scenario would bring rain with snow mixing in at times. 

Check back later tonight for an update from the weather graphics team that will visually depict these scenarios, and thanks for your interest in our information. (Forecasters Mike N., Connor M., Jason M., Zach F., Meteorologist Alex D., Advisor R. Foot)


Wednesday, March 20, 2013

2 comments:
Spring? Winter? Are we still sure?

7:25 PM EDT 3/21/13 
(A special report from our North Georgia & Metro Atlanta Team) 

Good Evening! As we stated yesterday... the system that heading our way for tonight into tomorrow is a very complicated system. 

With the newest information we have made significant changes to our map and accumulations amounts. We will continue to monitor the situation and will update if it needed through the evening.



VARIABLES THAT CAUSED THESE CHANGES:
  • Cooler air is expected to effect the entire region with temperatures that will be at or
  • below freezing area-wide.
  • More moisture will affect the western portions of Georgia.
PRECIPITATION AMOUNTS:
  • West Central & Southwestern Metro Atlanta: Up to a Dusting
  • Northeast Georgia Mountains: Up to a Dusting
  • All Other Sections of North Georgia: No Accumulations Expected
We will continue to keep you up to date with any changes...


7:00 PM EDT 3/20/13 (Forecaster Isaacs: Special Report from our Surf & Sail Team)

Good Evening Everyone! As we stated earlier in the day...welcome to Spring! Are you ready for the warmer temperatures? Well...this will not be the case for us tonight going into tomorrow. Look at the picture...what do you see?  Even though it is from a few years ago, if the winter weather advisories hold true... well, there could really be SNOW...on the first day of Spring-- and on the beach,  believe it or not!

Photo credit: marylandonmymind.com from the Boardwalk of Ocean City, Maryland



  • SNOWFALL AMOUNTS: We believe that the ADVISORY area has the potential to receive 1 to 1 1/2 inches of snow with some isolated amounts up to 3 inches. Most of the snowfall will occur on grassy surfaces and should not cause major impacts on area roadways due to the recently warm temperatures.
  • HAZARDS: As with any snowfall event, the potential for some slushy roadways during the pre-dawn hours on untreated side roads are possible and precautions should be taken if you plan to travel during this time. 



We hope that you enjoy this minor snowfall event! Please share some pictures on our page!

Monday, March 18, 2013

9 comments:

Who's down for an early Spring warmup?

REPEATING 50-DAY PATTERN OF TROUGHS AND WARMUPS SINCE EARLY WINTER 
POINTS TO EARLY APRIL SURGE OF ABOVE NORMAL TEMPS IN EASTERN U.S. 


3/18/2013 (Forecaster Nic Roberson and the Long Range Team) 

If you are ready to be "done" with the recurring cold spells, our team is with you on that! We have been looking down the road to pick out signs for what could lead to a nice warm up in the east toward late March and early April. We offer this analysis of the pattern going back from early December, and moving forward to present day. these indicators. 

(Image: 8-14 day temperature projections from the NOAA Climate Prediction Center) 
  • A DECEMBER START Using the "Lezak Recurring Cycle" hypothesis (LRC) helps us find a starting point to the seasonal trends, in this case we go back to Dec 10 2012 as shown below. This image   shows much above normal temps can be seen across a good portion of the south east US into the Mid Atlantic. 
  • A JANUARY REPEAT Going forward 51 days from that period brings us to Jan 30, 2013. Take notice of how the orientation of the upper level troughs in both situations led to more above normal temps in parts of the East -- for both mid December and end of January. 
  • WHAT IS NEXT? Going forward from late March into early April, we expect to see this trough arrangement to repeat once again, giving rise to another warm up ahead of it, propagating East with time. The warm spell will likely start in interior sections after Easter, and reach the coast by start of April. However, one area that may yet escape this warmth may be upper portions of the Northeast, which could still be under heavy snowcover by then. 

