Chinook

Friday (Saturday 00z)- The SPC has a slight risk for severe storms in Kansas. The NAM has this area somewhat capped. The 00z Euro has about 1200 J/kg of CAPE, which is not too crazy. However, the GFS has gone crazy. Usually the GFS is too low with CAPE, right?

A grand total of 68 tornadoes have been confirmed from April 13-15. You might not have thought that after only about 10 tornadoes showed up on SPC storm reports on April 13th (before all prelim. reports and official storm surveys came in). This graphic is from USTornadoes twitter feed: https://twitter.com/USTornadoes

Yes, it looks like Kansas and Oklahoma are in the game. The last 2 runs of the NAM show some 2000-3000 J/kg of CAPE (or more like 1500 J/kg at 00z) in a narrow east-west zone (see STP chart posted above). This is much more CAPE than the GFS was forecasting in this area. So perhaps the SPC will eventually extend the slight risk to far northeast Kansas, northwest Missouri, and parts of Iowa. I think a dryline will extend up to Tulsa, and a cold front will be the forcing mechanism north of that.

If you check the soundings for Thursday, you'll realize that this is going to be a waste of a favorable 0-1km SRH and 0-3km SRH for Oklahoma City, considering there's some CAPE and a dryline/cold front. There's a cap that's fairly strong, so Thursday is probably going to be dry. Friday may be worthy of a slight or enhanced risk for Louisiana, Arkansas, Missouri, and northeast Texas. Possible slight risk scenario for Saturday, east of the Mississippi River.

possible tornado near Jackson MS radar station

yes, that is one well-detected tornado. I am even seeing a delta-v of 130kt or 140kt, and I am using GRLevel3.

TDFW high-resolution radar near McKinney

Isn't there somebody on this board from Richardson, a couple miles away from this tornado warning?

Next week: (April 14-15) I wonder if we could get a severe weather outbreak in the central-southern Plains and a blizzard in the northern Plains on the same day. Today's GFS has a low pressure of 972 mb next Friday.

SPC day-3 (Friday) outlook includes northeast Texas and southwest Arkansas. Tonight's 3km NAM shows this impressive sounding near Texarkana, AR. This is some nifty eye-candy. It is In the warm sector, before scattered storms develop in Oklahoma/Arkansas. The only weakness here would be winds that are weaker at 300mb-250mb, compared to 500mb.

This is the new graph, with the new value for April at about 5.99 tornadoes/day. This is very close to the value from UStornadoes.com web site, which is 5.93 tornadoes/day, if you just divide their number by 30. Also, their value for June is 7.6 tornadoes/day, vs. my calculation at 6.8 tornadoes/day. So that is a kind of interesting deviation from the long-term dataset.

For this data, I have looked at 2010-2017, 8-year climatology of severe weather reports per day. All numbers come from http://www.spc.noaa.gov/climo/online/monthly/newm.html March tornadoes have been relatively low in this 8-year time period, compared to April. This is probably due to weak severe weather setups in March, over a period of years. -- Edit: a longer-term climatology of tornadoes/month is posted here: http://www.ustornadoes.com/2016/04/06/annual-and-monthly-tornado-averages-across-the-united-states/ --

A little Easter freezing rain at Kansas City (yes, it is FZRA at KC International Airport.) Gee, cut us some slack, it's Spring. Let's not have freezing rain.

The last time we saw a decent amount of severe weather was March 19th and 20th. Considering prospects for tornadoes are not too high over the next few days, this means we have gone through another dorky March with respect to severe weather. Not that I want anyone to have damage/fatalities from these things, it's just that cool weather patterns prevailed in March 2013, 2014, 2015, and 2018 for sure.

There seem to be even more tornado warnings, even into the nighttime. Here's a confirmed tornado -- ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 900 PM CDT FOR NORTHERN CALHOUN COUNTY... At 830 PM CDT, a confirmed tornado was located near Jacksonville State University, or near Jacksonville, moving east at 40 mph. HAZARD...Damaging tornado. SOURCE...Radar confirmed tornado.

Not sure if we are talking about the same thing, but the area near the HTX radar is now tornado warned (8 mi west of radar). Interestingly, google maps shows terrain with 800 ft vertical differences there.

The models show that DFW metro area will be near a surface warm front, with dryline existing at some point in central Texas tomorrow. SBCAPE values are forecast to be over 2000 J/kg south of the warm front. It is possible that severe storms will form near the warm front. The SPC could upgrade this area to a limited-area slight risk or keep it at a marginal risk.

I was searching around on Youtube and I found a very good lecture series about tornado forecasting done by Rich Thompson of the SPC. Hopefully this link will take you to the whole playlist, including 9 lectures.

SPC has a day-3 slight risk outlook for Arkansas/Tennessee

The GFS is usually not this crazy about freezing rain accumulation, but the NWS doesn't appear to be overly concerned, with just a winter weather advisory. What's the deal?

Freezing rain in Kansas City metro

There is a plot of snowiest month of the year (climatological) done by climatologist Brian Brettschneider on this page. Scroll towards the bottom of the page. http://us-climate.blogspot.com/search?updated-max=2014-10-11T23:33:00-07:00&max-results=10&start=40&by-date=false

If you take the general ideas of the 06z/12z GFS, you might start to expect a 0.05" to 0.25" freezing rain for southwest Missouri. So, that's not crazy (as the Euro shows?) but may be quite dangerous for vehicles anyway.

I'm surprised we haven't had any people post directly from Houston. Didn't we have some members there? Houston: 27 degrees with -FZRAPL and with 15 kt winds. Yikes!

Rain changed to freezing rain and then snow at Longview (center of this image)