Texas Summer 2017

[Ralph's Weather]

Tornado warning for Van Zandt County for circulation moving east just south of I-20.

[bubba hotep]

MESOSCALE PRECIPITATION DISCUSSION 0675
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
856 PM EDT SAT AUG 12 2017

AREAS AFFECTED...SOUTHEAST OK...SOUTHWEST AR...NORTHEAST TX...EXT
NORTHWEST LA

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

VALID 130100Z - 130600Z

SUMMARY...UPSCALE GROWTH OF MCS STARTING TO EVOLVE WITH
STRENGTHENING LOW LEVEL JET THROUGH EARLY OVERNIGHT CROSSING
SATURATED SOILS CONTINUING TO POSE LIKELY FLASH FLOODING.

DISCUSSION...EXPERIMENTAL GOES-16 WV SUITE DEPICTS THE COMPACT
SHORTWAVE ACROSS W OK HAS SHEARED A BIT ACROSS THE STATE EXTENDING
FROM NE OK THROUGH TO NORTHWEST TX/ROLLING PLAINS WITH CONTINUED
RIGHT ENTRANCE SUPPORT OF 3H JET ACROSS SE KS/SW MO. LOW LEVEL
SUPPORT HAS BEEN LACKING OVER THE EVENING HOURS WITH LIMITED FLOW
LEADING TO SCATTERED DISORGANIZED CLUSTERS OF THUNDERSTORMS IN THE
VICINITY OF THE SURFACE FRONT. THIS FRONT ENHANCED BY
DIFFERENTIAL HEATING EXTENDS FROM AQV TO CRS TO GDJ AND N OF SJT
WITH WEAK SFC REFLECTIONS ALONG IT. CELLS NORTH OF THE BOUNDARY
ARE TREATED TO A DEEPER MIXED MOISTURE SOURCE WITH TPWS NEAR OR
ABOVE 2.25" THOUGH GENTLER LAPSE RATES FURTHER NORTH AND LACK OF
HEATING OF THE LOW LEVELS SUPPORT VERY LIMITED MUCAPES (00Z OUN
RAOB)...WITH ONE EXCEPTION ACROSS ARKLATEX AND SE OK...ALSO
RESPONDING WITH AN INVERTED SURFACE TROF FROM CRS TO DEQ. AS SUCH
THE ENVIRONMENT ALONG/SOUTH OF THE RED RIVER AS WELL AS THE
OUACHITA MTN REGION APPEAR PRIMED FOR CONVECTIVE EXPANSION.

RAPID REFRESH GUIDANCE SUCH AS THE HRRR/ESRL HRRRV3 AND RAP
SUPPORT STRENGTHENING SWLY LLJ FROM 03-05Z INCREASING ISENTROPIC
ASCENT AND WITH SELY FLOW CONVERGING THROUGH THE TROWAL/INVERTED
SFC TROF...MST CONVERGENCE AND SLOW CELL MOTIONS/UPSTREAM
PROPAGATION VECTORS WILL ONLY FURTHER EXACERBATE CONVECTION
CAPABLE OF 2-2.5"/HR RATES AND SUPPORT POCKETS OF 3-5" TOTALS
THROUGH 06Z (TO BE FURTHER INCREASED AFTER 06Z). WHILE FFG VALUES
HAVE REBOUNDED THIS SEEMS QUITE INFLATED AS SOILS ARE SATURATED
PER AHPS 7 DAY ANOMALIES OVER 500% OF NORMAL (3-4 INCHES) MAINLY
NORTHEAST OF METRO DFW ACROSS NE TX/SE OK/SW AR. AS SUCH THESE
EXPECTED TOTALS WITH ANTECEDENT CONDITIONS WARRANT LIKELY FLASH
FLOODING PROBABILITIES.

GALLINA

[bubba hotep]

WPC with a southward shift for the MOD. I wonder if FWD will pull the trigger on expanding the Flash Flood Watch?

[bubba hotep]

This cell has a lot to work with, 00z FWD sounding shows 2,500+ CAPE and SPC of 14+

[Ntxw]

That storm is about to cross DFW airport

[Ntxw]

It's holding together pretty well, Northern Dallas county and southern and central Collin county will likely get another round out of this storm also.

