FXUS64 KOUN 150324
AFDOUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
924 PM CST MON DEC 14 2009
.UPDATE...THE GOING FORECAST IS IN GOOD SHAPE...AND THE MODELS
TEND TO DO WELL WHEN COLD ADVECTION IS THE DOMINANT WEATHER
INFLUENCE. AN UPPER TROUGH TO OUR WEST WILL MAINTAIN SOME MID AND
HIGH CLOUDS TONIGHT...AND REGIONAL RADARS SHOWED A WELL DEFINED
BAND OF ECHOES APPROACHING THROUGH THE TEXAS PANHANDLE. SOME
FORCING WILL OCCUR...AS FRONTOGENESIS AROUND 700MB SLIDES THROUGH
OUR WESTERN AND SOUTHERN FORECAST AREA. VERY DRY AIR AND BRISK
WINDS BENEATH THAT LEVEL...HOWEVER...SHOULD EVAPORATE THE WOULD-BE
PRECIPITATION BEFORE IT REACHES GROUND. WE HAVE KEPT THE FORECAST
DRY.
OF GREATER CONCERN ARE WIND CHILL TEMPERATURES...WHICH HAD ALREADY
DROPPED TO THE SINGLE DIGITS ABOVE ZERO FROM INTERSTATE 40
NORTHWARD. WE ADJUSTED THE FORECAST TOWARD MET MOS WINDS...WHICH
WERE PERFORMING A LITTLE BETTER THAN THE NAM SURFACE WINDS. BUT
EVEN WITH WINDS SLIGHTLY GREATER THAN PREVIOUSLY FORECAST...IT IS STILL
LIKELY THAT A GRADUAL DECREASE IN SPEEDS WILL OFFSET WITH THE SLOWLY
FALLING AIR TEMPERATURE...TO KEEP WIND CHILLS WITHIN A FEW DEGREES
OF ZERO. THIS IS NOT QUITE TO ADVISORY CRITERIA...SO WE WILL
CONTINUE TO USE CAUTIONARY WORDING IN OTHER PRODUCTS SUCH AS THE
SHORT TERM FORECASTS AND THE HAZARDOUS WEATHER OUTLOOK.
&&
BURKE
&&
.PREV DISCUSSION... /ISSUED 529 PM CST MON DEC 14 2009/
AVIATION...VFR CONDITIONS SHOULD CONTINUE THROUGH THE PERIOD...AS
DRY CONTINENTAL HIGH PRESSURE CONTINUES TO BUILD IN FROM THE
NORTH. AN UPPER TROUGH WILL SPREAD BKN TO OVC CLOUDS ACROSS THE
REGION BETWEEN TWELVE AND TWENTY THOUSAND FEET. VERY COOL AIR OVER
NORTHWEST OKLAHOMA COULD YIELD A BRIEF DECK OF LOW STRATUS...BUT
WITH VERY LITTLE LIFT OCCURRING...WE WILL LEAVE THAT OUT OF THE
TAFS FOR NOW. THE MAIN QUESTION IS WHETHER WINDS WILL DIMINISH...
OR IF COLD ADVECTION CAN MAINTAIN THE 12 TO 15 KNOT WINDS THAT
WERE OBSERVED THIS AFTERNOON. WE LEANED TOWARD AN EARLIER DECLINE
IN WIND SPEEDS COMPARED TO MOS GUIDANCE...AS COLD ADVECTION SHOULD
WANE AFTER 06 UTC.
&&
PREV DISCUSSION... /ISSUED 257 PM CST MON DEC 14 2009/
DISCUSSION...
A SLOWLY MOVING WAVE IN THE MID/UPPER-LEVEL FLOW WILL GRAZE OUR
WESTERN AND SOUTHERN COUNTIES OVER THE NEXT SEVERAL DAYS. THIS
WILL BRING INCREASINGLY THICK CLOUDS INTO THOSE AREAS TONIGHT...
LINGERING INTO MID-WEEK. VIRGA IS LIKELY WITH THIS SYSTEM... BUT A
RATHER THICK LAYER OF DRY AIR WILL PROBABLY PREVENT ANY
SIGNIFICANT PRECIPITATION FROM REACHING THE GROUND. CANNOT RULE
OUT A TINY BIT OF FREEZING DRIZZLE OR FLURRIES OVERNIGHT TONIGHT
OR TOMORROW MORNING... BUT THE PROBABILITIES ARE EXTREMELY LOW.
THE ECMWF REMAINS THE PREFERRED MODEL THIS TIME AROUND... AND IT
STILL MAINTAINS A COOL WEEK... FOLLOWED BY A COLD WEEKEND. HAVE
MADE A FEW MINOR ADJUSTMENTS TO THE LATER PERIODS OF THE FORECAST
TO ACCOUNT FOR THE FEW CHANGES THAT HAVE COME UP IN THE LATER
PERIODS OF THE MEDIUM-RANGE FORECASTS.
BOTH THE ECMWF AND THE GFS FORECAST SOME RATHER UGLY WINTER-
WEATHER SCENARIOS FOR NEXT WEEK -- BEYOND OUR DAY 7. THEIR TIMING
IS NATURALLY VERY DIFFERENT... BUT BOTH FORECAST SOME TYPE OF
SIGNIFICANT FROZEN OR FREEZING PRECIPITATION AROUND THE MIDDLE OR
END OF NEXT WEEK. THAT IS STILL A WAYS OFF... SO MUCH CAN CHANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 19 36 25 47 / 0 10 0 0
HOBART OK 23 40 26 48 / 0 0 0 0
WICHITA FALLS TX 25 42 26 51 / 10 10 0 0
GAGE OK 14 35 19 51 / 0 0 10 0
PONCA CITY OK 11 32 17 45 / 0 0 0 0
DURANT OK 25 41 28 50 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
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