Severe Weather Risk
9:45 PM Update:
Radar showing storms now moving through the west side of the viewing area, the most concentrated area may stay along and NW of the I-35 corridor. So far aside from some small hail reports and winds gusting to 55 MPH near Topeka there hasn’t been too many severe weather reports in the last hour or so. MT is watching the situation and will have updates @ 9:45 10:15 and 10:45 with quick updates at the top and bottom of the 10PM hour
8PM Update…an impressive line of storms has congealed across Central KS and is moving towards the ENE. There have been at least one tornado associated with this activity. Here is radar from just before 8PM.
The tornado warned cell is 115 miles WSW of Downtown KC. It should weaken over the next 90 minutes as it moves towards the NE at close to 50+ MPH. Our dewpoints have risen into the middle 50s. What will be interesting to watch is it looks like the big storm down there will be outrunning the best instability.
Timing of the line of storms arriving would be between 10PM and Midnight. The activity won’t last long and while there may be some heavy rainfall, it too won’t last long. My main concern continues to be the potential for 55-65MPH winds. it should be noted that should that storm continue to do well for the next hour, there is a tremendous amount of low level helicity available for it to continue to rotate as it moves closer to the metro.
8:20 Update: NEW Tornado WATCH issued on KS side.
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My apologies for the later blog today. I spent most of the day in Pleasant Hill with my colleagues from the NWS going over severe weather preparation for the upcoming season and discussing various ways of improving certain things. So that’s why the weather blog will be running late today.
Probably just as well, because I was wanting to see how today was going to evolve and how the threat of thunderstorms was going to evolve as well as the day went along. We’ve seen one batch of rain move through the region over the past couple of hours. Seems like rainfall amounts are in the .10-.25″ range, just looking at a few of the reporting airports from the 3PM hour.
Here is the latest 3PM surface map, showing the storm at the surface across the Western Plains states, with a warm front on the back door.
There is also a dry line stretching from the storm south through W KS W OK and W TX. This marks the dividing line between the gulf moisture streaming northwards and the drier desert air moving in from the SW and W. The winds are circulating around the storm and have increased to the point that the dust is being sucked into the storms circulation. Take a look at this satellite picture showing the blowing dust.
Interesting that the sand from the White Sands, NM area is being entrained into the storm! Click on that link for a closer view of this phenomena!
So what is going to happen for the rest of the day and night. Here is what I think. Eventually this evening storms will fire up towards the west of the region and fly to the ENE and NE at close to 50 MPH and should move in before midnight. Until that time, temperatures which are in the 50s now will continue to warm up this evening, perhaps to near 60°. The surface dewpoints will rise to near 55°, if now a bit above that. Since the storms will form so far to the west of the area over the next 4 hours or so, they should weaken somewhat as they approach the region. The thing that needs to be watched is that the winds aloft are forecasted to be close to, if not above 60 MPH. Here is a look at the 5K feet winds this evening.
Those 50-60 MPH winds will expand heading towards midnight, so any storms that come this way would be moving into that region of fast winds and the turbulent mixing inviolved with convection may be strong enough to promote some of those stronger winds to make it to the surface. So severe weather in the form of wind gusts of 55-65 MPH will be possible. The freezing level will also be down to about 8-9K feet so IF we get the storms the potential for some hail will be there as well.
To me the main threat would be the winds, and not so much because the storms themselves will be so strong, it’s more because of the strong wind field that the storms will be moving into. In other words, if those strong winds aloft were,’t there, I really wouldn’t be that concerned about the situation at all.
SPC agrees with those ideas as they have highlighted the region with a somewhat better chance of seeing severe level winds with the storms.
After this storm moves through, we’ll stay mild-warm on WED and THU.
Here is a look at future radar off the HRRR model…showing the line of storms on top of us and approaching us @ 11PM tonight.
Again my main concern out of this will be the gusty winds.
I’ll keep an eye on things later this evening and update as needed.