Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 7

[Quixotic1]

Snow, hail and tornadoes in central Mexico. The Mexico city-Puebla highway, a very busy road, was closed due to snow

cierran_autopista_Mexico-Puebla-autopista_Mexico-Puebla_MILIMA20150312_0072_8.jpg

cierran_autopista_Mexico-Puebla-autopista_Mexico-Puebla_MILIMA20150312_0078_8.jpg

Nice!

[bubba hotep]

Good QPF total on the 12 GFS, so sure hope that verifies. We really need 3 inches of rain over N. Texas, especially west of FW. But, color me skeptical....

 

The Euro and EPS have started to lock in on widespread rainfall across much of Texas over the next 10 days.  It will be interesting to see what happens after this MJO pulse moves out of 7 and crashes back towards the COD.  The analog years that seem to jive with the PDO and ENSO are pretty dry looking for the eastern half of Texas but look wetter for South and West Texas in the MAM period. 

[Roy]

Starting to look a bit more likely at least. Sure hope you are wrong about MAM being dry for east TX. It's starting off better than last year, with above normal precip so far.

[Quixotic1]

Another good AFD from FWD. This one about warm core systems. Seems unusual for this early in the year....

http://forecast.weather.gov/product.php?site=FWD&issuedby=FWD&product=AFD&format=CI&version=1&glossary=1

[Srain]

Morning briefing from Jeff:

 

After a couple of dry and pleasant days, rainfall looks to return as early as Tuesday night and again for the end of the week.

 

Storm system located off the west coast of Mexico this morning near Baja will eject eastward on Tuesday and across TX Tuesday night/Wednesday. Moisture will increase off the Gulf of Mexico today into Tuesday and peak Wednesday morning with PWS of roughly 1.5-1.7 inches which is fairly impressive for mid March. Strong lift comes to bear across a moist atmosphere late Tuesday night into Wednesday morning with widespread showers and thunderstorms expected. Will focus the heaviest rainfall across our western counties Tuesday night where the potential exists for a period of cell training and then across nearly the entire area on Wednesday. Thunderstorms will be possible, but not expecting any severe weather. Rainfall amounts of .25-.50 of an inch on average with isolated totals of 2-4 inches possible especially west of I-45.

 

Surface front may slow and stall across the area on Thursday, but just enough dry air may push in to end rain chances. Next storm system heads for the region Friday and Saturday and this one is looking wet. Rains start in earnest on Friday and continue into Saturday. Too early to tell if there will be a flood threat, but wet grounds and potential for several inches of rainfall during this period certainly is worth watching.

 

Hydro:  

Watersheds are in recession over the region, but still elevated. The lower Trinity remains above flood stage and will remain in flood through most of this week due to upstream releases. All other watersheds are back within banks. Additional rainfall this week will likely result in additional rises and some potential to return to flood stage given the saturated grounds.

 

[wxmx]

Snow in the high terrain, flooding, tornadoes, waterspouts and well above normal precipitation for most of MX, all courtesy from the two last ULLs.

 

Personally, for my backyard, we are about 350% above normal precipitation for the first 16 days of March. Currently, for the month, we are at 12/16 rain days...bringing the total from Nov to date to 56 rain days, 32 rain days above normal. I haven't seen the sun the last 4 days, and I probably won't see it for the next 4-6 days.

[Srain]

Briefing from Jeff:

 

Two storm systems will affect TX over the next several days with additional widespread rainfall…some heavy.

 

An upper air storm system near Baja this morning will begin to move eastward today spreading lift from west to east across TX. At the surface warm southerly flow is bringing moisture back to the area with dewpoints into the low to mid 60’s which will likely result in some sea fog. Expect a mostly dry Tuesday followed by increasing rain chances tonight as the lift from the approaching upper level low spreads into the region. Will favor areas along and west of a Palacios to College Station line overnight for showers and even a thunderstorm or two.

