Hail and Damaging Winds in Texas, February 10, 2013

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1143 PM CST SAT FEB 9 2013

.UPDATE...
QUICK UPDATE TO INCLUDE SEVERE THUNDERSTORM WATCH UNTIL 7AM FOR
ALL BUT THE FAR SOUTHEAST COUNTIES. LINE OF MAINLY ELEVATED
CONVECTION FILLING IN TO THE WEST AND WILL BEGIN ITS MARCH
EASTWARD OVER THE NEXT SEVERAL HOURS. LARGE HAIL AND DAMAGING
WINDS WILL REMAIN THE PRIMARY HAZARDS THROUGH THE OVERNIGHT HOURS.

DUNN

&&

.AVIATION...
CONCERNS...IFR TO LIFR CEILINGS/VISIBILITIES UNTIL TSTORMS ARRIVE.
           LINE OF STRONG TO SEVERE THUNDERSTORMS 10-14Z.
           GUSTY WESTERLY WINDS 16Z SUNDAY THROUGH 00Z MONDAY.

A WARM FRONT EXTENDED NORTH OF LINE FROM KMKN /COMANCHE/ TO KINJ
/HILLSBORO/ TO KDKR /CROCKETT/ AT 05Z. A COLD FRONT EXTENDED FROM
JUST WEST OF K0F2 /VERNON/ TO KSWW SWEETWATER/ LINE. LOW
CLOUDS...WIDESPREAD FOG AND AREAS OF DRIZZLE WILL CONTINUE IN THE
AREA NORTH OF THE WARM FRONT AND EAST OF COLD FRONT. A LINE OF
SHOWERS AND THUNDERSTORMS HAD FORMED JUST EAST OF THE COLD FRONT
AND THESE STORMS WILL MARCH EAST ACROSS THE REGION OVERNIGHT.
CURRENT TIMING BRINGS THE LINE OF STORMS TO THE METROPLEX TAF
SITES AROUND 10Z AND TO WACO AROUND 11Z. WINDS WILL BECOME
SOUTHWESTERLY AT 10 TO 15 KNOTS BEHIND THE LINE OF STORMS...THEN
WESTERLY AT 15-20 KNOTS 16-17Z. GUSTS AROUND 25 KNOTS ARE
EXPECTED IN THE METROPLEX 16Z-00Z. THE GUSTS WILL DIE OFF AS
SUNSET APPROACHES.

58

&&

.PREV UPDATE...
.UPDATE...
LATEST MODEL DATA COMING IN SUGGESTS LITTLE CHANGE IS NEEDED TO
THE CURRENT FORECAST. MADE SOME MINOR TIMING ADJUSTMENTS BASED ON
LATEST HIGH RESOLUTION GUIDANCE AND UPPED POPS TO 100 PERCENT
ACROSS MOST OF THE AREA.

FORECAST SOUNDINGS CONTINUE TO INDICATE STRENGTHENING CAPPING
ACROSS THE AREA...AND THIS IS SUPPORTED BY AIRCRAFT SOUNDING DATA
WHICH NOW SHOWS A STOUT CAP AROUND 750MB ALONG WITH 50KT WINDS
AROUND 900MB. STEEP LAPSE RATES ARE PRESENT ABOVE THE CAP AND THIS
WILL CONTINUE TO SUPPORT A HAIL THREAT ACROSS THE REGION. AS THE
FRONT MOVES EAST...CAPPING WILL ERODE AND A LINE OF THUNDERSTORMS
IS EXPECTED TO INCREASE IN AREAL COVERAGE FROM NORTH TO SOUTH. THE
MAIN THREAT WITH THESE STORMS WILL BE HAIL AND DAMAGING WINDS AS
WIND FIELDS ARE STRONG AND SHEAR IS SUFFICIENT FOR ROTATING
UPDRAFTS. TIMING STILL APPEARS TO BE MIDNIGHT TO 2AM FOR STORMS
ENTERING THE CWA...AROUND 4AM IN THE METROPLEX...5-6AM IN
WACO/TEMPLE/KILLEEN...AND NEAR SUNRISE FOR THE EASTERN COUNTIES.
GRAPHICS ON THE WEB HIGHLIGHT TIMING AND EXPECTED SEVERE THREATS.

DUNN

&&

.PREV DISCUSSION... /ISSUED 327 PM CST SAT FEB 9 2013/
WARM FRONT EXTENDED FROM GRAHAM TO WACO TO NORTH OF LUFKIN. THE
FRONT HAS MADE ONLY SLOW NORTHWARD PROGRESS TODAY...AND
TEMPERATURES HAVE REMAINED IN THE 40S AND LOWER 50S NORTH OF THE
FRONT. STILL EXPECT THE FRONT TO MOVE NORTH TONIGHT AS INCREASING
SOUTH WINDS HELP PUSH THE WARM AND MOIST AIR NORTHWARD. EXPECT
TEMPERATURES TO REMAIN STEADY OR SLOWLY RISE IN MOST AREAS AHEAD
OF THE PACIFIC FRONT MOVING IN FROM THE WEST LATER TONIGHT.

SHOWERS AND A FEW THUNDERSTORMS HAVE DEVELOPED ACROSS PARTS OF
NORTH TEXAS THIS AFTERNOON IN THE WARM ADVECTION REGIME...AND
EXPECT THAT TREND TO CONTINUE THIS EVENING.

