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Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sat Sep 05, 2015 10:32 am
by Ptarmigan
Bring on the cool weather. :twisted:

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sat Sep 05, 2015 10:50 am
by Rip76
Nice little rain shower already this morning, and the start of college football.
Not a bad start.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sat Sep 05, 2015 10:57 am
by txflagwaver
Lots of thunder this am...kind of nice to have it on a Saturday when I am at home to enjoy it.
No rain though...Seabrook is in the hole of the donut on radar. :lol:

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sat Sep 05, 2015 12:53 pm
by Rip76
There are some big towers forming west of Houston.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sat Sep 05, 2015 2:23 pm
by mckinne63
We had a nice storm in Stafford about an hour or so ago. Rainied pretty hard for about 20 minutes. Everything is really stiff now. Still cloudy, but no motion on the trees.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sat Sep 05, 2015 4:32 pm
by DoctorMu
Two brief showers deposited 0.72 in IMBY with onshore flow and weaker ridge - First rain accumulation of more than 0.1 in since July 1 in CLL.

8-)

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sun Sep 06, 2015 2:19 pm
by srainhoutx
Interesting work week ahead in the weather department. The general trend via the 12Z guidance suggests several features coming together over Texas. A frontal boundary begins to nudge South into the Southern Plains and Texas by mid to late this week with TS Linda and its mid/upper level moisture spreading NE across Mexico into Texas ahead and along the advancing frontal boundary. Now the European model with some support from other guidance suggests the potential of a tropical low organizing near Brownsville moving NE toward Beaumont and SW Louisiana next week. It appears rain chances may need to be increased, if these various features are indeed a possibility.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Sun Sep 06, 2015 4:57 pm
by sambucol
srainhoutx wrote:Interesting work week ahead in the weather department. The general trend via the 12Z guidance suggests several features coming together over Texas. A frontal boundary begins to nudge South into the Southern Plains and Texas by mid to late this week with TS Linda and its mid/upper level moisture spreading NE across Mexico into Texas ahead and along the advancing frontal boundary. Now the European model with some support from other guidance suggests the potential of a tropical low organizing near Brownsville moving NE toward Beaumont and SW Louisiana next week. It appears rain chances may need to be increased, if these various features are indeed a possibility.
An interesting week ahead for sure!

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 3:01 am
by srainhoutx
Hurricane Linda continues to rapidly intensify off the West Coast of Mexico and could approach Category 3 strength offshore of the Baja Peninsula before reaching cooler waters and begins to unravel by mid week. Its mid/upper level moisture does appear to become entangled with an approaching cold front increasing moisture levels over Texas later this week. There continues to be some indications that a coastal low begins to develop near Brownsville next weekend along the stalled frontal boundary along the NW Gulf around next Sunday. The GFS has joined the European computer model with a surface wave developing just inland near Corpus Christi next Monday heading generally NE bringing heavy rain and storms into SE Texas in about 8 days. The European model is suggesting that a closed surface low organizes offshore of Brownsville and quickly strengthens to a Tropical or sub tropical storm moving inland along the Middle and Upper Texas Coast. While it is too soon to know with any certainty of what may or may not develop more than 5 days out, it is a bit interesting to see the various computer schemes suggesting the frontal boundary that increases our shower and storm chances Thursday into Friday may bring an additional feature into our forecast beginning next weekend.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 7:31 am
by cperk
srainhoutx wrote:Hurricane Linda continues to rapidly intensify off the West Coast of Mexico and could approach Category 3 strength offshore of the Baja Peninsula before reaching cooler waters and begins to unravel by mid week. Its mid/upper level moisture does appear to become entangled with an approaching cold front increasing moisture levels over Texas later this week. There continues to be some indications that a coastal low begins to develop near Brownsville next weekend along the stalled frontal boundary along the NW Gulf around next Sunday. The GFS has joined the European computer model with a surface wave developing just inland near Corpus Christi next Monday heading generally NE bringing heavy rain and storms into SE Texas in about 8 days. The European model is suggesting that a closed surface low organizes offshore of Brownsville and quickly strengthens to a Tropical or sub tropical storm moving inland along the Middle and Upper Texas Coast. While it is too soon to know with any certainty of what may or may not develop more than 5 days out, it is a bit interesting to see the various computer schemes suggesting the frontal boundary that increases our shower and storm chances Thursday into Friday may bring an additional feature into our forecast beginning next weekend.
Will be anticipating the 12oz Euro run.The Euro shifted a little to the west on the last run.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 7:42 am
by Katdaddy
From this mornings Houston-Galveston AFD. Interesting days ahead

