Late-May News and Updates

Hello Grotonweather Fans! I have been working very hard over the past couple of months on new and exciting things. I thought I would type up a blog to explain and promote some of these things.

First off is Finger Lakes Weather (www.fl-weather.com), my new weather forecasting and consulting business. It is my hope that Finger Lakes Weather will become my career, helping local businesses, organizations, and the public with private and customizable weather forecasts. Finger Lakes Weather offers a variety of "Forecast Packages" tailored specifically towards various groups. For the spring, I offered a frost forecast package and was able to do some free-trial forecasting for Fox Run Vineyards and Three Brothers Vineyards, both on Seneca Lake. I have plans for a forecast package for construction workers. Right now, I am offering a special on vacation forecasting...but more on that later. Check out Finger Lakes Weather (the website again is www.fl-weather.com) and join the Finger Lakes Facebook page.

Next up is the Grotonweather Radar Page (www.grotonweather.com/radar). I recently got some top-notch radar software that is used by many meteorologists, especially storm chasers and others interested in thunderstorms. This software allows me to upload the radar to the website, so that is what I have done. Furthermore, I can display things such as areas of possible hail, rotation in thunderstorms, winds, and watches and warnings. I can also zoom right in on a storm down to street-level. So far, this has been a HUGE success with hundred of views despite an overall quiet thunderstorm season thusfar.

A severe thunderstorm approaches Ithaca.

Success does not come without price, however. And in this case, the price is measured in bandwidth. For those not familiar, bandwidth is basically the amount of data transferred to and from a website. The radar page uploads large image files every few minutes and quickly ate up my monthly bandwidth limit. That in turn forced me to purchase a more expensive hosting plan. My costs for running Grotonweather.com, not including time spent, is now approaching $200 a year.

Since 2006, when I started this operation, I have not received any revenue from my website. I am dedicated to keeping the website free. As costs continue to rise, something has to be done to offset some of these costs. Rather than charge money for Grotonweather and rather than flat out asking for donations, I decided a fund-raiser would be the best idea.

This is where the vacation forecasting package from Finger Lakes Weather (www.fl-weather.com/vacation) comes back into play. As a fund-raiser, I am offering this service at a reduced price of just $10 per day or $50 per week. What does that entail? I will forecast for your travels to and from your vacation destination. I will forecast for you each morning of your trip so that you can know what to expect. If you have plans to engage in a certain activity- whether a day at the beach, a horseback ride, a bicycle tour...anything at all- I will forecast specifically for that activity and how the weather might impact your plans.

Furthermore, I will do severe weather forecasting for you. Say you are driving down the highway in Kansas and you see storms ahead. You can give me a call- no matter what time of day or night- and ask me if they are severe. Or, if you are enjoying your vacation (which you should be!), but storms (or a hurricane!) are coming, I will reach out to you and let you know.

I think this is a really neat and unique service and I believe it will help you make the most of your vacation. And it would really help relieve some of the costs I have. So please, consider signing up before June 10th to get the sale price. Even if your vacation is in August or later, book it now. Here is the link again: www.fl-weather.com/vacation

Moving on now, I am slowly working on a redesign of Grotonweather.com. I am really excited about how it looks so far. I did a survey a couple of weeks ago on displaying confidence and uncertainty in forecasts. The results were a tremendous help, so thank you to all who participated! I am now doing a smaller follow-up survey on a proposed forecast layout change. Please, if you could take a moment and fill it out, I would be very grateful. Here is the link: www.grotonweather.com/survey

If that was all not enough, I also started a new project on Facebook in an attempt to 1) combine my strong religious beliefs with my love for the weather 2) help those threatened by severe weather on a national level and 3) expand my forecasting beyond just the Finger Lakes. The result is the Storming Heaven Facebook group. If you believe in the power of prayer, go ahead an join up.

Back in late March, the Groton Public Library invited me to give an hour-long presentation. I presented on the Blizzard of 1993. Thank you to the library for the opportunity to speak! If you would like me to speak at your event or in your class (I've spoken at 3 schools since November), just send me an email or let me know on Facebook!

