FXUS64 KOUN 080455
AFDOUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
1100 PM CST MON DEC 7 2009
.AVIATION...
MVFR CEILINGS EXPECTED TO CONT TO DROP INTO IFR CAT OVERNIGHT. STILL
APPEARS THAT MANY OF THE SITES WILL HAVE A PERIOD OF POTENTIAL ICING
ISSUES OVERNIGHT INTO FIRST PART OF DAY ON TUESDAY WITH PERIODS OF
FREEZING DRIZZLE OR LIGHT FREEZING RAIN BEFORE TEMPS RISE TO ALLOW
PRECIP TO TRANSITION TO LIQUID RAIN OR END. OTHERWISE STRENGTHENING
SFC LOW WILL MEAN AN INCREASE IN WIND SPEEDS ALONG WITH WIND SHIFT A
COLD FRONT ENTERS NORTHWEST AROUND 00Z WED AND THROUGH ALL REMAINDER
SITES BETWEEN 02Z AND 03Z.
30
&&
.PREV DISCUSSION... /ISSUED 1002 PM CST MON DEC 7 2009/
.UPDATE...
ALTHOUGH ELEVATED ECHOES HAVE BEEN SHOWING UP ON AREA RADARS DURING
THE EVENING...LITTLE IF ANY PRECIP HAS BEEN REACHING THE GROUND.
HOWEVER...IN THE LAST HOUR OR SO LIGHT RETURNS HAVE BEGUN TO SHOW
UP CLOSER TO THE RADARS...ESP KTLX AND KFDR. THIS MAY BE
INDICATIVE OF LIGHT DRIZZLE BEGINNING TO DEVELOP. EXPECT THIS
TREND TO CONTINUE OVERNIGHT WITH WAA INCREASING. WILL EXPAND THE
WINTER WX ADVY A ROW OF COUNTIES FURTHER SOUTH AS MESONET SHOWS
TEMPS IN THESE STILL BELOW FREEZING AND THIS IS ALSO WHERE SURFACE
OBS SHOW VSBYS LOWERING IN FOG/DRIZZLE. OTRW...GENERAL TREND OF
THE FORECAST APPEARS TO BE ON TRACK AND WILL NOT MAKE ANY CHANGES
FURTHER OUT.
&&
.PREV DISCUSSION... /ISSUED 510 PM CST MON DEC 7 2009/
AVIATION...
MVFR CEILINGS WILL GRADUALLY DROP INTO IFR CATEGORY LATER TONIGHT
RESTRICTED VISIBILITIES ALONG WITH THE POTENTIAL TO SEE SOME
FREEZING DRIZZLE WILL ALSO OCCUR... MAINLY AFTER MIDNIGHT. CEILING
WILL AGAIN TRANSITION BACK INTO MVFR CATEGORY BY MIDDAY ON TUESDAY
AS SFC WINDS INCREASE. THESE WINDS ARE LIKELY TO BECOME QUITE STRONG
BY LATE IN THE FORECAST PERIOD...ESPECIALLY ACROSS SOUTHWEST OK INTO
WESTERN NORTH TEXAS.
30
PREV DISCUSSION... /ISSUED 242 PM CST MON DEC 7 2009/
DISCUSSION...
STRONG STORM SYSTEM TAKING SHAPE ACROSS THE SOUTHWESTERN STATES WILL
BRING A MIX OF WEATHER CONDITIONS TO THE FA TONIGHT INTO TUESDAY
NIGHT. MODELS HAVE/ARE STRUGGLING WITH NEAR SURFACE TEMPERATURES
IN THE WAKE OF RECENT COLD FRONT. APPEARS MAIN PRECIP WITH THIS
SYSTEM WILL FALL WEST/NORTH AND EAST OF FA...BUT SHOULD SEE AREAS
OF FREEZING DRIZZLE AND/OR LIGHT FREEZING RAIN TONIGHT INTO
TUESDAY. MODEL SOUNDINGS ALSO SUGGEST THAT PRECIP ACROSS
NORTHWEST/NC OKLAHOMA TONIGHT MAY START AS LIGHT SNOW. ISSUED
WINTER WEATHER ADVISORY FOR THIS EVENING INTO TUESDAY. HAVE HAD
SYSTEMS IN THE PAST THAT HAVE PRODUCED LIGHT AMOUNTS OF PRECIP BUT
HAVE CAUSED SIGNIFICANT IMPACTS TO TRAVEL. WOULD LIKE TO GIVE SOME
LEAD TIME WITH THE THOUGHT THAT HAZARDOUS CONDITIONS MAY DEVELOP
ON SOME ROADWAYS WITHIN THE ADVISED AREA.
ASSOCIATED SURFACE LOW WITH MID/UPPER TROUGH WILL MOVE ACROSS FAR
NORTHERN/SOUTHERN KANSAS TUESDAY/TUESDAY NIGHT. 8H WINDS AROUND
50-60 KTS ARE EXPECTED ACROSS SOUTHERN HALF OF FA. ENOUGH CLEARING
AND MIXING MAY ALLOW FOR WINDS TO APPROACH 45-50 MPH ACROSS SOUTHWEST
OK/WESTERN NORTH TEXAS. APPEARS BETTER TIMING FOR STRONGER WINDS
WILL BE ACROSS TEXAS PANHANDLE. WILL DEFER TO LATER SHIFTS FOR WIND
ADVISORIES ETC.
STRONG CAA AND GUSTY NORTHWEST WINDS WILL PRODUCE SINGLE DIGIT
WIND CHILL VALUES ACROSS NORTHERN HALF OF OKLAHOMA TUESDAY
NIGHT. MOST OF THE PRECIP WILL BE NORTH AND EAST OF
AREA BY MID EVENING TUESDAY.
ANOTHER COLD DAY IS FORECAST FOR WEDNESDAY WITH VERY COLD TEMPS
EXPECTED BY THURSDAY MORNING. GENERALLY CLEAR SKIES AND
MUCH LIGHTER WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING. MANY
AREAS MAY SEE THE COLDEST READINGS SO FAR THIS SEASON.
WILL MAINTAIN LOW POPS FOR LATE THURSDAY INTO FRIDAY AS A WEAK
WAVE APPROACHES WITHIN FAST WESTERLY FLOW.
BOTH THE GFS AND EC BUILD "TRUE" ARCTIC AIR SOUTHWARD FRIDAY INTO
THE WEEKEND. EC IS MUCH MORE AGGRESSIVE WITH CENTER OF 1035 HIGH
OVER EASTERN NEBRASKA BY 12Z SUNDAY. AGREE WITH DDC THAT THIS
SITUATION HAS MAJOR BUST POTENTIAL SUNDAY INTO EARLY NEXT WEEK.
PROBLEM WITH EC MODEL IS HOW QUICKLY THE COLD AIR IS ERODED. FOR
NOW...WILL TWEAK NUMBERS DOWN TO THE COLDER SIDE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 31 43 21 31 / 60 60 10 0
HOBART OK 29 44 21 35 / 60 40 0 0
WICHITA FALLS TX 32 52 25 39 / 20 30 10 0
GAGE OK 21 45 12 29 / 60 60 0 0
PONCA CITY OK 26 39 18 27 / 70 80 30 0
DURANT OK 34 47 29 38 / 50 70 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 9 AM CST TUESDAY FOR OKZ014>031-
033>036.
WINTER WEATHER ADVISORY UNTIL 4 PM CST TUESDAY FOR OKZ004>013.
TX...NONE.
&&
$$
02/30
