Winter Weather in Texas, February 7, 2014

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
611 AM CST FRI FEB 7 2014

.AVIATION...
CONCERNS...LIGHT SNOW POSSIBLE AT THE METROPLEX TAF SITES THROUGH
MID AFTERNOON. SOME FREEZING DRIZZLE OR LIGHT FREEZING RAIN POSSIBLE
THIS MORNING IN THE WACO AREA.

VFR CEILINGS SHOULD LOWER TO MVFR BY MID MORNING /15Z/ AND THESE
CEILINGS SHOULD REMAIN THAT WAY UNTIL LATE AFTERNOON /23Z/. SOME
LIGHT SNOW HAS DEVELOPED ACROSS PARTS OF WEST TEXAS AND RADAR
SHOWS SOME LIGHT RETURNS ACROSS THE WESTERN PARTS OF NORTH TEXAS.
EXPECT SOME LIGHT SNOW TO AFFECT THE METROPLEX TAF SITES AFTER
15Z BUT THIS SNOW SHOULD BE LIGHT. SOME 3SM -SN BR IS POSSIBLE
18-21Z BUT THE BEST CHANCES WILL BE NORTH OF THE TAF SITES.
THE SNOW IS NOT SPECIFICALLY MENTIONED IN THE TAFS AT THIS TIME.
PRECIPITATION CHANCES SHOULD END ACROSS THE METROPLEX BEFORE 00Z.
LIGHT NORTHEAST SURFACE WINDS WILL BECOME EASTERLY DURING THE
AFTERNOON AND SOUTHEAST BEFORE 00Z.

58

&&

.PREV DISCUSSION... /ISSUED 445 AM CST FRI FEB 7 2014/
IT IS UNUSUAL FOR NORTH TEXAS TO HAVE TWO SEPARATE SNOW EVENTS ON
CONSECUTIVE DAYS...BUT THIS WINTER HAS BEEN ANYTHING BUT USUAL.
ALTHOUGH ON A SIMILAR TRACK (WITH SIMILAR SPEED)...OUR NEXT
SHORTWAVE WILL NOT EXPERIENCE THE SHEARING THE THURSDAY SYSTEM
UNDERWENT. IN ADDITION...THE LOWEST SEVERAL THOUSAND FEET OF THE
ATMOSPHERE ARE NEARLY SATURATED AND WILL REMAIN SO TODAY...MEANING
LITTLE IF ANY PRECIPITATION WILL BE LOST TO SUBLIMATION. NOW
SWINGING THROUGH THE DESERT SOUTHWEST...THE APPROACHING MID-LEVEL
TROUGH AXIS WILL STAY AHEAD OF ITS ASSOCIATED JET STREAK. THE PEAK
WINDS AT 500MB WILL APPROACH 100KTS AS THE JET STREAK ROUNDS THE
BASE OF THE TROUGH TODAY OVER THE LONE STAR STATE. SUCH AN EVOLUTION
WILL RESULT IN TWO DISTINCT DIFFERENCES FROM THE THURSDAY EVENT:

(1) INSTEAD OF LIFTING A THERMODYNAMICALLY STABLE LAYER IN THE
MID-LEVELS...LAPSE RATES WITHIN THE DENDRITIC GROWTH ZONE WILL BE
STEEPER. THIS INSTABILITY WILL ENHANCE ANY AREAS OF CSI...WHICH WILL
BE FOCUSED NEAR THE THETA-E GRADIENT INVOF 500-600MB. THERE IS STILL
EXCELLENT AGREEMENT AMONG GUIDANCE WITH THE PLACEMENT OF THIS AREA
OF FORCING...PUTTING IT BETWEEN THE I-20 CORRIDOR AND THE RED RIVER.
THIS SNOW WILL BE LIGHT...BUT THE HEAVIEST BANDS WILL LIKELY BE
ORIENTED PARALLEL TO THEIR DIRECTION OF MOVEMENT. AS A RESULT...SOME
AREAS COULD SEE SNOW ACCUMULATIONS OF AN INCH OR MORE WITH
SUFFICIENT DURATION. AN ADVISORY HAS BEEN ISSUED FOR THE NORTHERN
TWO ROWS OF COUNTIES THOUGH SOME AREAS WITHIN THE ADVISORY WILL
LIKELY SEE LESS THAN 1/2 INCH OF SNOW. REGARDLESS OF TOTALS...ANY
ADDITIONAL SNOWFALL WILL ACCUMULATE ON ROADWAYS...RESULTING IN
IMPACTS TO TRAVEL.

