SE Texas weather thread - Strong storms Sun/Mon

[JenBayles]

Now doesn't that figure? I have to play handbells in church all morning tomorrow. That is, if I'm not flooded in as always happens when we get a couple inches of rain....

[jeff]

Heavy rainfall event expected Sunday into Monday.

Parameters coming together to produce a sustained rainfall / flash flood / severe threat over the next 48 hours.

Warm front off the TX coast this morning will start returning northward this afternoon. Moisture levels increase greatly this afternoon and tonight with PWS values exceeding 2.3-2.4 inches or nearing October maximum values of 2.5-2.6 inches for mid October. Standard flash flood threat increases greatly with values over 1.5 standard deviations above normal and values will likely average at least 2.0 deviations above normal. Warm front will move northward across the area Sunday afternoon and evening. Low level jet pumps tremendous western Gulf of Mexico moisture into the region with widespread heavy rainfall developing along and north of the warm front. Upper level winds become strongly divergent as a short wave moves up the TX coast. Flash Flooding is becoming a serious threat given the upper dynamics, incredible moisture, and well defined surface boundaries to focus the rainfall.

Sunday night:

Warm front lifts across the area with strong low level moisture advection in place and howling 850mb winds. Storms along the warm front will have the potential to go tornadic given the low level shear values in place and forecasted helicity of 250-350 m^2/s^2 Sunday afternoon and evening. Favorable low level wind pattern along with upper air divergence will maintain numerous thunderstorms training SSW to NNE across the area. Storms will produce excessive short term rainfall rates with hourly rates of 2-3 inches possible.

Monday:

Potent upper air low over the SW US ejects into TX. Strong jet dynamics overspread a forecasted "record" moist air mass with the GFS progging PWS of 2.7 inches! WOW. Numerous thunderstorms will result with flooding rains likely...only helpful aspect may be fast storm motion of 15-20mph, however training in SSW to NNE bands may negate the fast forward motions. Severe squall line or MCS should rake the area during the afternoon Monday bringing somewhat drier air into the region and ending the rainfall for a short period...only to return by Wednesday and Thursday

Rainfall:

Given the very high moisture levels forecasted significant rainfall amounts are expected. Widespread 2-4 inches will be possible on Sunday alone with isolated 7-9 inch amounts. Given the PWS south of Brownsville this morning it would not be surprising if somebody Sunday and Monday saw 10-15 inches of rainfall. Flash Flood Watches south of our area now will be expanded NNE on Sunday and SE TX will need a Watch for Sunday through Monday given the flood potential at hand.

The GFS appears too aggressive in developing an area of low pressure along the TX coast. I prefer the NAM over the GFS...with that said the NAM is plenty wet with very high QPF across SE TX.

[Extremeweatherguy]

Thanks for the update jeff! Your input is always greatly appreciated.

I have one more question though: Is there any chance for a widespread tornado outbreak out of this if we see some sun tomorrow?

[Yankeegirl]

Ill tell you what, that mess in the gulf looks nasty!!!

http://www.goes.noaa.gov/ECIR4.html

[JenBayles]

Yes, I'm watching that with a very jaundiced eye and not liking it one bit. It's a day late and a dollar short, but at least some our Texas reservoirs, aquifers, cattle tanks and ponds will get a good filling out of this system.

[JonathanBelles]

where exactly is that low going? any chance for florida?

[vbhoutex]

where exactly is that low going? any chance for florida?

All the progs currently have it, if it develops any further, currently have it continuing its' NE or NNE track which would take it inland somewhere along the Upper TX/SW LA coast or the the LA coast.

[Yankeegirl]

I dont think there is going to be anything forming outta this, just a lotta rain for us here in Houston... Wonder when they are going to be putting up the Flash Flood Watch boxes... I would think sometime around midnight?

[Yankeegirl]

You know, as I check the radar of that blob down there in the gulf, I am getting the sence that it might be moving a little bit more to the east, not so sure if its even going to give us alot of rain... Everytime I check the location of it, its more and more to the east...I thought it was supposed to ride up the coast? Seems like its getting farther and farther away from the coast... Is there anyone else seeing this? I am always a skeptic when they issue an 80% chance of rain anyways... we never seem to get any of it... Its just an observation..Any other thoughts on this?

[Extremeweatherguy]

You know, as I check the radar of that blob down there in the gulf, I am getting the sence that it might be moving a little bit more to the east, not so sure if its even going to give us alot of rain... Everytime I check the location of it, its more and more to the east...I thought it was supposed to ride up the coast? Seems like its getting farther and farther away from the coast... Is there anyone else seeing this? I am always a skeptic when they issue an 80% chance of rain anyways... we never seem to get any of it... Its just an observation..Any other thoughts on this?