Thank you for reading this long post and for your continued support and interest in Grotonweather.com and the other projects I am working on. Stay tuned for more great features coming up...I am only getting started!!!

Was Irene Really a Bust?

In the days leading up to Irene, the media was alive with dire warnings about how bad Irene could be. In the days following the hurricane, the buzz is about how terrible of a job the predictions were. Really? Or, rather, I should say "You've got to be kidding me!?"

If you were expecting a monster storm surge to flood into New York City like in the movie, "The Day After Tomorrow" (left), then of course you will be calling this storm a bust. That is Hollywood and nothing like that was ever predicted. The real storm surge predictions were 4-8 feet. In an area unaccustomed to hurricanes, such a storm surge could catch people unaware and prove to be deadly. It does not take much of a storm surge to be destructive. But never, ever was total destruction of New York City actually forecast. Many areas met this storm surge prediction and it was a good forecast.

The forecasts called for Irene to be a weak hurricane or strong tropical storm as she moved over top of New York City. At 9am EDT on Sunday, the center of Irene moved directly over Central Park- a remarkably accurate positional forecast which should be applauded, since one of the harder things to predict about a hurricane is its future position. When Irene moved over, the winds were at 65 mph- a strong tropical storm, as expected. Additionally, Central Park received nearly 7" of rain. That is nearly double the average amount of rain Central Park gets in August. What more do you people want before this is labeled significant?

If you are still not satisfied, we can chalk New York City up to being spared the worst and, if you really wish to believe so, over-hyped by the media (not the meteorologists). But the miss was pretty much only for there. It is extremely insensitive and just plain wrong to say Irene was a bust.

As of this writing, 2.5 million homes and businesses were still without power, 2-3 days after Irene came through. Roads throughout the Northeast are washed out or impassible due to fallen trees. Homes have been washed away. Entire towns have been flooded or cut off completely. Some towns have lost all their bridges. Some of these bridges that were washed out have been in service for over 150 years. Even part of the New York State Thruway remains closed. If this storm was such a bust...such a run-of-the-mill storm...nothing worse than a nor'easter...then why all the unprecedented destruction?

And that is just the material loss. At least 40 people have died from this "over-hyped bust" of a storm. Any loss of life is tragic. Those 40+ deaths translate to 40+ tragedies. Ask the family members of any of those who lost their lives if Irene was blown out of proportion. Perhaps they would have a different perspective.

The bottom line is this: even large weather systems like Irene have small subtitles that are not understood and certainly not possible to forecast. The geography of an area also plays a significant role in what exactly happens during a storm. Just because New York City was spared destruction does not mean other areas were. Look beyond your own backyard, your own town, even your own part of the state. It is easy to forget the sufferings of other and blast the forecasters for crying wolf. Just because the wolf didn't get you this time doesn't mean that next time you will be so lucky.

No Alert Mode this time...

A potentially significant severe weather outbreak across much of the northeast, including our area is beginning. However, Grotonweather.com will NOT be going into alert mode for this event. As I mentioned in the Alert Mode blog, I take the issuing of Alert Mode very seriously. I only issue them when it seems like widespread, life threatening weather is likely.

Today's event is very close to that criteria, and I cannot say for sure that I will not issue Alert Mode status later in the day. At this point though, I do not think the storms will organize quite fast enough to bring the high risks necessary for an Alert Mode. If this site was for Chenango, Monroe and Otsego counties, I very likely would be going into Alert Mode. The worst of this event, in terms of spatial coverage and intensity, will likely be just to our east.

That being said, storms are already starting to develop in our area and just to the west. These storms will not take long to become severe, and our threats for wind damage and hail remain at a 'MODERATE' level. Winds up to 80mph and two inch hail are not totally out of the question. Stay tuned for updates!

Severe Weather Awareness Week

This week is Severe Weather Awareness Week. In light of the recent severe and tornadic thunderstorms, I think its very important that we realize that dangerous and deadly weather can and does occur in our area. The first step to keeping yourself safe is education. I will be updating this blog each day with links to the National Weather Service pages for each day of Severe Weather Awareness Week.