[bubba hotep]

Looking at the wide view regional radar and it appears that training cells are setting up along and north of I20. Nothing really to move that boundary and the low level jet is kicking in.

[bubba hotep]

Collin County is lighting up like a Christmas tree

[Ntxw]

Collin County is lighting up like a Christmas tree

Sure is. When you look at surface analysis the boundary is fairly far to the south than some models anticipated and not moving much. So instead of a southern Oklahoma thing we are benefiting. PWATS remain very high >2" and are efficient heavy rain makers as you mentioned earlier. Might be an interesting night with that LLJ and all the activity to our west streaming in.

[Ntxw]

Right where the rain needed to be for the books.

 https://twitter.com/NWSFortWorth/status/896566426206695424




August also averages 1.91". I'll have to look back at some numbers but with this, this summer along with June and July might be a top 10 wettest

[bubba hotep]

Right where the rain needed to be for the books.

 https://twitter.com/NWSFortWorth/status/896566426206695424

Based on radar, it looks like more rain to come for the airport tonight.

[Brent]

So much lightning!

I guess this sort of makes up for last weekend when I wasn't here lol

This is the day last year DFW hit 107 then didn't hit 100 again in August

[Texas Snowman]

Pretty significant wind damage reported by a friend near Sadler.

No big wind or hail at my house here in Denison but more than one inch of rain.

[bubba hotep]

And the 18z GFS drops nearly 10" of rain at DFW over the next two weeks lol

[Yukon Cornelius]

Good bit of on and off rain throughout the day. The last storm that came through dropped just over an inch. Not sure on the total for today though.

[Texas Snowman]

Just CRAZY heavy rain right now in Denison. A Biblical flood kind of rain happening here with lightning and thunder.

The Austin College weather gauge west of Sherman is showing 4.48-inches for the month of August...and it hasn't updated in the past 15 minutes.

[Texas Snowman]

Flood Advisory
National Weather Service Fort Worth TX
244 AM CDT SUN AUG 13 2017

TXC147-181-130945-
/O.NEW.KFWD.FA.Y.0196.170813T0744Z-170813T0945Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grayson TX-Fannin TX-
244 AM CDT SUN AUG 13 2017

The National Weather Service in Fort Worth has issued a

* Flood Advisory for...
Grayson County in north central Texas...
Fannin County in north central Texas...

* Until 445 AM CDT.

* At 242 AM CDT, Doppler radar indicated a band of thunderstorms
that were producing heavy rainfall stretching from Denison to
Whitesboro and moving east and southeast. This band of
thunderstorms will produce heavy rainfall on an area that has
already received one round of heavy rainfall as it moves east
across Grayson and into Fannin County. Excessive runoff from these
thunderstorms will cause urban and small stream flooding. Areas
that are low lying or usually experience poor drainage are most
likely to experience flooding. This means some low water crossings
in the region may become impassable.

* Some locations that will experience flooding include...
Sherman, Denison, Bonham, Whitesboro, Howe, Pottsboro, Honey Grove,
Collinsville, Whitewright, Bells, Tom Bean, Savoy, Ector, Dodd
City, Knollwood, Ravenna, Dorchester, Bonham State Park, Eisenhower
State Park and southeastern Lake Texoma.

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.

&&

LAT...LON 3384 9585 3349 9586 3349 9694 3382 9694
3385 9663 3382 9653 3377 9650 3378 9643
3369 9634 3377 9629 3376 9619 3381 9616
3381 9618 3384 9615 3384 9605 3386 9603
3384 9602 3387 9600 3386 9595 3389 9594

$$

[Texas Snowman]

North Texas Regional Airport (NTRA) west of Denison is showing 0.96 inches in the past hour (most of that has been in the last 20 to 30 minutes) and it is still just pouring like crazy here in Grayson County.

One of the heaviest rainfalls I can ever remember.

Just CRAZY for August.

[Texas Snowman]

NTRA has measurerd 2.33-inches of rainfall in the past hour!



That takes us to over 5 1/2 inches for the month of August.

[Texas Snowman]

Just saw this from last night. This came from the NWS during Round #2 (we're now in Round #3);

"At 931 PM CDT, trained weather spotters reported heavy rain due to thunderstorms. Specifically---one spotter observed just over half an inch of rain in under 10 minutes."

Not sure if I can ever recall a similar 10-hour period of severe storms and torrential rainfall in August.