Tricky Forecast: Flooding Update, Heavy Rain, Storms

Forecast is very tricky with lots of small details over the next 18 hours.  Temperatures remain in the mid 30s with rain/sleet and reports of freezing rain as of 11AM.. Rain is moving northeast.




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Breaks in the rain during the afternoon as temperatures start to climb into the 40s. Winds will increase especially into the evening. The highest temperatures will not occur until after sundown where lower 50s are definitely possible.

The main line of rain and storms moves through mid to late evening. Winds could gust to 40-50 mph with a slight chance for strong storms.

Rainfall will be close to 1/2" or more in spots over the next 24 hours!

 

Snow water content is greater than 3 inches in many areas.

River levels will start to climb fast overnight tonight and early Friday. Here are the early Thursday morning river level forecasts. ALL will be well above flood stage by midday Friday!

Flooding Potential Increasing for Northern Ohio

Fresh 3-8 inches of snow Tuesday the 18th have increased the overall snow cover to well over 15 inches across a good portion of northern Ohio

Later in February and early march, the influence of the sub-tropical jet stream driving short bursts of "warmth" becomes stronger. The Polar jet which drives the winter pattern often bounces back and forth as the southern branch shows flashes of dominance. Both jet streams can blend together as troughs become deeper in the middle of the continent.  Waves travel along the jet stream which develop into deep circulations at the surface and aloft inside the large scale trough. These waves can deepen rapidly causing rapidly rising temperatures and heavy rainfall.

Four components are coming together for a potential big flooding event because of this active jet stream:

1) Rising temperatures: Temperatures will make a run at 50
2) Heavy snow cover: Only 7 other winters since the late 1930s have had at least 13" of snow cover this late in the winter: 2008 (15"), 2007 (17"), 1993 (21"), 1987 (13"), 1984 (13"), 1960 (13") and 1954 (13")
3) Strong winds
4) Steady rainfall of at least 1/2" over 13" of snow cover

Snow water equivalent is greater than 3" in many locations:

 

How often has all FOUR of these components come together this late in the winter?

NOT SINCE 1938 WHEN SNOW DEPTH RECORDS BEGAN AT HOPKINS AIRPORT

River levels will need to be monitored Friday and Saturday especially the Huron, Chagrin, Black and Grand Rivers. All should be well above flood stage Friday.

River Flooding Level website here for updated information 

Milan could see the worst flooding according to Wednesday morning river forecasts:

Winter 2013-14 In Some Pretty Exclusive Company

It's the winter that won't end.


Continuous cold, frequent snows, perpetual snow cover and extremely cold nights have, at the very least, made our dispositions a little testy. We are all short fused. Lake Erie has frozen over with ice cover at levels not seen since the late 1970s for the 3rd week of February. We're infected with cabin fever with only small glimmers of spring-like temperatures on the 8day forecast.

We all--most of us--want this to end NOW!

How exclusive a winter has this been through February 17th?  First, we need to categorize the winter elements and see where this winter ranks. I use these four as an overall measure of winter's severity: TOTAL SNOWFALL, DAYS WITH SNOW ON THE GROUND, AVERAGE TEMPERATURE & NIGHTS BELOW 10 DEGREES. 

1. Total Snowfall for 2013-14 now ranks 10th

2. Days with Snow Cover at or more than 1 inch ranks 7th

3. Overall Average Temperature since December 1st ranks 29th

4. Number of night below 10 degrees ranks 16th

The winter is ranked ery high in some categories and not so high in others. So I looked for the winters that are ranked HIGHER than this winter in EACH of these FOUR categories. What did I find? 

ONLY FOUR WINTERS ranked higher in 3 categories...

1917-18, 1976-77, 1962-63 & 1969-70

ONLY ONE ranked HIGHER in EVERY CATEGORY: 

The winter of 1977-78!

When did we see our first string of "milder" temperatures
(5 days at or about 50 degrees) in these years?  Was spring warmer or colder than normal? That answer later this week...