Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Norman OK
1216 am CDT Thursday Oct 2 2014
the taf package is quite complex this period...with several
factors impacting aviation. Initially...expect scattered rain showers/thunderstorms and rain to
persist overnight into the daylight hours Thursday. A cold front will
then sweep from northwest to southeast...and with upper support
increasing...a line of storms is expected to develop along the
I-44 corridor ahead of the front. This would impact terminals from
kpnc to kokc/koun...southwest to just east of klaw in the 12z to
19z timeframe. Storms should rapidly move east of terminals by 21z
to 22z. Strong and gusty winds...and very heavy rainfall can be
expected with stronger storms...with brief IFR visibilities. Behind the
front...gusty northwest winds can be expected with gradually
clearing skies. By 22z to 23z...VFR conditions should return to
Previous discussion... /issued 940 PM CDT Wednesday Oct 1 2014/
updated probability of precipitation for this evening and overnight with numerous showers
and storms expected near and just east of retreating dryline.
Highest probability of precipitation will be west of Interstate-44. A few of the storms
will likely reach severe levels with hail at least half-dollar in
size an briefly larger and marginal wind threat. Storms should
continue through the night and progress northward.
Previous discussion... /issued 632 PM CDT Wednesday Oct 1 2014/
the first part of the taf period will feature VFR conditions.
Some isolated thunderstorms and rain may develop in the 06z to 12z timeframe...but
confidence is rather low. A strong upper level storm and surging
cold front will move from northwest to southeast overnight and
through the afternoon hours Thursday. A line of storms is likely
to develop along this front...possibly affecting taf sites from
ksps/klaw northeast to kokc and kpnc. Will maintain prob30s for
potential thunderstorms and rain and associated reduction to visibilities. Primarily VFR
conditions should return to all terminals sometime after 21z.
Previous discussion... /issued 301 PM CDT Wednesday Oct 1 2014/
primary forecast concern remains focused squarely on ongoing
thunderstorms and development overnight through Thursday.
Currently... a line of cumulus and isolated showers/thunder continue to
develop along a narrow corridor of instability/lift from central
through northestern OK. This boundary is visibly on WV... similar to a pre-
frontal trough... associated with a 310k isentropic response. Given
cape values of 2000-3000 j/kg and 0-6km shear of 30-40kts across
central Oklahoma... any updrafts that develop this afternoon will have
the potential for being strong to severe. However... the better
potential exists in far north/NE Oklahoma and across eastern Kansas/western MO this
aftn/evening... where ongoing convection remains supported by a
better ll moisture/shear environment. For central OK... hail to the
size of half dollars and damaging wind gusts to 60 miles per hour will be the
primary concerns. Tornado potential remains low across central and
southern OK... with the better chances along the northestern OK/Kansas border
and southeastern Kansas... where the better ll shear environment exists... with
0-1km srh values increasing this afternoon to near 300 m2/s2.
Overnight... the larger western trough will dig across The Rockies
forcing a pre-frontal trough across the Southern Plains. Shower and
thunderstorm activity will increase along this boundary overnight...
timing/location of activity remains a challenge... as isolated to
scattered convection is expected initially. Better chances for
precipitation will increase late tonight/early Thursday morning as the primary
front finally pushes in from the northwest. Precipitation chances will exit to the
east through the late morning/aftn. Overall... continue to carry
slight to chance probability of precipitation across northwestern and central/southern OK... with better
chances across north central and eastern OK.
Behind the front... gusty north winds will usher in more Fall like
weather... with highs tmrw in the 70s across northwestern OK to the middle 80s
in central OK to the upper 80s across texoma. Expect temperatures to top
out in the 70s on Friday.
For the weekend... temperatures will rebound as upper level ridging
continues to build over the western Continental U.S.. highs will be back in the
80s by Sunday... continuing to climb well above average into early next
week as S/SW flow continues to persist. With h850 temperatures in the upper
teens/lower 20s by Wednesday... highs will mix out into the upper
80s across OK to the lower 90s across texoma.
Preliminary point temps/pops...
Oklahoma City OK 53 72 46 76 / 10 0 0 0
Hobart OK 52 74 48 78 / 0 0 0 0
Wichita Falls Texas 56 79 50 80 / 10 0 0 0
gage OK 45 71 44 79 / 0 0 0 0
Ponca City OK 51 69 40 73 / 10 0 0 0
Durant OK 57 78 48 75 / 20 0 0 0