August 2017: Looking Back at Harvey 5 Year Later

[StormOne]

Fun looking cell merger about to take place. Placing my money on a FF warning being needed in the next hour somewhere in Harris County East of the 45.

EDIT: Do I get a prize?

[djjordan]

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
1223 AM CDT TUE AUG 8 2017

The National Weather Service in League City has issued a

* Flash Flood Warning for...
Southern Montgomery County in southeastern Texas...
Northeastern Fort Bend County in southeastern Texas...
Southeastern Waller County in southeastern Texas...
Harris County in southeastern Texas...

* Until 330 AM CDT.

* At 1222 AM CDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Reports
are coming in that Bear Creek Village is flooding.

Up to three inches of rain have already fallen. Flash flooding is
already occuring.

* Some locations that will experience flooding include...
Northern Sugar Land, northern Missouri City, Stafford, Bellaire,
Humble, West University Place, Katy, Richmond, Tomball, Jacinto
City, Jersey Village, Brookshire, Hunters Creek Village, Bunker
Hill Village, Piney Point Village, Pinehurst, Downtown Houston,
Greenway / Upper Kirby Area, Kingwood and Spring Branch North.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

[Texaspirate11]

That alert definitely woke me up.
We've already had a little over 3 inches the past 2 days
and its pouring!

[srainhoutx]

Flash Flood Warning Update from Jeff:

Flash Flood Warning for Harris and Fort Bend Counties until 330am.

Band of excessive rainfall with numerous locations over 1.0 inch in 15 minutes from Katy to The Woodlands. Strong cells over SC Harris County will merge with this band from Aldine to West Houston to Alief over the next 30 minutes resulting in intense rainfall rates of 1-2 inches in 30 minutes. Deep street flooding is likely in the flash flood warning area.

South Mayde Creek at Greenhouse:

3-4 inches across the watershed today with 1.5-2.5 in the last hour. Creek is rising rapidly and may reach bankfull overnight

Several watershed across the western portions of Harris County are rising rapidly, but remain well within banks at this time.

Significant rises on White Oak, Buffalo, and Brays Bayous will be possible over the next 2-3 hours as excessive rainfall shifts over these watersheds.

[djjordan]

Flood Advisory
National Weather Service Houston/Galveston TX
1258 AM CDT TUE AUG 8 2017

TXC015-089-080800-
/O.NEW.KHGX.FA.Y.0207.170808T0558Z-170808T0800Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Colorado TX-Austin TX-
1258 AM CDT TUE AUG 8 2017

The National Weather Service in League City has issued a

* Flood Advisory for...
Northeastern Colorado County in southeastern Texas...
Southeastern Austin County in southeastern Texas...

* Until 300 AM CDT.

* At 1257 AM CDT, Doppler radar indicated heavy rain due to
thunderstorms. This will cause minor flooding in the advisory area.
Up to three inches of rain have already fallen.

* Some locations that will experience flooding include...
Sealy, Eagle Lake and San Felipe.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

[djjordan]

FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON, TX
1259 AM CDT Tue Aug 8 2017

...The National Weather Service in Houston/Galveston has issued a flood warning
for the following rivers...

South Mayde Creek Near Greenhouse Road affecting the following counties in
Texas...Harris


For the Addicks Reservoir at Greenhouse Road, Minor flooding is occuring.

The current weather is dominated by a slow moving cluster of thunderstorms.
This weather system will produce rainfall amounts ranging from 3 to 6 inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Persons are urged to stay away from the river until water levels recede.

Motorists should avoid any water covered roads and find an alternate route.

Livestock and equipment should remain out of the flood plain for the next few
days.

[djjordan]

Flood Advisory
National Weather Service Houston/Galveston TX
103 AM CDT TUE AUG 8 2017

TXC071-201-291-080900-
/O.NEW.KHGX.FA.Y.0208.170808T0603Z-170808T0900Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chambers TX-Liberty TX-Harris TX-
103 AM CDT TUE AUG 8 2017

The National Weather Service in League City has issued a

* Flood Advisory for...
Northwestern Chambers County in southeastern Texas...
Southwestern Liberty County in southeastern Texas...
Northeastern Harris County in southeastern Texas...

