Thursday, January 9, 2014

Northern Lights Visible Tonight To Some

Strong coronal mass ejection, CME, from the Sun has arrived to Earth.

Space forecasters say that a strong CME arrived to earth around 1pm MT Thursday.  According to NOAA, a large Earth-facing solar event happened on the Sun January 7, 2014 sending the energy towards Earth.

Sunspots on Sun
(Click image to see larger version.)
Is this unusual?  Not at all.  CME's happen frequently through the year.  This CME comes from one of the largest sunspots in the current solar cycle. (see right image)  The sunspot area covers 124,000 miles.  The largest core within the region is three times larger than the Earth.

NOAA forecasters predict this event will be a G3-class.  That classifies it as "strong" with minor affects to power systems and could produce intermittent GPS navigation disruption along with high-frequency radio transmissions.  With a G3-class event, auroras can be seen as far south as Oregon, Wyoming and Illinois.

The aurora borealis, also known as the Northern Lights, will likely not be visible in southern Colorado.  However, they might be visible in northern parts of the state. If you want to give it a try, go out once the sky is dark.  If you are in southern Colorado look north along the horizon.

X-ray image of the Sun from
GOES satellite.
(Click image to see larger version.)
Daniel Barker, director of CSU-Boulder's Labratory for Atmospheric and Space Physics, describes the aurora borealis "They are brilliant dancing lights in the night sky caused by intense interactions of energetic electrons with the thin gases in Earth's upper atmosphere," said Baker. "The aurora are most commonly seen in Alaska, northern Canada and Scandinavia when the sun sends out powerful bursts of energy that can strike Earth's protective outer magnetic shield called the magnetosphere."

Additional Information:

Sunday, January 5, 2014

9:30am Weather Update

Things are still looking on track with winter storm moving through the Midwest today.  I have already seen reports of 3" to 5" of snow across the St. Louis area and 1" to 3" across central Indiana.

National radar composite from 10:23am CT.
I have been hearing several people complain about rain falling this morning in parts of Missouri and Indiana.  Keep in mind, all day yesterday I had said there would be rain in the morning and it would change over to snow in the afternoon.  That is still expected to happen in a couple of hours.  Patience.

I have been taking a quick glance at some of the data coming in this morning.  I'm feeling pretty good with most of my snow forecast but I am going to make a few minor tweaks.

SNOW FORECAST

ILLINOIS:
  • Mt. Vernon:  8"-11"
INDIANA:
  • Columbus:  4"-7"
  • Indianapolis:  8"-12" (Locally higher amounts possible.)
  • Lafayette:  9"-13"
MISSOURI:
  • Cape Girardeau:  4"-7"
  • Poplar Bluff:  4"-7"
  • St. Louis:  8"-11" (Locally higher amounts possible.)
FREAK-OUT-METER
Normally the Freak-Out-Meter is based off precipitation but this time the numbers are going to be a little higher because I'm combining snow with the dangerous cold air coming in.

Keep in mind, the Freak-Out-Meter is based on a 0-10 scale.

ILLINOIS:
  • Mt. Vernon: 7
INDIANA:
  • Columbus: 6
  • Indianapolis: 8
  • Lafayette: 8
MISSOURI:
  • Cape Girardeau: 6
  • Poplar Bluff: 6
  • St. Louis: 8
BOTTOM LINE
  • Snow will continue through Sunday afternoon/night.
  • For places like Poplar Bluff, Cape Girardeau, and Columbus (IN) there will likely be a period of rain during the morning.  It should change over to snow by late morning/early afternoon.
  • The snow could be heavy at times during the afternoon with snow rates in excess of 1" per hour.
  • Winds will increase and there will be drifting snow.
  • COLD air will arrive Sunday and linger through Tuesday.  Wind chills will drop to -30° to -40° in some areas.
  • Because of the cold air coming, be sure to not have your gas tank on empty.  Gas could freeze if your car is parked outside.
  • Travel is not advised Sunday night and Monday.  If you must go out, be sure to have blankets and other survival items in your vehicle in case you get stranded.
  • Be extremely careful when you go out to shovel snow Sunday evening and Monday morning.  I'm not talking about slick spots in the driveway, but be careful of the bitterly cold air.  Frostbite will be a serious concern.
As always, for more frequent updates follow me on Twitter: @johndissauer.

12:30am Weather Update

A quick update to show you what the evening run of the computer models are suggesting.  Generally speaking, they have come in a little "wetter", meaning they are suggesting there is more moisture to play with.

Here is a look at a matrix of snow amounts I have come up with for 26 various computer model runs.
(Click image to see larger version.)
You can compare the numbers to what the morning runs were suggesting by going to my earlier blog post.

When you compare Saturday morning's versus Saturday evening's runs this evening's runs are roughly 8%-15% higher.  That being said, the above numbers are numbers straight from forecast models.

My overall thinking hasn't changed much, although I am tweaking the numbers a little bit.  In some situations, there may be a little bit more rain during the morning in places like Cape Girardeau, Poplar Bluff, Carbondale, Bloomington, IN and Columbus, IN.  By afternoon, it should change back over to all snow.  In fact, the snow could be heavy at times during the afternoon along I-70 from St. Louis to Indianapolis and across areas north and south of I-70.

SNOW FORECAST

ILLINOIS:
  • Mt. Vernon:  8"-11"
INDIANA:
  • Columbus:  6"-9"
  • Indianapolis:  8"-12" (Locally higher amounts possible.)
  • Lafayette:  9"-13"
MISSOURI:
  • Cape Girardeau:  5"-8"
  • Poplar Bluff:  4"-7"
  • St. Louis:  8"-11" (Locally higher amounts possible.)
FREAK-OUT-METER
Normally the Freak-Out-Meter is based off precipitation but this time the numbers are going to be a little higher because I'm combining snow with the dangerous cold air coming in.

