Winter Weather Advisory 21, NWS Norman, OK

Atoka County, OK, Beckham County, OK, Bryan County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Hughes County, OK, Jackson County, OK, Jefferson County, OK, Johnston County, OK, Kiowa County, OK, Lincoln County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Oklahoma County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Foard County, TX, Hardeman County, TX, Knox County, TX, Wichita County, TX, Wilbarger County, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
541 PM CST SAT FEB 21 2015

.AVIATION...
00Z TAFS...EXPECT VFR CONDITIONS TO PREVAIL WITH EAST TO
NORTHEAST WINDS THROUGH AROUND 05Z SUN. A POTENT FRONT WILL MOVE
FROM NORTH TO SOUTH...BRINGING GUSTY NORTHEAST WINDS...AND
WIDESPREAD MVFR/IFR CIGS TO MANY TERMINALS BY 12Z SUN.
ADDITIONALLY...SNOW AND BLOWING SNOW WILL BECOME A CONCERN FOR
NORTHWESTERN TERMINALS...SPECIFICALLY KGAG AND KWWR...WHERE SNOW
MAY REDUCE VSBYS TO LESS THAN 2 SM BETWEEN 08Z AND 15Z SUN. AREA
OF SNOW AND OR RAIN AND SNOW WILL MOVE SOUTH THROUGH THE FIRST
HALF OF THE DAY SUNDAY...POSSIBLY AFFECTING KCSM AND KOUN/KOKC IN
THE 14Z TO 18Z TIMEFRAME. EXPECT MVFR/IFR CIGS TO PERSIST INTO
SUNDAY EVENING.

AUSTIN

&&

.PREV DISCUSSION... /ISSUED 154 PM CST SAT FEB 21 2015/

DISCUSSION...
SEVERAL SMALL TO MEDIUM EVENTS WILL ARRIVE OVER THE NEXT WEEK.
BEGINNING TONIGHT, STRONG UPSLOPE FLOW WITH THE ARRIVAL OF MUCH
COLDER AIR WILL BE THE PRIMARY DRIVER FOR SNOW IN NORTHWEST
OKLAHOMA TONIGHT. THE WESTERLY MID-LEVEL FLOW WILL BE MODULATED BY
SEVERAL WEAK UPPER LEVEL TROUGHS THAT MOVE EAST OF A STRONG LOW
MEANDERING OVER NV AND CA INTO THE EARLY WEEK. VERTICAL VELOCITY
SIGNALS ARE STRONGEST OVERNIGHT AND EARLY SUNDAY IN NORTHWEST
OKLAHOMA WHERE A NEARLY SATURATED LAYER IN THE DENDRITIC GROWTH
ZONE IS LIKELY. A SNOW ADVISORY EXISTS FOR THE FIRST HALF OF
SUNDAY FOR UP TO 4 INCHES, WITH 2 TO 3 INCHES ACROSS MOST OF THE
ADVISORY AREA. THERE IS EXPECTED TO BE A LULL IN PRECIPITATION
HERE SUNDAY AFTERNOON, BEFORE A WEAKER UPPER LEVEL WAVE MAY BRING
ANOTHER INCH OR SO.

LIGHT SNOW MAY OCCUR OVER CENTRAL OKLAHOMA DURING THE DAY SUNDAY
WITH A GOOD CHANCE FOR RAIN MID-DAY IN SOUTHERN OKLAHOMA. THE
RATE OF COOLING IN THE DEEPENING COLD AIRMASS IS EXPECTED TO
CHANGE RAIN TO A MIXTURE OF RAIN AND SLEET LATE SUNDAY IN SOUTHERN
OKLAHOMA. QPF FROM MODELS REMAIN DIVERGENT FOR THIS AREA WITH THE
NAM SHOWING 1/4 INCH BY SUNSET. SINCE THIS AREA IS EXPECTED TO BE
IN THIS MIXED PRECIPITATION OF RAIN/SLEET, IT DOESN'T CURRENTLY
APPEAR THAT AMOUNTS WOULD BE SUFFICIENT FOR A WINTER STORM. IT IS
EXPECTED THAT AN ADVISORY WILL BE NECESSARY IN THIS AREA LATER
SUNDAY.

THE COLD AIR WILL BE MODULATED BY WARMING DOWNSLOPE WINDS AND
WEDNESDAY BEFORE A SIMILARLY COLD AIRMASS ARRIVES LATE WEDNESDAY
OR EARLY THURSDAY. AN UPPER LEVEL TROUGH SLOWLY APPROACHING THE
SOUTHER PLAINS WILL KEEP A CHANCE FOR SNOW IN THE FORECAST FOR THE
REST OF THE WEEK.

