Long Awaited Storm System Brings Some Rain, Wind and Thunder

Saturday, October 7th:  Though it was not much to write home about for the Lawrence area, the long anticipated storm system that was stuck out west for days exited stage right and barreled across eastern Kansas overnight Friday into Saturday.  Although the storms ahead of the front weakened rapidly as they approached Friday night, the front itself managed a revival of sorts as it moved across the Lawrence area between 5 and 6 AM Saturday.

The accelerating but weakening upper trough caused the powerful storms that developed across central Kansas Friday on evening to decrease and split apart as they pushed  eastward overnight.  Of course, atmospheric destabilization from solar heating was also gone by the overnight hours.

Nevertheless, thundershowers ahead of the front made it into the Lawrence area  around 11:30 PM Friday, lasting until about 2 AM Saturday, with the rain falling in two main bands.  These two primary surges of ‘thunder rain’ during this period dropped 0.46 inches at the Lawrence Airport and 0.61 inches at my home weather station in southwest Lawrence.  (The totals from my home weather station and manual rain gauges agreed almost exactly with this system.)

Following the system, some morning instability clouds and cool, west winds gave way to sunny skies and quite mild temperatures in the afternoon.  The afternoon high managed to reach 76 degrees at the Lawrence Airport (78 at my home weather station) with the dew point down into the comfortable lower 50s.  By sunset, which is shortly before 7 PM these days, the temperature had dropped off to 70 and the dew point was back up in the low 60s, as the ground and vegetation apparently exhaled the recently fallen rainfall.

The 24 hour precipitation total at the Lawrence Airport (up to 7 AM Saturday) was 0.58 inches.  The 7-station city average was 0.65 inches.  My residence in southwest Lawrence had the highest of these reports with 0.75 inches.  Within the Topeka NWS area of responsibility, amounts ranged up to 1.69 inches at Concordia, followed by 1.49 inches at Manhattan.  Topeka came in with 37 hundredths.   A bit farther west, Salina reported 1.88 inches, the Great Bend Airport 1.83 inches and Hutchinson 1.25 inches.

Speaking of Great Bend, the very intense storm that struck there just before sunset Friday (see previous post) brought the highest CoCoRaHS amount  in Kansas for October 7th.  A CoCoRaHS site in the northeast part of Great Bend reported with 3.34 inches of precipitation.   A nearby CoCoRaHS report on the northwest side of town came in with 2.05 inches.  Large hail also fell, reported up to 1.75 inches in diameter.  To the southwest about 10 miles, near Durdee, hail up to 2.5 inches was reported with severe wind damage to some power lines.

Back in the more tranquil Lawrence area (where we are safe!) the 72-hour rainfall total for this system as a whole came in at  0.92 inches at the Lawrence Airport, while the Lawrence city average came out to 1.25 inches.   While this was perhaps not as exciting as the powerful storms that pummeled Great Bend (or hit from Salina to Manhattan), it was better than a smack in the head by large hailstone.  Ouch!

upaCNTR_500a

The Saturday morning 500 MB chart shows the core of the upper trough near Lawrence with the upper the main upper trough energy splitting off to the south.  The other marks show the position of the low and trough in 12-hour intervals going back 48 hours.  The upper trough was stuck out west for a few more days previous to its slow push eastward shown here.

upaCNTR_500-1

By Saturday evening the upper trough was weakening and accelerating northeastward as another very strong jet stream and upper trough started digging into the Pacific Northwest and northern Rockies.  Could it be deja vu all over again?   Or, will the new incoming system be more progressive – that is, not get stuck out west in a blocking pattern?  The latter is scenario is currently forecast.

g13.2017280.1445_US_vis

9:45 AM Saturday satellite image shows the storm front has bast us with low clouds wrapping around behind the front into northeast Kansas.  Nate is pushing rapidly to the north-northwest toward the Gulf Coast as it rounds a strong subtropical high to the east.

g13.2017280.2145_US_vis

At 4:45 PM, our system continues eastward and weakens while Nate has a last burst of intensification in its core (raised, high topped clouds in the center, even casting a late day shadow) as it nears the southeast tip of Louisiana.  Meanwhile, to our northwest, a new strong jet stream pushes in.  Standing wave clouds can be seen along the northern front range of Colorado from this increasing jet stream flow.

upaCNTR_250

At jet stream level Saturday morning:  A new powerful jet stream pushing in near the international border is finally kicking our stuck weather system eastward.

upaCNTR_250-1

By Saturday evening, the jet stream to our northwest is even stronger at around 125 knots while our once stuck weather system accelerates quickly to the northeast across Wisconsin and Illinois.

Now for us diehards, a blow by blow account of the strong but waning (and then kind of regenerating) storm front as it crossed our region:

20171007_020536_BREF1_gray

At 9:05 PM, our front is prominent to the west on Topeka Radar.  Salina (circled) is about to get clobbered by a powerful line of storms.  Residents of Great Bend are sighing in relief, no doubt, as the powerful storm that hit there has pushed eastward, morphing into the line approaching Salina.

20171007_030545_BREF1_gray

An hour later, at 10:05 PM, Salina is just out of intense rainfall (west circle) and Manhattan is now in it (center circle).  Lawrence, still well to the east of the action, awaits its turn which is destined to come in the late night hours, as often seems to be the case.

20171007_040104_BREF1_gray

At about 11 PM – finally some development around Lawrence as Topeka is hit by a narrow line of storms.  Manhattan is still in pretty heavy rain and thunder.  Salina is in the moderate rain area with embedded thunder behind the main band, which extends almost to Great Bend.  A good soaking is happening in that region, as has been the case quite a bit lately.

20171007_042906_BREF1_gray

At about 11:30 PM, rain and thunder move into Lawrence (arrow)..!  Manhattan is in a temporary lull.  The Salina region is still in good rainfall and getting thoroughly drenched.

20171007_060544_BREF1_gray

At 1:05 AM a second and heavier band of rain and thunder is moving across the Lawrence area.  Manhattan is getting some light rain and Salina is finally out of it.

20171007_062541_BREF1_gray

At about 1:25 AM, the most intense part of the second surge of rain is now over the Lawrence area (large circle) with the Topeka and Lawrence airport sites in the smaller circles and Lawrence underlined.  It could have been better, but we will take what we can get.

20171007_095328_BREF1_gray

But wait, there’s more!  Just before 5 AM, the actual front generates a new narrow band of heavy rain that is moving across Topeka here.  Notice the difference in the winds ahead of, near and behind the front.

20171007_103131_BREF1_gray

The frontal band pushes across Lawrence about 5:30 AM.  It brought another quick 0.12 inches of rainfall to the Lawrence Airport and my residence, along with some gusty winds.

20171007_105016_BREF1_gray

By 5:50 AM, the front has moved on but with winds gusting up to 34 MPH at the Lawrence Airport, enough to bring down a lot of leaves, twigs and small branches I saw as I drove into work.

After a brisk and cool morning with temperatures around 60 degrees, a sunny and mild afternoon ensued on downslope western winds and late day temperatures in the upper 70s.  It was a good evening for a bike ride to Clinton Lake after work, which my wife finally talked me into doing!  The ride out was perfect under clear skies, light winds and lower humidity.  The ground was moist but not terribly muddy on the Mound Point lookout trail by the lake with many gulls, some Pelicans and lots of spiders spinning their webs on the bushes, which I think may be preparing for a long distance, wind-borne  flight.

$$

 

 

 

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s