Keep in mind, the Freak-Out-Meter is based on a 0-10 scale.

ILLINOIS:
  • Mt. Vernon: 7
INDIANA:
  • Columbus: 7
  • Indianapolis: 8
  • Lafayette: 8
MISSOURI:
  • Cape Girardeau: 6
  • Poplar Bluff: 6
  • St. Louis: 8
BOTTOM LINE
  • Snow will start early Sunday morning.  It will continue through Sunday afternoon/night.
  • For places like Poplar Bluff, Cape Girardeau, and Columbus (IN) there will likely be a period of rain during the morning.  It should change over to snow by late morning/early afternoon.
  • The snow could be heavy at times during the afternoon with snow rates in excess of 1" per hour.
  • Winds will increase and there will be drifting snow.
  • COLD air will arrive Sunday and linger through Tuesday.  Wind chills will drop to -30° to -40° in some areas.
  • Because of the cold air coming, be sure to not have your gas tank on empty.  Gas could freeze if your car is parked outside.
  • Travel is not advised Sunday night and Monday.  If you must go out, be sure to have blankets and other survival items in your vehicle in case you get stranded.
  • Be extremely careful when you go out to shovel snow Sunday evening and Monday morning.  I'm not talking about slick spots in the driveway, but be careful of the bitterly cold air.  Frostbite will be a serious concern.
As always, for more frequent updates follow me on Twitter: @johndissauer.

Saturday, January 4, 2014

Major Winter Storm To Hit Midwest

You've likely heard about it for days.  A major winter storm is taking aim on the Midwest and now we are twenty-four hours from it's arrival.

First and foremost, in my opinion the BIGGEST impact from this storm is going to be the barbaric cold air coming down from the arctic for Monday and Tuesday.  Temperatures projected to be experienced early in the week haven't been felt in this part of the country for nearly 20 years (if not longer).

Temperatures Monday morning are expected to drop well below zero.
12z ECMWF - Projected low temperatures Monday morning.
(Click the image to see larger version.)
Don't expect the air to warm much through the day Monday.  Many locations, especially in central Indiana will struggle to reach -5° during the afternoon.  We're talking temperatures in some locations of Indiana, Illinois and Missouri 40° to 50° below normal.
12z ECMWF - Temperature departure from normal Monday afternoon.
(Click the image to see larger version.)
The most asked question I have received in last three days is about snow.  Yes, there is going to be snow across much of the Midwest.  My concern is not so much with the snow, but instead when people go out to shovel the snow... Spending 30-45 minutes clearing their driveway and not being prepared for below zero temperatures and wind chills -20° to -35°.  Frost bite will be a BIG concern Monday morning along with exposure.

SAY IT AIN'T SNOW

Now to get on to what everyone wants to know.  "How much snow are we getting?"

I have been holding off on putting out numbers until close to the event because the storm still had a few wobbles in it and I didn't feel comfortable putting out numbers I didn't feel confident in.  Now that we are within 24-hours from the start of the storm, and now that all the morning computer model runs are in, I feel a bit more confident with the numbers.

I have gone over 26 computer models from this morning's runs and have come up with the snow matrix below.
(Click the image to see larger version.)
In the snow matrix you can see how much snow I think the computer model is suggesting.  It includes a blending of snow ratios I think we could be dealing with.  Due to the cold air coming in towards the tail end of the system, we could see snow ratios as high as 23:1 in some locations.  At the same time, some locations near the Ohio River, could see several hours of rain mixed in.

Keep in mind, the numbers on the snow matrix is not my forecast.  Here is what I am thinking as of this morning.

ILLINOIS:
  • Mt. Vernon: 8"-11"
INDIANA:
  • Columbus: 7"-10"
  • Indianapolis: 8"-11" (Wouldn't be surprised by a 12" amount somewhere.)
  • Lafayette: 8"-12"
MISSOURI:
  • Cape Girardeau: 4"-7"
  • Poplar Bluff: 4"-7"
  • St. Louis: 6"-10" (An 11" amount wouldn't surprise me.)
The majority of snow in Illinois, Indiana and Missouri will end by Sunday night and will start anywhere from Saturday evening through early morning Sunday.

I mentioned rain mixed in for some areas.  Some of the data is suggesting temperatures will be warm enough at the start to keep things rain until the cold air arrives.  Once it does so, rain should quickly change over.  Also, in southern Indiana (Columbus) it could start as snow early morning Sunday, change over to rain for a few hours, then change back to snow by Sunday afternoon.  For Columbus, if the changeover to rain does not happen, we could add another 2" to 3" of snow to the total I mentioned above.

FREAK-OUT-METER:
Normally the Freak-Out-Meter is based off precipitation but this time the numbers are going to be a little higher because I'm combining snow with the dangerous cold air coming in.

Keep in mind, the Freak-Out-Meter is based on a 0-10 scale.

ILLINOIS:
  • Mt. Vernon: 7
INDIANA:
  • Columbus: 7
  • Indianapolis: 8
  • Lafayette: 8
MISSOURI:
  • Cape Girardeau: 6
  • Poplar Bluff: 6
  • St. Louis: 8
BOTTOM LINE
  • Snow will being Saturday night through Sunday morning.  It will continue through Sunday afternoon/night.
  • Winds will increase and there will be drifting snow.
  • COLD air will arrive Sunday and linger through Tuesday.  Wind chills will drop to -30° to -40° in some areas.
  • Because of the cold air coming, be sure to not have your gas tank on empty.  Gas could freeze if your car is parked outside.
  • Be extremely careful when you go out to shovel snow Sunday evening and Monday morning.
As always, for more frequent updates follow me on Twitter: @johndissauer.

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