Monday- Overview
Tuesday- Severe Thunderstorms
Wednesday- Severe Weather Preparedness
Thursday- Tornado Watches & Warnings
Friday- Flood Preparedness
Saturday- Communication of Hazardous Weather Information

What does an "Alert Mode" mean?

Every once in a while, grotonweather.com will go into "Alert Mode" for various weather phenomenon. Flooding, heavy snow and severe thunderstorms are the three most common prompters of an Alert Mode. But what exactly do I mean by this, and how do I determine when to go into Alert Mode. This post will hopefully help you understand this better.

The Alert Mode is reserved for special instances of exceptionally dangerous weather that will impact the lives of those in and around the Grotonweather.com forecast area. The weather during an Alert Mode threatens lives and property. Precautions to stay safe need to be taken during these events. These are among the most significant weather events our area sees, and are accompanied by widespread watches and warnings issued by the National Weather Service. The Alert Mode is meant as another way to highlight the potential dangers.

Obviously, not every significant weather event is worthy of an Alert Mode, and the decision to send Grotonweather.com into Alert Mode is taken very seriously. Only a few Alert Modes are issued each year. A combination of things has to be taken into account when going into Alert Mode:

First, the weather needs to be significant enough to create widespread dangerous conditions. Every severe thunderstorm is dangerous, and even a little freezing rain can cause deadly automobile accidents. However, most of the time, these dangerous weather events are more localized events that most Central New Yorkers are probably used to. For an event to garner an Alert Mode, it has to be above and beyond the "average" bad weather situation.

Secondly, there has to be a good deal of confidence this life threatening situation will occur. Often times, Alert Modes are prompted during an evolving situation. Such is often the case with severe thunderstorms and flash flooding. These situations will also lead to shorter Alert Mode times, as the dangerous weather is often shorter lived. Other situations, including snow and some flood events, may have Alert Modes lasting days due to the prolonged nature of the event. Typically, these types of Alert Modes can be issued further in advance due to a greater certainty of the event occurring. Still, Alert Modes will almost never be issued more than 24 hours prior to the start of an event. Instead, Grotonweather.com will go into Standby to raise awareness of the potential for devastating weather.

When an Alert Mode is issued, pay extra attention to Grotonweather.com and other weather media sources for frequent updates on the dangerous weather. The weather during these situations may rapidly change. It is strongly recommended that you become a follower of Grotonweather.com on Facebook and/or Twitter for these situations, as updates are frequently issued there. (Click here for our Facebook and Twitter pages). Often times (but not always due to other time restraints), special Grotonweather features are available during these times, including Weather Chats, Videos, safety tips and special maps.

The bottom line is this: as a meteorologist, I personally feel a responsibility to keep you informed and safe during severe weather. The absolute worst thing I can imagine is having a weather related fatality under my watch. The Grotonweather.com Alert Mode is meant to help prevent that from ever becoming a reality. If you see an Alert Mode has been issued, stay aware and "keep checking back for updates!"

Are we done YET?

6:45 PM Update: A severe thunderstorm warning is in effect for the very southern most portions of Tompkins and Cortland counties, but the storm is pretty much south of the county lines. Looking upstream, the more impressive thunderstorms should pass well to our west and east as the cold front begins to press through. As a result, I think we are pretty much done with severe weather here in the Grotonweather forecast area. There will likely be a shower or two...maybe even a light thunderstorm...over the next few hours...but the biggest hazard from here on out through tomorrow morning should be some areas of dense fog.

5PM Update: The storms over Ontario County have struggled to organize and are falling apart into just showers.

UPDATE 4:30PM: As I suspected (but a bit quicker I must admit), a healthy looking cell has broken off the lake breeze and is holding itself together nicely over Ontario County with some new development along its southern flank. If it keeps holding together, it should reach Cayuga Lake about 5:15-5:30 before heading into the Grotonweather forecast area between 5:30 and 7pm.