 

Strong lift spreads eastward on Wednesday with showers and thunderstorms likely across the region. There is some debate on exactly how strong the sub-tropical ridging over the Gulf of Mexico will be and if that may keep the bulk of the activity north and west of metro Houston, but the latest short term guidance is fairly aggressive will thunderstorms over the central counties from late morning into early evening. A few of the storms could be on the strong side, but instability is generally lacking. Will favor the threat for isolated heavy rainfall especially NW of a line from Palacios to Waller to Cleveland where a low level boundary may establish.

 

 

Weak frontal boundary may stall across the area on Wednesday night into Thursday so cannot completely pull rain chances on Thursday with a low level focus in the region. Expect coastal areas to remain in the light onshore flow which will keep 60 degree dewpoints over the cool nearshore waters…so sea fog is a good bet Wednesday-Friday.

 

Friday-Sunday:

Another strong upper level system will dig into the SW US and then head for TX…very El Nino like…with widespread rain and thunderstorms likely Friday and Saturday. This system appears stronger and has more moisture to work with than the first system tomorrow so concern is growing for a possible flooding threat due to the longer duration of the event and possible higher totals. Could again see some thunderstorms with this system also Friday night and Saturday.

 

Hydro:

Grounds remain wet across the region with additional rainfall likely Wednesday and Friday/Weekend. Main river stems are in recession from the rainfall last week, but forecasted rainfall amounts over the next 3-5 days suggests widespread amounts of 1-3 inches with isolated totals up to 5 inches will be possible. This amount of rainfall will generate new rises on areas watersheds and likely require flood gate operations on area reservoirs.  

 

 

[icebreaker5221]

Snow in the high terrain, flooding, tornadoes, waterspouts and well above normal precipitation for most of MX, all courtesy from the two last ULLs.

 

Personally, for my backyard, we are about 350% above normal precipitation for the first 16 days of March. Currently, for the month, we are at 12/16 rain days...bringing the total from Nov to date to 56 rain days, 32 rain days above normal. I haven't seen the sun the last 4 days, and I probably won't see it for the next 4-6 days.

 

Share the wealth!

[wxmx]

Share the wealth!

Ha! The Monter®eys are complete opposites right now. Not to rub it on you, but this is the 13th rain day of the month, and it's currently raining moderately (looks like a training setup for several hours). If the Niño holds or strengthens then we'll be able to share the wealth.

[Roy]

Well, looking like central/south Texas will again be the ones to get any real helpful rainfall from the Thursday night/Friday system. Some will impact N Texas though.

[Quixotic1]

Well, looking like central/south Texas will again be the ones to get any real helpful rainfall from the Thursday night/Friday system. Some will impact N Texas though.

 

Looks like the models picking up on the MCS cutting off low level flow over N Texas were right.  

[Srain]

Skies are clearing behind the batch of light rain that spread across the Region early this morning. There is a meso High Pressure cell building in that could bring gusty NW along the Coast today. Temperatures where the sunshine breaks out could near 80F. There is a chance of some isolated storms to fire this afternoon mainly across the Hill Country underneath the cold pocket aloft associated with the upper low.

 

[1900hurricane]

The usually more reserved QPF-wise NAM has been hinting at some pretty impressive rainfall totals along a stalled front draped from Laredo to Nacogdoches or thereabouts to close out the week for a few runs now. The latest 00Z run has widespread 3-5" totals along that line. The GFS had been showing lesser totals, but now it too seems to be ramping up QPF. With very high PW air in excess of 1.8" and near unidirectional winds aloft, I'm thinking we could see some impressive rainfall totals in places.

[jm1220]

It'll be interesting to see if this rain event bucks the recent trend of favoring I-35 only to shift east at the end. It's been about average rain-wise here but much wetter in E TX. The rain this morning underperformed here and again favored places east.

[Srain]

Areas across the Hill Country and S have been placed in a Slight Risk for excessive rainfall Friday into Saturday.

[Srain]

Morning briefing from Jeff:

 

Another strong storm system will approach TX early this weekend with widespread rainfall likely.

 

A weak frontal boundary is nearly stationary this morning from C TX into E TX, south of this boundary the air mass is moist and even a little unstable with dewpoints in the 60’s. High dewpoints over the cool nearshore waters is leading to sea fog formation and this will plague the coast for the next few days. Radar also shows a cluster of showers over Jackson and Colorado Counties moving NNE at around 10mph.

