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Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 1:27 pm
by tireman4
Andrew wrote: Thu Dec 06, 2018 1:10 pm The biggest thing we need to watch for with flooding tomorrow is the location of the early to late afternoon activity. GFS has a shortwave in the midlevels rotating through Southeast Texas during that time, focusing some of the heavier precipitation in this region. If that happens that is where you really could run into some flooding issues especially with the main line of storms coming through shortly later overnight. If we can escape the early afternoon training, the line of storms overnight will likely move through quickly enough that street flooding will be the biggest cause of concern (assuming we don't have any training ahead of the line). Unfortunately, as many of our heavy rain events go, we will have to wait until the radar lights up to know exactly where that heaviest rainfall threat exists.
Yes. Yes. Yes and wait..yes...:)

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 1:40 pm
by Andrew
stormlover wrote: Thu Dec 06, 2018 1:21 pm What is euro showing
Widespread 2-3 inches isolated 5-7 inches

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 1:54 pm
by Cromagnum
Any concerns for hail and wind?

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 2:01 pm
by srainhoutx
Update from Jeff regarding River Flood Potential:

Significant rainfall event is likely over the region producing major rises on area watersheds.

Several major rivers are forecast to go into at least minor flood over the weekend if current rainfall forecasts verify over the area. These forecasts will change some as the rainfall begins to impact the area.

Trinity: minor to moderate flooding is expected along the entire river below Riverside
San Jacinto: minor to moderate flooding is expected on the West Fork. Minor flooding on the East Fork
Cypress Creek: minor flooding is forecast from Katy Hockley to West Fork of the San Jacinto River
Brazos: Minor flooding is expected at Hempstead and Bryan and will likely see at least minor at Richmond and Rosharon
San Bernard: Minor to moderate flooding along the entire channel
Colorado: Minor flooding from Bastrop downstream to Wharton
Tres Palacios: Minor to moderate entire channel.

To view forecasts for SE TX:

https://water.weather.gov/ahps2/index.php?wfo=hgx

Note: for the west fork of the San Jacinto moderate flooding is currently forecast, but major flooding is certainly possible.

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 2:28 pm
by srainhoutx
The Weather Prediction Center expands their Moderate Risk for Excessive Rainfall across S Central and SE Texas to include most locations except for Coastal tier of Counties.
12062018 20Z Excessive Rinfall 98ewbg.gif
Afternoon Updated Low Track as of 20Z
12062018 20Z Low Track lowtrack_ensembles.gif

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 2:48 pm
by srainhoutx
Updated Thursday afternoon Quantitative Precipitation Forecast suggest a swath of 5 to 7 inches of rainfall mostly tomorrow into early Saturday across SE Texas.

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 3:12 pm
by srainhoutx
Cromagnum wrote: Thu Dec 06, 2018 1:54 pm Any concerns for hail and wind?
There is a risk for damaging winds and a quick spin up tornado or two mainly for the Coastal tier of Counties. That is a big wildcard in our local SE Texas forecast mainly for the overnight hour late Friday into early Saturday.

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 3:12 pm
by srainhoutx
srainhoutx wrote: Thu Dec 06, 2018 3:12 pm
Cromagnum wrote: Thu Dec 06, 2018 1:54 pm Any concerns for hail and wind?
There is a risk for damaging winds and a quick spin up tornado or two mainly for the Coastal tier of Counties. That is a big wildcard in our local SE Texas forecast mainly for the overnight hours late Friday into early Saturday.

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 3:14 pm
by srainhoutx
We also need to monitor mid next week. Another potent Pacific Storm looks to bring rain back into the forecast next Wednesday night/Thursday across a good portion of Texas.

Re: December 2018: Friday/Saturday Heavy Rainfall Potential

Posted: Thu Dec 06, 2018 8:39 pm
by sau27
The 0z update from WPC looks like it shifted the QPF bullseye a bit closer to the coast. Let’s see if that trend continues.