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BigB0882 wrote:Wow, we just had an absolute downpour here in my part of Baton Rouge. I saw a trash can floating down the street and our streets never flood. I wonder how much it rained. Is there a site which lists rainfall amounts? Weather.com used to but they changed their layout and now the precipitation measurement is gone.
Severe Weather Threat
Weak frontal boundary over N TX this morning will sag southward today while aloft a short wave moves southward over the region on the eastern edge of the high pressure cell to our west. Front and short wave will reach our northern counties around early afternoon as surface temperatures reach the upper 90’s (the trigger temperatures for today). Expect thunderstorms to develop as the air mass becomes very unstable (CAPE of 2500-4500 J/kg) by early to midafternoon.
Forecast soundings show dry air in the mid layers of the atmosphere which will help support strong downburst winds and strong outflow boundaries. Strong damaging winds will be the main threat with these storms. Storms should move S to SSW toward the I-10 corridor by late afternoon and may collide with the inland moving seabreeze front helping to enhance coverage near I-10. With the loss of heating, the activity should begin to die off around 7-8pm.
Weak front/outflow boundary from today will be located across the southern regions on Saturday and this may help foster additional storms especially as the seabreeze begins to move inland south of I-10. Boundary washes out and begins to lift back northward on Sunday with rain chances returning to isolated.
Will discuss TD # 7 later today.
CajunMama wrote:David, you know that severe thunderstorm watch you had last night that got cancelled? Help! I need it!!! Got woken up to some serious storms this morning....twice!
Changes from hot and dry to wet and cooler on the way.
High pressure over the SW US will gradually shift further west and combine with building high pressure over the NW US to carve out a deep downstream eastern US trough. This pattern will unlock so fairly cool air by August standards and send it southward over the northern plains and then SE toward the Ohio Valley and east coast this weekend. Across TX the cold front will arrive into the state Thursday and slowly sag southward over the weekend. Main brunt of the cold air advection will be to our NE, but the front or its associated outflow boundaries from thunderstorms will likely sag into central TX and our northern counties by late Saturday.
The combination of the frontal boundary, increasing moisture from both the Pacific and the Gulf, and short wave riding down the backside of the trough and across the frontal boundary will support much better rain chances starting Friday and continuing into the weekend. Should see some decent organization of the storms both along the frontal boundary and the inland moving seabreeze front, so most locations should see some rainfall. Pattern does favor heavy rainfall and will need to keep an eye on this aspect as the boundary will linger into early next week providing several days of wet weather.
Big wild card is whether or not some sort of tropical system will try and spin up over the western Gulf of Mexico late this weekend into early next week. GFS has been consistent on moving the remains of TD #7 across central America and the Yucatan then into the Bay of Campeche where it slows the wave and closes it off into a weak surface low. The EURO and CMC continue the wave axis westward and into mainland Mexico with no development. The GFS has performed very well this year in the tropics with both Debby and Ernesto and TD #7, so it could be on the right track. With that said, shear looks to be increasing over the western Gulf in response to the tail end of the trough over the eastern US and I think the GFS is too strong with any surface low that may develop. That pattern fits a classic western Gulf of Mexico surface trough that may close off into a weak low, but is highly sheared and all the weather is N and NE of its surface center. If the EURO is correct the frontal boundary would stall across the northern Gulf and this would also help increase the surface gradient with lowering pressures to the south.
For now will keep the frontal boundary stalled near/over our area inland of the coast and any tropical development weak. Combination of these features will keep rain chances high into early next week and if low pressure does form in the western Gulf, rain chances would likely increase into the middle of next week.
One more day of dry and hot before the pattern begins to change.
Large ridge of high pressure that has been anchored over W TX and NM for weeks has weakened and shifted westward allowing a downstream trough to develop over the central and eastern US. This unusually deep trough for mid August will allow a rare cold front to move into TX later today and approach SE TX over the weekend. Gulf moisture begins to increase later today and really on Friday with PW values increasing to 2.0 inches by Friday afternoon. With weakening low level winds and building moisture, expect the seabreeze to become active on Friday while thunderstorms from the north move southward during the afternoon and may clip our N and NE counties.
Saturday-Sunday:
Slow moving/stalling frontal boundary arrives into/near the area as moisture increases even more off the western Gulf. Expect a good round of thunderstorms on Saturday with heating both from the seabreeze and the stalling front. GFS and EURO are really hammering away at Sunday as being the wettest day. Once again widespread storms are likely at really any point from late Saturday night into Sunday evening. Weak short waves in the NW flow aloft could develop storms in a highly moist air mass and nearly anytime during that period. Starting to get slightly concerned on the rainfall totals with the potential for a surface boundary in the area and deep tropical moisture in place. Both of those factors point to a locally heavy rainfall threat.