SUNDAY THINGS BEGIN TO GET CONCERNING... MODELS
HAVE BEEN HAVING SOME ISSUES WITH DEVELOPMENT OF TROUGHING ALOFT
OVER TX/MEXICO THE LAST FEW RUNS...DOING SO THEN BACKING OFF. NOW
BOTH THE 00Z GFS/ECMWF HAVE BEGUN TO COALESCE TOWARDS A VERY WET
SOLUTION STARTING LATE NEXT SUNDAY FOR THE GFS EXPANDING NORTHWARD
INTO SETX EARLY MONDAY THROUGH TUESDAY...WHILE THE ECMWF IS 6
HOURS OR SO SLOWER BUT MORE INTENSE...PW SURGING TO 2.5-2.6"!
BOTH MODELS DEVELOP A VERY ORGANIZED LOW PRESSURE SYSTEM (PERHAPS
INITIALLY A COASTAL TROUGH ON THE TAIL END OF THE REMNANT FRONT)
THAT QUICKLY WRAPS UP AND MOVES INTO SETX. THIS SCENARIO MAY HAVE
THE POTENTIAL FOR TROPICAL DEVELOPMENT. STAY TUNED.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 8:15 am
by cperk
Katdaddy wrote:From this mornings Houston-Galveston AFD. Interesting days ahead

SUNDAY THINGS BEGIN TO GET CONCERNING... MODELS
HAVE BEEN HAVING SOME ISSUES WITH DEVELOPMENT OF TROUGHING ALOFT
OVER TX/MEXICO THE LAST FEW RUNS...DOING SO THEN BACKING OFF. NOW
BOTH THE 00Z GFS/ECMWF HAVE BEGUN TO COALESCE TOWARDS A VERY WET
SOLUTION STARTING LATE NEXT SUNDAY FOR THE GFS EXPANDING NORTHWARD
INTO SETX EARLY MONDAY THROUGH TUESDAY...WHILE THE ECMWF IS 6
HOURS OR SO SLOWER BUT MORE INTENSE...PW SURGING TO 2.5-2.6"!
BOTH MODELS DEVELOP A VERY ORGANIZED LOW PRESSURE SYSTEM (PERHAPS
INITIALLY A COASTAL TROUGH ON THE TAIL END OF THE REMNANT FRONT)
THAT QUICKLY WRAPS UP AND MOVES INTO SETX. THIS SCENARIO MAY HAVE
THE POTENTIAL FOR TROPICAL DEVELOPMENT. STAY TUNED.

I like that our Houston/Galveston NWS is being proactive on this.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 8:22 am
by srainhoutx
The 06Z GFS continues with suggesting that the Coastal trough/low that may begin to transition to some form of tropical or sub tropical entity next Sunday into Tuesday may have some validity. The precipitation totals are steadily increasing via all of the reliable computer schemes with the 06Z GFS showing some locations nearing 8-10 inches of potential rainfall.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 9:42 am
by Rip76
This is very interesting indeed.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 10:14 am
by Electric Lizard
cperk wrote:
Katdaddy wrote:From this mornings Houston-Galveston AFD. Interesting days ahead

SUNDAY THINGS BEGIN TO GET CONCERNING... MODELS
HAVE BEEN HAVING SOME ISSUES WITH DEVELOPMENT OF TROUGHING ALOFT
OVER TX/MEXICO THE LAST FEW RUNS...DOING SO THEN BACKING OFF. NOW
BOTH THE 00Z GFS/ECMWF HAVE BEGUN TO COALESCE TOWARDS A VERY WET
SOLUTION STARTING LATE NEXT SUNDAY FOR THE GFS EXPANDING NORTHWARD
INTO SETX EARLY MONDAY THROUGH TUESDAY...WHILE THE ECMWF IS 6
HOURS OR SO SLOWER BUT MORE INTENSE...PW SURGING TO 2.5-2.6"!
BOTH MODELS DEVELOP A VERY ORGANIZED LOW PRESSURE SYSTEM (PERHAPS
INITIALLY A COASTAL TROUGH ON THE TAIL END OF THE REMNANT FRONT)
THAT QUICKLY WRAPS UP AND MOVES INTO SETX. THIS SCENARIO MAY HAVE
THE POTENTIAL FOR TROPICAL DEVELOPMENT. STAY TUNED.

