August 2016: Rain Chances Continue.

[Skyguy]

.

Will just have to watch how activity to our east unfolds over the next 24-36 hours and how defined the circulation remains

.

Do you have any data on that, Srainhoutex? I can't call anybody out there right now, 'cause my cell phone keeps giving me the "no signal" message. Would appreciate your help.


BTW:

1.Where can I send an e-mail to Mario Gomez? I would like to wish him well in his retirement.

2. From this graphic It still looks to me like Houston will escape the worst of the rains. Do you agree, Srainhoutex?

[worrybug]

Dear pro mets:

These two items from the HGX AFD are a little beyond my personal comprehension.

719
FXUS64 KHGX 130025
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
725 PM CDT Fri Aug 12 2016

.AVIATION...
VFR conditions to continue overnight with a possibility of some
patchy MVFR ceilings around sunrise tomorrow morning. Winds
overnight will be southerly at 5 to 10 knots.

Showers and thunderstorms will gradually increase in coverage
during the day on Saturday. Isolated showers late Saturday morning
will become scattered to numerous showers and thunderstorms by
late afternoon. The heaviest precipitation will move in to SETX
airspace from the east with conditions worsening after 21Z. I
addressed the afternoon precipitation with a VCTS in this TAF
package, however I am considering a PROB30 after 21Z tomorrow for
the 06Z TAF package. Keehn/44

&&

.PREV DISCUSSION... /ISSUED 410 PM CDT Fri Aug 12 2016/

DISCUSSION...
A heat advisory remains in effect for all of SE TX until 7 PM this
afternoon. The forecast gets tricky heading into tomorrow as a
front begins its approach from the northwest and a disturbance
currently hammering Louisiana begins to shift westward. Showers
and thunderstorms should start to get going during the day
Saturday, but the main event should occur in the Saturday night
through Sunday night time frame. WPC currently has much of SE TX in
a slight risk for excessive rainfall both Saturday and Sunday.
Current thinking is for around 3 to 5 inches of QPF through early
Monday, primarily over the northern and eastern areas. However,
isolated totals of up to 10 inches cannot be ruled out. We have
been discussing the possibility of a Flash Flood Watch for
Saturday Night through Sunday Night but have decided to hold off
for now.

Note I have put the statements I don't understand in bold.

1. What do they mean by "conditions worsening?" What kind of conditions are they looking for? TC-like?

2. Notice the forecaster identified the main area of concern as the

northern and eastern areas

. I live in southwest Houston, south of I-10. Is my risk of severe weather less than those locations just mentioned.

Get back with me as soon as you can.

[worrybug]

Dear pro mets:

These two items from the HGX AFD are a little beyond my personal comprehension.

719
FXUS64 KHGX 130025
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
725 PM CDT Fri Aug 12 2016

.AVIATION...
VFR conditions to continue overnight with a possibility of some
patchy MVFR ceilings around sunrise tomorrow morning. Winds
overnight will be southerly at 5 to 10 knots.

Showers and thunderstorms will gradually increase in coverage
during the day on Saturday. Isolated showers late Saturday morning
will become scattered to numerous showers and thunderstorms by
late afternoon. The heaviest precipitation will move in to SETX
airspace from the east with conditions worsening after 21Z. I
addressed the afternoon precipitation with a VCTS in this TAF
package, however I am considering a PROB30 after 21Z tomorrow for
the 06Z TAF package. Keehn/44

&&

.PREV DISCUSSION... /ISSUED 410 PM CDT Fri Aug 12 2016/

DISCUSSION...
A heat advisory remains in effect for all of SE TX until 7 PM this
afternoon. The forecast gets tricky heading into tomorrow as a
front begins its approach from the northwest and a disturbance
currently hammering Louisiana begins to shift westward. Showers
and thunderstorms should start to get going during the day
Saturday, but the main event should occur in the Saturday night
through Sunday night time frame. WPC currently has much of SE TX in
a slight risk for excessive rainfall both Saturday and Sunday.
Current thinking is for around 3 to 5 inches of QPF through early
Monday, primarily over the northern and eastern areas. However,
isolated totals of up to 10 inches cannot be ruled out. We have
been discussing the possibility of a Flash Flood Watch for
Saturday Night through Sunday Night but have decided to hold off
for now.

Note I have put the statements I don't understand in bold.

