FXUS64 KOUN 071146
AFDOUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
546 AM CST MON DEC 7 2009
.AVIATION...
12Z TAFS... LOW CIGS FORECAST TO BREAK UP AND LIFT SLIGHTLY TODAY
BASED ON MOS GUIDANCE AND RH PROGS... THEN FILL BACK IN TONIGHT
LEAVING CONDITIONS BY 12Z TUE MUCH AS THEY ARE NOW. SATELLITE
LOOP CONTRADICTS THIS TREND WITH STRATUS SPREADING W AND N ACROSS
MUCH OF W AND N TX... SUGGESTING AT LEAST SW OK AND NCENTRAL TX
WILL CONTINUE WITH LOW CIGS OR FILL BACK IN THIS MORNING. WILL
SIDE WITH THE GUIDANCE FOR NOW. SOME -FZDZ/-SN POSSIBLE N OK LATE
TONIGHT BUT CHANCES TOO LOW TO INCLUDE IN TAFS AT PRESENT.
&&
.PREV DISCUSSION... /ISSUED 425 AM CST MON DEC 7 2009/
DISCUSSION...
CANADIAN AIR IS MOVING INTO PLACE OVER THE AREA IN WAKE OF THE
TROUGH NOW RACING ACROSS THE OH VALLEY/GREATLAKES... WHILE THE
MOTHER SHIP IS STARTING ITS TURN TO THE SE OVER N CA. ASSOCIATED
SFC LOW WILL DEEPEN OVER CENTRAL/S ROCKIES AND IS STILL PROGGED TO
TRACK QUICKLY E SOMEWHERE NEAR THE KS/OK BORDER TUE AND TUE
EVENING. MODEL DIFFERENCES MOSTLY INVOLVE SPEED/TIMING. THERE IS
STILL SOME GROUND FOR SKEPTICISM THAT THE LOW WILL TRACK THIS FAR
N INTO THE LOW LEVEL COLD AIR... WHICH TYPICALLY WOULD BE AN
OBSTACLE TO SFC-BASED PRESSURE FALLS. THIS COULD BECOME IMPORTANT
AS IT NOW APPEARS THERE WILL BE A RELATIVELY SHARP GRADIENT
BETWEEN LITTLE OR NO WINTER PRECIP TO THE S AND BIG-TIME SNOW AND
BLOWING SNOW TO THE N. CURRENT TRACK OF SYSTEM WOULD KEEP ALL THE
BAD STUFF JUST TO OUR N WITH ONLY A LOW-END CHANCE OF SOME
ADVISORY-TYPE -FZDZ OR -SN ACROSS N OK. BUT ONLY A SLIGHT S-WARD
SHIFT IN THE TRACK OF THE LOW WOULD INCREASE THE WINTER-WX
POTENTIAL CONSIDERABLY IN NW/NCENTRAL OK. THIS WILL NEED TO BE
MONITORED CLOSELY OVER THE NEXT 24-36 HRS. AS IT NOW STANDS...
THE COLD AIR MASS IS NOT TOO EXTREME AS FAR AS ARCTIC AIR MASSES
GO... AND SINCE ALL THE MODELS ARE STICKING TO THEIR GUNS ON A
TRACK ACROSS N OK OR S KS... WE WILL GO WITH THE FLOW. WARM
ADVECTION WILL INCREASE TONIGHT WITH LIGHT PRECIP MOST LIKELY
BREAKING OUT OVER FAR N AND SE PARTS OF THE CWA. ANY STUFF IN N OK
LIKELY WOULD BE -ZN OR -FZDZ BASED ON FORECAST TEMPS/SOUNDINGS...
WITH COLD -RA/DZ SE. IF THE LOW TRACKS AS FORECAST... WINDS WILL
VEER TO THE S AND ALL AREAS WILL GO ABOVE FREEZING BY TUE
AFTERNOON. CLOUDS AND THE EXISTING COLD AIR MASS WILL KEEP MOST
AREAS CHILLY THOUGH... AND SO THE FORECAST HIGHS TUESDAY HAVE BEEN
KICKED DOWN A FEW PEGS IN MANY AREAS. ANOTHER COLD SURGE WILL
OCCUR TUE NIGHT BEHIND THE EXPANDING/ORGANIZING SFC LOW AS IT
MOVES QUICKLY TO NEAR CHICAGO BY 12Z WED. SOME WRAPAROUND -RA/SN
MAY LINGER INTO TUE NIGHT IN THE NE/E ZONES.
MAIN STORY WITH THIS ONE STILL IS MOST LIKELY TO BE WINDS AS THE
MORE NORTHERN TRACK FAVORS A DRY SLOT OVERSPREADING MUCH OF THE
AREA. STRONG S WINDS WILL VEER TO SW WITH PASSAGE OF THE SFC LOW.
PROGGED 0-1 KM WINDS ARE 30-40KT OVER MUCH OF THE AREA BY
AFTERNOON... AND 40-50KT OVER HIGHER TERRAIN OF W TX. CURRENT
FORECAST WINDS EASILY WILL SUPPORT WIND ADVISORY OVER PARTS OF FAR
W OK SOUTHWARD TUE AFTERNOON... AND SOME AREAS COULD HIT HIGH WIND
CRITERIA. AND... WE WILL MENTION PATCHY BLOWING DUST IN THE
AFTERNOON. BEHIND THE LOW AND ASSOCIATED COLD FRONT... NW WINDS
AGAIN COULD HIT ADVISORY LEVELS BUT AT LEAST WILL CREATE A
SIGNIFICANT CHILL. COMPUTED WIND CHILLS STILL ARE COMING OUT NEAR
ZERO IN FAR NW OK TUE NIGHT... WITH SINGLE DIGITS AND TEENS OVER
MOST OF THE AREA.
REST OF THE FORECAST AS BEEN INITIALIZED MOSTLY FROM STANDARD IN-
HOUSE PROCEDURES. SLOW MODERATION OF TEMPS BY THE WEEKEND AS
STRONGEST WESTERLIES SHIFT FARTHER N CLOSER TO THE N PLAINS AND
NE. WE STILL WILL BE DEALING WITH BOUTS OF COLD AIR IN THIS
PATTERN... BUT THE COLDEST AIR WILL STAY WELL TO OUR N. WE WILL
ADD SOME LOW POPS FOR THU NIGHT INTO FRI NIGHT FOR A WEAK FAST-
MOVING WAVE THAT MOST MODELS BRING ACROSS DURING THAT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 38 31 43 24 / 0 20 30 10
HOBART OK 40 29 44 24 / 0 20 10 0
WICHITA FALLS TX 45 35 52 28 / 10 20 10 10
GAGE OK 29 24 45 15 / 10 20 30 0
PONCA CITY OK 35 30 39 21 / 10 30 60 30
DURANT OK 48 40 47 32 / 10 30 30 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/24/24
