Why is Lake Effect So Localized?

Why is lake effect snow so localized? Moisture often times converges in pockets or streaks depending on the weather setup. Check out this great visible satellite photo which shows the streaks of clouds cover and sunny breaks in between. Each streak of cloud cover has bursts of lake effect embedded within it.

BTW, the 850 mB temperatures will be falling to -18 with a lake water temperature of +8 (yes, all in celsuis). You need around a 13 degree temperature difference. Notice that later today, tonight and early tomorrow, temperature differences approach 25! This means heavy bursts of snow IN LOCAL AREAS!

Saturday afternoon radar image...CURRENT NORTHERN OHIO RADAR LOOP HERE

How Rare Are "NOVEMBER SEVERE WEATHER HIGH RISK" Forecasts? VERY!

Damage from Washington, Illinois (Chicago Tribune)

Several requests on the history of MODERATE and HIGH RISKS for the US and OHIO in November. I found some answers on the Storm Prediction Site.

Only 2 other instances where the Storm Prediction Center issued forecasts for HIGH RISK FOR SEVERE WEATHER in November:  2002 and 1998.  None of these HIGH RISKS were for any part of Ohio. Both of these featured large tornado outbreaks.

Image courtesy Greg Carbin, SPC

This is what Sunday's event looked like with storm report dots superimposed over the risk areas

Image courtesy: Eric Fisher/Jesse Ferrell on Twitter

Only 10 MODERATE RISK AREAS have been issued in November since 1998. 4 of the 10 were issued on the same date or later in the month. NONE WERE ISSUED IN OHIO!!!

Image Courtesy Greg Carbin, SPC

Aerial Photo of Tornado Path in Washington, Illinois

Notice the swirls along the path. This tornado was on the ground for 46.2 miles a an EF4 which had winds between 170-190 mph. This tornado had winds greater than any hurricane or Typhoon in recorded history!

Here are some other aerial photos courtesy of the Chicago Tribune.

Crying Wolf? I Think Not: Severe Weather Definitions

It never fails.

During and after each and every severe weather event, there are a few people that selfishly say "Where are the storms? You all said we'd have severe weather. All we're getting is wind and some rain. You weather people never get it right!" Nothing gets me more fired up more than idiotic comments like this. Tell this to the families who lost loved ones in this house in Nashville, Illinois.

My blood pressure is climbing just writing this......errrrrr!

I have written many times about how our perceptions and preconceived notions tend to govern our thoughts especially when events occur that seem to support and reinforce our biased notions. I try to tell these individuals that severe weather forecasts are approximations. That's why tornado watches are as large as a state not a city. 

People will think the way they want to think regardless of how much data you present them to the contrary.  How often have our biases surfaced during election years (economic issues), in our day-to-day lives perhaps when we interact with others?  See my posts about cognitive biases and  cognitive dissonance relating it to weather HERE and HERE. Note the parts in red print if you want the Cliffs Notes version.

Anyway, maybe these basic severe weather definitions will clarify some of these misconceptions and perceptions about severe weather. Bottom line is this: When the Storm Prediction Center has a region in a MODERATE to HIGH RISK for severe weather, bad things will happen. This is not something to be taken lightly.

 

OHIO SEVERE WEATHER UPDATE: 8PM

TORNADO WATCH still in effect for all of northern Ohio until 12AM. This means CONDITIONS are still FAVORABLE. No confirmations of any touchdowns in northern Ohio. Watch might be cancelled before 12AM. Stay tuned...

CHECK OUT MY TWITTER FEED FOR ANY WARNINGS ISSUED

Earlier today, updates here projected the main line of storms to be approaching western areas of Ohio by 6PM. Here was this initial map created by the HRRR model.

Here is the radar image at 8PM...line is moving a bit faster CLICK ON THE RADAR IMAGE FOR THE CURRENT RADAR LOOP OVER OHIO

Between 8 and 10PM, expect fast moving (50-60 mph) storms across northern Ohio. Some will be severe

By 10PM, the majority of the storms should be out the area...

Notice the temperature drop behind the front circled in BLUE.

We'll wake up to temps in the lower to mid 40s Monday morning.

SEVERE WEATHER UPDATE: Sunday NOON UPDATE

Everything is still pointing to a HIGH POTENTIAL for severe thunderstorms THIS AFTERNOON AND THIS EVENING.

TORNADO WATCH ISSUED FOR NORTHERN INDIANA, FAR WESTERN OHIO UNTIL 8PM

Remember, a SEVERE STORM is a storm with 58 mph winds AND/OR 1" hail or a tornado. When any one of these criteria are met, a SEVERE THUNDERSTORM WARNING is issued. A TORNADO OR SEVERE THUNDERSTORM WATCH means conditions are favorable. WARNING means its occurring now!

RADAR SNAPSHOT AT OF 11:30AM

CLICK HERE TO SEE THE MOST RECENT RADAR LOOP

Plenty of sunny breaks which will only destabilize the atmosphere which will promote more storm development. Visible satellite image here...

The discussion posted here yesterday still holds:

High resolution HRRR model brings the main line of strong/severe storms into western Ohio by 6PM...8PM across northern Ohio

Storm Prediction Center has shifted the MODERATE and HIGH RISK area further east. HIGH RISK now in western Ohio!!!

To put this into perspective, Ohio is put into a HIGH risk SEVERE WEATHER area about once every 3-5 years. 

Tornado chances seem higher in Illinois and Indiana

Super strong jet stream...left front exit region over Lake Erie

Upper level diverging air at 500mB (18,000 feet) which translates into rising air at the surface.

A very large temperature gradient. Sunday morning temperatures are already pushing 60 across northern Ohio

All of these conditions will produce very strong winds at the surface in excess of 40-45 mph later today.