1. What do they mean by "conditions worsening?" What kind of conditions are they looking for? TC-like?

2. Notice the forecaster identified the main area of concern as the

northern and eastern areas

. I live in southwest Houston, south of I-10. Is my risk of severe weather less than those locations just mentioned.

Get back with me as soon as you can.

[Skyguy]

Dear pro mets:

These two items from the HGX AFD are a little beyond my personal comprehension.

719
FXUS64 KHGX 130025
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
725 PM CDT Fri Aug 12 2016

.AVIATION...
VFR conditions to continue overnight with a possibility of some
patchy MVFR ceilings around sunrise tomorrow morning. Winds
overnight will be southerly at 5 to 10 knots.

Showers and thunderstorms will gradually increase in coverage
during the day on Saturday. Isolated showers late Saturday morning
will become scattered to numerous showers and thunderstorms by
late afternoon. The heaviest precipitation will move in to SETX
airspace from the east with conditions worsening after 21Z. I
addressed the afternoon precipitation with a VCTS in this TAF
package, however I am considering a PROB30 after 21Z tomorrow for
the 06Z TAF package. Keehn/44

&&

.PREV DISCUSSION... /ISSUED 410 PM CDT Fri Aug 12 2016/

DISCUSSION...
A heat advisory remains in effect for all of SE TX until 7 PM this
afternoon. The forecast gets tricky heading into tomorrow as a
front begins its approach from the northwest and a disturbance
currently hammering Louisiana begins to shift westward. Showers
and thunderstorms should start to get going during the day
Saturday, but the main event should occur in the Saturday night
through Sunday night time frame. WPC currently has much of SE TX in
a slight risk for excessive rainfall both Saturday and Sunday.
Current thinking is for around 3 to 5 inches of QPF through early
Monday, primarily over the northern and eastern areas. However,
isolated totals of up to 10 inches cannot be ruled out. We have
been discussing the possibility of a Flash Flood Watch for
Saturday Night through Sunday Night but have decided to hold off
for now.

Note I have put the statements I don't understand in bold.

1. What do they mean by "conditions worsening?" What kind of conditions are they looking for? TC-like?

2. Notice the forecaster identified the main area of concern as the

northern and eastern areas

. I live in southwest Houston, south of I-10. Is my risk of severe weather less than those locations just mentioned.

Get back with me as soon as you can.

Well, I can' really answer either question for you, Mr. Worrybug. But I do have a little tidbit from Beaumont's AFD that kinda parallels what HGX has been saying:

We are monitoring our southeast Texas area for a Flash Flood Watch which may be needed as early as Saturday morning if the westward trend of heavy rain continues and forecasted QPF values increase. However. StormTotal QPF currently does not support the issuance of the FFA at this time for southeast Texas as 3.5 to 3.75 inches of rain is forecasted through Sunday morning over the much drier soil

Could somebody help out Mr. Worrybug, please?

[TexasBreeze]

http://radar.weather.gov/Conus/southpla ... e_loop.php

I see this event being more beneficial for dry Texas more than anything. The moisture around the low to the east looks to be colliding with the moisture from the southward moving cold front to the northwest. Could make for a wetter day Saturday earlier.

[StormOne]

1. What do they mean by "conditions worsening?" What kind of conditions are they looking for? TC-like?

Not TC like. They mean an increase in rain and storm coverage.

I live in southwest Houston, south of I-10. Is my risk of severe weather less than those locations just mentioned.

What they were saying here is that, for now, the highest areas of precipitation seems to be in the Northern and Eastern areas. However, things are changing constantly, so that could very well change. Regardless, everyone can and will see rain from this, heavy at times.

[worrybug]

1. What do they mean by "conditions worsening?" What kind of conditions are they looking for? TC-like?

Not TC like. They mean an increase in rain and storm coverage.

I live in southwest Houston, south of I-10. Is my risk of severe weather less than those locations just mentioned.

What they were saying here is that, for now, the highest areas of precipitation seems to be in the Northern and Eastern areas. However, things are changing constantly, so that could very well change. Regardless, everyone can and will see rain from this, heavy at times.

Is this any different from the April 18th rain event? (I'll assume you know what I'm talking about, so I can help you maintain family friendliness.)

[Skyguy]

1. What do they mean by "conditions worsening?" What kind of conditions are they looking for? TC-like?

Not TC like. They mean an increase in rain and storm coverage.

