Springtime Low Pressure System Bringing Heavy Snow, Tornadoes 3/23/2016

It’s spring! & in spring like fashion the weather is being volatile. Heavy snow for parts of the Colorado Front Range (18+ inches from where I’m currently writing this post) and severe weather for parts of extreme southeastern Nebraska, Southwestern Iowa, Northwestern Missouri and Northeast Kansas as well as eastern Oklahoma, western Arkansas, Southwestern Missouri and Northeast Texas (including parts of Dallas, Fort Worth).

Tornado Risk
Tornado Risk

 

Here’s a look at the heavy snow from the northern suburbs of Denver, CO.

Heavy Snow in the trees
Heavy snow weighing down limbs of trees around the Denver, CO area today

Here’s our vantage of the snowstorm today from Erie, CO 

 

While Denver is digging out of today’s snowstorm,  a severe weather setup is shaping up in the warm sector. Just a bit ago, a Mesoscale Discussion was issued by the SPC.

Mesoscale DiscussionA Tornado Watch has just been issued:

 

Tornado Watch 51

Here’s the wording for the Tornado Watch from the Storm Prediction Center:

Primary Threats Include...
A Couple of Tornadoes Possible
Scattered Large Hail and Isolated Very Large Hail Events, 2 inches in diameter possible
Isolated Damaging Wind Gusts to 70 mph possible.

The Warm Front is already well defined on visible satellite. Any storm that can “latch on” to the warm front has a greater tornado risk today as the warm front acts to increase the storm relative helicity  (surface winds are more backed along the warmfront). Storm Relative Helicity – is essentially a measurement of the rotational potential for a storm’s updraft.

Visible satellite imagery clearly shows the warmfront in southern Nebraska
Visible satellite imagery clearly shows the warmfront in southern Nebraska

There is ample wind shear in the warm sector today, SPC Mesoanalysis is analyzing over 50kts of Effective Bulk Shear in the risk area today. [Wind shear is the change in wind speed and /r direction with height in the atmosphere – wind shear helps storms become more organized as it separates the updraft of the storm from the falling precipitation.]

Bulk Shear

There is also ample CAPE for storms to work with today. [CAPE- Convective Available Potential Energy- is a measure of atmospheric instability, essentially how much energy an updraft has to work with.] Mesoanlaysis is analyzing over 1000 j/kg of surface based CAPE today.

CAPE

Here’s a recent surface analysis chart from the WPC (Weather Prediction Center) showing the surface low pressure system and dryline progressing eastward in Kansas.

Surface Analysis

 

Forecast soundings for near St. Joseph, MO today are indicative of potential tornadoes.

forecast hodographs

 

For a comprehensive list of severe weather analysis tools and weather links, check out our Weather Link’s Page.

Here’s what the 18z run of the HRRR says for storms by 00z

HRRR
HRRR forecast for storms at 00z (7pm CDT) via http://www.pivotalweather.com/

If you haven’t already, make sure you have your tornado sheltering plan in place! Charge your batteries on your NOAA weather radios and stay tuned to local tv/ radio stations for weather alerts.

Plan Ahead!

Remember: a Tornado Watch means conditions are favorable for tornadoes to form, Tornado Warning means a tornado is occurring and to seek shelter immediately.

Stay weather aware!

Lauren Forney
WAS*IS (Weather & Society Integrated Studies), NWA, VORTEX 2

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