Wednesday, March 6, 2013

30 comments:

Celebrating St. Patrick's Weekend With You!
Connect with local forecasters in these Featured Zones across 30 states, UK  & New Zealand: 


Zones Listed By Region 
8 comments:
Another Storm That Just...Wasn’t 



7:00 PM EST 3/6 (Mid-Atlantic Winter Stormcast Director Zach Fasnacht)

Today, many meteorologists, Foot’s included, were wrong on their forecasts as a major winter snowstorm turned into no more than a rain and snow mix for most areas. Although some places did receive decent snow accumulations today, many other regions, including areas of our highest readership in Baltimore and Washington D.C., this storm was a major bust. The Winter Storm Warnings that were issued, disappeared quietly and some  students were making mud angels in puddles rather than snow angels.

SO WHAT WENT WRONG? Going into this storm some of us worried that an easterly flow could keep things too warm, but the models disagreed and so we put a little too much faith in the models in predicting the precipitation type. 

  • It turned out that a mixture of cloud cover Tuesday night and an easterly flow kept surface temperatures too warm for snow in many places. Other areas saw snow, but due to the lack of intensity it did not accumulate as the high sun angle this time of year wreaks havoc on accumulation. 
  • Without the cold air in place or heavy precipitation, we lacked the ingredients to create a widespread major snowstorm. When making our forecast we outlined some of the factors that could affect it, but in the long run we did not assess this as much as needed and they came back to beat us:     (http://www.footsforecast.org/2013/03/just-when-you-thought-it-was-safe.html).

LIFE LESSONS Without making any excuses for the forecast, meteorology is still an imperfect science. Many of us at Foot’s are currently studying in college to improve the science whether through computer modeling, atmospheric science research, or other related fields of study. 

Unfortunately, despite that dozens of team members collaborated for hours on end in this this storm, the forecast ended up wrong. We aim to continue earning your trust and readership, and hope you will not turn away from our authentic local weather source due to this one event. Earning your loyalty is key for us, as we seek to always put our best Foot forward trying to improve and provide you with the best forecast possible. 

Enjoy the rest of your week and hint hint, some warmer weather could make some smiling faces this weekend!

Yours Truly,
Winter Stormcast Team
(Director Zachary F., Advisor Rich F., Meteorologist Alex D., Michael M., Connor M., Jason M., Nikki B., Greg J., Dakota S.)
87 comments:
A Series Of Unfortunate Events?
- Headline derived from the 2004 Disney film starring Jim Carrey 

What turned out a "Nomageddon" for some places along I-95 
in Maryland was a winter wonderland for others farther inland. 
(L: southern Baltimore County; R: Carroll County, MD)

3:50 PM EST 3/6 (Winter Stormcast Team) STORM MESSAGE: For those who saw snow today, among the reasons were simply geography and sun angle. Your location being farther inland and away from moderating influence of an Easterly wind created a more favorable environment for snow to form at upper levels -- and reach the surface to accumulate. 

Our headline is also a fancy way of saying what makes forecasters the world over cringe: A bust

Those who did not receive the snow we forecasted, the reasons were outlined as wild cards in our Monday 8 PM post, "Just When You Thought It Was Safe" where Forecaster Mike stated the following (note we are not trying to "explain away" the storm ;-)

"SNOW FACTORS: Given that it is late in the season there are many factors that could affect accumulations. 
  • SUN ANGLE: Since we are nearing the start of Spring, the angle of direct sunlight is increasing with each passing day. This could limit snowfall accumulations during the day. Areas that see higher snow rates however should not see this as an issue as the snow rates will overcome any melting from the sun. Additionally, sun angle also influences road temperatures (believe it or not) as solar radiation passes through the cloud layer.
  • TIMING: The time of day is also an issue as it is easier for the snow to start accumulation overnight than during the day.
Below is our previous update from 7:30 AM this morning

Tuesday, March 5, 2013

48 comments:
Knock, Knock, Knocking On (Mid-Atlantic's) Door


11:40 PM EST 3/5 (Winter Stormcast Team) Are you seeing snow or rain yet? Let us know!

STORM OVERVIEW: The day many of us never expected would happen this Winter is less than 12 hours away. Yes, in less than 12 hours a major snowstorm will be affecting much of the mid-Atlantic region. 

  • Precipitation should begin moving into the region around midnight with heavy snow likely through the day Wednesday. By the time the snow ends Wednesday night, many areas of central Maryland, northern Virginia, eastern West Virginia, and southern Pennsylvania should have a significant accumulation of snow on the ground. 
  • There will be many impacts from this storm including school closures, flight cancellations, and scattered power outages making this a high impact event.

