Severe Thunderstorm Warning 308, NWS Fort Worth, TX

023 
WWUS54 KFWD 200329
SVSFWD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
929 PM CST WED DEC 19 2012

TXC113-200339-
/O.EXP.KFWD.SV.W.0308.000000T0000Z-121220T0330Z/
DALLAS TX-
929 PM CST WED DEC 19 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN DALLAS COUNTY EXPIRES
AT 930 PM CST...

AT 929 PM CST THE SEVERE THUNDERSTORM THAT PROMPTED THE WARNING MOVED
OUT OF THE AREA AND THE WARNING EXPIRED.

RADAR INDICATED THAT HEAVY RAIN...SMALL HAIL...AND GUSTY WINDS WERE
STILL POSSIBLE FROM THE THUNDERSTORM.

LAT...LON 3298 9664 3298 9652 3282 9652 3274 9703
      3287 9697 3299 9685 3299 9684 3299 9683
      3299 9665
TIME...MOT...LOC 0329Z 258DEG 45KT 3289 9648

$$


CAVANAUGH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
647 PM CST WED DEC 19 2012

.UPDATE...
HAVE UPDATED THE FORECAST TO INCLUDE HIGHER POPS ACROSS ROUGHLY
THE EASTERN HALF OF THE AREA. 0Z SOUNDING AND MORE RECENT ACARS
DATA SHOWS VERY IMPRESSIVE DYNAMIC LIFT IS OCCURRING OVER THE AREA
RIGHT NOW. THE CAP HAS BEEN ESSENTIALLY ERODED AND PARCELS JUST
ABOVE THE SURFACE ARE CONDITIONALLY UNSTABLE. MOISTURE REMAINS A
LIMITING FACTOR...BUT GIVEN THE DYNAMIC SUPPORT FOR LIFT AND THE
STRONG CONVERGENCE ALONG THE FRONTAL BOUNDARY...WE SHOULD SEE
CONVECTION FIRE ALONG THE FRONT AS IT REACHES A GAINESVILLE TO DFW
TO LAMPASAS LINE. CONVECTION WILL LIKELY FILL INTO A BROKEN OR
SOLID LINE ALONG THE FRONT AS IT MOVES THROUGH THE EASTERN ZONES
WHERE WE HAVE BUMPED UP POPS TO 40 PERCENT. SEVERE THREAT IS A BIT
AMBIGUOUS GIVEN LIMITED INSTABILITY VALUES...BUT SHEAR WILL BE
STRONG AND STORMS ALONG THE FRONT MAY BRING STRONG WINDS ALOFT
DOWN TO THE SURFACE. TR.92

&&

.AVIATION...
A DRYLINE STRETCHES FROM A DEEP SURFACE LOW OVER NORTHERN OK
SOUTHWARD TO JUST WEST OF NORTH TEXAS. AHEAD OF THE
BOUNDARY...SOUTH WINDS HAVE DECREASED WITH THE SETTING SUN TO
MAINLY IN THE 15-20 KT RANGE. WE SHOULD SEE THE DRYLINE MAKE A
PUSH TO THE EAST THIS EVENING AS A STRONG UPPER LOW MIGRATES EAST
ACROSS THE PLAINS. WILL CONTINUE WITH THE WIND SHIFT TO THE WEST
IN THE METROPLEX AT 04Z AND WACO AT 05Z...WITH SUSTAINED SPEEDS
INCREASING TO AROUND 20KTS. A STRONG COLD FRONT CURRENTLY DRIVING
SOUTHEAST THROUGH WESTERN OK AND NORTHWEST TX WILL QUICKLY FOLLOW
THE DRYLINE...BRINGING MORE OF A NORTHWESTERLY COMPONENT TO THE
SURFACE WINDS AND EVEN HIGHER SPEEDS. WILL INDICATE FROPA AT 06Z
AND KEEP AN EYE ON THE BOUNDARY AS IT APPROACHES THIS EVENING.
THERE COULD BE A FEW ISOLATED SHOWERS WITH THE FRONT BUT AT THIS
TIME IT APPEARS THAT THE BEST POTENTIAL FOR PRECIP WILL BE WELL
EAST OF THE TAF SITES.

FOR DFW...CROSS WIND ISSUES WILL BE PREVALENT THROUGH MOST OF THE
NIGHT. WINDS WILL REMAIN GUSTY DURING THE DAY THURSDAY BUT SHOULD
BE AROUND 10KT LESS THAN THE UPCOMING OVERNIGHT PERIOD. WINDS WILL
SUBSIDE THURSDAY EVENING AS HIGH PRESSURE BUILDS IN FROM THE WEST.