I live in southwest Houston, south of I-10. Is my risk of severe weather less than those locations just mentioned.

What they were saying here is that, for now, the highest areas of precipitation seems to be in the Northern and Eastern areas. However, things are changing constantly, so that could very well change. Regardless, everyone can and will see rain from this, heavy at times.

Is this any different from the April 18th rain event? (I'll assume you know what I'm talking about, so I can help you maintain family friendliness.)

This from Brooks Garner on Facebook:

Nearly a foot of rain flooded huge portions of Louisiana last night and indications suggest Houston could be in line for a piece of this heavy rain Saturday evening, night and Sunday morning. Head's-up if you have any plans. Flooding potential certainly exists... This thing closely resembles an inland tropical depression. The heaviest rain will most likely occur just east of the Houston metro, but we will tap some of that deep tropical moisture, resulting in less prolonged, but comparably heavy downpours this weekend.

I think some people will have problems, but, like Brooks said, it all depends on how far west this thing moves. FWIW, given the superficial resemblance to a tropical system, it could easily make a sudden turn to the E/NE and the heavy rains miss Houston altogether.

[houstonia]

9:11 pm update:
000
FXUS64 KHGX 130211
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
911 PM CDT Fri Aug 12 2016

.DISCUSSION...
The deep layer low was located over Louisiana this evening. By 9
PM, showers and isolated thunderstorms were approaching the far
northern set of counties from the north. Very dry air was still
over the southern portions of the forecast area. This can be seen
on the 00Z soundings -- CRP had a PW of 1.31 while LCH had a PW of
2.46. This is in line with the the latest model runs which were
still showing the best chances on Saturday.

Tweaked the isolated chances a bit further to the south to account
for the current coverage.

[Ounce]

Bug,
Recommend letting time pass until mid-Saturday afternoon and see how things are shaking out, plus re-read what Brooks wrote.

[worrybug]

Bug,
Recommend letting time pass until mid-Saturday afternoon and see how things are shaking out, plus re-read what Brooks wrote.

Well, sure. But one things bothers me:

Wouldn't a tropical airmass that interacts with a cold front be rich in lightning?

[Skyguy]

Bug,
Recommend letting time pass until mid-Saturday afternoon and see how things are shaking out, plus re-read what Brooks wrote.

I agree that Worrybug should let time pass, but I'm a little skeptical about re-reading what Brooks wrote on Facebook. Things are apparently constantly changing, as one forum member said.

My guess is that he's responding to the images of epic flooding from Louisiana, and is concerned about it happening to us. Who wouldn't be, after all the flooding we've had. Plus, it's been my understanding that one forum member posted a special bulletin on twitter in which NWS Houston is thinking about treating this as a dangerous event.

Now, Bug, we're not out to hang you but please be honest with this forum: Are you afraid that maybe something worse than happened on April 18th will happen with this semi-tropical low that is under discussion?

[worrybug]

Bug,
Recommend letting time pass until mid-Saturday afternoon and see how things are shaking out, plus re-read what Brooks wrote.

I agree that Worrybug should let time pass, but I'm a little skeptical about re-reading what Brooks wrote on Facebook. Things are apparently constantly changing, as one forum member said.

My guess is that he's responding to the images of epic flooding from Louisiana, and is concerned about it happening to us. Who wouldn't be, after all the flooding we've had. Plus, it's been my understanding that one forum member posted a special bulletin on twitter in which NWS Houston is thinking about treating this as a dangerous event.

Now, Bug, we're not out to hang you but please be honest with this forum: Are you afraid that maybe something worse than happened on April 18th will happen with this semi-tropical low that is under discussion?

Yes.

[houstonia]

11:27 pm Aviation report:

000
FXUS64 KHGX 130427
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1127 PM CDT Fri Aug 12 2016

.AVIATION...
No major changes to TAF package. VFR conditions overnight with a
possibility of some patchy MVFR ceilings around sunrise. Winds
overnight will be southerly at 5 to 10 knots.

