FXUS64 KTSA 221129
AFDTSA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
529 AM CST TUE DEC 22 2009
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KMLC/KXNA/KFYV/KFSM.
DETERIORATING FLIGHT CONDITIONS ARE EXPECTED THROUGH THE FORECAST
CYCLE FOR ALL TAF SITES. LOW CLOUDINESS WILL CONTINUE TO EXPAND
THROUGH THE MORNING HOURS...WITH PREVAILING MVFR CEILINGS LIKELY
TOWARD NOON. INCREASING MOISTURE AND APPROACHING STORM
SYSTEM WILL ACT TO FURTHER LOWER CEILINGS AND PRODUCE PATCHY
DRIZZLE DURING THE EVENING. INCREASING CONVECTION LIKELY LATER
TONIGHT AT WHICH TIME IFR/LIFR CONDITIONS WILL BE COMMON.
&&
.PREV DISCUSSION... /ISSUED 333 AM CST TUE DEC 22 2009/
DISCUSSION...
SEVERAL DAYS OF ACTIVE WEATHER ARE ON TAP FOR
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS. AN
UPPER LEVEL LOW THAT IS CURRENTLY ACROSS THE
NORTHWESTERN UNITED STATES WILL DROP DOWN INTO
THE SOUTHWEST TONIGHT BEFORE SWEEPING ACROSS THE
PLAINS DURING THE WEDNESDAY THROUGH THURSDAY
TIME-FRAME.
THE CHANCES OF SHOWERS WILL ENTER THE FORECAST
THIS AFTERNOON ACROSS PORTIONS OF SOUTHEAST OKLAHOMA
AND WEST-CENTRAL ARKANSAS AS ISENTROPIC LIFT
INCREASES ACROSS THE REGION. SHOWERS AND EVEN
THUNDERSTORMS WILL BECOME MORE PREVALENT TONIGHT
AS THE THE LOW LEVEL JET INCREASES AND A MID-LEVEL
SHORTWAVE MOVES ACROSS THE REGION.
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE
ON WEDNESDAY AS A COLD FRONT ASSOCIATED WITH THE
UPPER LEVEL LOW MOVING OUT OF THE SOUTHWEST UNITED STATES
PUSHES INTO CENTRAL OKLAHOMA BY MID-AFTERNOON. THUNDERSTORMS
ARE EXPECTED TO DEVELOP IN THE VICINITY OF THIS SURFACE BOUNDARY
WEDNESDAY AFTERNOON AND TREK OFF TO THE EAST AS THE DAY WEARS ON.
SOME OF THESE STORMS COULD BE STRONG TO SEVERE WITH SURFACE BASED
CAPE VALUES APPROACHING 1000 J/KG AS TEMPERATURES SOAR INTO THE
60S AND DEWPOINTS TOP OUT IN THE 50S. THE THREAT FOR SHOWERS AND
THUNDERSTORMS WILL END WEDNESDAY NIGHT AS THE UNSTABLE AIRMASS
AHEAD OF THE SURFACE BOUNDARY MOVES EAST OF THE AREA. HOWEVER...
THE CHANCES OF PRECIPITATION WILL PERSIST IN THE WAKE OF THE FRONT
AS MOISTURE WRAPS AROUND AN ASSOCIATED SURFACE LOW AS IT MOVES OUT
OF NORTHEAST OKLAHOMA AND INTO WESTERN MISSOURI. LOOKS LIKE THERE
WILL BE A CHANGE OVER TO SNOW ACROSS MUCH OF THE AREA BEFORE THE
PRECIPITATION ENDS LATE THURSDAY NIGHT. THE MODELS (GFS/ECMWF/WRF)
ARE SUGGESTING THAT THE AREA WILL BE AFFECTED BY THE DRY SLOT
AND SNOW AMOUNTS WILL BE LIMITED. HOWEVER...COULD STILL SEE AN INCH
OR SO NEAR THE KANSAS/OKLAHOMA BORDER.
COLD AND WINDY CONDITIONS WILL BE THE MAIN CONCERN ON CHRISTMAS
DAY AS THE SURFACE LOW SPINS ACROSS NORTHERN MISSOURI AND SOUTHERN
IOWA. THE TEMPERATURES WILL ONLY MODERATE SLIGHTLY AS WE MOVE
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK AS HIGH PRESSURE
PREVAILS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 57 52 64 43 / 10 80 80 100
FSM 56 51 64 50 / 20 90 90 100
MLC 58 55 66 46 / 10 60 60 90
BVO 54 47 63 41 / 10 80 80 90
FYV 55 50 60 48 / 10 80 90 100
BYV 54 47 59 49 / 20 90 90 90
MKO 57 51 64 45 / 10 80 70 100
MIO 54 49 63 45 / 10 80 90 100
F10 56 53 66 44 / 10 70 60 90
HHW 60 57 66 47 / 20 60 70 90
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...07