I like that our Houston/Galveston NWS is being proactive on this.
Indeed. It never hurts to see that the car(s) is all fueled up towards the end of the week. If you were planning to trim your trees anyway, see if you can get it done this week. Are your (and your parent's) meds in need of refill? Grab some extra cash when you're at the ATM this week. BBQ propane tank full? There's certainly no need to go crazy, but if you're gonna do it anyway, get it done.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 10:20 am
by cperk
I could'nt agree more.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 2:42 pm
by srainhoutx
Labor Day afternoon briefing from Jeff:

Frontal boundary to bring increased rainfall late this week.

Upper level ridge of high pressure will break down and shift westward over the next 24-36 hours while a large scale upper level storm system develops over the Great Lakes. Hurricane Linda in the eastern Pacific Ocean will track NNW to the west of Baja, but allow mid and high level moisture to spread northeast into the southern plains.

Expect scattered showers and thunderstorms over the region this afternoon and again on Tuesday afternoon. Coverage may be slightly less on Tuesday as drier air moves into the region from the east. Coverage will start to increase on Wednesday and peak either Thursday or Friday as a frontal boundary sags into the area. PWS pool to around 2.0-2.2 inches Thursday as both Gulf and Pacific moisture advect across the region. Short waves and lift along the front will make for active weather during this period (Thursday and Friday). Not sure if/when the front will actually make it into the Gulf waters or if it stalls over SE TX. A few models want to bring some drier air into at least the northern counties of SE TX by early Saturday, but the latest 12 GFS keeps it very wet into the weekend for a large part of SE TX.

Given high moisture levels and a stalling frontal boundary the threat for heavy rainfall will certainly be on the increase Thursday into Friday. Large scale flow becomes increasing parallel to the frontal boundary which would support cell training in bands. Expect rainfall rates to increase and given the tropical nature of the air mass 1-3 inch per hour rates will be possible. Grounds north of I-10 are generally dry, but south of I-10 are wet from the recent rainfall over the past month. Too early to be concerned with a flood threat…but something to keep an eye on especially in those urban areas with the high hourly rainfall rates.

Weekend/Early Next Week:
Complicated forecast with potential coastal trough/tropical cyclone formation over the western Gulf of Mexico.

Upper level energy dives into northern MX this weekend with downstream surface trough likely developing near/along the tail end of the early weekend cool front off the lower TX coast by late in the weekend. It is a little early for such a coastal trough (more common in the cool season months), but the model agreement is fairly decent on this feature forming. Deep tropical moisture will become entrained into this feature especially along and to the east side of the trough axis. A few of the models are actually closing the trough off into a surface low and moving this surface reflection northward along the lower TX coast into the mid/upper TX coast early next week. This could be a tropical or hybrid (sub-tropical) system.

For now will go with the more board surface trough reflection over the more concentrated and developed tropical system suggestion being offered by the ECMWF. Several models do show a tremendous moisture surge with PWS of 2.5-2.7 inches arriving into the area late Sunday-Tuesday. Should this surge of moisture verify a very wet period would be likely with significant amounts of rainfall possible. This part of the forecast is low confidence and changes should be expected from late this week into the early part of next week.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Mon Sep 07, 2015 10:18 pm
by Ptarmigan
Tropical development could make this month interesting.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Tue Sep 08, 2015 5:52 am
by Katdaddy
Heavy rains still looking possible for late this week across SE TX and still lots of uncertainty for any potential tropical development in the W GOM next week.

Today is the 115th anniversary of the 1900 Galveston Hurricane. Isaac Cline did his best to warn people who were playing in the surf enjoying the "overflow". Little did those people know, a life and death situation would occur later that night and many would not survive to see morning daylight on the 9th.

Re: September 2015: Wet & Unsettled Pattern Returns

Posted: Tue Sep 08, 2015 10:07 am
by wxman57
I'm keeping an eye on the western Gulf for next week, but I don't buy the 00Z Euro's forecast of a strong tropical storm moving into the central Gulf in 10 days. More likely a weak low on the front that tracks northward into the TX or LA coast toward the middle of next week. A rain threat rather than a wind threat.