Joe’s Weather Blog: KC storm chances and Harvey (SAT-8/26)

Good afternoon…pretty day for late August in the KC region with lots of sunshine and moderate but seasonable dew points. Temperatures will be a bit warmer this afternoon but overall not too bad for this time of the year. Rain chances increase again on Sunday but beyond that things are looking pretty dry for the region for quite some time…and rather pleasant as well from a temperature standpoint.


Forecast:

Tonight: Fair skies and pleasant with lows in the 60s

Sunday: Variable clouds with increasing rain and storm chances. Highs are sort of tricky depending on the timing of the rain because IF the rain is widespread enough, temperatures may actually fall during the rain and then goo back up after the rain is done. Let’s shoot for highs around 80° (warmer with more sunshine in spots).

Monday: Looks great with highs in the upper 70s to around 80°


Discussion:

So about our rain chances…

We’ve seen over the last day or so some areas of storms/rain develop towards the I-80 corridor…they’ve been moving SE and weakening as they approached NW MO. Tonight there may be a few more of those storms in NW MO that develop a bit closer to us. By Sunday there may be some storms in our area as well. The timing would suggest from mid to late morning into the middle of the afternoon. I’m not convinced on the total coverage of this activity though…so that’s why I don’t think it’s a slam dunk that you’re going to get the rain. IF you do there may be some downpours with it though.

The question then during the afternoon is will we become unstable again after whatever happens in the morning. There are signs that we may start to clear skies out again…allowing some instability to rebuild. Should that occur and since the front that will be moving in won’t get here till later in the afternoon at least there may be some redevelopment. So there are a few chances of rain on Sunday.

Beyond that though…not much is expected aside from some really nice weather for several days afterwards. Pleasant afternoons and cool mornings.

Harvey:

Harvey came ashore last night near Rockport, TX. There has been a lot of damage near there and sadly reports of 1 death (so far)around Rockport and Port Aransas. Harvey was intensifying as it came to land. A combination of little to no shear aloft (to rip the storm apart) and warm Gulf waters on it’s path towards land provided the needed ingredients to allow for the strengthening. At landfall winds were near 130 MPH. A buoy ENE of Port Aransas measured a wind gust to 132 MPH

Yesterday I wrote about the incredible length between storms of this strength to hit the USA. Almost 4350 days passed since the last category 4 hurricane (winds 130 MPH-155 MPH) hit.

Once we teeter into cat 3 status a hurricane is considered a “major” hurricane. This was a cat 4 hurricane at landfall.

If you look carefully at the above radar animation…you can actually see little spins within the eye of the storm. That is pretty incredible to see if you haven’t seen them before…and what’s fascinating (amongst other things) is what the center of a hurricane looks like…believe it or not it’s called the “stadium effect”. The surrounding part of the hurricane spinning around it’s center…takes on the look of a stadium as if you were on the 50 yard line. The storms/clouds/rain build up around the eye of the storm like the seating in a stadium. From above it looks like this…

As the eye of a hurricane approaches a location…you get into the most ferocious winds and then within the eye the winds are much lighter…the air is much “heavier” and there are lots of birds and insects flying around. We can actually see that using doppler radar.

Now imagine part of your job is going out and launching a weather balloon just hours before the hurricane comes ashore. That’s what the NWS in Corpus Christi had to do last night before 7PM…in the middle of the various squalls that were affecting that area…check this next video out…they were fighting the winds hard…trying to launch a decent sized balloon that had a mid of it’s own too!

The pressure of Harvey, as I mentioned was dropping as it was coming ashore…

938 milibars is equal to about 27.70″…the average barometer reading is around 29.92″ and today here in KC it’s running about 30.14″ at last report. That’s a pretty intense hurricane.

Again the wind damage is somewhat confined it appears…now there will be an increasing threat of additional flooding basically because the steering pattern is almost non-existent down there…there’s nothing to really move the storm along.

Notice as well…far removed from the center of the storm…the significant outer bands of storms and torrential rains hitting the Galveston/Houston region this afternoon.  Rainfall there, well away from the core of Harvey is already approaching/exceeding 10″ as the auto-update of doppler rainfall below suggests.

\

While Harvey goes through a gradual evolution away from tropical storm status today…the flooding threat really is just starting believe it or not. The slow movement of the storm and the meandering nature of the storm means copious rainfall and with moisture streaming into the eastern TX region from the Gulf…those rain totals are going to be eye-popping down that way.

You can see the moisture streaming into the storms center by looking at the water vapor loop.

Here are the last 24 hours of rain in the Houston area…

Via Harris County Flood Control

and on top of all that there will be a prolonged tornado  threat as well. They will be fast movers too if any form. Tough to warn on those as well.

At this point though one has to step back…and recognize the power of what can happen when it comes to weather…whether it be in the tropics or even up here in KC. It’s sobering to think about  that it only took 44 hours go from from a harmless tropical wave in the atmosphere to a 130 MPH monster hurricane…44 hours…less than 2 days.

Really just an incredible storm…

Joe

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 )

Twitter picture

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

Facebook photo

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

Google+ photo

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

Connecting to %s