Severe Thunderstorm Warning 17, NWS Fort Worth, TX

Area Forecast Discussion
National Weather Service Fort Worth TX
1155 PM CST Sun Jan 15 2017

.AVIATION...
/06Z TAFs/

Metroplex airports--The rain is ending from west to east across
the Metroplex, and should be east of KDAL by 07-08Z. Light and
variable winds will become more westerly overnight. VFR cigs will
become clear in a few hours and there's a decent potential light
fog will develop due to moisture in place and a wet ground from
the rain. Will be keeping a close eye on this potential and for
now will indicate a 2SM from 09-16Z. Otherwise, VFR conditions are
expected but there may be a few low clouds as a front moves
through the region later today. The winds will shift to the
northwest late this afternoon with this front.

Waco airport--Showers and thunderstorms will continue near the
airport through 08-09Z. As the ceilings clear in a few hours,
light fog may develop due to moisture in place and a wet ground from
the rain. Will carry a 2SM from 10-16Z but keep a close eye on
this development during the overnight hours. Otherwise, VFR
conditions are expected. The winds will become westerly overnight
and then become northwesterly late Monday afternoon as a front
moves through the region. There may be a few showers or an
isolated thunderstorm near the front in the afternoon hours but at
this time the best rain potential is southeast of the airport.

JLDunn

&&

.UPDATE...
Main update was to address ongoing convective trends this evening.
In addition, adjusted temperatures downward a little towards the
west and northwest in the wake of the front. Finally...added a
mention of patchy fog across western and northwestern zones.

A large line of showers and thunderstorms continued this evening
across North and Central TX. Overall severe activity has waned a
little bit as the strong upper trough responsible for convection
lifts northward into the TX and OK panhandles. Showers and storms
should still march eastward as there remains some instability
where the intrusion of warm air lifted northward earlier today.
Adjusted PoPs upward near and just east of the line as there still
remains some around 250-500 J/kg of CAPE. A moist lower
troposphere will also still support a moderate to brief heavy rain
threat with echoes and additional flash flooding may be possible,
especially for slow moving/training echoes. Temperatures in the
wake of the front have fallen into the 40s. With the low level
moisture not being completely scoured out, we will have to
maintain a watch for some patchy fog, especially for areas that
experienced rain earlier today. For now, I'll carry a mention of
patchy fog along and northwest of a Comanche to Fort Worth to
Sherman/Denison line. I wouldn't be surprised if some of the fog
became dense in spots, but I'll defer to the midnight shift to
make the call on this.

24-Bain

&&

.PREV DISCUSSION... /ISSUED 321 PM CST Sun Jan 15 2017/

Water vapor imagery shows the powerful upper low across far West
Texas this afternoon. This feature is spreading strong forcing for
ascent across most of Texas at this time and regional radar shows
an expansive area of showers and thunderstorms from the Panhandle
south into the Big Bend. Farther east...strong low level warm
advection has aided in the development of showers and a few
thunderstorms across parts of the Hill country northward into
Oklahoma.

At the surface...a warm front is slowly retreating northward but
will begin to accelerate as the upper low gets closer later this
evening. The boundary is currently located from south of
Sweetwater to near Waco then extends northeast to near Sulphur
Springs. South of the boundary...temperatures have warmed into the
low/mid 60s and visibilities have improved...while north of the
boundary temperatures are generally in the 50s with areas of dense
fog persisting. Visibilities will improve across the remainder of
the area this evening as the warm front continues north.

Through the remainder of the afternoon into the early evening we
will continue to watch the northward advancement of the front and
the expanding warm sector. Dewpoints have climbed into the
mid/upper 60s across our southeastern counties which is several
degrees higher than some of the guidance was indicating resulting
in a little more surface based instability. As we go through the
next 2-4 hours...low level wind fields will continue to strengthen
with the approach of the upper low. This should result in an
uptick in convective activity ahead of the main line from the Hill
Country northward into North Texas. We're already seeing some
indication of this on radar and the trend is expected to continue.
A few of the cells in the warm sector have shows some signs of
rotation and this will be the primary concern in the short term.
Any robust updrafts that can develop in the warm air will have the
potential to rotate and could produce a brief fast moving tornado.
This threat will be highest south of I-20 through early evening.

Later tonight...as stronger forcing spreads eastward...the line of
thunderstorms across West Texas will enter our area. Given the
strength of the wind fields associated with the upper
trough...there will be a threat for damaging winds with any bowing
segments. A surface low is expected to track across our northwest
counties closer to midnight on the northern end of the more
intense convection. This will effectively keep the low level flow
backed to the east of the main line. This will continue to result
in a favorable shear profile for embedded tornadoes within the
line. Any discrete activity ahead of the line will also have the
potential to rotate. North of the warm front...elevated convection
will be possible with lightning and small hail being the main
threats.  The main limiting factor to a more widespread severe
weather threat and tornado threat will be the limited surface
based instability. So while the potential is there...the overall
threat is lower than if we had more available instability. We will
continue to monitor for any mesoscale changes through the
evening.

