000
FXUS64 KOUN 201656
AFDOUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
1155 AM CDT SAT MAR 20 2010
.UPDATE...
AS THE CENTER OF THE MID LEVEL CIRCULATION ASSOCIATED WITH THE
CURRENT WINTER STORM TRACKS ACROSS SOUTHERN OKLAHOMA...A BREAK IN
THE ACTION IS BEING EXPERIENCED ACROSS MUCH OF SOUTH CENTRAL
OKLAHOMA. SNOW BANDS ARE PRESENT JUST EAST OF THE OKC METRO
AREA...WITH AT LEAST LIGHT SNOW PERSISTING OVER NORTHERN OK.
SNOWFALL ASSOCIATED WITH WRAPAROUND MOISTURE ON THE BACK SIDE OF
THE LOW HAS MOVED INTO SOUTHWESTERN OK AND WESTERN NORTH TX. WE
ARE EXPECTING SNOW TO GRADUALLY END FROM WEST TO EAST IN THIS AREA
THIS AFTERNOON AS THE LOW CONTINUES ITS EASTWARD TRACK. GREATEST
CONCERN IS STILL FOR AREAS OF EAST CENTRAL INTO NORTHERN OKLAHOMA
THAT SHOULD SEE THE LONGEST DURATION OF SNOWFALL THIS AFTERNOON
INTO TONIGHT.
POPS HAVE BEEN REVISED TO REFLECT THE DECREASING CHANCES IN THE
WEST...WITH OTHER ASPECTS OF THE FORECAST CHANGING LITTLE.
TAYLOR
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT SAT MAR 20 2010/
AVIATION...
MVFR TEMPO IFR/LIFR IN -SN/BR AND EVENTUALLY SOME BLSN ONCE SNOW
STARTS TO ACCUMULATE. HAVE FOLLOWED THE 06Z NAM WHICH DEPICTS 2
MAIN PULSES OF POTENTIALLY HEAVIER SNOW... ONE MOVING NE INTO
NCENTRAL OK THIS MORNING AND A 2ND WAVE ENTERING SW OK AROUND 18Z
AND MOVING NE TO AFFECT CENTRAL/NCENTRAL OK 21-03Z. SNOW ENDING
KGAG THIS AFTERNOON AND OVER THE REST OF THE W OK TAFS AND KSPS
THIS EVENING/OVERNIGHT FOLLOWED BY GRADUAL BREAKUP OF THE LOWER
CIGS IN THESE AREAS.
PREV DISCUSSION... /ISSUED 352 AM CDT SAT MAR 20 2010/
DISCUSSION...
UPPER LOW IS PROGGED TO TAKE A NEAR-OPTIMAL TRACK FOR HEAVY SNOW
ACROSS NORTHERN-CENTRAL-EASTERN OK AS IT MOVES FROM NM ESE-WARD
ALONG/NEAR THE RED RIVER INTO THE ARKLATEX BY SUNDAY MORNING.
MULTITUDE OF PRECIP TYPES BEING REPORTED WITH THE INITIAL
TRANSITION THIS MORNING... BUT THE CHANGEOVER TO SNOW SHOULD BE
MORE SWIFT LATER TODAY AS DYNAMIC COOLING ARRIVES AHEAD OF THE
APPROACHING UPPER LOW. WE WILL ADD A FEW MORE COUNTIES IN SE OK TO
THE WARNING... AND THE REST OF THE AREA NOT IN THE WARNING WILL GO
TO AN ADVISORY FOR SNOW AND BLOWING SNOW. THE CURRENT EXPIRATION
TIMES ARE GENEROUS GIVEN THAT MODEL QPFS BEGIN SHUTTING DOWN THE
SNOW IN THE W/NW BY THIS AFTERNOON. LATER SHIFTS WILL LIKELY BE
HACKING AWAY AT THE WARNING/ADVISORY AREAS AS THE SNOW TAPERS
OFF.
THIS EVENT WILL LIKELY BRING OKC TO A NEW SEASONAL RECORD FOR SNOW
BY THE TIME IT ENDS. IT MIGHT HAVE SET MORE RECORDS THAN THAT HAD
THERE BEEN MORE COLD AIR ESTABLISHED OVER THE AREA PRIOR TO THE
EVENT. AS IT IS... MUCH OF THE EARLY PART OF THE EVENT WILL BE
RAIN OR MIXED PRECIP. THERE IS ALSO THE CONSIDERATION OF BLIZZARD
OR NEAR BLIZZARD CONDITIONS... AND PERHAPS THE NEED TO UPGRADE TO
A BLIZZARD WARNING. AT THIS TIME WE ARE NOT CONFIDENT ENOUGH THAT
WIND SPEEDS AND VISIBILITIES WILL JUSTIFY THAT... AND SINCE WE
HAVE MAINTAINED EMPHASIS ON THE WINDS AND BLOWING SNOW FROM THE
BEGINNING... WE WILL STICK WITH A WINTER STORM WARNING FOR NOW.
SNOW SHOULD WIND DOWN THIS EVENING OVER MUCH OF W OK AND OUR TX
ZONES... AND EARLY SUNDAY OVER CENTRAL OK. SNOW COVER WILL KEEP
TEMPS DOWN FOR A WHILE THEREAFTER... BUT IT TYPICALLY DOES NOT
LINGER VERY LONG THIS LATE IN THE SEASON AND SO WE WILL BRING
TEMPS BACK UP TO MORE SPRINGLIKE LEVELS AGAIN BY AROUND TUESDAY.
NO SIGNIFCANT CHANGES IN REASONING FOR MID-LATE WEEK. ANOTHER
SYSTEM MOVES THROUGH AROUND WED-THU BUT LOOKS WEAKER AND WITH LESS
COLD AIR.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 29 27 37 27 / 100 40 20 0
HOBART OK 32 23 40 27 / 80 10 0 0
WICHITA FALLS TX 33 28 44 30 / 80 30 0 0
GAGE OK 33 24 45 20 / 70 10 0 0
PONCA CITY OK 30 28 34 22 / 100 50 30 0
DURANT OK 38 31 38 31 / 100 60 40 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WARNING UNTIL 7 PM CDT SUNDAY FOR OKZ007-008-012-
013-017>020-023>032-040>042.
WINTER STORM WARNING UNTIL 7 AM CDT SUNDAY FOR OKZ004>006-
009>011-014>016-021-022-033>036.
WINTER WEATHER ADVISORY UNTIL 7 AM CDT SUNDAY FOR OKZ037>039-044-
045.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT SUNDAY FOR OKZ046-050>052.
WINTER STORM WARNING UNTIL 7 PM CDT SUNDAY FOR OKZ043-047-048.
TX...WINTER WEATHER ADVISORY UNTIL 7 AM CDT SUNDAY FOR TXZ083>090.
&&
$$
03/32
