Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
803 PM EDT Mon Apr 22 2024

Day 1
Valid 01Z Tue Apr 23 2024 - 12Z Tue Apr 23 2024

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Orrison


Day 2
Valid 12Z Tue Apr 23 2024 - 12Z Wed Apr 24 2024

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Roth/Kleebauer


Day 3
Valid 12Z Wed Apr 24 2024 - 12Z Thu Apr 25 2024

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

...In and near OK...

Guidance continues to show an area of convective development across
central and eastern OK within a low-level convergence field
associated with a stalled boundary over the southern plains north
of the Red River. Modest instability located over the region due
to active return flow regime will aid in the convective pattern and
create an environment capable of low-end flash flooding concerns,
especially within any training cells within the confines of the
stalled front. All guidance, to some degree has a QPF maximum
focused between north-central OK over into the Lower Mississippi
Valley which correlates well with recent ML guidance placement, as
well as CIPS historical analogs within a similar synoptic
evolution. The conundrum becomes a two fold issue of QPF magnitude,
as well as agreement within the deterministic on where the best
threat will lie. Spread within the latest NBM and GFS/ECMWF
ensemble suites remains high with the lower and upper quartile
outputs a solid 1-1.5" apart with a slightly higher skewed mean
closer to the 75th percentile. This lends credence to potentially a
MRGL risk implementation in later forecasts, but there was not
enough consensus to warrant an upgrade at this time when factoring
in higher FFG indices in place over the areas in question.
Considering the setup, this is likely a better case of short term
upgrades in the D1/2 periods as CAMs enter the equation and can
provide some answers on the convective placement, and QPF footprint
when incorporating hi- res ensembles. Have maintained the nil
forecast as a result.

Kleebauer


Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt
Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt