Discussion By Greg Whitworth/Fox 25 Forecaster

Two monkey wrenches were thrown into the forecast today and there's two
more with the 0Z run.

Old problems:
1. GFS, although consistent, does not agree with NAM on Thursday storm.
2. GFS created a new cold front arriving Saturday morning which was not
there yesterday.

New problems:
3. GFS wants to bring the shortwave on Tuesday into northern OK instead
of leaving it in Kansas. This would result in snow far northern OK
Tuesday BUT I can't believe it because dryline would have passed,
sweeping moisture out. Perhaps a few high clouds/snow virga in northern OK.
4. GFS had a storm system coming out Sunday/Monday which now appears bogus.

I just looked at what was out from the 0Z run.. GFS run is not complete
yet but out to 114 hours. It should be a very mild start to Monday.
HPC frontal positioning looks completely off and was discarded for this
forecast. They had the warm front in western OK by sunrise when it
appears to already be technically sitting near the Oklahoma-Arkansas
border and wrapping back up to Topeka and west to Hays where it
intersects a developing trough that runs back into eastern New Mexico.
This will eventually turn into a dryline as it surges eastward Monday night.

Challenge for today was to decide how warm it would get, and how would
cloud cover play an impact? It appears we have two players.. mid level
and high level clouds. The high level clouds will continue to stream
across the state throughout the day. Mid-level clouds around 10,000
feet seen on visible satellite and surface obs out west will cover
Oklahoma by sunrise then move into the eastern part of the state during
the afternoon. The end result is that the western half of the state
will see scattered mid-level clouds, with a cirrus shield sitting above.

Models have been consistently too moist, but the GFS MOS hasn't been
doing too bad. I used it for temperatures, and went with highs in the
lower 70s widespread with 60s east of OKC. As a result of lower than
expected dew points, fire danger has been very high. Wildfires will be
a big concern again today with gusts over 40 mph much more common and
possibly some 50 mph gusts in western OK as pressure gradient is out of
control. With dryline moving into northwest Oklahoma during the
afternoon, dew points will drop. Hopefully we won't repeat the
situation we had west of Laverne where a 3/4 mile by 12 mile long area
burned Sunday. I think the dryline should pass OKC around midnight Monday.

NAM/WRF was showing stratus surging northward from Ardmore to Grove and
east into western Arkansas by 9 p.m. Monday night. Models have been
wanting to develop some convection in this area as all levels will be
pretty much saturated. I suspect it may wait until the dryline/front
passes which would be central Arkansas on Tuesday.

With southwest winds, lows will be near 40 going into Tuesday. The cold
front should arrive around 9 a.m., turning winds to the northwest.
Gradient will be quite tight again behind the front, and some models are
saying Tuesday morning's winds may be the worst yet. Winds will die
down quickly though on Tuesday and full sun will prevail. With dry air
in place, lows should fall back into the low 20s for Wednesday morning.

Winds pick up out of the south on Wednesday with full sun prevailing
again. This should push highs back up into the mid 50s in many areas,
with gusts over 30 mph again. It will also keep us from dropping below
freezing on Thursday. This is important in the upcoming winter storm
scenario.

There may be very little diurnal range in temperatures on Wednesday.
GFS and NAM/WRF are in significant disagreement on this storm. GFS
seemed to lose the Nebraska cold front attached to this system for one
run but has figured it out now and coming into better agreement with the
NAM. NAM tracks the low from northwest to southeast across the state.
GFS drops the low to Amarillo, then pulls it southeast to Wichita Falls
and eastward. This is significantly further south than it's previous
run and would place any heavy snow and roughly from Enid north and east
to Kansas City. I think we'll still get some in OKC but probably 1" or
less. GFS has not been consistent at all, waffling back and forth north
and south. NAM frontal solution looks better overall, however new
NAM/WRF leaves system almost completely dry through Thursday morning.
There is some upper support with this system coming out of the southwest
US so I don't think we should buy the dry solution. I am updating the
web feature graphic with the latest GFS snow forecast.

Friday should be completely sunny behind this system, with it becoming
windy out of the south again. A couple of weak short waves pass Friday
evening and Saturday which could lead to extensive high clouds Saturday
and Sunday. New GFS repeats the last one in having a cold front on
Saturday. It appears to be the tail end of a front in the great lakes
but does have a supporting low in western Okla. It was timing to pass
OKC around 3 a.m., now it looks like it may wait until Saturday
afternoon. This will end the moisture return and create another cold
night Sunday morning with lows perhaps near freezing. I was fidgeting
with temperatures and wound up leaving them the same. I did drop Sunday
some to account for this possible front, and additional cloud cover.

New 0Z run appears cloud cover will not be as widespread on Sunday. I
suspect I should have kept the high of 60. Winds will be strong out of
the south as a system develops west of the rockies. Stratus should
return by Sunday night. GFS is showing it's old ugly bias of developing
precip in the stratus Monday morning. This should be discarded. This
system almost looks to be a twin of the system we have going on right
now. In that case, it is entirely possible we may not see a drop out of
it. Upper trough is almost 24 hours slower with the new 0Z run. Appears
lead shortwave will arrive the following Tuesday morning. If we're
lucky we might see a line of storms Monday night out of it, I'm
thinking. Looks like any snow behind it would fall across the northern
TX panhandle and possibly NW Okla.

No surprise that winds turn to the south the following Wednesday as
another low develops along the lee of the Rockies. Perhaps another
chance of snow a week from Friday.

Forecast graphics:
http://www.okcfox.com/newsroom/wx/images/WEB_KOKH_STATE_FORECAST_1.JPG
http://www.okcfox.com/newsroom/wx/images/WEB_KOKH_STATE_FORECAST_2.JPG
http://www.okcfox.com/newsroom/wx/images/WEB_KOKH_7day.JPG

New GFS snow forecast:
http://www.okcfox.com/newsroom/wx/images/WEB_FEATURE.JPG