Other than the severe threat...there will also be a threat for
locally heavy rainfall with storms moving quickly to the north and
the overall line moving east through the night. Widespread
rainfall amounts of 1 to 2 inches can be expected although there
could be some localized amounts in excess of 2 inches in a short
period of time.

The main line of storms should be entering our western areas
between 7-9 pm this evening and along the I-35 corridor by around
midnight. With the main upper trough pulling off to the
northeast...this will tend to take the best forcing with it. The
line may weaken some as it pushes east of the I-35 corridor with
the best rain chances across our eastern counties after midnight.

The line of convection will be east of the area Monday morning
with a Pacific front moving through and westerly winds in place
through much of the day. By evening...a shot of cooler continental
air will move into the region. This front will also stall out to
the south of the area with warm moist air streaming north over the
cooler surface air. This will result in continued cloudy
conditions and several chances for additional rainfall through mid
week...mainly south of Interstate 20. There is still some
disagreement among the models with the handling of a slow moving
upper trough during the mid/late week timeframe. This results in
low confidence with respect to PoPs both Wednesday and Thursday.

Another strong storm system may swing through the Southern Plains
next weekend but moisture appears to be much more limited with
this system.  We'll continue to monitor this potential.

Dunn

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    52  68  43  59  45 / 100  10   0   5  20
Waco                54  72  46  57  46 / 100  20  10  30  40
Paris               56  67  44  57  43 / 100  50  10   5  20
Denton              45  65  39  56  41 / 100  10   0   5  20
McKinney            51  66  41  57  42 / 100  20   0   5  20
Dallas              53  69  44  59  46 / 100  20   0   5  20
Terrell             56  68  45  59  45 / 100  40  10  10  20
Corsicana           57  70  48  61  47 / 100  40  10  20  40
Temple              52  71  47  56  46 / 100  20  20  50  50
Mineral Wells       41  66  38  56  41 / 100   5   0  10  20

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&

82

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1104 PM CST SUN JAN 15 2017

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-161200-
MONTAGUE-COOKE-GRAYSON-FANNIN-LAMAR-YOUNG-JACK-WISE-DENTON-COLLIN-
HUNT-DELTA-HOPKINS-STEPHENS-PALO PINTO-PARKER-TARRANT-DALLAS-
ROCKWALL-KAUFMAN-VAN ZANDT-RAINS-EASTLAND-ERATH-HOOD-SOMERVELL-
JOHNSON-ELLIS-HENDERSON-COMANCHE-MILLS-HAMILTON-BOSQUE-HILL-NAVARRO-
FREESTONE-ANDERSON-LAMPASAS-CORYELL-BELL-MCLENNAN-FALLS-LIMESTONE-
LEON-MILAM-ROBERTSON-
1104 PM CST SUN JAN 15 2017

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL TEXAS.

.DAY ONE...TONIGHT.
THUNDERSTORMS WILL CONTINUE THROUGH THE OVERNIGHT HOURS MAINLY ALONG
AND EAST OF A SHERMAN TO GRANBURY TO LAMPASAS LINE. A FEW STORMS
MAY APPROACH SEVERE LIMITS WITH THE MAIN THREATS BEING STRONG
STRAIGHT LINE WINDS...AND SMALL HAIL. THERE WILL BE A RISK FOR A
BRIEF TORNADO OR TWO...BUT OVERALL THIS THREAT CONTINUES TO DECREASE.
IN ADDITION...HEAVY RAIN MAY RESULT IN ISOLATED INSTANCES OF
FLOODING...ESPECIALLY ACROSS POOR DRAINAGE AREAS.

OTHERWISE PATCHY FOG WILL BE POSSIBLE FOR AREAS ALONG AND NORTHWEST
OF A COMANCHE TO FORT WORTH TO SHERMAN LINE. VISIBILITY MAY FALL INTO
THE 1 TO 2 MILE RANGE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.
ON MONDAY...THE BULK OF THE THUNDERSTORM ACTIVITY WILL BE EAST OF
THE I-35 CORRIDOR. A FEW STRONG TO NEAR SEVERE THUNDERSTORMS WILL BE
POSSIBLE WITH A THREAT FOR STRONG WINDS AND HAIL.

THUNDERSTORM CHANCES WILL CONTINUE TUESDAY THROUGH THURSDAY...MAINLY
ACROSS CENTRAL AND EAST TEXAS. AFTER A BREAK ON FRIDAY...
THUNDERSTORMS RETURN TO THE FORECAST ON SATURDAY.

.SPOTTER INFORMATION STATEMENT...
LIMITED SPOTTER ACTIVATION MAY BE REQUESTED OVERNIGHT MAINLY FOR
AREAS SOUTH OF THE INTERSTATE 20 CORRIDOR.

24-BAIN

Special Weather Statement
National Weather Service Fort Worth TX
1133 PM CST SUN JAN 15 2017

TXZ159-160615-
McLennan TX-
1133 PM CST SUN JAN 15 2017

...SIGNIFICANT WEATHER ADVISORY FOR MCLENNAN COUNTY UNTIL 1215 AM
CST...