30

&&

.PREV UPDATE...
.UPDATE...
HAVE EXPIRED THE WIND ADVISORY THAT WAS IN EFFECT OVER THE SOUTH
CENTRAL ZONES. ANOTHER WIND ADVISORY REMAINS IN EFFECT FOR ALL OF
NORTH TEXAS FOR THE STRONG NORTHWEST WINDS BEHIND THE FRONT
TONIGHT. THESE WINDS TONIGHT WILL BE STRONGER THAN TODAY...WITH
GUSTS OVER THE NORTHWEST ZONES LIKELY PUSHING 45-50 MPH...TAPERING
DOWN TO 35-40 MPH GUSTS OVER THE SOUTHEAST ZONES. OTHERWISE HAVE
PULLED THE RED FLAG WARNING EARLY AS WINDS HAVE DIMINISHED WITH
THE LOSS OF HEATING.

NO OTHER SIGNIFICANT CHANGES TO THE FORECAST...BUT MADE SOME
UPDATES TO THE HOURLY GRIDS TO SHOW THE SHARP CHANGES WITH THE
DRY LINE AND COLD FRONT LATER TONIGHT.

OF NOTE IS THE HRRR DEVELOPING RAIN ALONG THE FRONT FARTHER TO THE
WEST...POSSIBLE AFFECTING THE I-35 CORRIDOR THIS EVENING. MAY HAVE
TO PULL THE POPS BACK TO THE WEST...BUT WILL AWAIT THE FULL 0Z
FWD SOUNDING AND LOOK OVER A FEW MORE THINGS BEFORE TOUCHING THE
POP FORECAST. A PRELIM LOOK AT THE 0Z SOUNDING DOES SHOW THE CAP
HAS BEEN LIFTED AND REMOVED FROM THE AREA.

TR.92

&&

.SHORT TERM...
DESPITE PERSISTENT CLOUD COVER AND THE WEAK DECEMBER SUN...THE
DROUGHT-PARCHED GROUND ALLOWED TEMPS TO SOAR TO RECORD HIGHS AT
BOTH DFW AND WACO. THIS OCCURRED WITH DUE SOUTH WINDS AND
AFTERNOON DEW POINTS NEAR 60F. (DFW SET ITS RECORD BEFORE NOON.)

DESPITE CONSIDERABLE LIFT WITH THIS POTENT STORM SYSTEM...MOISTURE
REMAINS VERY SHALLOW. THERE WILL BE A BRIEF WINDOW FOR CONVECTION
IN FAR EASTERN ZONES...WITH THE FLOW QUICKLY VEERING THIS EVENING.

DRIER AIR HAS MIXED TO THE SURFACE IN FAR WESTERN ZONES...BUT THE
DRYLINE REMAINS TO THE WEST. AT 3 PM...ABILENE (KABI) HAD A DEW
POINT OF 47 WHILE 50 MILES TO THE WEST IN SWEETWATER (KSWW) THE
DEW POINT WAS 19. BLOWING DUST CONTINUES ACROSS THE HIGH PLAINS OF
WEST TEXAS...WHERE WINDS HAVE GUSTED TO 60 MPH. A COLD FRONT HAS
NOW ENTERED THE PANHANDLE AND WILL CONTINUE DRIVING SOUTH. THE
DRYLINE WILL REACH THE I-35 THIS EVENING...WITH THE FRONT QUICKLY
OVERTAKING IT. THE ENTIRE CWA WILL BE UNDER A WIND ADVISORY BY THE
06-12Z (MIDNIGHT-6 AM CST) TIME FRAME. SUSTAINED WIND SPEEDS WILL
OCCASIONALLY TOP 30 MPH...WITH PEAK GUSTS IN EXCESS OF 40 MPH.

LIGHT WINDS THURSDAY NIGHT WILL ALLOW TEMPERATURES TO PLUMMET
AREAWIDE. A HARD FREEZE WILL OCCUR FRIDAY MORNING...WITH LOWS
DIPPING INTO THE TEENS IN LOW-LYING AND OTHER OUTLYING AREAS.

25

&&

.LONG TERM...
GUIDANCE CONTINUES TO SUGGEST A WEAK SHORTWAVE WILL SWING THROUGH
THE SOUTHERN PLAINS CHRISTMAS EVE...WELL IN ADVANCE OF THE STORM
SYSTEM STILL IN THE NORTH PACIFIC. THIS WILL FORCE A WEAK FRONTAL
BOUNDARY INTO NORTH TEXAS...BUT THE ARCTIC PUSH WILL NOT OCCUR
UNTIL TUESDAY NIGHT. THE POTENTIAL REMAINS FOR LINGERING
PRECIPITATION WELL BEHIND THE ARCTIC INTRUSION...SUPPORTED BY BOTH
THE ECMWF AND CANADIAN. THE OPERATIONAL GFS IS CURRENTLY LESS
FAVORABLE...BUT ENSEMBLE MEMBER SPREAD REMAINS TOO LARGE TO HAVE
CONFIDENCE IN ONE SINGLE SOLUTION. THE AFTERNOON PACKAGE ENDS
PRECIPITATION DURING CHRISTMAS DAY WELL BEFORE TEMPERATURES ARE
COLD ENOUGH TO SUPPORT SNOW.