 

Boundary just to our north may sag into our northern counties today and with heating into the upper 70’s may spark a shower or two from College Station to Livingston.

 

Main show gets underway Friday evening and all day Saturday as the next Baja low moves across TX. Expect an increase in showers Friday evening and overnight as moisture increases off the western Gulf of Mexico and lift increases from the SW. The boundary to our north will very slowly sag into the area and add an additional focus for rainfall especially on Saturday. Will likely see periods of heavy rainfall in training bands on Saturday especially from Columbus to Conroe northward, but the entire area will see rainfall. Not expecting any severe weather with limited instability. Sea fog will continue along the coast likely through Sunday morning.

 

Rainfall amounts Friday-Sunday will average 1-2 inches across the region with isolated totals of 3-5 inches possible. The highest threat for the heaviest rainfall will be along and NW of US 59 or across the areas that have already been hard hit over the last week with heavy rainfall. Flooding concerns especially on already elevated watersheds is possible this weekend into early next week.

 

Hydro:

River continue in recession from last week’s rainfall with only the lower Trinity still in flood from releases from Lake Conroe. Forecasted rainfall amounts this weekend will almost certainly produce new rises and with wet grounds run-off will be maximized across the region. New rises to flood stage will be possible this weekend into early next week on several of the local rivers.

 

 

 

[Roy]

FWD mentions chance of MCS over N Texas. Let's hope for something somewhat organized, for yesterday was a joke. Of course, the real show looks to be to the south and east. They need rain as well, so happy for them. But man, our lakes need some real moisture. And all the winter weather delayed our new house closing by a couple weeks, so if we get some good rains now, it shouldn't push it back any more.

[jhamps10]

FWD mentions chance of MCS over N Texas. Let's hope for something somewhat organized, for yesterday was a joke. Of course, the real show looks to be to the south and east. They need rain as well, so happy for them. But man, our lakes need some real moisture. And all the winter weather delayed our new house closing by a couple weeks, so if we get some good rains now, it shouldn't push it back any more.

Agreed, yesterday was a joke... Yeah more rain for east Texas while DFW and areas nw got not a whole lot... More rain for lakes west of dfw please

[bubba hotep]

The recent HRRR runs look pretty good for those wanting some heavy stuff in DFW this evening.

[Roy]

Tech WRF looks good as well for at least 820 North with something at least south.

[wxmx]

The pattern of west coast ridge and energy below said ridge will probably continue in the medium range. For tomorrow's/Saturday event, it appears like a good soaking around MBY. I won't bet against it, not this year.

[Srain]

Evening briefing from Jeff:

 

Strong storm system will bring another round of heavy rainfall to SE TX Friday night/Saturday…flooding will be possible.

 

Impressive moisture return is underway across the region from both the Gulf of Mexico and Pacific Ocean with moisture values forecasted to peak near the climatological 99^th percentile late Friday into early Saturday morning. This coupled with strong lift from an approaching upper level storm system and a slow moving surface front will set the stage for widespread heavy rainfall. Expect activity to develop over C TX midday Friday and begin to spread into our western counties late Friday afternoon into the evening hours. Cell training from SW to NE appears likely on Friday night with an enhanced flash flood threat as strong low level inflow brings copious moisture northward into this system. Overall slow motion points toward several hours of potentially heavy training rainfall from midnight to noon on Saturday.

 

With grounds still soggy from frequent rainfall of late, run-off will be maximized across the region. Hourly rainfall rates may approach 2.0 inches in the stronger storms leading to quick run-off problems. Widespread rainfall amounts of 1-3 inches is likely with isolated totals of 4-6 inches possible. Models have been suggesting the heaviest rainfall axis falls along and NW of a Columbus to Conroe to Livingston line, but latest 18Z guidance has shifted this southward a little and closer to metro Houston/Harris County.