Original 4PM post: The Grotonweather forecast area has been hit hard twice today, with only the northern portions of Cortland County missing out on the active weather (but not by much, as southern Onondaga County has been hammered too!) Numerous severe weather reports have come out of the area, the most notable being trees and powerlines down in Lansing early this afternoon and a recorded wind gust of 55mph in Locke, 1.25" hail in Dryden and 1" hail in Cortland with the second round of storms.

So...are we done yet? For a little while at least. What has been happening is lake breeze fronts from Lake Erie and Ontario have been triggering storms between Rochester and Buffalo. These storms have been sitting and redeveloping over the same area for hours. As the individual cells move away from the lake breeze, they have been tracking southeast across the Finger Lakes, right into our neck of the woods. the last big storm that went through our area stabilized the atmosphere a good deal, and so as the cells break off of the lake breeze, they have started to quickly die out. I tend to doubt this will remain the case though. The sun is out and already working to destabilize the area once again. Eventually, I believe that another storm will have enough fuel to head down towards us once again, probably in the 1-3 hour time frame. After that, the lake breeze will start to die out. However, the cold front still has to come through and encounter a still unstable airmass across Western New York. more storms may fire up along that as it moves east...especially if it does so while the lake breeze is still adding extra lift to the atmosphere.

Bottom line: we may not be done yet...so stay tuned!

1PM Severe Weather Update

2PM Update: SEVERE THUNDERSTORM WARNING FOR S. CAYUGA COUNTY UNTIL 2:45 pm. A severe storm over Ontario county will move into S. Cayuga county over the next 30-60 minutes. I expect the warning to be extended/overlapped as the storm moves into the area. If the storm remains severe (and there is not really any reason for it not to), Groton, Homer and Cortland will have to watch out for this storm between 3-4 pm. Interesting note: All of the Grotonweather forecast area but extreme northeast Tompkins and northern Cortland Counties have been under severe thunderstorm warnings at some point today already! And our watch goes for 6 more hours.

Original 1PM post: Lots going on this afternoon already. A severe storm tore through central Tompkins county last hour. It is looking a bit less organized as it moves into S. Cortland county. I was in Ithaca, on the 11th floor of Bradfield Hall, Cornell as the storm passed. There was rotation with it, and I got some awesome pictures I will post tonight. The storm produced 1" hail in Trumansburg and took out "many" trees and powerlines in Lansing. No other reports yet (as of 1PM).

While all this was going on, the SPC moved us into a moderate risk. This is primarily for the threat of damaging winds. Now, we've already experienced severe weather...but is more on the way? Our watch goes until 8pm, afterall. The answer is yes, our threat still continues. There are more showers and storms forming over western New York back into Canada. The cold front itself stretches from Ontario back into Ohio and Indiana. The air just upstream is very unstable, and the storms we've already had shouldn't have much of an effect on our instability for the middle or latter part of the afternoon.

If you haven't become a fan of Grotonweather on facebook or a follower on Twitter, you will want to do so now! I've been posting up a storm (pun intended) on those two sites all morning with the latest updates and will continue to do so through the day. Also, the Grotonweather Toolbar is a great way to keep your eye on the latest forecast. Download it here. And, as always, the main site/blog will be updated throughout the day to keep you safe!

That's all for now. Keep checking back!

Tornado Watch to the south

An early morning tornado watch is in effect for the counties just south of Tompkins and Cortland counties down through Pennsylvania and Ohio. There are severe thunderstorm warnings for those same counties (Chemung and Tioga specifically) as thunderstorms out ahead of a cold front move across the area. The cold front is back over Western New York/Pennsylvania, with the low itself sitting over Western New York. With severe storms and a tornado watch on our doorstep, I felt a blog update would be more prudent for today.


