April 2016 Recap: Regional Flood/Severe Weather

[unome]

MESOSCALE DISCUSSION 0512
NWS STORM PREDICTION CENTER NORMAN OK
0738 AM CDT SAT APR 30 2016

AREAS AFFECTED...SOUTHEAST TX...SOUTHWEST LA

CONCERNING...SEVERE THUNDERSTORM WATCH 129...130...

VALID 301238Z - 301345Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
129...130...CONTINUES.

SUMMARY...PRIMARY RISKS SHOULD REMAIN AS ISOLATED DAMAGING WINDS AND
PERHAPS A BRIEF TORNADO INTO LATE MORNING AS A PAIR OF MCS/S LIKELY
MERGE DURING THE NEXT COUPLE HOURS.

DISCUSSION...FORWARD MOTION OF A LEAD MCS THAT HAS CROSSED THE
SABINE RIVER INTO SOUTHWEST LA WAS ONLY ABOUT 20 KT...WHILE AN
UPSTREAM MCS APPROACHING THE NORTHERN HOUSTON METRO WAS MOVING EAST
AROUND 40 KT. THIS SHOULD RESULT IN MERGING OF THESE MCS/S IN THE
NEXT COUPLE HOURS NEAR THE MOUTH OF THE SABINE. 12Z LCH SAMPLED ONLY
SLIGHTLY WEAKENED MLCIN...AROUND 100 J/KG...RELATIVE TO 00Z. AS
SUCH...THIS LEAD CONVECTION MAY CONTINUE TO HAVE MODEST FORWARD
SPEED UNTIL UPSTREAM COLD POOL AMALGAMATION OCCURS. BEYOND THE FLASH
FLOODING THREAT HIGHLIGHTED IN WPC MPD 154...ISOLATED DAMAGING WINDS
AND PERHAPS A BRIEF TORNADO WILL BE THE PRIMARY SEVERE RISKS.

..GRAMS.. 04/30/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LCH...HGX...

[nuby3]

now to start watching to see if the tail end starts to drag at all

[unome]

[unome]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
713 AM CDT SAT APR 30 2016

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHWESTERN HOUSTON COUNTY IN SOUTHEASTERN TEXAS...
WEST CENTRAL LIBERTY COUNTY IN SOUTHEASTERN TEXAS...
WALKER COUNTY IN SOUTHEASTERN TEXAS...
WESTERN SAN JACINTO COUNTY IN SOUTHEASTERN TEXAS...
NORTHEASTERN WALLER COUNTY IN SOUTHEASTERN TEXAS...
EASTERN GRIMES COUNTY IN SOUTHEASTERN TEXAS...
MONTGOMERY COUNTY IN SOUTHEASTERN TEXAS...
HARRIS COUNTY IN SOUTHEASTERN TEXAS...
SOUTHEASTERN MADISON COUNTY IN SOUTHEASTERN TEXAS...
SOUTHWESTERN TRINITY COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 800 AM CDT

* AT 711 AM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
EXTENDING FROM 6 MILES SOUTH OF BEDIAS TO 7 MILES WEST OF TODD
MISSION TO WALLER...MOVING NORTHEAST AT 40 MPH.

HAZARD...60 MPH WIND GUSTS AND PENNY SIZE HAIL.

SOURCE...RADAR INDICATED WINDS IN EXCESS OF 55 KNOTS JUST OFF THE
SURFACE WITH THESE STORMS.

IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. TOPPLED
TREES.

* LOCATIONS IMPACTED INCLUDE...
NORTHWESTERN BAYTOWN...CONROE...HUNTSVILLE...HUMBLE...KATY...TOMBALL...
JERSEY VILLAGE...WILLIS...HUNTERS CREEK VILLAGE...PINEHURST...SPRING
VALLEY...BARRETT...SPRING BRANCH WEST...NEAR NORTHSIDE HOUSTON...
SPRING...ALDINE...SPRING BRANCH NORTH...CLOVERLEAF...GREATER
GREENSPOINT AND ADDICKS PARK TEN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF IN THE PATH OF THESE STORMS...FOR YOUR PROTECTION MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUILDING.

&&

LAT...LON 3071 9524 2977 9501 2979 9580 3014 9596
3087 9593 3130 9525
TIME...MOT...LOC 1211Z 231DEG 51KT 3068 9596 3024 9595 3007 9592

HAIL...0.75IN
WIND...60MPH

$$

[Andrew]

Should see plenty of sunshine and clearing once this line moves through. Satellite shows a sharp gradient behind it. Plenty of dry air too.

[ticka1]

no rain from this system at all for me here in baytown. what happened to the forecast?

[Cromagnum]

Nailed it.

When nobody expects it or really talks about it we get hammered.

When its been hyped up all week nothing happens.

Figures.

[wxman57]

Well this is interesting. One of our respected pro-mets is playing it up with an abundance of caution, and another saying just a street flooding issue... snip...