* Until 400 AM CDT.

* At 102 AM CDT, Doppler radar indicated heavy rain due to
thunderstorms. This will cause minor flooding in the advisory area.
Up to one inch of rain has already fallen, with additional heavy
rain on the way.

* Some locations that will experience flooding include...
Northwestern Pasadena, Baytown, Deer Park, Galena Park, Jacinto
City, Liberty, Dayton, Beach City, Cloverleaf, Channelview,
Highlands, Barrett, Crosby, Mont Belvieu, Old River-Winfree,
Hardin, Kenefick, Cove, Morgan`s Point and Dayton Lakes.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

[djjordan]

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
116 AM CDT TUE AUG 8 2017

The National Weather Service in League City has issued a

* Flash Flood Warning for...
Southeastern Montgomery County in southeastern Texas...
Northwestern Chambers County in southeastern Texas...
Southwestern Liberty County in southeastern Texas...
Northeastern Harris County in southeastern Texas...

* Until 415 AM CDT.

* At 115 AM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Up to two inches of rain have
already fallen with additional heavy rainfall on the way. Flash
flooding is expected to begin shortly.

* Some locations that will experience flooding include...
Liberty, Dayton, Barrett, Crosby, Mont Belvieu, Patton Village,
Roman Forest, Old River-Winfree, Ames, Hardin, Plum Grove,
Kenefick, Dayton Lakes, Lake Houston Dam, Lake Houston, Sheldon and
southeastern Atascocita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

[djjordan]

Flood Advisory
National Weather Service Houston/Galveston TX
120 AM CDT TUE AUG 8 2017

TXC039-080915-
/O.NEW.KHGX.FA.Y.0209.170808T0620Z-170808T0915Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Brazoria TX-
120 AM CDT TUE AUG 8 2017

The National Weather Service in League City has issued a

* Flood Advisory for...
Southeastern Brazoria County in southeastern Texas...

* Until 415 AM CDT.

* At 119 AM CDT, Doppler radar indicated heavy rain due to
thunderstorms. This will cause minor flooding in the advisory area.
Radar estimates up to two inches of rain have already fallen, with
isolated accumulations around three inches.

* Some locations that will experience flooding include...
Lake Jackson, northwestern Freeport, Clute, Richwood and Oyster
Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

[869MB]

MESOSCALE PRECIPITATION DISCUSSION 0651
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1034 PM EDT MON AUG 07 2017

AREAS AFFECTED...SOUTHEAST TX

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

VALID 080234Z - 080834Z

SUMMARY...THUNDERSTORMS ARE BEGINNING TO FIRE WITHIN THE SOUTHEAST
QUADRANT OF AN MCV. HOURLY RAIN TOTALS UP TO 2.5" AND LOCAL
AMOUNTS TO 5" ARE EXPECTED.

DISCUSSION...RADAR IMAGERY REVEALS AN MCV FROM MORNING
THUNDERSTORM ACTIVITY IN SOUTH-CENTRAL TX MOVING INTO THE REGION,
TO THE EAST-SOUTHEAST AT 10-15 KTS. CIN HAS DEVELOPED ACROSS THE
REGION, WHICH IS ALLOWING THE INSTABILITY ALOFT/MU CAPE TO ITS
SOUTHEAST TO BE TAPPED, ON THE ORDER OF 1000-3000 J/KG. WHILE
VAD WIND PROFILES SHOW CYCLONIC INFLOW OF 20 KTS, RADAR-BASED CELL
MOTIONS IMPLY THAT 30 KTS IS A BETTER INDICATION OF THE 850 HPA
INFLOW. THIS IS 10 KTS ABOVE THE LEVEL OF THE MEAN 850-400 HPA
FLOW. EFFECTIVE BULK SHEAR OF ~30 KTS EXISTS NEAR THE MCV.
PRECIPITABLE WATER VALUES ARE 2-2.2" PER GPS DATA.

