Quantitative Precipitation Forecast
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000
FOUS30 KWBC 121546
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1146 AM EDT Tue Mar 12 2024

Day 1

Valid 16Z Tue Mar 12 2024 - 12Z Wed Mar 13 2024


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

Oravec/Kleebauer.


Day 2

Valid 12Z Wed Mar 13 2024 - 12Z Thu Mar 14 2024

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

Oravec.


Day 3

Valid 12Z Thu Mar 14 2024 - 12Z Fri Mar 15 2024

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE LOWER ARKANSAS VALLEY INTO THE LOWER MISSISSIPPI VALLEY...

The low level southerly flow is expected to strengthen
significantly late Thursday into early Friday across the eastern
portions of the Southern Plains into the Lower Arkansas and Lower
Mississippi Valleys downstream of the strengthening closed low
over the Southern Great Basin,  PW values expected to rise to 2 to
2.5+ standard deviations above the mean in this increasing PW
axis.  Overall favorable large scale conditions, strong frontal
convergence, well defined upper difluence, in this anomalous PW
axis will support increasing convection late Thursday into the
early hours of Friday along and ahead of the strong front pushing
southeast through the Southern Plains into the Lower Arkansas
Valley.  There continues to be north-south model spread with
respect to where the max convective qpf axis will set up.  The NAM
is the farthest north, EC, EC mean and CMC, the farthest south and
the GFS, GEFS mean and UKMET in between.  The slight risk was
drawn to encompass the current model spread, with only some minor
changes from the previous outlook for this period.  The slight
risk is across areas that have had below average precip over the
past few weeks and subsequently relative high FFG values.   The
heaviest precip totals over the past few weeks and the most
saturated soils area well to the southeast of the slight risk area
across portions of the South and Southeast.  Given this and the
continued spread in the max qpf axis, the risk was kept at slight
for the time being.  The biggest change to the previous outlook
was to trim the north end of the marginal risk to the south from
northern Illinois to southern Missouri/far southern Illinois.
Model consensus is for mostly moderate precip amount here, across
a region where soils are not saturated.

Oravec




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


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