Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tulsa OK
442 am CST Monday Dec 22 2014
concerning taf sites ktul/krvs/kbvo/kmlc/kxna/kfyv/kfsm/krog.
MVFR/IFR ceilings...drizzle...and light fog will continue through the
first several hours of the valid taf period before a shift to
westerly winds finally scours out the low level moisture that has
been present for the last several days. VFR conditions are
expected by this evening at all terminals...and should continue
into tomorrow morning. Improvement will generally occur from west
to east...with the western Arkansas terminals the last to become
Previous discussion... /issued 253 am CST Monday Dec 22 2014/
low clouds along with patchy drizzle/areas of light rain will
persist again today...with a weak surface boundary pushing through
late in the day. May have enough drier air behind this boundary
too see some breaks in the clouds across parts of eastern OK late this
afternoon...with additional clearing likely overnight for much of
Available guidance in reasonable agreement that a portion of the
longwave trough will close off across OK by late Tuesday and quickly
track east into Arkansas by Wednesday morning. Could see a mix of rain/sleet
and snow initially develop across portions of NE OK Tuesday
evening...with the light wintry precipitation developing into far NE
OK and northwest Arkansas later Tuesday night into early Wednesday. Potential
accumulations appear low at this time...with perhaps up to an inch
possible in the higher terrain of northwest Arkansas.
After a chilly Wednesday...temperatures will quickly rebound
Christmas day as south winds develop ahead of the next upper wave.
The forecast for the coming Holiday weekend may be getting a bit
messy...as extended models differ on handling of next upper wave.
00z European model (ecmwf) is the strongest...slowest and farthest south...and
develops more precipitation across the forecast area (mainly south
of I-40). GFS keeps the area dry while the Gem is somewhat inbetween
the ECMWF/GFS. Precipitation type will be highly dependent on
surface temperatures...and it's not out of the question to see a period of
some light freezing rain across southeast OK early Saturday. Have opted to
introduce slight chance probability of precipitation for now...but I must stress that this
is a very low confidence forecast.
Have kept the remainder of the extended forecast seasonally cool and
dry for now...although European model (ecmwf) is hinting at another potential wintry
mess early next week.