Showers and thunderstorms will gradually increase in coverage
during the day tomorrow. Isolated showers late tomorrow morning
will become scattered to numerous showers and thunderstorms by
early evening. The heaviest precipitation will move in to the SETX
airspace from the east with conditions deteriating between
21-00Z. Shower and thunderstorm coverage should be fairly
widespread by tomorrow evening so I went with prevailing
-shra/tsra late in the TAF periods. Thunderstorm activity will
decrease in coverage and intensity after sunset tomorrow evening,
however showers and stratiform rain should continue overnight over
much of the area. Keehn/44

&&

[StormOne]

Plus, it's been my understanding that one forum member posted a special bulletin on twitter in which NWS Houston is thinking about treating this as a dangerous event.

Hey, someone on here actually reads those!

There is no worrying needed. April 17/18 set a new standard for a flooding crisis, which we thought the standard was set Memorial Day 2015. Even the GFS model, which is overdoing it in my opinion, is not nearly as high as it was before the April event. And if things do get dangerous, this forum will keep you covered, I will keep you covered on Twitter, and news stations will keep you covered. I am not going to lie and say it won't be dangerous, because some people may see flooding. However, no need to excessively worry, as if things get bad, we will be here for you.

[Skyguy]

Plus, it's been my understanding that one forum member posted a special bulletin on twitter in which NWS Houston is thinking about treating this as a dangerous event.

Hey, someone on here actually reads those!

There is no worrying needed. April 17/18 set a new standard for a flooding crisis, which we thought the standard was set Memorial Day 2015. Even the GFS model, which is overdoing it in my opinion, is not nearly as high as it was before the April event. And if things do get dangerous, this forum will keep you covered, I will keep you covered on Twitter, and news stations will keep you covered. I am not going to lie and say it won't be dangerous, because some people may see flooding. However, no need to excessively worry, as if things get bad, we will be here for you.

There you go, Bug.

P.S. Don't put him on the inactive list. For now, I'll take responsibility for Worrybug, if that's okay.

Hmm, the GFS overdoing something. Interesting. Tell me more, Storm One.

[DoctorMu]

Out of town and sprinklers on...thus it's a cinch.

2-4 in with significant variation seems reasonable.... Day by day.

[StormOne]

Out of town and sprinklers on...thus it's a cinch.

2-4 in with significant variation seems reasonable.... Day by day.

Good to see GFS is more realistic now. Had a nearly 10" bullseye over us earlier and that's not counting for isolated higher amounts either.

[jasons2k]

Y'all, even the Euro is starting to show over 9" (9.22" just west of H-town) in places out to 120 hours...don't want to get into specific locations because it doesn't matter yet - but something to watch.

[srainhoutx]

Mid level vorticity was centered around Lake Pontchartrain around midnight and slowly drifting West. The core rains were still situated to the West of the mid level circulation over Southern/SW Louisiana meandering slowly West as well.

MESOSCALE PRECIPITATION DISCUSSION 0555
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
204 AM EDT SAT AUG 13 2016

AREAS AFFECTED...SOUTHWESTERN TO SOUTHERN LA...

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 130603Z - 131103Z

SUMMARY...THUNDERSTORMS CONTINUE TO FLARE UP ON THE NORTH SIDE OF
THE CIRCULATION OVER SOUTHERN LA. THE THERMODYNAMIC AND KINEMATIC
ENVIRONMENT REMAIN FAVORABLE FOR HEAVY RAINFALL WITH FLASH
FLOODING LIKELY IN AREAS WITH SATURATED SOILS.

DISCUSSION...THE PARENT MID-LEVEL CIRCULATION HAS NOT MOVED
SIGNIFICANTLY IN THE PAST 24 HOURS WITH THE CENTER IN THE VICINITY
OF LAKE PONTCHARTRAIN. POSITIVE VORTICITY ADVECTION WITHIN THE
CYCLONIC CIRCULATION CONTINUE TO DRIVE UPWARD VERTICAL MOTIONS IN
THE PRESENCE OF VERY CONFLUENT LOW-LEVEL FLOW. 00Z SOUNDINGS FROM
LCH/LIX INDICATE TROPICAL MOISTURE REMAINS IN PLACE WITH PWATS
NEARING 2.50 INCHES. THIS IS ACTUALLY ABOUT 0.25 INCHES LOWER THAN
THE PREVIOUS NIGHT OVER LIX. FURTHER...WET-BULB ZERO HEIGHTS ARE
RATHER HIGH...ON THE ORDER OF 15 TO 16 KFT SUGGESTING WARM RAIN
PROCESSES WILL DOMINATE. WHILE THE INSTABILITY HAS WANED AS
INDICATED BY THE WARMING TOPS...LOCAL ADVECTION CONTINUES TO
ADVANCE HIGHER CAPE AIR INTO THE AFFECTED REGION. THIS SHOULD HELP
BOLSTER THE CONVECTIVE POTENTIAL OVERNIGHT ACROSS MUCH OF SOUTHERN
LA.