TIMING: Precipitation is already moving into southern portions of the region and will move into the remainder of the Mid Atlantic over the next couple hours:

  • We expect precipitation to continue across much of West Virginia, Virginia, Delaware, Maryland, and Pennsylvania throughout the day on Wednesday. 
  • Precipitation should taper off during the late evening across West Virginia and western portions of Maryland, Virginia and Pennsylvania. 
  • For areas farther to the east across the Delmarva and eastern Pennsylvania, precipitation may not clear out until the early morning hours on Thursday.

PRECIPITATION TYPE:
As with many of the storms this winter, precipitation type could be an issue for some portions of the mid-Atlantic: We expect a mix of rain and snow at onset around the I-95 corridor before changing to heavy snow. 
  • To the west of I-95 and the Baltimore-D.C. metro area, expect all snow which will be heavy at times on Wednesday. 
  • Areas east of I-95 could see mixing continue through the day, limiting snowfall accumulations. 
  • Further east along the coast, expect mainly rain with some snow mixing in at times.

IMPACTS: In areas that do experience snowfall, we expect there to be fairly significant impacts. Due to the duration of the event, both the morning and evening commutes will be extremely difficult, especially west of I-95. 
  • As a result of the marginal air mass associated with this storm, snow that falls will have an extremely high moisture content, which can be very heavy in large amounts. This poses a threat to power lines, trees, and weakened structures where snow is able to accumulate. 
  • Although the majority of vulnerable trees and limbs have already fallen victim to recent weather events, we still expect there to be power outages in the area and urge residents to be prepared. 
  • Many school closures are expected on Wednesday so make sure to check your school before heading out the door. Also, local airports have already begun canceling flights by the hundreds and we expect this to continue. 
  • Lastly, due to the heavy nature of the snow, please take many breaks and stay hydrated while attempting to remove snow from your property.

ACCUMULATIONS: Snow is expected to be heavy at times, especially across central Maryland and southern Pennsylvania where rates could reach 2-3” per hour. The Baltimore-Washington metro area could see 4-8” with places to the west seeing higher amounts. Below is a list of snowfall accumulations expected per city:
Washington D.C.: 4-8” | Baltimore, MD: 4-8”Westminster, MD: 4-8" | Annapolis, MD: 3-5”Ocean City, MD: Mainly rain | Dover, DE: 2-4”
Hagerstown, MD: 8-12” | Martinsburg, WV: 8-12”Pittsburgh, PA: 4-6” | Harrisburg, PA: 4-8”Philadelphia, PA: 4-8” | Atlantic City, NJ: 2-4
Winter Stormcast Team 
(Winter Stormcast Director Zachary Fasnacht, Mid-Atlantic Director Greg J., Advisor Rich F., Meteorologist Alex D., Michael N., Connor M., Jason M., Nikki B.)

69 comments:
" Really? Really..."
-Amy Pollard and Seth Meyers, Saturday Night Live

Mostly clear skies in Baltimore City, MD
as the sun sets before the storm
5:35 PM EST 3/5 (Forecasters Foot and Natoli) For those basking in sunshine across the eastern Mid-Atlantic today, it is hard to imagine that winter is about to make a serious comeback tonight into Thursday. Today's conditions, with highs in the upper 40s to 50 in the Washington DC are a weather forecast version of the famous SNL News Update skits by Amy and Seth. 

You probably got "the look" from someone today when you asked, "Ready for the storm?" [big smile]. To which your colleague said, "What storm??"

And we know a few folks then said either. "Oh, you'll find out..." or "I have my sources." Thanks for making our team one of your sources, because our site traffic shows that obviously someone was reading, to the tune of 200,000 hits to this page over 2 days! 

That said, we are not resting on our snow-covered laurels, and hope to address some good questions from readers below regarding our snow forecasts, as shown in the preliminary forecast map as issued on Monday 3/4 at 6:00 PM.





WILDCARD # 1 - Could Forecasted Snow Amounts Be Too HIGH? 
  • Mixing - We are watching the potential for east winds to bring in warmer air off of the Chesapeake Bay around midday Wednesday, which could cause some areas to re-mix with or change to snow. 
  • Lower Rates - This storm involves the low pressure in the Ohio Valley weakening, then a new one strengthening on the coast. While energy is transferring, we may see lower precipitation rates, which would limit the ability of the storm to bring down cold air from the upper atmosphere. 

