FXUS64 KOUN 061145
AFDOUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
545 AM CST SUN DEC 6 2009
.AVIATION...
12Z TAFS... CIRRUS CIGS WILL MOVE OUT W TO E BY 18Z... BUT
STRATUS/STRATOCU NOW ADVANCING N AHEAD OF FRONT NEAR NW CORNER OK
AND ADVANCING S BEHIND IT. RH PROGS SUPPORT GENERAL DECREASE IN
CIGS TO AT LEAST MVFR BY THIS EVENING. MOS GUIDANCE AGAIN LIKELY
TO BE TOO LOW ON CIGS IN SHALLOW LAYER OF HIGH RH TONIGHT... BUT
IFR CIGS WILL BE POSSIBLE. WIND SHIFT TO N OR NE SHOULD OCCUR ALL
TAF SITES BY 06Z. SOME PATCHY -DZ/BR POSSIBLE THIS AFTERNOON
MAINLY N OK.
&&
.PREV DISCUSSION... /ISSUED 352 AM CST SUN DEC 6 2009/
DISCUSSION...
TODAY THROUGH MONDAY... COLD FRONT CURRENTLY ACROSS KS INTO OK/TX
PANHANDLES WILL MOVE ONLY SLOWLY E/SE TODAY. UPPER TROUGH
CURRENTLY SWINGING E ACROSS UT/AZ LOOKS FAIRLY IMPRESSIVE ON
SATELLITE. LATEST NAM TRACKS THE ASSOCIATED SFC LOW CIRCULATION...
NOW OVER NE NM... E/NE INTO KS AND INTO NW MO BY 12Z MON. ON THIS
TRACK WE MOST LIKELY WILL BE DRY SLOTTED... BUT WE WILL MAINTAIN
LOW POPS N AND E FOR -RA/-DZ AS LOW LEVELS MOISTEN UP NEAR THE
FRONT AND IN THE S/SE FLOW AHEAD OF IT. AIR BEHIND THE FRONT IS
NOT EXTREMELY COLD BY ARCTIC STANDARDS BUT SHOULD BE COLD ENOUGH
TO CHANGE ANY LIGHT PRECIP TO -SN OR -FZDZ ACROSS N OK. COLDER AIR
WILL PUSH S ACROSS THE AREA BEHIND THE FRONT TONIGHT AND MONDAY.
MON NIGHT THROUGH TUE NIGHT... A MORE ROBUST UPPER TROF WILL RACE
FROM THE SW CONUS TO THE MS VALLEY AS ASSOCIATED SFC LOW
INTENSIFIES AND TRACKS QUICKLY FROM CO TO IL/IN BY WED MORNING.
PRIOR THINKING WAS THAT COLD AIR WOULD FORCE THE SFC LOW SLIGHTLY
FARTHER S... BUT MODELS REMAIN FAIRLY CONSISTENT IN KEEPING THE
TRACK NEAR THE KS/OK BORDER. WILL CONTINUE WITH HIGHEST POPS E AND
ESPECIALLY N IN THE LOW-LEVEL WARM ADVECTION REGIME AHEAD OF THE
SYSTEM MON NIGHT AND TUE. SETUP AGAIN SUGGESTS AREA GETTING DRY
SLOTTED BY LATE TUE... AT LEAST ACROSS NCENTRAL TX AND MUCH OF S
OK WHERE POPS ARE LOWERED TO LESS THAN 20. SOME WRAPAROUND PRECIP
MAY LINGER OVER THE N/E ZONES INTO TUE EVENING AS THE SFC LOW
ORGANIZES OVER MO. COLD AIR AGAIN POURS S IN WAKE OF THIS LOW
WHICH WOULD LEAD TO A MIX OR CHANGEOVER TO -SN. NW WINDS LIKELY TO
GET AFTER IT TUE NIGHT BEHIND THE LOW... PROBABLY MAKING WIND/COLD
THE MAIN FEATURE OF THIS SYSTEM FOR OK. WIND CHILLS LIKELY TO DROP
TO NEAR OR PERHAPS A LITLE BELOW ZERO IN PARTS OF NW OK LATE TUE
NIGHT.
LATTER HALF OF WEEK... UPPER HIGH OVER AK PROGGED TO WEAKEN BY
END OF WEEK AND EVENTUALLY BE UNDERCUT BY AN ACTIVE WESTERLY FLOW
ACROSS THE PACIFIC. TYPICAL FOR EL NINO. RESULTING PATTERN IS A
SPLIT FLOW WITH AN ACTIVE SOUTHERN BRANCH BUT A STRONGER NORTHERN
BRANCH WHICH SETS UP FROM W CANADA INTO THE NE CONUS. THAT SHOULD
KEEP THE COLDER AIR TO OUR N/NE BY LATE WEEK... LEADING TO
MODERATING TEMPS. THE ACTIVE SOUTHERN BRANCH PROBABLY WILL BRING
ONE OR MORE ROUNDS OF PRECIP ACROSS THE AREA POSSIBLY BEGINNING AS
EARLY AS FRI /GFS/ OR SAT /ECMWF/. WILL KEEP POPS BELOW 20 FOR NOW
BASED ON UNCERTAINTIES REGARDING TIMING AND MOISTURE AVAILABILITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 45 27 40 34 / 10 0 10 20
HOBART OK 49 24 39 31 / 0 0 0 20
WICHITA FALLS TX 52 30 45 36 / 10 0 10 20
GAGE OK 37 15 33 27 / 10 0 0 20
PONCA CITY OK 44 21 38 32 / 30 20 10 30
DURANT OK 45 31 47 41 / 30 20 10 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/24/24