THE GUIDANCE HAS A SMALL BUT AGREEABLE MAXIMUM SCATTERED ACROSS
THE REGION OF 5", WHICH IS LIKELY DUE TO THIS MCV. RAINFALL
EFFICIENCY IS EXPECTED TO INCREASE WITH TIME AS THE MEAN 850-400
HPA FLOW WEAKENS TO 5-10 KTS BY 09Z. THE 18Z SSEO NEIGHBORHOOD
PROBABILITIES OF EXCEEDING THE THREE HOUR FLASH FLOOD GUIDANCE
SHOW SMALL 50%+ SPOTS BETWEEN 05 AND 09Z. HOURLY RAIN RATES UP TO
2.5" ARE POSSIBLE NEAR ITS CENTER AND WITHIN ITS SOUTHERN AND
EASTERN QUADRANTS. DUE TO RAINFALL OVER THE PAST 18 HOURS, FLASH
FLOOD GUIDANCE IS COMING DOWNWARD. CONSIDERING THE AMOUNTS
EXPECTED, FLASH FLOODING IS A CONCERN, PARTICULARLY WITHIN URBAN
AREAS.

ROTH

[869MB]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1016 PM CDT Mon Aug 7 2017

.UPDATE...
Though the radar quieted down for several hours as the atmosphere
had been pretty well worked over in the wake of rain earlier
today, it is now beginning to spark back to life. A mesoscale
convective vortex (MCV) has been very conspicuously spinning in
the area of College Station, drifting roughly to the ESE at 15 or
so knots. Additionally, onshore flow is resuming from the coast -
the quality of this return flow is made very apparent by the
sparking of showers along the coast in the last hour or so near
what is effectively a frontal boundary between unstable Gulf air
and the depleted air from earlier today.

To date, the new showers along the SE edge of the MCV have been
only sporadically impressive. Though boasting individual cores
with instantaneous dual pol rates of 4+ inches per hour, the
surrounding areas have been pretty light, and with pretty quick
individual cell motion being pretty quick, the highest of MRMS one
hour QPE are isolated pixels a tad over 1 inch. That said - as the
influx of more unstable air continues, and flow aloft weakens and
veers to be more line parallel, these characteristics should
change for the worse.

Though performance from the CAMs lately has been pretty lousy, it
seems to have had a not awful handle on this MCV, and so am
reluctant to abandon its guidance entirely. Recent HRRR runs seem
to peg out in the 5 inch neighborhood for QPF. The experimental
HRRR time lagged ensemble shows a relatively strong signal for
exceeding 3 inches of rainfall in a 6 hour period, and a slight
hint in this convergent area for exceeding 6 inches. Though it`s
not yet matched in rain occurring, think 2ish inches per hour and
isolated spots of 3-5 inches accumulation seems reasonable given
that factors should come to support heavier rainfall. This should
be capable of causing some localized flooding issues at the least.

The really big question is where the heaviest rain will come down.
With the MCV motion, this preferred area for rainfall will be
drifting slowly towards the Houston metro, with storms already
occurring in extreme NW Harris County. At this time, think the
line motion is slow enough that its location that the heaviest
rain will fall northwest of the more vulnerable urban locations.
However, a faster drop of the line, or if significant rain starts
developing in the inflow, and that scenario could change.

For further information, please visit the WPC website and read
Mesoscale Precipitation Discussion 651.

