00:00Well, we have some concerns about flash flooding in parts of eastern Kentucky, West Virginia, and a big chunk of
00:06Ohio moving through the middle of the week, initially north and eventually farther south.
00:10And some of the real estate, some of the terrain here, the way the geography is laid out, is prone
00:17to make flooding worse because of the hillsides and the fact that many places that are actually buildable,
00:24the smaller pieces of flat land happen to be near Creek sometimes in eastern Kentucky and also into West Virginia.
00:30So there are some big concerns associated with that.
00:32Big picture here into midweek, the area that we're facing these repetitive storms will be running from the Midwest into
00:40the central Appalachians.
00:42Initially, the storm track is a little farther north, deeper into the middle of the week, it becomes oriented a
00:47little farther south.
00:48So the storms are going to be distributed over somewhat of a variety of areas, initially a little farther north.
00:55But this whole zone here is going to be an area of significant flood concern, flash flood concern.
01:02It's not just flooding.
01:04There are other hazards that we're facing here.
01:06And with some of the thunderstorms on Tuesday and Tuesday evening, damaging wind and flash flooding, along with isolated tornadoes.
01:13We have some populated areas like Indianapolis, Cincinnati, Columbus, Charleston, and Huntington, West Virginia, facing some of these hazards as
01:20well.
01:21But we're going to get into it here, and then we're going to come back to our flood graphics just
01:25to kind of summarize the big picture.
01:27But one thing that's changed compared to a week ago, the big ridge of high pressure that is still present
01:34across the west, it's getting squashed.
01:37And it's not quite as robust as it had been a big ridge.
01:41Now it's being flattened out.
01:44And also, along with that, a strong zone of high pressure, of low pressure aloft, big low aloft, over the
01:52Hudson Bay is beginning to push south.
01:54You're going to see it's going to be kind of nudging southward here.
01:57And that's going to lead to this corridor.
02:00And I just want to show you how it does move a little farther south.
02:02You can see this lobe of low pressure that really kicks down through northern New York State.
02:07And that's indicative of generally this pouch of lower pressure digging farther south.
02:13So what does this do for us?
02:14I'm going to go back to maybe Tuesday night, Wednesday morning.
02:18It's going to effectively put this transitional zone into a squeeze play with colder air getting a little closer.
02:26It's not really there, but it's getting a little closer from the north.
02:30And the heat is still holding in areas farther south.
02:34So the squeeze play, this temperature contrast, is going to become greater.
02:38And that focuses the storm track in a more vigorous way across this area.
02:43And you can see each of these weak disturbances here, these zones here, are going to be sparking rounds of
02:51storms.
02:52There comes another one, Wednesday night into Thursday.
02:54And then you have another one behind that a little farther south, Thursday night into Friday.
02:58So a big picture here, and I don't want you to look at the details too much, but you can
03:02see that the storms on Tuesday, Ohio, parts of the Ohio Valley, northern Kentucky, sinking into West Virginia.
03:09That's the GFS.
03:10Here's the NAM.
03:11Similar theme, maybe a little farther north.
03:14And then here's the European, European with numerous drenching thunderstorms.
03:19And again, the heaviest will be Kentucky and West Virginia at the end of that.
03:22Wednesday, a new episode, Ohio, West Virginia, Kentucky.
03:26And the NAM, Wednesday, new episode, Ohio, West Virginia, maybe a little farther north.
03:31The NAM is trending a little farther north than the others.
03:33European, Wednesday, farther south by a big margin compared to the NAM.
03:38But the general theme is, it's the Ohio Valley, the eastern Ohio Valley into the mountains.
03:43Then Thursday, another episode farther south with the GFS.
03:47The NAM kind of cuts off around 8 p.m.
03:50And then the European, maybe a little farther north than the GFS by about a state.
03:56But the theme is Ohio, West Virginia, Kentucky at times, southwest Pennsylvania facing this repetitive threat for thunderstorms.
04:04And the dew points are very high in the green, the sea green, in the blue even.
04:10In the blue here, I'm going to highlight, this is a 75 degree dew point over parts of Illinois, Indiana.
04:16We talk about the concept of corn sweat, extra evapotranspiration, moisture leaving the leaves of corn.
04:23Millions of acres of cornfields in Illinois sending more moisture into the atmosphere.
04:29And then into Thursday, it gets suppressed a little farther south, Illinois, Indiana, Kentucky.
04:33And what you might notice is, I'm going to go back to Wednesday, the wind here.
04:39We can find kind of these converging wind streamlines where there's flow from the north and flow from the south.
04:47And we often call this frontogenesis.
04:51And I'm going to take some liberties here, but it's kind of tracing the boundary between these conflicting winds.
04:57And if you have air coming together in low levels, it has to go somewhere.
05:00It's not going to go into the ground, so it comes up.
05:02And that frontogenetic forcing, frontogenesis, it actually produces more thunderstorms and rain.
05:09Sometimes in the winter, we see more snow production there.
05:11So, again, the color scheme of this map is a little wild here.
05:15But where you see the greens, the magentas, the reds, the oranges, that's frontogenesis.
05:19That's where you have winds conflicted, cool air coming in, warm air coming in,
05:23and working together to produce extra lift in the atmosphere.
05:27And, again, the opposite is frontolysis.
05:29But frontogenesis here, you can see some of the modeling suggesting at this general corridor here
05:34where we're facing some extra lift in the atmosphere.
05:39And, again, just kind of the squeeze play.
05:41Cold air coming in from the north, warm air coming northward from the south.
05:44And that is going to lead to more storms and rain production.
05:48And this map here shows precipitable water.
05:51How much moisture would come out of the atmosphere if you wrung out all the moisture in the vertical column
05:55than maroons where we have high moisture content.
05:58And it's in a stripe right across Kentucky into West Virginia, southwest Pennsylvania at times,
06:03especially with that NAM that runs a little farther north.
06:05So, again, we're looking at lots and lots of rainfall.
06:08Here you can see a model forecast in the magentas of 3-plus inches of rain, 3.9 near Charleston,
06:13by 8 p.m. Thursday in the GFS.
06:16I see some deep blues in northern Kentucky up into areas near Lewisburg and Tollsboro in Lewis County, I should
06:22say.
06:23Potential for 5, 6, 7, 8 inches of rain.
06:25That's a little hot, but then into areas like the European model, Cincinnati, 4 inches potential.
06:30So what do we do with all that here as a forecast operation?
06:34You know, we have to give you a specific forecast.
06:38We're going to highlight the dark green zone with flash flood risk that will be significant.
06:42And if we were to put numbers on this here in the final seconds of the forecast feed,
06:464 to 8 inches in a widespread area, Ohio to West Virginia.
06:505.
06:518.
06:5110.
06:5111.
06:5211.
06:5215.
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