PRECIPITATION

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  28  28  19  23 /  20  40  40  50
HOBART OK         27  28  17  20 /  20  50  50  60
WICHITA FALLS TX  35  36  20  22 /  10  60  60  70
GAGE OK           20  21  12  21 /  80  60  40  50
PONCA CITY OK     24  25  13  23 /  20  40  20  30
DURANT OK         36  38  25  27 /  10  60  60  70

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 11 AM CST
     SUNDAY FOR OKZ004-005-009>011-014>016.

TX...NONE.
&&

84/11

HAZARDOUS WEATHER OUTLOOK...UPDATE
NATIONAL WEATHER SERVICE NORMAN OK
600 PM CST SAT FEB 21 2015

OKZ004>048-050>052-TXZ083>090-221800-
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-
NOBLE-ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-
BECKHAM-WASHITA-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-
CLEVELAND-POTTAWATOMIE-SEMINOLE-HUGHES-HARMON-GREER-KIOWA-JACKSON-
TILLMAN-COMANCHE-STEPHENS-GARVIN-MURRAY-PONTOTOC-COAL-COTTON-
JEFFERSON-CARTER-JOHNSTON-ATOKA-LOVE-MARSHALL-BRYAN-HARDEMAN-
FOARD-WILBARGER-WICHITA-KNOX-BAYLOR-ARCHER-CLAY-
600 PM CST SAT FEB 21 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN...
WESTERN...CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH
TEXAS.

.DAY ONE...THROUGH TONIGHT...

.WINTRY WEATHER...
LIGHT TO MODERATE SNOW IS EXPECTED ACROSS PORTIONS OF NORTHERN
AND WESTERN OKLAHOMA MAINLY AFTER MIDNIGHT TONIGHT...CONTINUING
INTO THE MORNING HOURS SUNDAY. SNOW ACCUMULATIONS OF 1 TO 3 INCHES
WILL BE LIKELY ALONG AND NORTH OF A LINE FROM CHEYENNE...TO ENID...TO
PONCA CITY...WITH GREATER ACCUMULATIONS ACROSS FAR NORTHWESTERN
OKLAHOMA INTO THE TEXAS AND OKLAHOMA PANHANDLES. ROADS WILL LIKELY
BECOME SLICK AND HAZARDOUS BY EARLY SUNDAY MORNING. TRAVEL SHOULD BE
AVOIDED IN THESE AREAS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY...

.WINTRY WEATHER...
WINTER PRECIPITATION WILL BE POSSIBLE THROUGHOUT THE DAY ON SUNDAY
BUT THERE MAY BE A BRIEF LULL BETWEEN THE OCCURRENCES OF HEAVIER
PRECIPITATION WITH MAINLY JUST SOME LIGHT SNOW OR RAIN. ANOTHER
ROUND OF WINTER WEATHER WILL BEGIN LATE SUNDAY AFTERNOON AND
EVENING THEN CONTINUE INTO MONDAY. NORTHERN AND CENTRAL OKLAHOMA
WILL MAINLY SEE SNOW WHILE PARTS OF SOUTHERN OKLAHOMA AND WESTERN
NORTH TEXAS COULD SEE A WINTRY MIX OF SNOW... SLEET... AND
POSSIBLY FREEZING RAIN.

BY MONDAY... SNOW AND SLEET ACCUMULATIONS OF SEVERAL INCHES WILL
BE POSSIBLE IN PARTS OF WESTERN AND SOUTHERN OKLAHOMA... AND
WESTERN NORTH TEXAS. THIS WILL LIKELY IMPACT TRAVEL ACROSS THE
AREA...AND ROADS IN SOME AREAS MAY BECOME VERY DIFFICULT TO
NAVIGATE.

THERE ARE STILL UNCERTAINTIES REGARDING HOW MUCH SNOW AND SLEET
WILL FALL...AND WHERE. STAY TUNED FOR UPDATES AS THIS WINTER
WEATHER SITUATION EVOLVES...AND PREPARE NOW FOR POSSIBLE IMPACTS
TO TRAVEL SUNDAY AND MONDAY.

WINTRY WEATHER MAY RETURN WEDNESDAY NIGHT THROUGH FRIDAY...WITH
ADDITIONAL SNOW ACCUMULATIONS.

.DANGEROUS COLD...
WIND CHILLS WILL DROP TO THE SINGLE DIGITS IN MANY PLACES
MONDAY MORNING. BE SURE AND BUNDLE UP IF YOU PLAN ON BEING
OUTSIDE.

GET GRAPHICS AND MORE DETAILS AT WEATHER.GOV/NORMAN...AND FOLLOW
OUR WEATHER FORECAST OFFICE ON TWITTER AND FACEBOOK.

MBS/EM/AUSTIN