As of 4pm Saturday, the following alerts have been issued by the National Weather Service in Cleveland for northeastern Ohio:
A FLOOD WATCH is in effect from late SUNDAY NIGHT through TUESDAY EVENING
and
A HIGH WIND WATCH is in effect from MONDAY AFTERNOON through TUESDAY MORNING.
Stay tuned to YoungstownWX HQ and my Twitter feed, @ytownwx for updates.
Hurricane Sandy continues to move up the East coast, currently located off the Carolinas. Sandy is expected to combine with a cold front and associated low pressure over the next 48 hours and create a large “post-tropical” cyclone. It is this end product that could provide some of the nastiest weather we have seen in the Mahoning Valley and western PA over recent memory.
There are still a few questions regarding the final outcome of Sandy, but confidence is increasing that we will have quite a bit of impact from the storm. The two main events will be rain and wind. Let me break down each of these for you.
Rain: The cold front that moved through the area yesterday will be the focus for scattered showers today and Sunday. As Sandy merges with this system, we will see heavier rain Monday through Wednesday, with Monday night into Tuesday possibly being the worst of the three days. If the center passes closer to us than currently forecast, we would see lower rain totals. Sandy will be a “hybrid” system, so not completely tropical. In a tropical cyclone, the heaviest rain and winds are close to the center. However, with Sandy, the storm is expanded and taking on both tropical and non-tropical characteristics. This means that the effects will actually be worse over a large area.
Wind:This brings us to our next concern, the wind. With the wind field of Sandy expanding away from the center of circulation, the pressure gradient between the storm and high pressure in the midwest will create a large wind field. While the strongest winds associated with the storm will occur near the coast where Sandy comes ashore due to the lack of friction, we are expected to see tropical storm force winds for a time, especially Tuesday. Most winds will be between 20 and 30 mph with gusts to over 40 mph at times from Sunday through Thursday. However, on Monday and Tuesday, sustained winds of 40-50 mph with gusts over 60mph will be possible at times. We will have to monitor this, and the National Weather Service has already discussed potential wind headlines to go into effect later this weekend.
Like I said, there are still a few questions regarding the final track of Sandy which would change our rain totals and wind speeds slightly. The things we do know though are that we will have a long duration event of wind and rain. While it won’t be raining every minute of every day today through Thursday, we will have heavy rain and strong winds at times. Here’s one current total precipitation graphic issued by the HPC. This puts our area right on the edge of the 3 to 5 inch total rainfall through Thursday.
I will try to post as much information as I can over the next few days as these details continue to come together. Remember you can follow me on Twitter, @ytownwx as I will be posting a lot about Sandy over the week.
For a forecaster, predicting a week in advance has its challenges, let alone 3 or 4 months. However, one question I get a lot, especially in the Mahoning Valley, is “what’s it going to be like this winter?”
Let’s try and tackle that question today, shall we? The graphic below shows how far from average the ocean temperatures are in the Pacific for the past month. Why does this matter? El Nino was predicted a few months ago to have been increasing by this time. (El Nino generally is a warming in the east equatorial Pacific) However, there has been no real warming over the past month, as shown below, and that may impact what this winter brings.
Change in Pacific SST anomalies during the last month. Courtesy: NOAA
With a warming of the equatorial Pacific, the jet stream in the northern hemisphere is affected. The jet stream is one atmospheric element that determines the strength and track of large storm systems. Another critical feature is called the NAO (North Atlantic Oscillation) which influences temperature fluctuation and is one reason for cold spells and warm spells in both Europe and North America. The NAO isn’t predictable this early in the season, so we can only look to the Pacific for the primary way of forecasting long term.
So, back to the question at hand – what is this winter going to be like for eastern Ohio and western Pennsylvania. In previous months, with the onslaught of El Nino expected to influence the winter, forecasters including myself were expecting a greater chance of above average snowfall and cooler than normal temperatures, because of the active southern jet stream. However, since there hasn’t been any recent developments with El Nino, there is less certainty that this will happen for our winter.
I don’t want to make it sound like we won’t have a bad winter, but I also don’t want to say it’s going to be another “Snowmaggedon” year like 2010-11 was. Here’s what NOAA came up with for temperature and precipitation for the 3 month winter period, though:
Temperature probability for December 2012 – February 2013
Precipitation probability from December 2012 – February 2013
The Mahoning Valley through Pennsylvania from the NOAA predictions call for “equal chances” of above or below average temperatures and precipitation for the months from December 2012 to February 2013. Snowfall averages range from around 30-50 inches in the Mahoning Valley and parts of western PA, and from 60 to 100 inches in the lake effect areas of Cleveland to Erie.
In conclusion, there is no definite reason to believe this will be a bad winter, BUT if El Nino decides to wake up, we can have an active pattern set up. The intensity and frequency of lake effect snow also has its effects on snow totals for parts of the area.
Predicting a seasonal forecast is almost as accurate as shutting your eyes, spinning around, and pointing at one of the options. But know that you can come to ytownwxHQ for all of your winter forecasting information, and we’ll keep you ahead of any storms that occur the upcoming winter – no matter what it MIGHT bring.
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