Luchs

[869MB]

Jeff Lindner‏ @JeffLindner1 13m13 minutes ago
More
.@hcfcd Heavy rain at Brays Bayou @ SH 6 near Alief. High water possible. http://dlvr.it/PcYR26

[djjordan]

Flash Flood Statement
National Weather Service Houston/Galveston TX
211 AM CDT TUE AUG 8 2017

TXC157-201-339-473-080830-
/O.CON.KHGX.FF.W.0031.000000T0000Z-170808T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery TX-Fort Bend TX-Waller TX-Harris TX-
211 AM CDT TUE AUG 8 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 AM CDT FOR
SOUTHERN MONTGOMERY...NORTHEASTERN FORT BEND...SOUTHEASTERN WALLER
AND HARRIS COUNTIES...

At 207 AM CDT, the public reported flooding from heavy rain in Bear
Creek Village. Up to 5 inches of rain have already fallen. Flash
flooding is already occuring. Additional rainfall amounts of around
2 inches are possible in the warned area as moderate to heavy rain
continues to fall.

Some locations that will experience flooding include...
Northern Sugar Land, northern Missouri City, Stafford, Bellaire,
Humble, West University Place, Katy, Richmond, Tomball, Jacinto City,
Jersey Village, Brookshire, Hunters Creek Village, Bunker Hill
Village, Piney Point Village, Pinehurst, Downtown Houston, Greenway /
Upper Kirby Area, Kingwood and Spring Branch North.

Flood waters are moving down Mayde Creek near Greenhouse. Flood
waters will be impacting homes shortly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

[869MB]

MESOSCALE PRECIPITATION DISCUSSION 0653
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
307 AM EDT TUE AUG 08 2017

AREAS AFFECTED...SOUTHEAST TX & SOUTHWEST LA

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

VALID 080706Z - 081306Z

SUMMARY...BANDS OF THUNDERSTORMS CONTINUE TO ROTATE AROUND THE
SOUTH AND EAST SIDE OF AN MCV. HOURLY RAIN RATES UP TO 2.5" WITH
LOCAL AMOUNTS TO 5" ARE EXPECTED.

DISCUSSION...PER NON-OPERATIONAL GOES-16 INFRARED IMAGERY, COOLING
CLOUD TOPS CONTINUE TO EXPAND WITH THUNDERSTORMS SOUTH AND EAST OF
AN MCV WHICH APPEARS TO BE SLOWING ITS PROGRESSION TO THE
SOUTHEAST, WITH MOTION OF 5-10 KTS OVER THE LAST SEVERAL HOURS. A
HINT OF A WARM ADVECTION BAND HAS SHOWN UP IN RECENT RADAR IMAGERY
ACROSS JEFFERSON INTO SOUTHEAST LIBERTY COUNTY WHILE FEEDER BANDS
FROM SLIGHTLY MORE UNSTABLE AREA ARE BEING DIRECTED IN FROM
HALLETTSVILLE TX. PRECIPITABLE WATER VALUES OF 2-2.5" EXIST IN
THIS AREA. BOTH VAD WIND PROFILES AND STORM MOTIONS INDICATE THAT
INFLOW AT 850 HPA IS 25-30 KTS AROUND THE MCV, NEARLY DOUBLE THE
MEAN 850-400 HPA WIND. THE INFLOW AROUND THE MCV IS IMPORTING MU
CAPE VALUES OF 1000-3000 J/KG AROUND ITS SOUTHERN AND EASTERN
PERIPHERY, WITH SOME SLIGHT UPWARD TRENDS NOTED IN SOUTHWEST LA
OVER THE PAST SEVERAL HOURS.

