FXUS64 KOUN 220419
AFDOUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
1019 PM CST MON DEC 21 2009
.UPDATE...
SOME MINOR ADJUSTMENTS WERE MADE TO A FEW GRIDS TONIGHT TO BETTER
MATCH CURRENT CONDITIONS.
FOCUS REMAINS ON THE LATE-WEEK SYSTEM... AND 00Z MODELS APPEAR TO
BE THROWING ANOTHER CURVE. NAM... AND NOW GFS... HAVE TURNED THE
MAIN 500-MB LOW FARTHER N INTO CENTRAL PLAINS WED NIGHT AND
THURSDAY. WHILE BOTH STILL INDICATE A VIGOROUS SHORTWAVE TROF
SWINGING ACROSS THE AREA... THE NEW TREND WOULD HAVE US DEALING
WITH A DRY SLOT AND SHARPLY REDUCED PRECIP CHANCES. WE WILL NOT
BITE ON THIS YET.. BUT WILL NEED TO TWEAK THE SPS AND HWO TO PLACE
MORE EMPHASIS ON THE STILL-LIKELY COMBO OF WIND AND COLD THAT WILL
ARRIVE BY XMAS EVE... AND LESS ON THE SNOW AND BLOWING SNOW.
&&
.PREV DISCUSSION... /ISSUED 540 PM CST MON DEC 21 2009/
AVIATION...
00Z TAFS...WE HAVE HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD
AT KGAG/KWWR/KCSM/KHBR. ELSEWHERE...LOW LEVEL MOISTURE RETURNING
NORTHWARD MAY BRING IFR CEILINGS OVER OTHER TERMINALS BEGINNING AROUND
09-10Z. MODEL LOW LVL RELATIVE HUMIDITY FORECASTS INDICATE THAT
THE EDGE OF THE IFR CEILINGS MAY BE NEAR KSPS/KLAW/KOKC/KOUN/KPNC.
WE LEFT THE IFR CONDS ALREADY EXISTING FROM PREVIOUS FORECASTS IN
THE TAFS SINCE LOW CIGS AT THESE TERMINALS ARE STILL VERY
POSSIBLE...THOUGH NOT DEFINITE.
TAYLOR
PREV DISCUSSION... /ISSUED 215 PM CST MON DEC 21 2009/
DISCUSSION...
PRIMARY FOCUS WAS ON UPCOMING STORM SYSTEM/WINTER WX. STRATUS AND
POSSIBLY SOME PATCHY FOG WILL DEVELOP LATER TONIGHT AS MOISTURE
SPREADS NORTHWARD INTO THE FA. GULF MOISTURE WILL CONT TO MOVE
NORTHWARD TUESDAY AHEAD OF THE APPROACHING STORM SYSTEM. AS MOISTURE
INCREASES RAIN/DRIZZLE WILL BECOME POSSIBLE IN EASTERN PORTIONS OF
FA TUESDAY. BOUNDARY WILL HANG OUT IN THE FA UNTIL FINALLY MOVING
SOUTH AS A COLD FRONT WEDNESDAY. AIRMASS AHEAD OF THE UPR STORM
SYSTEM... THAT WILL EVENTUALLY MOVE ACROSS THE SOUTHERN PLAINS...
WILL ALSO CONT TO WARM OVER THE NEXT COUPLE OF DAYS LEADING TO
PRECIP LIKELY BEGINNING AS RAIN. ARCTIC AIR WILL MOVE INTO THE
SOUTHERN PLAINS WED NIGHT/THURSDAY LEADING TO PRECIP CHANGING OVER
TO SNOW. WHEN THIS OCCURS WILL BE DEPENDENT ON HOW FAST THE COLD AIR
MOVES INTO THE REGION AND WILL ALSO AFFECT SNOWFALL AMOUNTS. RIGHT
NOW MOST LIKELY AREA TO RECEIVE A DECENT AMOUNT OF ACCUMULATION
/MAYBE SEVERAL INCHES/ WILL BE ACROSS NORTHERN OK PRIMARILY DUE TO
WRAP AROUND PRECIP. HOWEVER... MODELS HAVE BEGUN TO INDICATE ANOTHER
SWATH OF ACCUMULATING SNOW IN SW PORTIONS OF FA NEAR THE UPPER LOW.
BLOWING SNOW COULD ALSO LIKELY BECOME AN ISSUE AS SFC LOW DEEPENS
AND STRONG NORTH TO NW WINDS DEVELOP. WILL HANDLE THE WINTER WX IN
HWOOUN... SPSOUN... AND GRAPHICS FOR NOW. HOWEVER... LATER SHIFTS
MAY NEED TO ISSUE A WATCH FOR CERTAIN LOCATIONS. AFTER THE STORM
SYSTEM EXITS THE AREA... THE COLD AIR WILL CONT TO AFFECT THE REGION
THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 41 59 43 57 / 0 20 30 60
HOBART OK 39 58 40 53 / 0 10 20 50
WICHITA FALLS TX 45 67 48 62 / 0 10 10 50
GAGE OK 24 49 33 44 / 0 10 20 60
PONCA CITY OK 36 53 43 53 / 0 20 50 60
DURANT OK 47 63 55 67 / 0 20 40 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
24/03
