Thunderstorms Possible During The Week

I received a very good AFD from Putnam Reiter. I agree with many of
his thoughts and will echo much of it here.

- Scattered to numerous severe thunderstorms are possible late Sunday
into Monday. Primary threats are large hail and damaging winds. However,
isolated tornadoes are possible with discrete storms during the
overnight hours.

- Severe thunderstorms are possible on Monday.

- Severe thunderstorms are possible late Wednesday into Thursday.

Discussion:

Models are in decent agreement. Our cold front from a couple of days
ago returns tonight as a warm front, bringing a surge of gulf moisture
back north. A few thunderstorms may develop across eastern Oklahoma
overnight. I think fog will be significantly limited tonight by
stronger winds. An upper level storm is spreading high clouds into
Nevada tonight. This system will impact our area on Monday. There is
little to no upper support for storms on Sunday. With a strong cap in
place, convection will likely hold off until after dark, when the low
level jet strengthens.

Dew points in the 60s will move into the state on Sunday so there will
definitely be plenty of moisture. Capes will approach 2500 j/k across
south-central Oklahoma by afternoon. The problem is lack of a
significant lifting mechanism. Cap will be exceptionally strong, too
strong to break until close to dark, despite some clearing ahead of the
dry line. Models suggest the dry line will be along the Oklahoma-Texas
line with a low near Woodward and a merged cold and warm front
stretching northeast toward Alva and west of Wichita. It appears the
cap will be weakest northeast of the low from Woodward northeast where
thunderstorms are expected to fire in a line near sunset. An area of
high helicity is noted moving in from southwest Kansas. This would
cause any storms to spin during the evening and overnight period (hence
a threat of tornadoes). As noted in Putnam's discussion, the
orientation of the semi-stationary front is of particular concern as any
storm that can move along this boundary would have an enhanced tornado
threat, in northwest Oklahoma during the overnight period. I cannot
rule out an isolated storm breaking the cap in southwest or west central
Oklahoma near nightfall. It is unlikely but if one were to go, it would
definitely be a large hail producer with a small threat for tornadoes.

On a side note, the merged front will drift back north as a warm front
early on Monday. Far northwest counties might see a brief cool period
Sunday evening and late Monday as the front makes two passes through the
area. There will continue to be a lack of rain across our far western
border counties. The drought situation is of concern, and with the dry
line surging east on Monday, there will be an enhanced risk of wildfires
from west-central into southwest Oklahoma, and possibly behind the cold
front in northwestern Oklahoma. Both areas will have gusty winds.

There are indications of elevated severe convection developing above the
capping layer overnight across much of the state Sunday night. There
has been a mention of heavy rain along the stalled stationary front in
north-central Oklahoma/southern Kansas. I believe storm motion and
general dynamics will probably keep any flooding concerns along a narrow
corridor where training may occur. I do not expect a widespread flood
threat. As this activity moves into northern OK and Kansas during the
morning, clouds will begin to erode across western Oklahoma allowing the
dry line to mix east. Due to upper level cold air moving in from the
west with the upper level storm, the cap is expected to be very weak on
Monday. Models may be underestimating lack of cap but we shall see.
Thunderstorms could be in the form of a squall line with isolated
hailers and maybe a few rotating storms on the tail ends of breaks in
the line.

Overall, if you're looking to chase storms, I would be in northwest
Oklahoma close to Woodward near nightfall on Sunday, then near or just
west of Enid by noon Monday in hopes of getting a tornado near the point
where all the fronts intersect (the triple point). Potential for
driving around wasting gas and seeing nothing on Sunday is very high.
Potential for a worthless squall line chase near highway 81 on Monday is
quite high.

The system clears out on Tuesday giving us sunshine and breezy north
winds with highs near 60. The cold front previously mentioned takes yet
another run back north as a warm front on Wednesday (we can't seem to
get rid of it!). Strong to severe storms may form along it as a weak
shortwave aids in severe development during the evening hours. The
front is expected to lift north through OKC around 7 p.m. A dry line
sets up across western Oklahoma early on Thursday leading to another
high wildfire potential day. The dry line surges east, passing OKC
before noon. A cold front sweeps in behind it, passing through OKC
around 4 p.m. Model runs differ on the timing but this is the general
consensus.

Friday will turn out to be very nice day with light winds and highs in
the 60s. Windy conditions return Saturday with some high clouds
streaming across. HIghs will be in the 70s. Gulf stratus may greet us
Sunday morning, with highs near 80.

A dry line sets up in western Oklahoma next Sunday as well. A shortwave
is seen crossing the area by mid-afternoon, so an attendant threat of
severe weather is expected next Sunday again. The system clears out the
following Monday leaving us with sunshine. Preliminary indications are
highs will be in the 60s.

OKC 56/75 64/76 45/61 40/62 54/71 45/67 43/73 55/79 50/67
10% Sunday, 70% Monday, 40% Wednesday, 20% Thursday morning, 30%
following Sunday.

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Greg....used with permission