As the cold front and low move east this morning, the wind fields will definitely be supportive of possible tornadoes, if more thunderstorms can form along the front. While I do not think there is enough instability this morning...and with all the clouds around I do not foresee us destabilizing...with the potential for a short lived tornado or two if storms were to form, I have to at least mention the possibility. What will likely happen is the cold front will move east of us and some more showers, maybe even a rumble of thunder, will effect us from time to time today. Keep a look out though, and listen for any potential warnings. The best chance for severe weather will be between now and the early afternoon. Beyond that, the front will move through and temperatures will drop, likely ending up in the 50s by sunset.

Ticking Time Bomb

I like severe thunderstorms. They are fun to try to forecast and I find them exciting to experience. I of course don't like it when they do major damage or pose a significant threat to the safety of people. So, you could say there is a certain intangible threshold where a situation goes from enjoyable, to scary. I think we've already crossed that threshold today, and the nearest storms are just starting to pop in eastern Michigan.

Now, if you checked my site early this morning, you would have seen that I had taken it down and had prepared it to sit dormant for the next 10 days or so due to a variety of circumstances. However, things are evolving in such a way that I really feel like I need to be updating today.

Ok, so whats going on. If you haven't stepped outside lately, go do so. You will be greeted by a blast of heat and oppressive humidity when you do. Temperatures have already shot up into the 80s, and dewpoints are in the low 70s. This has already led to instability levels that are rare for our area, and high even by the standards of the Great Plains. So often, I talk about the role of cloud cover in severe weather outbreaks. Often times in our area, clouds in the morning and early afternoon inhibit destabilization, which is why we don't see extreme instability like we are seeing now very often. But it has been sunny and will continue to be sunny through the afternoon, which means things will only continue to destabilze to levels that far exceed anything we have seen this year, possibly even the past few years.

Instability alone is not enough to create a severe weather outbreak. You also need a trigger to get storms going. For us, that is a disturbance moving towards the east along a cold front. Right now, it is over southern Michigan...which is why the storms are forming there. As it moves east, this energy will provide the lift needed to allow storms to continue to form. As they interact with the unstable air, they will intensify. One more piece is needed though, and that is shear, or a change in wind speed or direction with height or horizontal distance. In this case, we are looking at speed shear from both the ground up into the atmosphere, and horizontally from south to north. This is because of an area of strong winds in the jet stream called a 'jet streak' that is to our north. This will provide the shear needed to organize the storms into segments, or even a squall line.

The way I see it right now, all of the ingredients are evolving to come together for a significant severe weather event for all of Central New York. The only question I really have is whether or not a massive squall line will form out of those storms in Michigan, or if there will be multiple, but smaller lines of storms. That is something that will only be determined as the afternoon goes on. Regardless, there is the potential for strong, destructive winds after roughly 4pm tonight. It wouldn't hurt to take some precautions now by putting away lawn furniture, securing loose objects, etc. The biggest threat from the storms is definatly wind and, if I was updating my site as normal, I would likely place it in the 'high' category. I believe that most, if not all counties in Central New York will experience at least some wind damage to trees.

Another danger tonight will be flash flooding....some areas, especially in Cortland County, got 3"+ of rain yesterday, with mudslides and road closures overnight in Cortland County. It won't take much heavy rain to create more problems. NEVER drive through a flooded roadway! Flooding is the number 1 weather killer in the United States, and most of those fatalities occur in automobiles.

Watch for another update between 3 and 5pm, or sooner if a watch comes out. This is one forecast I hope I am not right on.

Risks Upgraded

There have been a couple of changes in the forecast this morning as things area already rapidly evolving. Probably the most significant of these changes is that, instead of all the clouds and rain the models had been forecasting for us this morning, skies are clear. This is causing the atmosphere to destabilize quicker and more intensely than had been forecasted. Another thing to look at is the radar. Thunderstorms are widespread just west of Buffalo, and already, there are some storms popping out ahead of this main area...so the question of whether or not storms will form is out the window.

The Storm Prediction Center has us in a 30-30-5% risk for wind-hail-tornadoes, respectively. All three of those are on the upper end of their 'slight' risk category. After looking at a couple things, I moved my hail and win up to moderate, and kept tornadoes at slight. Since storms are already firing, I moved the thunderstorm risk all the way up, which the NWS in Binghamton also did on their threat outlooks.