25

&&

FIRE WEATHER DANGER IS EXPECTED TO BE VERY HIGH ACROSS ALL OF
NORTH AND CENTRAL TEXAS THURSDAY...WITH SLIGHTLY LOWER FIRE
WEATHER DANGER ON FRIDAY.

ON THURSDAY...WINDS ARE EXPECTED TO REMAIN OUT OF THE NORTHWEST AT
20 TO 25 MPH WITH GUSTS TO 35 MPH. AFTERNOON RELATIVE HUMIDITY
VALUES WILL FALL BELOW 25 PERCENT FOR ALL OF NORTH TEXAS...WITH
AFTERNOON RH VALUES FALLING TO 15 PERCENT WEST OF INTERSTATE 35.
THE COMBINATION OF WINDS AND LOW RH MAKES IT NEARLY CERTAIN TO
VERIFY RED FLAG WARNING CONDITIONS ACROSS ALL OF NORTH TX
TOMORROW. WE DID NOT ISSUE A FIRE WEATHER WATCH TODAY THOUGH
BECAUSE HIGH TEMPERATURES ON THURSDAY ARE ONLY EXPECTED TO TOP OUT
IN THE MID 50S. THESE COOL TEMPERATURES WILL HELP KEEP FUEL
TEMPERATURES DOWN WHICH DOES NOT SUPPORT ERRATIC OR CRITICAL FIRE
BEHAVIOR BECAUSE LOW FUEL TEMPERATURES WILL MAKE IT HARDER TO
START AND SPREAD GRASS FIRES. REGARDLESS...FIRE WEATHER DANGER
WILL REMAIN VERY HIGH...AND OUTDOOR BURNING IS NOT RECOMMENDED.

CAVANAUGH

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  35  53  27  59  34 /  10   0   0   0   0
WACO, TX              37  57  23  61  32 /  20   0   0   0   5
PARIS, TX             37  51  26  57  30 /  30   0   0   0   5
DENTON, TX            32  51  21  60  31 /  10   0   0   0   0
MCKINNEY, TX          35  52  22  58  30 /  20   0   0   0   0
DALLAS, TX            36  52  28  59  36 /  20   0   0   0   0
TERRELL, TX           38  51  28  57  32 /  30   0   0   0   0
CORSICANA, TX         40  53  25  59  33 /  30   0   0   0   0
TEMPLE, TX            38  56  25  60  32 /  20   0   0   0   5
MINERAL WELLS, TX     31  54  24  62  28 /   5   0   0   0   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM CST THURSDAY FOR TXZ091>093-100>104-
115>120-129>133-141.

WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST THURSDAY FOR
TXZ094-095-105>107-121>123-134-135-142>148-156>162-174-175.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FORT WORTH TX
657 PM CST WED DEC 19 2012

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-210100-
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-
657 PM CST WED DEC 19 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...TONIGHT.
THUNDERSTORMS ARE POSSIBLE TONIGHT EAST OF A LINE FROM GAINESVILLE TO
DALLAS TO LAMPASAS. A FEW STORMS COULD BECOME STRONG TO SEVERE...
WITH DAMAGING WINDS BEING THE MAIN THREAT.

THIS EVENING A STRONG COLD FRONT WILL MOVE SOUTHEAST THROUGH
NORTH TEXAS. WINDS BEHIND THIS FRONT WILL SHIFT TO THE NORTHWEST
AND INCREASE IN SPEED TO 30 MPH WITH GUSTS TO 40 TO 45 MPH THROUGH
THE OVERNIGHT HOURS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.
FIRE WEATHER DANGER IS EXPECTED TO BE HIGH FOR MUCH OF THE AREA
THURSDAY AND FRIDAY.

ISOLATED THUNDERSTORMS ARE POSSIBLE ON MONDAY FOR LOCATIONS ALONG
AND SOUTHEAST OF A BONHAM TO TERRELL TO GOLDTHWAITE LINE.

.SPOTTER INFORMATION STATEMENT...
LIMITED SPOTTER ACTIVATION MAY BE REQUESTED TONIGHT MAINLY EAST OF
THE I 35/35 EAST CORRIDOR.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
714 PM CST WED DEC 19 2012

TXZ092-093-200145-
GRAYSON TX-COOKE TX-
714 PM CST WED DEC 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR...
  EASTERN COOKE COUNTY
  GRAYSON COUNTY

AT 714 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 8 MILES SOUTHEAST OF GAINESVILLE...MOVING
NORTHEAST AT 45 MPH.

