Scientific Forecaster Discussion
fxus64 ktsa 192320
Area forecast discussion
National Weather Service Tulsa OK
520 PM CST Fri Jan 19 2018
concerning taf sites ktul/krvs/kbvo/kmlc/kxna/kfyv/kfsm/krog.
Low level moisture pooled over East Texas will begin to surge
north across eastern OK and western Arkansas this evening, with MVFR
ceilings becoming prevalent after 06z at all locations.
Strengthening low level jet will lead to substantial low level wind shear
overnight, especially at kfsm where sfc winds will become light
and easterly. Ceilings should improve by 18-21z Saturday in most
locations with gusty south winds continuing through the period.
Previous discussion... /issued 225 PM CST Fri Jan 19 2018/
Fire weather concerns thru Monday, as well as rain/thunder
chances/severity over the weekend with the next upper system and
cold front, will be the main points of emphasis for this forecast.
The warming trend continues today and thru the weekend. Temps as
of 2 PM have climbed well into the 50s, and will climb into the
60s and even some 70s possible by Sunday. The warmer temps,
combined with breezy south winds and favorable fuel conditions,
will raise fire weather concerns. The fire danger is higher today
than it will be on Saturday and much of Sunday, mainly due to
increasing moisture/humidity from the south. However, by late Sunday
afternoon the Pacific front/dryline is expected to surge into
eastern Oklahoma. Areas along and west of the Highway 75 corridor
could see conditions approach red flag warning criteria. The main
question will be how low dewpoints/relative humidity values get behind the
boundary, and can they get low enough before the gusty winds start
to back off as mixing ceases. The current forecast parameters are
not sufficient to warrant a Fire Weather Watch at this time, but
this will need to be monitored. Expect another very breezy day on
Monday in the wake of the system/cold front, and with dry air in
place, another elevated fire weather day is looking likely.
Today's suite of model data is no more aggressive, maybe even less
so, in forecasting any appreciable instability ahead of the
Pacific front/dryline Sunday afternoon and evening across east OK
into west Arkansas. Data continues to suggest that the best chance for
showers/storms will stretch from southeast OK into west Arkansas Sunday afternoon
and evening, though some low chance could extend as far west as
the Highway 75 corridor. With less than 500 j/kg of MUCAPE to
work with, the prospects of any severe weather are low. With the
strengthening of the kinematic fields, there's a limited risk of
damaging winds with any of the storms that get going. This
activity will shift quickly east toward central Arkansas Sunday night.
Much of next week looks quiet, with temps above average for this
time of year. A storm system could bring another chance for
showers and storms by the end of next week.
Preliminary point temps/pops...
tul 44 61 52 69 / 10 10 10 30
fsm 38 59 52 68 / 10 10 10 60
mlc 46 62 56 69 / 10 10 10 50
bvo 38 60 46 68 / 10 10 10 30
fyv 40 57 51 65 / 10 10 10 50
byv 40 57 48 65 / 0 0 10 20
mko 41 60 52 69 / 10 10 10 50
Mio 40 56 49 67 / 10 10 10 30
f10 42 62 53 69 / 10 10 10 30
hhw 43 61 55 69 / 10 10 10 70