Here is what I am expecting for each threat:

Thunderstorms: Extreme-
Widespread thunderstorms can be expected with almost everywhere getting a storm. Frequent lightning should accompany the storms, and a fair number of them will likely be severe.

Wind: Moderate-
With the sun out this morning and strong upper level winds, wind damage is likely somewhere in Central New York, with some possibility of widespread damaging winds. 3 to 7 damaging wind reports are possible in the Grotonweather forecast area (Tompkins, S. Cayuga and Cortland Counties), with more elsewhere in Central New York. Should a widespread wind event evolve, this will be increased to high.

Hail: Moderate-
With extra instablity from the sun this morning, and indications of favorable hail formation from both the models, and current observations, hail could become a major factor today. 3 to 7 severe (0.75" of bigger) hail reports in the forecast area is possible, with more elsewhere in Central New York. Hail sizes should stay below 1.5", but an isolated storm could produce up to 2" hail. An upgrade to a high risk is not expected at this time.

Tornadoes: Slight-
Little changes to the tornado forecast have been made. A tornado somewhere in Western and Central New York seems almost likely. Multiple tornadoes could be possible, but this certainty isn't enough for a moderate risk at the time. However, with strong southeast winds at the surface, winds at low levels out of the southwest, and upper level winds coming in from the west, the threat for tornadoes will need to be watched closely.

Friday Afternoon's Severe Weather Outlook for 7/11

I spent the morning and early afternoon down at the National Weather Service in Binghamton, where I am an intern this summer, and used some of their in-house tools to try to get a better handle on the severe weather threat tomorrow. I will mention that the meteorologists there this morning believe tomorrow will be an active day and seem to have a high confidence level.

One of the tools I used this morning was a form called the 'severe weather checklist'. This form has you enter in forecasted values for a variety of severe weather parameters. After doing so, it returns the 5 most similar severe weather days in recent Central New York history. When completing this checklist this morning, it returned 4 days of 'isolated supercells', including May 16th, 2009, which had 3 tornadoes in the area, and May 31, 2002, which had 4 tornadoes. The fifth day was classified as a 'broken line'. Hail was the primary threat from the five days collectively. That tells me that not everywhere tomorrow will see a strong thunderstorm....some areas may barely even get any rain. However, there is certainly potential for some severe weather, and someone will likely have to deal with a damaging storm.

Here is a glance at where I have my threat levels, and an in depth look at exactly what I mean by each threat level, as well as what would need to happen for an upgraded risk:

Thunderstorms: moderate-
Thunderstorms are likely across much of the area. A few places, however, will be missed and get little to no rain. Frequent lightning will accompany some of the storms.

High Winds: slight-
Some storms may contain strong winds. Wind damage will be isolated to scattered, with 3 to 10 reports in Central New York. Sunshine in the morning would increase the chances of wind damage, and could get this bumped up to a moderate risk.

Hail: slight-
Small hail will be possible with stronger storms tomorrow, but most hail should remain uner 1" in diameter. The strongest storms may produce up to 1.5" hail. 5-12 Severe hail (over 0.75") events can be expected in Central New York. This is still rather uncertain, and could be upgraded to a moderate risk should the models show a bit better conditions for hail tomorrow morning.

Tornadoes: slight-
Conditions are favorable for rotating storms, and tornadoes could form. My best current guess is that somewhere in Western, Central and Southern New York will see a weak tornado, but as many as 2 or 3 wouldn't surprise me. This would most likely not be upgraded to moderate unless numerous storms that have already developed are showing signs of becoming tornadic.

Expect the next website update to occur between 9 and 11 am tomorrow. A blog update should occur within 30 minutes of that. There also could be a quick blog update tonight. During the afternoon tomorrow, I plan to have the weather chat open and will be updating th blog and website as needed. Stay tuned!