CITIES IN THE PATH OF THIS STORM INCLUDE BELLS...CALLISBURG...
COLLINSVILLE...DENISON...DORCHESTER...GAINESVILLE...GUNTER...HOWE...
KNOLLWOOD...LINDSAY...POTTSBORO...SHERMAN...TOM BEAN...VAN ALSTYNE...
WHITESBORO...WHITEWRIGHT...WILLIS AND EISENHOWER STATE PARK.

PENNY-SIZED HAIL AND WIND GUSTS TO 50 MPH CAN BE EXPECTED FROM THIS
STORM.

LAT...LON 3386 9686 3384 9670 3391 9665 3389 9659
      3384 9662 3373 9638 3340 9639 3342 9694
      3351 9695 3344 9705 3343 9733 3392 9723
      3390 9717 3380 9720 3372 9714 3382 9706
      3385 9710 3385 9703 3394 9700 3396 9692
TIME...MOT...LOC 0114Z 228DEG 39KT 3358 9702

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
756 PM CST WED DEC 19 2012

TXZ093-200230-
GRAYSON TX-
756 PM CST WED DEC 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR...
  GRAYSON COUNTY

AT 756 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 9 MILES EAST OF WHITESBORO...MOVING NORTHEAST AT
50 MPH.

CITIES IN THE PATH OF THIS STORM INCLUDE BELLS...COLLINSVILLE...
DENISON...DORCHESTER...GUNTER...HOWE...KNOLLWOOD...POTTSBORO...
SHERMAN...TOM BEAN...VAN ALSTYNE...WHITESBORO...WHITEWRIGHT...WILLIS
AND EISENHOWER STATE PARK.

PENNY-SIZED HAIL AND WIND GUSTS TO 50 MPH CAN BE EXPECTED FROM THIS
STORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CST THURSDAY MORNING
FOR NORTHEASTERN TEXAS.

LAT...LON 3395 9690 3387 9689 3385 9686 3388 9683
      3387 9679 3383 9676 3383 9671 3391 9665
      3389 9658 3384 9662 3382 9652 3378 9650
      3378 9641 3373 9638 3340 9639 3342 9694
      3395 9694
TIME...MOT...LOC 0156Z 229DEG 50KT 3370 9670

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
812 PM CST WED DEC 19 2012

TXZ118-131>133-200245-
HOOD TX-JOHNSON TX-SOMERVELL TX-TARRANT TX-
812 PM CST WED DEC 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR...
  EASTERN HOOD COUNTY
  JOHNSON COUNTY
  SOMERVELL COUNTY
  SOUTHERN TARRANT COUNTY

AT 813 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 16 MILES SOUTH OF GRANBURY...MOVING NORTHEAST AT
55 MPH.

CITIES IN THE PATH OF THIS STORM INCLUDE ALVARADO...BURLESON...
CLEBURNE...CROWLEY...EVERMAN...GLEN ROSE...GODLEY...GRANBURY...
GRANDVIEW...JOSHUA...KEENE...KENNEDALE...OAK TRAIL SHORES...RENDON...
CLEBURNE STATE PARK AND DINOSAUR VALLEY STATE PARK.

PEA-SIZED HAIL AND WIND GUSTS TO 50 MPH CAN BE EXPECTED FROM THIS
STORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CST THURSDAY MORNING
FOR NORTHEASTERN TEXAS.

LAT...LON 3254 9783 3256 9776 3255 9756 3263 9754
      3267 9713 3228 9709 3216 9756 3220 9759
      3221 9763 3209 9787 3223 9794
TIME...MOT...LOC 0213Z 243DEG 49KT 3221 9775

CAVANAUGH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
833 PM CST WED DEC 19 2012

TXZ103-104-200300-
DENTON TX-COLLIN TX-
833 PM CST WED DEC 19 2012

...SIGNIFICANT WEATHER ADVISORY FOR...
  WESTERN COLLIN COUNTY
  SOUTHEASTERN DENTON COUNTY

AT 833 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 4 MILES SOUTHWEST OF LEWISVILLE...MOVING
NORTHEAST AT 45 MPH.

CITIES IN THE PATH OF THIS STORM INCLUDE ALLEN...FAIRVIEW...FRISCO...
HACKBERRY...HEBRON...LEWISVILLE...LITTLE ELM...LOWRY CROSSING...
LUCAS...MCKINNEY...MURPHY...PARKER...PLANO...PROSPER...THE COLONY...
WYLIE AND LAKE LEWISVILLE.

PEA-SIZED HAIL AND WIND GUSTS TO 50 MPH CAN BE EXPECTED FROM THIS
STORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CST THURSDAY MORNING
FOR NORTHEASTERN TEXAS.

LAT...LON 3331 9654 3298 9648 3298 9709 3331 9684
TIME...MOT...LOC 0233Z 247DEG 40KT 3302 9699

CAVANAUGH