Oklahoma Area Forecast/NWS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
746 PM CST THU JAN 17 2008

.UPDATE...
COMBINATION OF SURFACE RIDGE OVER EASTERN OKLAHOMA...DRY
AIR AND CLEAR SKIES WILL ALLOW FOR GOOD RADIATIONAL COOLING
FOR AT LEAST THE FIRST HALF OF THE NIGHT. WINDS WILL INCREASE
OVER ~ THE WESTERN HALF OF THE FA AND CLOUDS WILL INCREASE
OVER NORTHWEST PARTS BY MORNING. ALSO EXPECT LOW CLOUDS
OVER TEXAS WILL REMAIN MAINLY SOUTH OF THE RED RIVER. THEREFORE
HAVE LOWERED TEMPS TONIGHT ACROSS EASTERN PARTS OF FA...
ESPECIALLY SOUTHEAST OK.

&&

.DISCUSSION...


&&

SIX


.PREV DISCUSSION... /ISSUED 341 PM CST THU JAN 17 2008/

DISCUSSION...IMPRESSIVE COLD AIR MASS IN PLACE TODAY...HOLDING
HIGHS IN THE 30S DESPITE NO SNOW COVER...FULL SUN AND LIGHT WEST
WINDS. BELOW NORMAL TEMPERATURES WILL CONTINUE THE MAJORITY OF THE
NEXT SEVEN DAYS...WITH EXCEPTION OF BRIEF WARM-UPS AHEAD OF
REINFORCING ARCTIC FRONTS BOTH FRIDAY AND SUNDAY. MAIN WEATHER OF
INTEREST...HOWEVER...WILL BE THE POTENTIAL FOR ICE AND SNOW EARLY TO
MID NEXT WEEK.

CLEAR SKIES TONIGHT WILL AGAIN ALLOW FOR COLD LOWS BELOW 20 DEGREES
IN MANY LOCATIONS. LIGHT SOUTH TO SOUTHWEST WINDS MAY HOLD TEMPS UP
JUST A BIT COMPARED TO LAST NIGHT IN THE NORTHWEST. THE NEXT
REINFORCING FRONT WILL MOVE ACROSS THE REGION RELATIVELY SLOWLY ON
FRIDAY...PROVIDING A SHARP CONTRAST IN HIGH TEMPS...RANGING FROM THE
LOW 30S NORTHWEST TO LOW 50S ALONG THE RED RIVER. LITTLE UPPER
SUPPORT WITH THIS FRONTAL PASSAGE...BUT ENOUGH MID LEVEL HUMIDITY TO
INCLUDE A MENTION OF SPRINKLES OR SNOW FLURRIES BEHIND THE FRONT.
FOR NOW...WILL KEEP POPS BELOW 20 PERCENT.

ANOTHER SURFACE HIGH SLIDES THROUGH ON SATURDAY...COOL BUT WITH
LIGHT WINDS. A MORE SUBSTANTIAL FRONT AND UPPER LOW WILL DROP INTO
THE ROCKIES AND HIGH PLAINS ON SUNDAY...SETTING UP A PERIOD OF
POTENTIALLY ACTIVE WEATHER. INITIALLY...THE CONCERN WILL BE WITH A
SOUTHERLY LOW LEVEL JET AHEAD OF THE WEATHER SYSTEM. COULD SEE SOME
BORDERLINE ADVISORY LEVEL WINDS...20 TO 30 MPH...ESPECIALLY NORTH
TEXAS THROUGH WESTERN AND CENTRAL OKLAHOMA. GIVEN THE DRY AIR MASS
IN PLACE...THIS WILL BE A CONCERN FOR FIRE WEATHER AS WELL. THE MAIN
LIMITING FACTOR WILL BE THE COOL TEMPERATURES. THE CURRENT FORECAST
IS FOR A MINIMUM HUMIDITY ONLY ABOUT 30 TO 35 PERCENT ON SUNDAY. IF
THIS TRENDS ANY LOWER...MAY CONSIDER A FIRE WEATHER WATCH FOR AT
LEAST PART OF THE AREA...BUT AT THIS TIME A WATCH DOES NOT APPEAR
WARRANTED.

BY SUNDAY EVENING...MOISTURE SHOULD BE INCREASING RAPIDLY FROM THE
SOUTH WHILE THE ARCTIC FRONT ENTERS THE REGION FROM THE NORTH.
PRECIP CHANCES WILL GO UP...FIRST WITHIN THE WARM CONVEYOR
BELT...THEN WITHIN LOW TO MID LEVEL FRONTAL ZONE. MAIN CHALLENGE IS
FORECASTING SURFACE TEMPERATURES AND HOW MUCH WINTRY PRECIP IS GOING
TO OCCUR. FOR THE CURRENT FORECAST...FELT THE ECMWF WAS TOO SLOW TO
BRING THE COLD AIR SOUTH. THE AIR ORIGINATES OVER ALASKA THIS
WEEKEND...SO SHOULD BEHAVE LIKE A SHALLOW ARCTIC AIR MASS...AND PUSH
EASILY DOWN THE HIGH PLAINS. PREFER THE GFS THROUGH MONDAY...BUT
THEN THE OPERATIONAL RUN BECOMES A SIGNIFICANT OUTLIER...PUSHING THE
FRONT VERY FAR TO THE SOUTH AND EAST. THE UPPER AIR PATTERN DOES NOT
SUPPORT SUCH A PUSH...AND THE ENSEMBLE MEAN MAY OFFER A BETTER
FORECAST...KEEPING THE SURFACE HIGH JUST NORTH OF OKLAHOMA...WITH
THE FRONTAL ZONE HANGING UP ACROSS NORTH TEXAS AND SOUTHERN OKLAHOMA.

WITH UNIMPEDED FLOW OFF THE GULF FOR A LONG DURATION NEXT
WEEK...THERE IS LIKELY TO BE A WIDE BAND OF PRECIPITATION ALONG AND
NORTH OF THE FRONT...UNTIL THE BASE OF THE UPPER TROUGH SWINGS
THROUGH FROM THE WEST. THE DETAILS OF PRECIP LOCATION AND
TIMING...AND SURFACE TEMPERATURE...ARE STILL VERY UNCERTAIN AT THIS
TIME. GENERALLY...THERE IS POTENTIAL FOR ACCUMULATING ICE OR SNOW
WITH LOCALLY SIGNIFICANT IMPACTS...BUT A LACK OF ORGANIZATION ON THE
LARGE SCALE MAY TEND TO LESSEN THE IMPACTS OVERALL. EXPECT THIS
FORECAST TO SLOWLY EVOLVE THE NEXT FEW DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 18 46 17 39 / 0 10 0 0
HOBART OK 17 43 18 43 / 0 10 0 0
WICHITA FALLS TX 20 49 20 44 / 0 0 0 0
GAGE OK 14 34 11 41 / 0 10 0 0
PONCA CITY OK 16 37 13 33 / 0 10 10 0
DURANT OK 17 46 21 41 / 0 10 10 0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

$$