I was only discussing the rainfall potential with respect to the huge amounts indicated by the HRRR model, I didn't say no chance of any severe storms. There is a slight risk of severe storms across Houston, but it's not looking like the HRRR's forecast of 14+ inches is going to verify.

[nuby3]

Nailed it.

When nobody expects it or really talks about it we get hammered.

When its been hyped up all week nothing happens.

Figures.

exactly

[srainhoutx]

Thankfully for those that were flooded out of their homes we dodged the worst of the Heavy Rainfall. I do see that there have been 5 deaths, some children in East Texas from this event...so far. Not sure "hype" is a word I would use regarding what was posted here in this forum or even from the forecasters and the local Professional Meteorologists we look to for advice, guidance and direction. There was a LOT of sensitivity given due to so many folks being impacted April 17-18th and are still reeling with recovery. I personally will err on the side of caution when we see a very complex and complicated pattern. Some may call it a bust...and that is fine. But most reasonable folks know when weather worries come our way, they can get the most reliable and accurate information Humanly possible right here on the KHOU Regional Weather Forum. Enjoy the day!

MESOSCALE PRECIPITATION DISCUSSION 0155
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
956 AM EDT SAT APR 30 2016

AREAS AFFECTED...UPPER TX COAST...SOUTHERN LA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 301355Z - 301800Z

SUMMARY...HEAVY CONVECTIVE RAINS WILL BE FOCUSING ACROSS THE FAR
UPPER TX COAST AND INTO SOUTHERN LA THROUGH EARLY AFTERNOON.

DISCUSSION...VERY DIFFLUENT FLOW ALOFT WHICH IS BEING FACILITATED
BY THE ARRIVAL OF A SHORTWAVE IMPULSE ACROSS EASTERN TX THIS
MORNING WILL CONTINUE TO HELP SUSTAIN AN AREA OF HEAVY SHOWERS AND
THUNDERSTORMS FROM THE UPPER TX COAST EASTWARD INTO SOUTHERN LA.
CLOUD TOP TEMPERATURES HAVE WARMED SOMEWHAT OVER THE LAST
HOUR...BUT CONFLUENT SOUTHERLY 850 MB FLOW OF 30 TO 40 KTS AIMED
INTO SOUTHERN LA IS EXPECTED TO CONTINUE TO TRANSPORT A RELATIVELY
MOIST AND UNSTABLE AIRMASS IN OFF THE GULF OF MEXICO.

BLENDED-TPW DATA ALONG GPS-DERIVED PWATS DO SHOW A SOMEWHAT DRIER
AIRMASS DOWNSTREAM ACROSS SOUTHEAST LA BUT THIS RELATIVELY DRIER
AIR SHOULD TEND TO FOCUS FARTHER EAST WITH TIME AND AWAY FROM THE
APPROACHING ACTIVITY FROM THE WEST. THE CONVECTION IS EMBEDDED
GENERALLY WITHIN AN AXIS OF 1.5 TO 1.7 INCH PWATS...AND BEING
AIDED BY A NOSE OF MLCAPE VALUES OF 1000 TO 2000 J/KG.

THE RAP GUIDANCE DOES NOT SUGGEST MUCH CHANGE IN THE THERMODYNAMIC
ENVIRONMENT OVER THE NEXT COUPLE OF HOURS...AND CONSIDERING THE
LARGER SCALE SHORTWAVE DYNAMICS APPROACHING FROM THE WEST ALONG
WITH A LARGER SCALE SPLIT UPPER JET PATTERN...THE CURRENT ACTIVITY
SHOULD TEND TO BE STEADY-STATE WHILE SHIFTING GRADUALLY EAST.

RAINFALL RATES OF 1.5 TO 2 INCHES/HR ARE LIKELY ACROSS THE FAR
UPPER TX COAST AND INTO SOUTHERN LA AND THERE IS SUFFICIENT W/E
ORIENTATION OF THE CONVECTION FOR THERE TO BE AT LEAST SOME
PERIODIC TRAINING POTENTIAL. THE 00Z WRF-ARW APPEARS TO HAVE THE
BEST HANDLE ON THE CURRENT ACTIVITY...AND SUGGESTS RAINFALL
AMOUNTS THROUGH 18Z OF 2 TO 4 INCHES...WITH ISOLATED HEAVIER
AMOUNTS. THIS MAY RESULT IN AT LEAST SOME RUNOFF/FLASH FLOOD
PROBLEMS...PARTICULARLY IN VICINITY OF URBANIZED AREAS.

ORRISON

ATTN...WFO...HGX...LCH...LIX...

[ticka1]

Is there anymore rain forecasted this weekend or we in for clearing skies and sunshine?

[Andrew]

Nailed it.

When nobody expects it or really talks about it we get hammered.

When its been hyped up all week nothing happens.

Figures.