WHILE THE MESOSCALE GUIDANCE FROM 00Z ZEROED IN ON THIS COMPLEX,
IN GENERAL IT APPEARS TO BE TRACKING THUNDERSTORMS ON ITS EASTWARD
FLANK 2-3 HOURS TOO SLOWLY TO THE EAST. VEERING INFLOW AT 850 HPA
WITHIN RAP MASS FIELDS SUGGESTS THAT THE HEAVY RAIN THREAT SHOULD
MOVE ACROSS THE GOLDEN TRIANGLE OF SOUTHEAST TX INTO IMPERIAL
CALCASIEU OVER THE NEXT SEVERAL HOURS AND SLOWLY OUT OF HOUSTON
TX. THE MODEL SIGNAL REMAINS FOR LOCAL AMOUNTS TO 5" DURING THIS
TIME FRAME, WITH HOURLY RAIN RATES TO 2.5" DUE TO CELL MERGERS AND
TRAINING. THIS RAINFALL WOULD PROLONG FLOODING ISSUES IN THE
HOUSTON TX AREA AND COULD INTRODUCE ISSUES IN AREAS FARTHER EAST
WHICH RECEIVED POCKETS OF 3-5" OF RAIN ON MONDAY.

[djjordan]

Flood Advisory
National Weather Service Houston/Galveston TX
228 AM CDT TUE AUG 8 2017

TXC015-089-157-481-081030-
/O.NEW.KHGX.FA.Y.0210.170808T0728Z-170808T1030Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Colorado TX-Wharton TX-Austin TX-Fort Bend TX-
228 AM CDT TUE AUG 8 2017

The National Weather Service in League City has issued a

* Flood Advisory for...
East central Colorado County in southeastern Texas...
Northeastern Wharton County in southeastern Texas...
Southeastern Austin County in southeastern Texas...
Northwestern Fort Bend County in southeastern Texas...

* Until 530 AM CDT.

* At 227 AM CDT, Doppler radar indicated heavy rain due to
thunderstorms. This will cause minor flooding in the advisory area.

* Some locations that will experience flooding include...
Sugar Land, Missouri City, Rosenberg, Stafford, Richmond, Wharton,
First Colony, Pecan Grove, Needville, East Bernard, Wallis,
Fulshear, Pleak, Simonton, Fairchilds, Beasley, Kendleton, Orchard,
Thompsons and New Territory.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

[869MB]

Jeff Lindner‏ @JeffLindner1 25m25 minutes ago
More
Watching numerous watersheds in W Harris: Bear, Langham, Horsepen, Mason. Structure flooding likely on S Mayde Creek #houwx #hounews

[djjordan]

Flood Advisory
National Weather Service Houston/Galveston TX
241 AM CDT TUE AUG 8 2017

TXC291-080945-
/O.NEW.KHGX.FA.Y.0211.170808T0741Z-170808T0945Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Liberty TX-
241 AM CDT TUE AUG 8 2017

The National Weather Service in League City has issued a

* Flood Advisory for...
Central Liberty County in southeastern Texas...

* Until 445 AM CDT.

* At 240 AM CDT, Doppler radar indicated heavy rain due to
thunderstorms. This will cause minor flooding in the advisory area.

* Some locations that will experience flooding include...
Ames, Daisetta, Hardin, Devers and Moss Hill.

[djjordan]

FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON, TX
301 AM CDT Tue Aug 8 2017

...The National Weather Service in Houston/Galveston has issued a flood warning
for the following rivers...

Rummel Creek MISSING Brittmoore Road affecting the following counties in
Texas...Harris


For Harris County Bayous at Brittmoore Road, Minor flooding is forecasted.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Persons are urged to stay away from the river until water levels recede.

Motorists should avoid any water covered roads and find an alternate route.

Livestock and equipment should remain out of the flood plain for the next few
days.

[djjordan]

FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON, TX
312 AM CDT Tue Aug 8 2017

...The National Weather Service in Houston/Galveston has issued a flood warning
for the following rivers...

Briar Branch at Campbell Road affecting the following counties in
Texas...Harris


For Buffalo Bayou at Campbell Road, Minor flooding is forecasted.

[djjordan]

FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON, TX
315 AM CDT Tue Aug 8 2017

...The National Weather Service in Houston/Galveston has issued a flood warning
for the following rivers...

Horsepen Creek at Trailside affecting the following counties in
Texas...
Harris


For the Addicks Reservoir at Trailside, Moderate flooding is occuring, with
river levels forecasted to decrease.