 

Hydro:

Rivers and creeks are still in recession from last week, and the magnitude of rainfall forecasted will certainly produce new rises likely to flood stage on some of the mainstem rivers. Main concerns are the Trinity, Navasota, San Bernard, San Jacinto, and possibly the lower Brazos along with many of the smaller feeder creeks and tributaries. Flood gate operations continues at Lake Livingston which is resulting in minor flooding on the lower Trinity River below Liberty. Gate operations at Lake Conroe may resume this weekend depending on rainfall patterns.

 

A Flash Flood Watch will likely be issued for portions of SE TX later tonight.

 

Residents near rivers and creeks should remain alert to the flooding potential over the next several days.

 

[1900hurricane]

Flash Flood Watches are now up for a rather large area, including where I am at.

[Roy]

Well, I don't think we even got any rain in North Tarrant County. Wunderground rainfall appears to show virtually nobody except far north exurbs got anything. Yikes. 

[bubba hotep]

Well, I don't think we even got any rain in North Tarrant County. Wunderground rainfall appears to show virtually nobody except far north exurbs got anything. Yikes.

Pretty big swing and miss... this whole week has been a disaster. The models seemed pretty looked in on 2 to 3" plus area wide for the week. The HRRR was still showing 1 to 2" for a pretty wide area of north Texas yesterday evening. I've gotten just a bit more than a trace imby

[jhamps10]

Pretty big swing and miss... this whole week has been a disaster. The models seemed pretty looked in on 2 to 3" plus area wide for the week. The HRRR was still showing 1 to 2" for a pretty wide area of north Texas yesterday evening. I've gotten just a bit more than a trace imby

Imby a whole lotta nothing... Except a good light show last night while I was out I could see the cloud to cloud vividly in SW FTW

[bubba hotep]

Looking like a nice little cell might clip us here in Downtown.

[jm1220]

Heavy rain commencing here just outside downtown Austin. Looks to be developing and training overhead. Should be a very nasty commute later with some flooding.

[jm1220]

1" of rain at Camp Mabry over the past few hours. Rain has let up but tonight/tomorrow could be pretty bad if models other than the GFS are right. 

[Srain]

Evening briefing from Jeff:

Heavy rainfall event underway over TX this evening.

Slow moving upper level storms system will combine with a slow moving frontal boundary to produce widespread showers and thunderstorms tonight/Saturday. Radar shows scattered to numerous showers/thunderstorms in progress this evening across the NW ½ of SE TX stretching SW to the Mexican border and NE to E TX. Radar indicates already 2.5 inches of rainfall has fallen over SE Walker County and portions of San Jacinto County and several more inches are likely. Surface frontal boundary is currently along a Columbus to Conroe line and sagging southward with the bulk of the rainfall along and behind this feature. A few showers have developed ahead of this boundary. Storms motions thus far have been on the slow side which is allowing for increased short term rainfall rates.

Meso scale models keep the bulk of the activity overnight across the NW ½ of SE TX closer to the best lift from the approaching upper level trough and behind the surface front. This appears to be where the greatest potential for heavy rainfall will be tonight into Saturday morning. Thus far the front has continued to move southward and this could bring the focus of heavy rainfall a bit southward than expected, but meso guidance does not suggest this at this time although observation trends of the frontal movement indicate otherwise.

Will continue with widespread rainfall amounts of 1-2 inches across much of the area with the lowest amounts near the coast and the highest amounts inland from Columbus to Livingston. Isolated totals could approach 4-6 inches especially north of HWY 105. This magnitude of rainfall on top of already saturated grounds (March rainfall running 200% of normal) suggests run-off will be maximized across the region.

Hydro:

Lake Conroe has increased their releases this evening to 1058cfs up from 529cfs this morning. Forecasted rainfall amounts over the headwaters of the San Jacinto River basin will likely require additional flood gate operations at Conroe.

Lake Livingston is continuing flood releases from last week currently releasing 16,000cfs into the lower Trinity River.

Forecasted rainfall over the inland portions of SE TX will almost certainly generate new flood waves on area rivers…and some rivers may rise to or above flood stage late this weekend or early next week. Persons along area rivers should monitor river levels and be prepared to act if needed.