SURFACE ANALYSIS AT MID AFTERNOON SHOWED A DEEPENING SURFACE LOW
IN SOUTHEAST COLORADO WITH A STRENGTHENING PACIFIC COLD FRONT
EXTENDING SOUTH ACROSS EXTREME EASTERN NEW MEXICO. THIS FRONT WILL
ACCELERATE AFTER DARK AS STRONG WESTERLY WINDS IN THE LOW AND MID
LEVELS HELP ACCELERATE THE COOLER AND DRIER AIR MASS TO THE EAST.
THE OBSERVED WIND GUST TO 72 KNOTS AT KGDP /GUADALUPE MOUNTAINS
NATIONAL PARK/ IS INDICATIVE OF THE STRENGTH OF THE WIND FIELDS
ASOCIATED WITH THE APPROACHING SYSTEM. THE FRONT SHOULD APPROACH
THE WESTERN SECTIONS OF NORTH TEXAS AROUND MIDNIGHT...THE DFW AND
WACO AREAS BY 3-4 AM...AND THE PALESTINE AREA BY 9 AM.

STILL EXPECT WIDESPREAD THUNDERSTORMS TO DEVELOP ALONG THE
ADVANCING PACIFIC FRONT...AND WILL MAINTAIN CATEGORICAL POPS IN
MANY AREAS TONIGHT. INSTABILITY VALUES /MUCAPE/ OF UP TO 1200 J/KG
SUGGEST A THREAT FOR DAMAGING WINDS AND LARGE HAIL WITH SOME OF
THE STORMS TONIGHT. AFTER THE FRONTAL PASSAGE...STORMS WILL END
QUICKLY AS DRIER AIR SPREADS INTO THE REGION.

DRY WEATHER FORECAST FOR SUNDAY AFTERNOON AND SUNDAY NIGHT AS
SYSTEM LIFTS INTO THE GREAT LAKES AND SHORTWAVE RIDGING DEVELOPS.
MODELS ARE IN VERY GOOD AGREEMENT ON THE NEXT SYSTEM AS IT DEVELOPS
INTO ARIZONA AND NEW MEXICO ON MONDAY...THEN MOVES ACROSS TEXAS
AND OKLAHOMA ON TUESDAY. RAIN CHANCES RETURN TO SOUTHERN AREAS ON
MONDAY AS WIDELY SCATTERED SHOWERS DEVELOP IN THE WARM ADVECTION
ZONE. SCATTERED SHOWERS AND THUNDERSTORMS SHOULD SPREAD ACROSS ALL
OF THE AREA MONDAY NIGHT INTO TUESDAY AS LARGE SCALE LIFT
APPROACHES. INSTABILITY APPEARS INSUFFICIENT FOR A SIGNIFICANT
SEVERE WEATHER THREAT ON TUESDAY.

DRY WEATHER FORECAST FOR WEDNESDAY THROUGH SATURDAY AS A BROAD
UPPER RIDGE DEVELOPS OVER THE WESTERN CONUS...WITH NORTHWEST FLOW
ALOFT ACROSS THE CENTRAL PART OF THE COUNTRY. THERE ARE SOME
UNCERTAINTIES LATE IN THE PERIOD WITH REGARD TO AMPLIFICATION AND
POSITION OF THE WESTERN RIDGE AND SUBSEQUENT DOWNSTREAM
TROUGHING...BUT MEDIUM RANGE ENSEMBLE MEANS SUPPORT A DRY
FORECAST AT THIS TIME.

09/GP

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  50  71  40  60  42 / 100  40   5  10  50
WACO, TX              57  72  40  62  43 / 100  50  10  20  40
PARIS, TX             45  68  37  59  40 / 100  70   5  10  50
DENTON, TX            50  70  37  60  39 / 100  30   5  10  50
MCKINNEY, TX          48  69  37  59  39 / 100  40   5  10  50
DALLAS, TX            51  70  42  59  43 / 100  40   5  10  50
TERRELL, TX           50  69  40  60  41 / 100  60   5  10  50
CORSICANA, TX         54  71  43  61  42 / 100  70  10  20  40
TEMPLE, TX            57  71  42  64  45 / 100  60  10  20  40
MINERAL WELLS, TX     51  70  35  61  39 / 100  10   5  10  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
314 PM CST SAT FEB 9 2013

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-101230-
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-
314 PM CST SAT FEB 9 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...TONIGHT.
SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTH TEXAS THIS
EVENING. LATER TONIGHT...A LINE OF THUNDERSTORMS WILL MOVE ACROSS
NORTH TEXAS AFTER MIDNIGHT AND SOME STORMS COULD BE SEVERE WITH
LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.
STRONG TO SEVERE THUNDERSTORMS SHOULD STILL BE OCCURRING OVER THE
SOUTHEAST COUNTIES AFTER DAYBREAK SUNDAY...BUT THEY ARE EXPECTED
TO EXIT THE REGION BY MID MORNING.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUESTED AFTER MIDNIGHT TONIGHT...
INITIALLY IN AREAS WEST OF THE I-35 CORRIDOR...THEN IN AREAS ALONG
AND EAST OF THE I-35 CORRIDOR FROM 3 AM THROUGH EARLY SUNDAY
MORNING.