Area Forecast Discussion
Issued by NWS Oklahoma City, OK

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000
FXUS64 KOUN 121129
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
629 AM CDT Tue Mar 12 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 251 AM CDT Tue Mar 12 2024

Return flow is ongoing tonight as southerly winds have brought low-
40s dewpoints across the entire area. Those winds are expected to
intensify this morning especially north of I-40 as the LLJ
translates eastward.

This eastward displacement of the LLJ is partially why greater wind
speeds aren`t expected this afternoon in spite of an otherwise
favorable environment. A weak surface front will leak into northwest
Oklahoma this afternoon. Ahead of it, expect the usual prefrontal
trough to develop with downsloping west-southwesterly surface winds,
strong mixing, and highs reaching into the low 80s. It is within
this corridor that fire weather is likely to be maximized this
afternoon. It is the relatively tame winds that will act as a
mitigating factor on higher-end fire weather, and elevated fire
conditions are expected across northwest and western Oklahoma.

The front will push toward the I-44 corridor before being subsumed
by a fresh slug of southerly return flow as the surface trough
reintensifies in southeast Colorado. Lows tonight will be well above
normal across western north Texas and southern and central Oklahoma,
where return flow will continue to increase moisture quality until
surface dewpoints are in the mid-50s. Several models show stratus
development in southeast Oklahoma just before daybreak, which
seems reasonable given the moisture advection in place.

Meister

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 251 AM CDT Tue Mar 12 2024

Several active weather days in a row are expected to begin the long-
term period, beginning on Wednesday. As a jet streak begins to move
into the western US, the northern branch of the recent split-flow
regime will depart, allowing the southern stream to dominate. The
lead wave of this southern stream will approach the southern Plains
tomorrow afternoon, and recent model guidance has strongly trended
toward amplification/negative tilting of this lead wave. This will
have sensible impact as cyclogenesis occurs in southwest Kansas,
sharpening the dryline during the day. To the west of this dryline,
a somewhat concerning signal exists for near-critical fire weather
across western Oklahoma and western north Texas. Here, guidance
(most notably the HRRR and TTU WRF) are bullish in developing a
low-level thermal ridge which translates eastward throughout the
day. Very dry air (widespread relative humidity at or below 15
percent), very warm conditions (highs in the low-to-mid 80s,
especially within the LLTR), winds gusting up to 30-35 mph, and
rapidly drying fuels (ERCS in the 70th-89th percentile across
northwest Oklahoma) will lead to near-critical fire weather. A
fire weather watch has been issued for the western two columns of
counties in our area, with the expectation that a red flag warning
will likely be necessary.

To the east of the dryline, which should be very near I-35, a
conditional potential for severe weather will exist. Mesoscale
models are notoriously poor at resolving convection with dryline
forcing early in the season, and all model biases are somewhat
obfuscating the potential for CI. A synoptic-based forecast process
would suggest that the potential for convection to initiate in our
area Wednesday evening is low, but non-zero - the main difficulty
will be for the boundary layer to receive enough heating to
destabilize under a rather warm EML, and to do so without mixing out
the richer boundary-layer moisture that does happen to advect in. We
will continue to monitor this forecast, but for now the SPC`s
marginal risk for severe weather east of I-35 tomorrow seems
appropriate.

Rain chances will increase significantly during the day on Thursday,
as a stronger cold front pushes into the area and impinges on rich
boundary-layer moisture in southeast Oklahoma. Medium-range guidance
is in agreement that moderate instability (perhaps 1,500-2,500
MLCAPE) will exist in the warm sector, and there is plenty of reason
to expect convection to initiate. Strong to severe thunderstorms
will be possible, particularly with a 75-knot 300 mb jet to provide
plenty of shear for updraft organization. However, the LLJ will
likely be displaced to the east of our area, and thus this looks
like a "sloppy" event with plentiful convection. Large hail with
initial updrafts and excessive rainfall are likely to be the two
major concerns.

Storms will continue into the night Thursday as the front pushes
through. Further rounds of showers and thunderstorms are possible on
Friday and Saturday mornings, particularly across western north
Texas, as the trough out west spins itself out and embedded STJ
waves eject around its southeast flank. There`s a fair amount of
model spread for the weekend and early next week, but the northern
stream looks likely to dominate once more, with northwest flow
giving us a good look at average or below-average temperatures.

Meister

&&

.AVIATION...
(12Z TAFS)
Issued at 624 AM CDT Tue Mar 12 2024

VFR conditions expected to dominate at terminals. Low probabilities
(less than 30%) for MVFR cigs at KSPS and KDUA this morning so
will leave out of this issuance. However, probabilities go up
significantly tonight after 06Z at KDUA. This stratus could spread
farther west and north in later forecasts. Winds will be strongest
across central portions of Oklahoma today with weak front moving
into northern/western Oklahoma toward and after 18Z. Winds all
terminals will have diurnal weakening after 00Z.


&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  77  55  80  55 /   0   0   0   0
Hobart OK         79  50  81  47 /   0   0   0   0
Wichita Falls TX  80  57  85  56 /   0   0   0   0
Gage OK           79  43  80  40 /   0   0   0   0
Ponca City OK     80  50  79  52 /   0   0  10  20
Durant OK         75  58  78  62 /   0   0  10  20

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for OKZ004-005-009-010-014>016-021-022-033>036.

TX...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for TXZ083>085-087-088.

&&

$$

SHORT TERM...04
LONG TERM....04
AVIATION...11


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