At 1132 PM CST, Doppler radar was tracking a strong thunderstorm near
McGregor, moving northeast at 35 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Waco, Hewitt, Robinson, Bellmead, Woodway, Lacy-Lakeview, McGregor,
West, Mart, Beverly Hills, Lorena, Bruceville-Eddy, Moody, Riesel,
Crawford, Golinda, Hallsburg, Northcrest, Gholson and Leroy.

LAT...LON 3132 9742 3159 9760 3186 9704 3152 9680
      3124 9734
TIME...MOT...LOC 0532Z 225DEG 31KT 3143 9746

30

Special Weather Statement
National Weather Service Fort Worth TX
1154 PM CST SUN JAN 15 2017

TXZ122-135-146>148-160700-
Van Zandt TX-Anderson TX-Freestone TX-Henderson TX-Navarro TX-
1154 PM CST SUN JAN 15 2017

...SIGNIFICANT WEATHER ADVISORY FOR FREESTONE...VAN ZANDT...
HENDERSON...ANDERSON AND SOUTHEASTERN NAVARRO COUNTIES UNTIL 100 AM
CST...

At 1153 PM CST, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles north of Golden to near Teague.
Movement was northeast at 45 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Palestine, Athens, Gun Barrel City, Canton, Teague, Fairfield, Grand
Saline, Chandler, Van, Malakoff, Edgewood, Elkhart, Frankston,
Wortham, Brownsboro, Eustace, Berryville, Trinidad, Fruitvale and
Edom.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with these storms.
Seek a safe shelter inside a building or vehicle.

&&

LAT...LON 3151 9573 3153 9576 3156 9571 3165 9574
      3160 9576 3162 9579 3141 9623 3180 9650
      3190 9629 3279 9587 3277 9577 3269 9560
      3248 9560 3235 9545 3223 9549 3208 9542
      3185 9545 3168 9528 3161 9526
TIME...MOT...LOC 0553Z 241DEG 48KT 3283 9557 3171 9631

30

Special Weather Statement
National Weather Service Fort Worth TX
1257 AM CST MON JAN 16 2017

TXZ122-135-160745-
Van Zandt TX-Henderson TX-
1257 AM CST MON JAN 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN VAN ZANDT AND
HENDERSON COUNTIES UNTIL 145 AM CST...

At 1256 AM CST, Doppler radar was tracking strong thunderstorms along
a line extending from near Edom to 11 miles south of Athens. Movement
was northeast at 25 mph.

Wind gusts up to 50 mph will be possible with these storms.

Locations impacted include...
Athens, Chandler, Brownsboro, Berryville, Edom, Coffee City,
Murchison, Poynor and Moore Station.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY rainfall is also occurring with these storms, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3201 9601 3235 9590 3250 9560 3248 9560
      3235 9545 3233 9546 3228 9545 3223 9549
      3218 9546 3215 9548 3209 9543
TIME...MOT...LOC 0656Z 236DEG 23KT 3235 9570 3204 9587

JLDUNN

Special Weather Statement
National Weather Service Fort Worth TX
119 AM CST MON JAN 16 2017

TXZ174-175-160745-
Robertson TX-Milam TX-
119 AM CST MON JAN 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR MILAM COUNTY UNTIL 145 AM CST...

At 118 AM CST, Doppler radar was tracking strong thunderstorms along
a line extending from near Cameron to 6 miles west of Tanglewood.
Movement was northeast at 55 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Rockdale, Cameron and Milano.

LAT...LON 3088 9711 3111 9681 3074 9661 3047 9714
TIME...MOT...LOC 0718Z 221DEG 47KT 3085 9706 3050 9710

jldUNN

Special Weather Statement
National Weather Service Fort Worth TX
210 AM CST MON JAN 16 2017

TXZ175-160845-
Robertson TX-
210 AM CST MON JAN 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN ROBERTSON COUNTY UNTIL
245 AM CST...

At 210 AM CST, Doppler radar was tracking a strong thunderstorm near
Bremond, or 17 miles north of Hearne, moving northeast at 45 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Bremond.

LAT...LON 3114 9674 3134 9635 3135 9632 3130 9632
      3130 9633 3129 9633 3127 9631 3125 9633
      3123 9631 3122 9632 3117 9630 3114 9630
      3104 9664
TIME...MOT...LOC 0810Z 229DEG 38KT 3112 9661

JLDunn

Special Weather Statement
National Weather Service Fort Worth TX
243 AM CST MON JAN 16 2017

TXZ146-147-161-160915-
Limestone TX-Freestone TX-Navarro TX-
243 AM CST MON JAN 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN FREESTONE...NORTH
CENTRAL LIMESTONE AND SOUTHEASTERN NAVARRO COUNTIES UNTIL 315 AM
CST...

At 243 AM CST, Doppler radar was tracking a strong thunderstorm over
Mexia, moving northeast at 40 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Mexia, Fairfield, Wortham, Angus, Navarro, Mildred, Eureka,
Tehuacana, Richland, Streetman and Kirvin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rainfall is also occurring with this storm, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3174 9611 3162 9657 3182 9665 3206 9633
TIME...MOT...LOC 0843Z 241DEG 34KT 3171 9651

JLDunn