(2) 850MB INFLOW WILL BE STRONGER (AND MUCH MORE MOIST AS WELL).
THIS WARM/MOIST UPGLIDE WILL ENHANCE THE INSTABILITY ABOVE IT...
RESULTING IN PRECIPITATION ACROSS CENTRAL AND EAST TEXAS...WHICH
LARGELY MISSED OUT ON THE THURSDAY EVENT. INITIALLY (EARLY THIS
MORNING)...THIS PRECIPITATION WILL BE SNOW FLURRIES OR LIGHT
FREEZING DRIZZLE. MORE SIGNIFICANT PRECIPITATION MAY DEVELOP OVER
THE COURSE OF THE DAY WITHIN THE PREVIOUS ADVISORY AREA. SNOW
ACCUMULATIONS WILL BE LIGHT...BUT ANY ICE ACCUMULATIONS WILL RESULT
IN SIGNIFICANT IMPACTS TO TRAVEL. IF THE PRECIPITATION REMAINS
LIGHT...TEMPERATURES WILL LIKELY TOP FREEZING THIS AFTERNOON WITHIN
THE ADVISORY AREA. ALTHOUGH SOME IMPACTS (AND ADDITIONAL RAIN/SNOW)
WILL BE POSSIBLE DURING THE AFTERNOON HOURS...THE THREAT OF ICING
WILL HAVE ENDED. THUS...THE ADVISORY WILL NOW END AT NOON. THOUGH
NOT EXPECTED...SIGNIFICANT PRECIPITATION COULD KEEP TEMPERATURES
BELOW FREEZING THIS AFTERNOON...AND THE ADVISORY MAY NEED TO BE
EXTENDED.

THE ONGOING PRECIPITATION ACROSS NORTH CENTRAL TEXAS IS ASSOCIATED
WITH ISENTROPIC LIFT AROUND 850MB...WHERE TEMPERATURES ARE SEVERAL
DEGREES BELOW FREEZING. THIS LIGHT SNOW IS UNLIKELY TO ACCUMULATE.
THE SIGNIFICANT SNOWFALL WILL BEGIN IN NORTHWESTERN ZONES THIS
MORNING AND SHIFT EAST ACROSS THE REGION TODAY. DALLAS/FORT WORTH
WILL LIKELY BE NEAR THE SOUTHERN FRINGE OF THE SNOW BANDING.
BEING WITHIN THE TRANSITION ZONE BETWEEN ADVISORY-WORTHY SNOW TO
THE NORTH AND FLURRIES (OR NO SNOW) TO THE SOUTH...LOCATIONS
WITHIN THE METROPLEX COULD SEE ANYWHERE FROM FROM ZERO SNOWFALL
(SOUTH) TO 1/2 INCH (NORTH).

25

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  33  26  55  34  49 /  30  10   0   0   0
WACO, TX              34  26  62  36  62 /  20  10   0   0   0
PARIS, TX             31  23  49  30  47 /  50  20   0   0   0
DENTON, TX            31  24  52  30  46 /  40  10   0   0   0
MCKINNEY, TX          31  23  51  29  48 /  40  10   0   0   0
DALLAS, TX            33  27  55  35  49 /  30  10   0   0   0
TERRELL, TX           32  25  54  33  53 /  40  20   0   0   0
CORSICANA, TX         34  27  58  38  59 /  30  20   0   0   0
TEMPLE, TX            33  26  63  38  65 /  30  10   0   0   0
MINERAL WELLS, TX     34  24  59  31  49 /  30  10   0   0   0

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ156>160-174-
175.

WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO NOON CST TODAY
FOR TXZ122-135-146>148-161-162.

WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR TXZ091>095-100>107.

&&

58/25

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE FORT WORTH TX
613 AM CST FRI FEB 7 2014

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-081215-
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-
613 AM CST FRI FEB 7 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...TODAY AND TONIGHT.
LIGHT SNOW TODAY ACROSS LOCATIONS ALONG AND NORTH OF A GRAHAM TO
DENTON TO SULPHUR SPRINGS LINE MAY RESULT IN ACCUMULATIONS OF 1/2
TO 1 INCH. THIS MAY CAUSE SOME TRAVEL HAZARDS...THUS A WINTER
WEATHER ADVISORY FOR LIGHT SNOW HAS BEEN ISSUED FOR THOSE AREAS.

SOME FREEZING DRIZZLE OR LIGHT FREEZING RAIN IS POSSIBLE THIS
MORNING ALONG AND SOUTH OF A LINE FROM LAMPASAS TO WACO TO
CANTON. THIS LIGHT FREEZING PRECIPITATION MAY CAUSE SOME TRAVEL
PROBLEMS...THUS A WINTER WEATHER ADVISORY IS IN EFFECT THOUGH
NOON FOR THOSE AREAS.

SOME LIGHT SNOW IS POSSIBLE ACROSS THE REST OF NORTH TEXAS TODAY
WITH ACCUMULATIONS RANGING FROM ZERO TO 1/2 INCH. THERE IS A
CHANCE FOR SOME LIGHT SNOW THIS EVENING MAINLY EAST OF
I-35/I-35E. SNOW ACCUMULATIONS WILL BE LIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.
A CHANCE FOR A LIGHT WINTRY MIX RETURNS TO AREAS NORTH OF A LINE
FROM GOLDTHWAITE TO CANTON LATE MONDAY NIGHT THROUGH TUESDAY
EVENING. THERE IS A SLIGHT CHANCE OF A WINTRY MIX MAINLY EAST OF
I-35/I-35E AFTER MIDNIGHT TUESDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.