Early Next Week:
Decent agreement in the model guidance through Sunday begins to diverge early next week. Tropical wave (old TD 7 remains) currently over the southern Yucatan and central America will lift WNW into the Bay of Campeche this weekend. GFS has backed away from its tropical cyclone development and has fallen in line closer to the EURO and CMC and keeping the system a tropical wave. Two main questions focus on early next week: 1) how much moisture is pulled northward from this tropical wave along the western Gulf coast and 2) how far south does the frontal boundary move. EURO and CMC try and push the front offshore early next week allowing a drier air mass the move into the region, while the GFS keeps the boundary over the area with deep tropical moisture in place. Convective outflows could push the front southward into the Gulf, but then again it is mid August. Will take a blend of the GFS and other guidance and show the front making slow progress toward the coast early next week. With several days of a stalling boundary and deep tropical moisture in place, many rounds of heavy rainfall appear likely. As the ground saturates over time with daily rains, will start to see increased run-off and the threat for flooding may increase especially if the boundary lingers into the middle of next week.
my Cowboys my Rockets my Astros my Cowboys my Rockets my Astros my Cowboys my Rockets my Astros vbhoutex wrote:Longer story short, it is pouring again!!! Last 24 hours we had 2.26" of rain with, as above, major CG and almost continuous thunder for a while during the heavier storms. Currently this is just a downpour without lightning and thunder. Still a very comfortable 72f. The question is whether this will let up enough for us to get out to the vehicle and go to church. What is coming in now is training along I-10 which means we may be in for another hour or so of heavy rain.
Jagno wrote:This horrific heat reminded me so much of what we faced immediately following Rita. My heart goes out to those who are trying to pick up the pieces in this sweltering heat.
The great news is that we got electricity back yesterday afternoon. I'm still shocked at how one utility pole went down and simply the tops from the cross sections on up snapped completely off the subsequent 6 poles down the line. This had to have been a small twister to just shear the tops off of these poles like that. This happened at our restaurant. One of our employees who lives near there said it sounded like a frieght train just as the electricity went off. We are so blessed compared to many. Our food service company made special arrangements to have a truck come in and deliver all of the replacement food on Labor Day. We had to throw everything out for safety concerns. Within 24 hours mold was already forming in the refrigerators. Wow, that was quick in this heat. Well after 2 days of pure elbow grease and alot of help, the state and local health inspectors came by and passed us with flying colors to reopen.
VBHoutex, I saw a mention in the talking tropics thread that we are supposed to have a cold front down into the gulf by next weekend? My extended forecast doesn't see it apparently but I'm praying we do get relief soon.
Slow moving cool front currently depicted in the surface observations along a line from NW LA to just north of College Station to south of San Antonio this morning. Meso low noted in radar images over C TX moving ENE at the present time while showers and thunderstorms are spreading northward into the coastal plains from the NW Gulf of Mexico. Moisture has increased over the region compared to yesterday with PWS in the 1.9-2.2 inch range and soundings nearly saturated. Water vapor images reveal mid and high level moisture tap spreading NE from TS Kristy in the EPAC off the western coast of Mexico. Storms yesterday were once again prodigious lightning producers and also produced some very heavy rainfall. Several locations picked up 1 inch of rainfall in 15 minutes or less and a few locations totaled nearly 4 inches. This proves this air mass is capable of some excessive rainfall in a short period of time especially if storm motions slow.
Set up over the area is starting to resemble some similarities to past fall flooding events with a stalling surface front, deep tropical Gulf moisture, upper trough slowly moving in from the west, and the EPAC tropical system tap. Thus far rains have remained fairly scattered, but with the frontal boundary entering the region today expect more organized rainfall. Additionally storm motions will be slowing as steering currents weaken. Frontal boundary should progress very slowly toward the coast tonight into Saturday and may limp offshore. Moisture levels will remain high as the upper trough remains west of the area. This trough begins to move eastward Saturday night/Sunday with increasing jet stream dynamics aloft. Still some timing differences in the models on when the main trough moves across the state and provides good lift and good chance of rainfall…currently looking like Sunday into Sunday night. Some sort of coastal low looks to develop along the boundary over the Gulf waters and this will help to spread rainfall along the coast and inland ahead of the upper trough.
Should start to clear and dry things out on Monday, but a secondary trough drops into the region by Tuesday with a potentially decent frontal passage. Not overly confident on the timing and moisture may linger into Monday producing scattered showers/thunderstorms.
Rainfall:
Some areas really were nailed yesterday with excessive rainfall, but most of these locations were localized and thus far widespread heavy rainfall has not occurred in our region. With that said, the current air mass is capable for some quick 2-3 inches in an hour or less and with the potential for storm motions to slow and become more organized along/near the frontal boundary does raise some red flags in the flooding department. Feel the best chances of excessive rainfall today will be west of I-45 and then toward the coast over the weekend (S of I-10). An additional 1-3 inches can be expected with isolated amounts up to 5 inches possible.
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