Area Forecast Discussion
Issued by NWS Oklahoma City, OK

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KOUN 292023
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
323 PM CDT Wed Mar 29 2017

.DISCUSSION...
Primary forecast focus is on continued rain chances today and a
return chance for thunderstorms, possibly severe, on Saturday.

Just a note, quite a significant and fascinating heavy rain and
flooding event last night for western north Texas into
southwestern Oklahoma and central Oklahoma. The heaviest swath of
rain fell, generally, along and near the I- 44 corridor. I
haven`t seen a stalled/backbuilding MCS quite like that since
perhaps May 31, 2013 over the OKC Metro. Looking back at the
ingredients, briefly this morning, how the event unfolded fits
quite well with Corfidi`s work with MCS maintenance and motion,
1996, 1998, and 2003. As the low levels began to saturate, it
fostered an unfavorable environment for the development of
convective downdrafts, overall. This would suggest a lack of a
decent mesohigh formation, resulting in low forward propagation
as new development would nearly offset any propagation. This was a
fascinating case, and will be looked at much closer, as there are
several details I`m sure I glossed over here.

This afternoon, scattered showers and light rain continue to develop
across portions of western Oklahoma into the Panhandles and western
Kansas. GOES-16 five minute water vapor imagery paints, quite
literally, a beautiful picture of the evolving progression of the
upper low. Of note on channel 10, low level water vapor, has been
the advancing dry slot from east of the Big Bend into eastern
Oklahoma. Oklahoma mesonet sites are picking up on this trend, with
recent dew points in the upper 40s cropping up along the I-35
corridor in far southern Oklahoma. With this in mind, confined the
best chances for rain to western and northern Oklahoma, where the
better isentropic ascent will reside as the upper low lifts
east/northeast through the evening and overnight.

Into tomorrow, the 500mb trough will continue to exit to the east,
finally sliding along the Ozark Plateau by midday. Low rain chances
will linger on the backside of the exiting trough, across north
central Oklahoma, through midday. Overall, still expect mostly
cloudy conditions for much of Oklahoma, as low clouds will trail the
exiting trough. Dry conditions can be expect through the remainder
of the day, with clearing in the afternoon helping temperatures push
back into the 70s across western north Texas. Upper level Ridging
will increase into Friday across the southern plains. A weak surface
trough will position itself west-east across the region, with warm
southerly flow resulting in highs in the upper 70s and 80s across
Texoma.

For Saturday, current water vapor shows a developing, off shore,
Pacific northwest low. Mid-range guidance remains in rather decent
agreement into the weekend. Expect the current Pacific Low to dig
across the Cascades, into the Intermountain west by Friday morning.
The 500mb trough axis will pivot over the Four Corners opening up
the southern plains to sufficient return flow from the Gulf through
Saturday morning. By daybreak, expect a defined dry line to be
shaping up along the Llano Estacado, with a potential for some
morning convection across northwestern Oklahoma, focused along a
pseudo warm front early. Through midday, the dry line will advance
eastward into western Oklahoma and western north Texas. Modest
instability, 800 to 1500 J/kg and shear will support scattered
thunderstorms, capable of severe hail and wind. Initially isolated
development, will merge into one or more complexes through the
evening, as storms move across central into eastern Oklahoma into
early Sunday.

Scattered showers and lingering thunder will hang around on Sunday,
as the parent, upper trough begins to swing and deepen towards the
Rio Grande Valley. Thunderstorms will remain possible through Monday
morning, across primarily southern into eastern Oklahoma, as the
upper trough finally lifts east by Monday night.

Kurtz

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  44  60  43  72 /  30  10   0   0
Hobart OK         43  67  43  74 /  30  10   0   0
Wichita Falls TX  47  71  47  83 /  10  10   0   0
Gage OK           39  63  39  66 /  40  10   0   0
Ponca City OK     44  51  39  66 /  40  40  10   0
Durant OK         48  65  46  80 /  20  10   0   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&

$$

06/04


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.