EVALUATING SOME OF THE RECENT CAMS...THE 00Z HRW-ARW/HRW-NMM-B AS
WELL AS THE LATEST HRRR/HRRR-PARALLEL HAVE A DECENT HANDLE ON THE
SITUATION. MEANWHILE...THE 00Z NAM CONUS NEST/NSSL-WRF WERE
DISPLACED EASTWARD WHICH DID NOT LOOK AS REASONABLE BASED ON
RECENT RADAR/SATELLITE TRENDS. THE GUIDANCE SUPPORT 6-HOUR
RAINFALL TOTALS IN THE 3 TO 5 INCH RANGE WHICH LOOKS REASONABLE
CONSIDERING THE ENVIRONMENT IN PLACE. OF COURSE THE HIGHEST FLASH
FLOOD RISK WILL BE AREAS WHICH HAVE BEEN IMPACTED BY RECENT HEAVY
RAINFALL WHERE 1 HOUR FFG VALUES ARE AROUND 0.25 INCHES. AS
SUCH...WILL MAINTAIN THE FLASH FLOODING LIKELY DESIGNATION.


RUBIN-OSTER

ATTN...WFO...JAN...LCH...LIX...




The morning 72 hour quantitative precipitation forecast seems reasonable. This is still a very challenging and complicated forecast as the 7 day quantitative precipitation forecast suggests rainfall is possible throughout the next 5 to 7 days. NWS Houston/Galveston covers all the forecasting challenges and uncertainties in their morning Discussion below.

The attachment d13_fill (15).gif is no longer available

Area Forecast Discussion
National Weather Service Houston/Galveston TX
421 AM CDT Sat Aug 13 2016

.DISCUSSION...
A change in the wx pattern is still on tap this weekend w/ chances
of rain and less-hot wx expected thru much of next week.

Upper low is still doing its thing in La early this morning,
unfortunately. Western edge of precip is now nearing the Sabine
River. This low will slowly edge into east Texas by Sunday. Look
for moisture levels to begin significantly increasing this
afternoon. PW's starting out between 1.6-2.1" this morning are
fcst to rise to 2.3-2.8+" across a good portion of the area later
this afternoon (near or above record levels). This moisture, a
seabreeze, daytime heating and an incoming frontal boundary from
the north will probably trigger showers and thunderstorms late
this afternoon...continuing thru the overnight hours. With the
exception of localized issues, believe most locations can handle
what falls during the daylight period. After coordinating w/
surrounding offices, we decided to forgo a flash flood watch for
today and let the next shift(s) evaluate trends for tonight/Sunday.
Will need to pay close attention to area where surface boundary/front
is located this evening, tonight & Sunday & possibly Mon. These
high PW airmasses can be efficient rain producers alone...and
throwing in a surface focusing mechanism could further enhance.

The upper low becomes stretched/sheared and leaves a general weakness
in the flow across Tx thru the middle to late parts of next week.
Moisture values remain elevated/high thru most of the period.
Expect fairly good chances of rain each day...probably eventually
taking on a diurnal trend (higher chances near coast/offshore late
at night and morning...then expanding inland during the day w/
heating).

A few notes about the forecast in these type patterns:
- There's considerable uncertainty pinpointing exact locations
that will see the highest rainfall amounts and what time it'll
occur. Sometimes even beyond about 12 hours or so. Models can,
and will, change from run-to-run and depict varying solutions.
- SE Texas can take a good amount of rainfall...if it's somewhat
steady and comes in days. Problems occur & magnify w/ high rainfall
rates.
- Potential will be there from later this afternoon thru much of the
week for localized street flooding. Atmosphere will be quite moist
and won't take much for a slow moving cell to dump several inches of
rain in a short time period.
- Not everyone will see significant amounts of rain. There will
probably be a wide range of totals each day. If guessing now, areas
closer to the Matagorda Bay area may see the lesser amounts overall.
47