2018 09 10 13 28 Update on Flash Flood Potential next 24 hours and Possible Gulf Development Later t


look we’re going to talk about the heavy rain flash flood potential over the next couple of days and then the possible development of a tropical system in the Gulf that could impact us late in the week just a quick summary of the main points we are expecting periods of heavy rain through tomorrow with some breaks in between some of our model guidance shows some heavier rains today and then kind of a little bit of a lull this evening and then more development overnight and Tuesday morning so it’s not going to be raining straight through the period but we are looking at periods of heavy rain we have seen some rain rates today on the order of two inches per hour and some of the heavier downpours and that’s kind of the airmass we’re in so those high rain rates especially when we have storms tracking over one area can well lead to flash flooding flash flood watch is in effect for the coastal two tiers of counties up till now it’s been out until 7 a.m. tomorrow but that’s going to be extended in time through much of the day on Tuesday and again we’re going to also talk about this the possibility of a tropical depression at least maybe even a tropical storm that could impact us late in the week and that that remains very much uncertain so this slide indicates the areas of greatest concern for flash flooding if you look this is what we call the excessive rainfall outlook and what you see there is really the coastal parts of Texas on inland a little ways are under a slight risk of a flash flood type rains and then the marginal area extends well inland so what does that mean it means for our forecast area if you look in the lower right you’ll see the counties in yellow are the ones that have the greatest risk for flash flooding but that there is some risk for flash flooding really for any county in our warning area in the upper right there you can see the current area covered by the flash flood watch and as I said it’s possible the rain will wane a little bit will let up some and then kick in again overnight and Tuesday this is the forecast rainfall and sort of an average an average rainfall looking at again higher amounts at the coast four to six inches and then a little bit lesser amounts inland but I want to really caution that these are average amounts as you all know very common for us here in Southeast Texas to get heavier bands that can generate quite a bit more than what we we have sort of on our average amount map there’s some brand a brand new 24 hour forecast it has just come out from the Weather Prediction Center in the lower-right and again you can see it’s really zeroing in on those coastal counties so kind of the tick away message here is that more heavy rain potentially in the next 24 to 36 hours the heaviest amounts do look to be along and near the coast and a little bit inland but there is some flash flood risk even well inland moving on to the tropical disturbance that the Hurricane Center has been highlighting since yesterday afternoon they’ve actually raised the chance of development into a tropical depression or tropical storm now to 30% in the next two days and fifth percent in the next five days and if you look at the frame on the left-hand side there that oranged hatched area that’s the zone where they would expect development or genesis to occur so what do we mean by that basically we have a fairly disorganized system right now but it actually looks fairly decent on satellite it could get a little more organized certainly over the next five days and we could see perhaps a tropical depression maybe even a tropical storm out of this and again just a 50% chance that transformation will occur so still very uncertain I know everyone’s wondering you know about how strong the system could be if it were developing that’s even more uncertain as far as aging the intensity of any tropical cyclone that does develop but the way the Hurricane Center is wording it in their outlook they’re saying a 50% chance of the development of a tropical depression in the next five days here’s a look again at that disturbance kind of latest satellite image you can see it there near the Yucatan and there is the well on the right-hand side on the air in all those thunderstorms there yes just a reading through Tuesday three inches per hour and if we see that over one area that’s when we would expect to see some flash flooding so because of that we do have a flash flood watch in the areas of most concern essentially two tiers of counties closest to the coast I showed you the watch area earlier that watch the forecasters are planning to extend that into or perhaps even through Tuesday so beyond on guard for that chance of rain each day this week and one thing the rain that is occurring now could do is perhaps set the stage for issues later on the set soils are becoming saturated some of the the water levels are rising so this prolonged wet period we do need need to be a little bit concern about that late week tropical wave as well or possibly even a depression or storm and that could bring another round of heavy rain late in the week as I mentioned whether it becomes a tropical depression or storm that aspect is pretty uncertain right now hurricane center gives it just a 50/50 chance of that happening and as I said that if that were to develop in perhaps into say a tropical storm or

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