Severe Storm Potential

I am very impressed with the atmosphere this morning and feel like this is perhaps the best severe weather set up we have had so far this spring. There is a cold front draped across eastern Ohio this morning that will move eastward and trigger thunderstorms. Ahead of that front, skies have cleared across western New York, creating an already unstable atmosphere even more so. I was surprised to see the instability indexes so high already this morning. You did not need me to tell you that, however, as the humidity this morning is making it feel very uncomfortable and muggy.

The main threat today is going to be large hail and damaging wind gusts. However, conditions also appear favorable for a tornado or two to form, so you will want to keep an eye to the sky. The Storm Prediction Center does not actually have us in a slight risk area today, for reasons that are beyond my understanding. I feel that the will reverse their thinking as the morning wears on and, with their 12:30pm update, add us to the slight risk area. You can check that by clicking here.

I will not be able to update this during the afternoon today. I will actually be down at the National Weather Service in Binghamton on my first day as a summer intern there. I do not think there could have been a better day for me to start, and I believe it will be a very active day down there. Click Here for the latest watches and warning, and click here for a look at the radar.

A Look at Watch #280

The Storm Prediction Center has issued a Severe Thunderstorm Watch that stretches across almost all of New York State. It remains in effect until 7pm tonight. Here is a look at the exact counties it includes. As you can see, Tompkins, Cortland and S. Cayuga are right in the middle of it.


The main threat from this event is going to be damaging winds. Hail will also be possible, and my gut feeling is there will be a tornado somewhere in the watch box. The official probabilities that the SPC has put with the watch:
Tornadoes

Probability of 2 or more tornadoes	Low (20%)
Probability of 1 or more strong (F2-F5) tornadoes	Low (5%)

Wind

Probability of 10 or more severe wind events	Mod (60%)
Probability of 1 or more wind events > 65 knots	Mod (30%)

Hail

Probability of 10 or more severe hail events	Mod (30%)
Probability of 1 or more hailstones > 2 inches	Low (20%)

Combined Severe Hail/Wind

Probability of 6 or more combined severe hail/wind events

High (80%)

Since it is at the top of the hour, the current observations and indicies will not be in for another 20-40 minutes. Looking at the data from noon, though, it is obvious to me that the atmosphere is quickly destabilizing. Also, a pocket of strong winds in the upper atmosphere is beginning to move into Western New York, and will spread over the rest of the state, enhancing the thunderstorms. Storms are going to develop from west to east, and have already begun to fire up across Western New York, Lake Erie and Lake Ontario. These storms should organize into a squall line eventually, which is when the greatest threat for wind damage will be. The highest tornado and hail threat will be just prior to that, when the storms are more individual cells.

Be sure to keep checking back through the afternoon for the latest!

First Watch of the Season!

12:45 Update: Severe Thunderstorm Watch issued! Full blog post analyzing the situation coming...

The Storm Prediction Center has outlined Central and Eastern New York as an area where a weather watch will "likely" be needed. The watch will likely be issued by 1PM. Stay tuned! I am watching this carefully and will have the watch up on the site within moments of its issuance!

>Click here for your full forecast

Here we go!

Winter Storm Watches have (finally) been posted for the grotonweather.com forecast area! I say finally because, if I had been working at the National Weather Service, I would have issued these watches yesterday. All season long, and going back into last season, the models have shown an eastward biased with storms coming up from the south. This is a large part of why a lot of last winter had a lot of hype about snow storms (myself included), only to have the storms start as snow, then change to ice and/or rain. The actual storm tracks have continuously come further west than the models suggest. So when I saw the models showing snow for Eastern New York and New England yesterday, I thought 'Thats going to hit CNY'....and now, it looks like it will.

The NWS has Winter Storm Warnings up for areas just south and east of us. I again have to say though...they are too far east! Even just a day or so ahead of this event, I do not trust the models to place the heaviest snow properly. So, I am diverging from them and the NWS and, while I haven't checked them, likely the local media as well.

So, what is this all about. An area of low pressure is over the southeast. As I said in this morning's discussion, severe thunderstorms, including torandoes, have been ongoing constantly since yesterday morning. This is indicative of the energy of this storm. As this storm comes up the coast, it will interact with the cold air left over from today's front, with the circulation just pulling more of it in. It will be a classic nor' easter...just not super powerful.