It isn't only the low that will bring us rain. The moisture from the pacific, the warm front, the weak cap, and the strong upper level winds will also have a major influence.

[Extremeweatherguy]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
251 PM CDT SAT OCT 14 2006

.DISCUSSION...
CONVECTION ALREADY INCREASING TO JUST SOUTHWEST OF CWFA. EXCEPT
FOR NORTHERN ZONES...MUCH OF REGION UNDER CONSIDERABLE CLOUD COVER.
SURFACE WINDS ALREADY BECOMING BRISK NEAR THE COAST AS PRESSURE GRADIENT
STARTS TO TIGHTEN UP IN RESPONSE TO DEVELOPING TROUGH OF LOW
PRESSURE. AS WITH EARLIER DISCUSSION...WE SHALL STAY CLOSER TO
ECMWF/UK/NAM SOLUTION. AS PER 245 PM QPFERD...GFS SUFFERING FROM
CONVECTIVE FEEDBACK. EXPECT PW VALUES TO INCREASE DRAMATICALLY
TOMORROW WITH STRENGTHENING ONSHORE FLOW. INCREASING DIFFLUENT
FLOW ALOFT AND DEVELOPING DIVERGENT FIELD OVER REGION SUNDAY AND
SUNDAY NIGHT. LOW LEVEL JET EXPECTED TO BE WELL ESTABLISHED ACROSS
REGION DURING THIS PERIOD (35-50 KTS). WE SHALL CONTINUE WITH
LOCALLY HEAVY RAINFALL IN FORECAST WORDING ALONG WITH POSSIBLE
SEVERE THUNDERSTORMS SUNDAY AND SUNDAY NIGHT. THIS WILL BE
MONITORED CLOSELY TONIGHT AND EARLY TOMORROW FOR POSSIBLE ISSUANCE
OF A FFA. APPROACHING STRONG UPPER LEVEL TROUGH ON MONDAY SHOULD
PUSH MUCH OF CONVECTIVE ACTIVITY EAST OF CWFA MONDAY NIGHT.
HOWEVER...LOWER LEVELS WILL REMAIN ON THE MOIST SIDE AS ONSHORE
FLOW CONTINUES. GFS INDICATE A STRONG COLD FRONT MAKING ITS WAY
ACROSS OUR REGION THURSDAY. HIGH PRESSURE INDICATED TO SETTLE OVER
REGION LATE NEXT WEEK AND INTO EARLY WEEKEND. WE SHALL SEE.
37

[Ptarmigan]

That blob in the Gulf of Mexico is more impressive right now.

[JonathanBelles]

i think this topic should be locked because of the topic in the Talkin tropics forum.

[JenBayles]

Killjoy.

[Extremeweatherguy]

i think this topic should be locked because of the topic in the Talkin tropics forum.

this thread is not about this system in particular. It is about weather in SE Texas as a whole. Go back and look at the last 20+ pages and you will see that quite clearly. Since this system involves SE TX weather, it should be able to be discussed here as well. There is no reason for a thread lock.

[southerngale]

i think this topic should be locked because of the topic in the Talkin tropics forum.

this thread is not about this system in particular. It is about weather in SE Texas as a whole. Go back and look at the last 20+ pages and you will see that quite clearly. Since this system involves SE TX weather, it should be able to be discussed here as well. There is no reason for a thread lock.

It's not going to be locked, until we get 25 pages anyway. I don't understand why he would even expect it to be locked. As of now, this isn't even a tropical system and SE TX & SW LA has a threat of very heavy rains, with possible flooding and severe weather, so this discussion is right where it should be. Should a tropical storm develop out of it, then you have the thread in the tropics. Even then, this one wouldn't be locked because of that one.

[JenBayles]

Thanks for the clarification 'Gale. I really like this thread and check it several times a day. Saves my middle-aged, reading-glasses eyes from looking at several different threads and web sites.

[jasons2k]

I like this thread too - and I'm happy to see it has about the best participation in the country. Go Texas!

[LAwxrgal]

The NWS forecasts for my area (out of New Orleans) have placed good chances of rain in the forecast for much of next week, and it's probably from this system.

This blob has "perked" me up and definitely has my attention, not just for me but for my sister who lives just west of Beaumont.

[Extremeweatherguy]

looks like the CPC thinks much of the nation will be chilly in the day 6-10 timeframe:

http://www.cpc.noaa.gov/products/predic ... mp.new.gif

and in the 8-15 day timeframe as well:

http://www.cpc.noaa.gov/products/predic ... mp.new.gif