I definitely wouldn't call 8+ inches over eastern Texas and the NE extent of SE Texas a bust. I never understand why people say it is a bust or nothing happens just because the most populated region only got an inch or two. The QPF totals were actually pretty well mapped, just further to the northeast than expected. We constantly warn on here that we do not have the capabilities to constantly and accurately predict mesoscale based rain events. If that line would have developed another 50 miles further south it would have been a totally different attitude.

[nuby3]

Thankfully for those that were flooded out of their homes we dodged the worst of the Heavy Rainfall. I do see that there have been 5 deaths, some children in East Texas from this event...so far. Not sure "hype" is a word I would use regarding what was posted here in this forum or even from the forecasters and the local Professional Meteorologists we look to for advice, guidance and direction. There was a LOT of sensitivity given due to so many folks being impacted April 17-18th and are still reeling with recovery. I personally will err on the side of caution when we see a very complex and complicated pattern. Some may call it a bust...and that is fine. But most reasonable folks know when weather worries come our way, they can get the most reliable and accurate information Humanly possible right here on the KHOU Regional Weather Forum. Enjoy the day!


[/i]

I was more just thinking of my own opinions and expectations of what's gonna happen than what you guys were saying. relative to what I personally was expecting, it didn't unfold nearly the way I thought it would. not that it's all that surprising, I suck at this

[txflagwaver]

Glad we dodged the heavy rain for the most part in our area... Maybe I CAN get the yard done tomorrow

[Cromagnum]

Nailed it.

When nobody expects it or really talks about it we get hammered.

When its been hyped up all week nothing happens.

Figures.

I definitely wouldn't call 8+ inches over eastern Texas and the NE extent of SE Texas a bust. I never understand why people say it is a bust or nothing happens just because the most populated region only got an inch or two. The QPF totals were actually pretty well mapped, just further to the northeast than expected. We constantly warn on here that we do not have the capabilities to constantly and accurately predict mesoscale based rain events. If that line would have developed another 50 miles further south it would have been a totally different attitude.

So the forecast was correct even though it verified somewhere else...got it.

[Texaspirate11]

I always go my the mantra "I'd rather you laugh at me then I cry over you."
Thanks to our mets for keeping us safe.
Never complain when I wake up and there is roof over my head and my peeps are safe.


Gentle rain failing now at the bay.
Thanks for you do on this forum.
On to the next system.

[Heat Miser]

Where's the beef?
The movers I hired almost cancelled on us last night due to the expected "event" in our area. You know we can't ensure that your furniture etc. won't get wet, we still charge by the hour regardless of heavy rain yada yada.
Told him to come on because we'll have a passing shower with maybe a rumble of thunder. Incredible how people get after a flood, a shower is the next Noah's Ark event. Movers will be here at 1300 and it looks like perfect timing, no indication so far of anything of significance building to our west at the moment.
For the Houston metro area I guess we dodged a bullet, which is fine with me.
Prayers to the families affected in north/east/northeast Texas, maybe far north/northeast southeast Texas.

[wxman57]

The GFS suggests that the rain threat is only beginning. It has a weak boundary across Houston through Tuesday. There's definitely a potential for heavy rain tomorrow afternoon/evening into Tuesday.

[Andrew]

Nailed it.

When nobody expects it or really talks about it we get hammered.

When its been hyped up all week nothing happens.

Figures.

I definitely wouldn't call 8+ inches over eastern Texas and the NE extent of SE Texas a bust. I never understand why people say it is a bust or nothing happens just because the most populated region only got an inch or two. The QPF totals were actually pretty well mapped, just further to the northeast than expected. We constantly warn on here that we do not have the capabilities to constantly and accurately predict mesoscale based rain events. If that line would have developed another 50 miles further south it would have been a totally different attitude.

So the forecast was correct even though it verified somewhere else...got it.

I think the general consensus across the board that where the heavier rain bands were going to setup was something we wouldn't know until it actually started to happen. So yes, I would say the forecast actually verified pretty well. The NWS for the most part had most of the precipitation further to the northeast away from SE Texas and that verified. The moderate risk of excessive rain/ concern for flooding was due to the sensitive grounds and reservoirs across Harris County in particular. Did Houston and points to the south receive less than expected, yes that is true, but the pockets of 8+ inches still occurred.

[srainhoutx]

The GFS suggests that the rain threat is only beginning. It has a weak boundary across Houston through Tuesday. There's definitely a potential for heavy rain tomorrow afternoon/evening into Tuesday.

Thanks wxman57. Since this is the last day of the month and particularly since you've already stated in the May Topic that you are not seeing much of a change in the upper air pattern in the days ahead. Let it serve as a reminder that we are in a transitioning period from El Nino to La Nina when we typically see the potential for continued storminess. In fact the overnight Euro and GFS Ensembles advertise the first 10 to 15 days of May could be rather unsettled with more storm systems diving out of the Gulf of Alaska and the continuation of a Western Trough.