Snow will likely begin to fall in our area sometime in the late afternoon tomorrow and become heavy into the night. This storm will be a pretty quick mover, so that will help in keeping totals down. I also think that, even with the eastward biased, the heaviest snow will stay just east of our area. I haven't had enough time to hammer out a snow map yet, but, on a whim, I am thinking 5-9" is likely for most of Tompkins County and Southern Cayuga County, with perhaps 6-10" over Cortland County.

And now...what you all really want to know....will there be school on Friday? After my epic failing on predicting a snow day last February, I considered not even doing snow days this season...but, due to popular request, I will. Since this storm is coming through at night, I would say there is certainly a chance. Just how much of a chance remains to be seen. You will have to keep checking back to find out!

Next projected update: 10-11:30PM: Snow map!

Abnormal September Tornado Threat

I can't say I saw this one coming, but I get up this morning and almost everything I look at points to today being a rough day across parts of Central New York. Last year in meteorology class, we went over tornado forecasting in quite some detail. A lot of the things we were told to look for have started to line up. The one thing that will probably prevent this from being an outbreak is the fact that the air aloft isn't all that cold. That warm air aloft should help keep the instability less than it would be on other days that are this humid. Regardless to say, the Storm Prediction Center has us in their '5%' chance of tornadoes.

There are meteorologists, however, who do not like the SPC's % system. One of them is Accuweather Senior Meteorologist Henry Margusity, who I have mentioned many times. Over the summer, he developed a scale to better address the threats of severe thunderstorms. His scale goes from 1-4 and outlines specific threats for each category. You will likely have to click the image to read it, but here is a look at his system:


Henry has placed us in his T3 Category today mainly for the tornado threat. It will be interesting to see how this one unfolds. Stay tuned!

Split Forecast Area

The grotonweather.com forecast area has been split by Severe Thunderstorm Watch 638. Cayuga County is under the watch, while Tompkins and Cortland got left out. In all honesty, however, that is just a technicality. Conditions are just as favorable for severe thunderstorms in Tompkins and Cortland Counties as they are in Cayuga...the SPC has to draw the line somewhere, however. I am expecting another watch to be issued later this afternoon that will include the rest of the area.




Numerous thunderstorms have developed over Western New York and Western Pennsylvania. These storms will track east, with damaging winds and hail the main threats. Other storms will develop as well, so it looks like we may have a decent severe weather event on our hands.

Severe t-storm approaching!

The National Weather Service in Binghamton has issued a Severe Thunderstorm WARNING for Northern Tompkins County and surrounding areas. This includes Groton. A large thunderstorm, likely containing hail, is currently just west of Cayuga Lake, moving east. Expect torrential downpours, hail and frequent lightning with this storm!

Severe Thunderstorm Watch

Thunderstorms have begun to develop all across the Northeast and Ohio Valley, including Central and Western New York. This has prompted the Storm Prediction Center to issue a Severe Thunderstorm Watch for all of the counties shaded in blue below, including Tompkins County pretty much smack dab in the middle of the watch:



The probabilities with this watch indicate that the SPC is most concerned with hail, followed closely by damaging winds. The chances of 10 or more hail reports in the watch area is 70%, with a 50% chance of 10 or more hail reports.

Looking at the regional radar, you can see lots of thunderstorms scattered about the area. These will continue to develop, increasing in strength and coverage.
Stay tuned for any warnings!

Here we go!

The 12:30PM Update of the SPC Outlooks has the moderate risk area bumped to the northwest. This shift puts the border of the moderate risk area right overhead. Our hail remains at 30% with hatching, which, if you didn't read today's first blog, indicates a 10+% chance of 2" hail or larger.



An hour ago, the radar was quiet. Now, thunderstorms have fired all across the state. Already a few of these have Severe Thunderstorm Warnings with them. As the afternoon progresses, more storms will develop and become severe.

Stay tuned for updates if any severe storms approach!