WILDCARD # 2 - Could Forecasted Snow Amounts be too LOW? 
  • Banding – As the storm strengthens, it pulls some local bands of heavy precipitation through, similar to what happened in Connecticut a month ago. This wouldn’t bring accumulations nearly that significant but possibly higher than what we are currently projecting. 
  • Stalling – We are also watching the potential for the low pressure system to slow down or stall off the coast, leaving precipitation and snow producing temperatures over the region through Wednesday night or Thursday early morning.
The High Resolution Rapid Refresh (HRRR) model 

The bottom line on our current forecast: No major changes.
Our team will issued a FINAL SNOWFALL FORECAST later this evening.
For links to our previous reports, visit these stories:

20 comments:
Can't Hardly Wait?

Preliminary snowfall for the Central Mid-Atlantic until 6 PM Wednesday

5:00 AM EST 3/5/12 Are you one of those who "Can't Hardly Wait?" for the next update or for every snippet of storm news, good or bad? For powderhounds, this upcoming storm will be a dream few can envision right now. But if you're in public safety, facilities or transportation or the health care industry, it's a slow-moving nightmare. 

Either way, we know you can't hardly wait to learn there are some BIG changes to the forecast, including: 

Monday, March 4, 2013

9 comments:
"Just When You Thought It Was Safe..."
- Jaws



8:00 PM EST 3/4 (Winter Stormcast Team) While many readers in the Mid-Atlantic this winter have sad watching in either dismay or glee as snowstorms affect other regions, this time, the sharks have come back to feed. If you want a snow-fueled frenzy, we have good news, and if falling back into winter's clutches is your worst fear, then prepare for bad news. 

major winter storm is expected to bear down on much of the mid-Atlantic Tuesday night into Wednesday. Many areas from Maryland, Virginia, West Virginia, Pennsylvania, and New Jersey could experience heavy snow from this system. Our preliminary snowfall map for the region as follows:



9 comments:
This. Is. Not. A. Drill.

HIGH-IMPACT SNOW EVENT FOR MID-ATLANTIC
Region faces most widespread storm since Jan 26, 2011

3:30 PM EST 3/4/13 | LATEST FROM OUR WINTER STORMCAST TEAM 
Forecasters Greg J., Michael N., Zachary F., Connor M., Jason M., Foot, Davies


As part of our team's pre-storm process to establish the basis for a snowfall forecast, we first introduce the data origins, that of "QPF" or "Quantitative Precipitation Forecast" The enclosed chart is based on NOAA data as rendered by the weather website coolwx.com.

THE GENERAL GIST? 
Several computer models have projected a general 1.5 to 2.0 inches of liquid for much of Virginia and Maryland, with up to 1.0 inches for southern Pennsylvania. With snow ratios expected to start "lower" due to marginal temperatures, we are anticipating much of the snow will fall at an 8:1 ratio, ending near 10:1 in western areas of the Mid-Atlantic.



RATIOS VS. SNOWFALL: 

The chart show indicates what is possible were this storm to "overperform" regarding both liquid amounts (closer to 2.0") and ratios. We expect snow to begin late Tuesday night, with the bulk of the heavy snow Wednesday morning to midday. This may cause ratios to decrease in areas near the coast, along I-95, with normally colder areas west of the major cities, along I-81 corridor staying with higher ratios.

BOTTOM LINE? We want readers in the Mid-Atlantic to be prepared for a heavy wet snow event that may produce 5-8 inches in the major mid- Atlantic cities by Wednesday noon. Much higher amounts of up to 12 inches are possible just west of those areas-- from southern PA to northern Baltimore County through Carroll, western Howard and down to west of DC and along I-81.

If liquid equivalent trends continue rising, and the storm begins Tuesday night as mostly snow, much of the region may face a significantly higher impact storm than is currently being forecasted by our team and other outlets.


