Area Forecast Discussion
Issued by NWS Oklahoma City, OK

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FXUS64 KOUN 272334

Area Forecast Discussion
National Weather Service Norman OK
534 PM CST Mon Feb 27 2017

The 00Z aviation discussion follows....


A few TSRA may still occur in southeast Oklahoma this evening, but
none are expected at our TAF sites. Very low ceilings over eastern
Oklahoma may expand west enough to reach KPNC or KOUN, but more
likely is a layer closer to 1,500 ft toward 04-06Z, mainly along
and east of I-35. These clouds should be shunted east tomorrow
morning as strong south-southwest winds develop in a tight
pressure gradient. Winds will be quite strong over parts of
western Oklahoma Tuesday afternoon, where vertical mixing will
tap into very strong winds at the 850 mb level. A cold front will
arrive in northwest Oklahoma shortly after the end of this TAF
period, then sweep rapidly southeast during the overnight/early
morning on Wednesday.


.PREV DISCUSSION... /issued 402 PM CST Mon Feb 27 2017/

Primary forecast concerns are fire weather conditions/severe
weather potential for tomorrow.

Isolated showers/storms will remain possible across southeast
Oklahoma this morning within an area of isentropic ascent, but
expect coverage to remain limited. Otherwise, expect widespread
stratus to develop later tonight--generally along and east of

For tomorrow, a mid/level trough with a 90+ knot mid-level jet
will eject into the Southern Plains. Strong (50-60+ knot),
veering, 850-700 mb winds will allow the dryline to mix eastward
as a surface low tracks eastward across southern Kansas.

Deep mixing behind the dryline will allow these strong winds
above the surface to (partially) mix to the surface. Expect wind
gusts >45 mph near the 100th meridian. Unseasonably warm
temperatures are expected with a low-level thermal ridge in place.
The only caveat that may slightly temper high temperatures is
abundant high clouds. Nevertheless, the aforementioned synoptic
pattern will result in critical to extreme fire weather
conditions. More details in the fire weather section below.

Strong to severe thunderstorms are still possible across eastern
Oklahoma, where a very moist airmass is expected. Dewpoints will
be in the 60Fs, which will result in 1000-1500 J/kg of MLCAPE.
In addition, effective bulk shear is progged to be >60 knots.
This combination of instability and shear will be more than
sufficient for strong to severe thunderstorms. Currently, it
appears the best chance of storms will be just east of I-35.

A cold front will pass by tomorrow evening into tomorrow night
with gusty northerly winds. Expect a return to more seasonable
temperatures in its wake on Wednesday. As a surface ridge shifts
into the Southern Plains, many locations may see a freeze Thursday

A warming trend is expected into next weekend as southerly winds
return across the area. Temperatures are expected to be well-above
average by Sunday as another low-level thermal ridge develops
across the Southern Plains.


Upgraded part of the Fire Weather Watch to a Red Flag Warning
where there is the greatest confidence for extreme to critical
fire weather conditions Tuesday afternoon.

Both the GFS the latest HRRRX also indicate there might be a
corridor of drier air near the I-44 corridor between the dryline
and cold front. This area coincident with the location of a low-
level thermal ridge. There is some uncertainty how far east this
corridor may make it; however, expanded the Fire Weather Watch
farther east into Central Oklahoma to account for the uncertainty.

Will maintain a 9 PM expiration time; however, there is the
possibility that an extension will be needed if critical fire
weather conditions continue past 9 PM--especially because of the
strong northerly shift that will pass by Tuesday evening.



Oklahoma City OK  57  77  40  59 /  10  10  10   0
Hobart OK         49  77  37  60 /   0   0   0   0
Wichita Falls TX  56  81  42  62 /  10  10   0   0
Gage OK           46  75  31  57 /   0  10  10   0
Ponca City OK     55  77  37  57 /  10  10  10   0
Durant OK         61  76  47  63 /  20  30  40   0


OK...Fire Weather Watch from Tuesday afternoon through Tuesday
     evening for OKZ005-006-011-012-017>019-023>025-027>029-038-

     Red Flag Warning from noon to 9 PM CST Tuesday for OKZ004-009-

TX...Fire Weather Watch from Tuesday afternoon through Tuesday
     evening for TXZ086-089-090.

     Red Flag Warning from noon to 9 PM CST Tuesday for TXZ083>085-



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