(Forecasters Foot, Connor, Jason, Greg, Zach; Meteorologist Davies)



10:30 AM EST 3/4 : Previous update from the Winter Stormcast Team 

NOAA/NWS WINTER STORM STATEMENTS:
  • Eastern US NWS Regional HQ:  Winter Storm Watches in effect for all of central & western Maryland, northern & central Virginia, the Baltimore-Washington metro areas and southern Pennsylvania.

WINTER STORM MODE Due to the likelihood of significant winter weather within the next 48 hours,  "Winter Storm Mode" is activated for the following zones. This is to notify our readers of increased coverage and postings in affected local zones:
  • ALL MARYLAND ZONES, ALL VIRGINIA ZONES, POTOMAC RIVER VALLEY
  • THREE RIVERS, SOUTHEAST PENNSYLVANIA, CENTRAL PENNSYLVANIA

SYNOPSIS: After anxiously waiting for months on end for a big snowfall, it appears as though many readers in the mid-Atlantic will finally receive THE snowstorm of the year in a powder-filled last hurrah. The latest computer projections of liquid equivalents in this storm are showing a possible 1.0" or greater for the Baltimore-Washington area into southern Pennsylvania. Some models, such as the short-range NAM (North American Mesoscale) show up to 0.79" of liquid falling as snow, whereas the GFS (Global Forecast System) reduces snow liquid equivalent to just 0.49" as snow, with a disruptive 1.12" of sleet as another possibility! 

If the storm starts as all snow, then snow-to-liquid ratios may start lower, but end higher, at a point in time when the storm is at its peak in the overnight hours into Wednesday.  If so, the resulting snowfall could become a significant event for the region.
  • Bulk of the snowstorm should move through from Tuesday night to Wednesday night providing a period of heavy snow to many areas of central mid-Atlantic. The exact track of heaviest snow is still an uncertainty, but at the moment much of central and western Maryland look to be the center point.
  • This storm is likely to be a high impact event for much of the region, causing difficult travel, widespread school closures, and flight cancellations Tuesday night through Thursday morning. Below we outline the current scenarios that we see for this significant snowstorm with the first being most likely. 

SNOWFALL SCENARIOS: The map shown below displays shows our two scenarios for the heaviest snowfall amounts. If you are not in the areas, it does not mean you will not see snow, it just means that you will likely not be in the heaviest snow area. We will have additional updates and preliminary snowfall totals posted later today.



SCENARIO A (Slower storm with a northerly component, heavy snow in MD)

TIMING: In this scenario, the storm is a bit slower and is able to push further north before moving offshore. Expect precipitation to push into portions of the mid-Atlantic Tuesday evening. Snow would be heaviest through the day Wednesday before coming to an end from west to east Wednesday night.  

ACCUMULATIONS: Central and western Maryland, along with and south central Pennsylvania could see significant to high snowfall accumulations. Other areas across southern Pennsylvania could see a moderate to significant snowfall, especially across Franklin and Adams counties. Further east across southern New Jersey and Delaware, precipitation should start as rain and might change to snow for a few hours before pushing offshore leading to slushy accumulations of a few inches.  

IMPACTS:  Portions of central and southern Maryland could start as rain before changing to heavy snow. An extended period of heavy snow is likely across Maryland and extreme south central Pennsylvania (southern Adams, Franklin, Fulton, and Bedford counties) which could last for up to 12 hours. 

The snow would be heavy wet snow and given the heavy accumulations, damage would be expected for weak structures than cannot handle the weight of the snow. This would cause travel problems Tuesday night through Thursday morning across Maryland and southern Pennsylvania. Many flights would likely be cancelled on Wednesday at Dulles and BWI.

SCENARIO B (Storm departs more quickly. heavy snow stays in Virginia)

TIMING: Precipitation would begin across the mid-Atlantic Tuesday afternoon. Heaviest snow would fall across Virginia Tuesday night and taper off around midday Wednesday. 
IMPACTS/ACCUMULATIONS: The storm could push offshore before developing and not provide much precipitation to the central mid-Atlantic. This could lead to a mix of rain and snow changing to heavy snow with significant accumulations across Central Virginia. 
Further north some light to moderate snow is possible, but rain may mix in and lower accumulations. The snow would be heavy wet snow, so damage is possible if enough of it piles up on a weak structure. Travel would be affected Tuesday afternoon through Wednesday afternoon across portions of central and northern Virginia.