Quantitative Precipitation Forecast
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000
FOUS30 KWBC 122001
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
401 PM 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

...A MARGINAL RISK OF EXCESSIVE RAINFALL IS IN EFFECT ACROSS
PORTIONS OF THE CENTRAL PLAINS AND MID-MISSISSIPPI VALLEY...

Sharpening trough out west will aid in the development of a lee
surface low within the front range of the Rockies on Wednesday,
strengthening through the period with accompanying 85H and 7H low
pressures ejecting eastward into the plains. A warm front will
develop ahead of the surface reflection across the central plains
and Mid-Mississippi Valley, lifting north through the afternoon
time frame. A surge of elevated theta-E`s will occur south of the
warm front with Gulf moisture advecting north thanks to prominent
southerly flow ahead of the surface low to the west. Instability
fields across guidance have become more robust over the past 24
hrs, along with the addition of the latest CAMs guidance at range
in agreement with the global deterministic. Mid-level shortwave
ejecting from the southwest within the difluent pattern aloft will
help trigger a round of convection across portions of the plains
within the confines of the warm front generally positioned over
eastern KS into western MO, advancing northward towards the NE/IA
border as the boundary continues its northward propagation.
Locally heavy rainfall in excess of 1"/hr is becoming more likely
with the latest 12z HREF probability fields signaling a stripe of
up to 30% probability for exceeding the above interval during the
Wednesday evening time frame, along with a 20-30% signal for at
least 2"/3-hrs positioned over southeastern NE into northwest MO.
This is generally along the warm front where hi-res deterministic
has been most bullish in the general placement of the boundary and
areal thunderstorm coverage during the initial development
tomorrow evening.

As we head through the overnight into Thursday AM, there`s some
discrepancies on the handling of the maturing 85H low as it ejects
eastward through KS. The trend has been for a strengthening of the
subsequent 85H low in-of central and northern KS which would
provide ample support for a band of heavy rainfall to the north of
the closed circulation within the developing CCB axis. Convective
risks will be much lower due to the lack of sufficient buoyancy
more co-located downstream along and south of the warm front.
However, the ample moisture available within a broad expanse of 2+
deviations above normal PWATs signifies another local QPF maximum
somewhere within the northern periphery of the low-level
circulation. As of now, the prime candidate is likely within
eastern NE where some deterministic shows north of 1" QPF within a
6-12 hr window after 00z Thursday, even some deterministic
eclipsing 2" over the time frame of note. Latest ECMWF ML model
output is also fairly consistent in showing a secondary QPF
bullseye within the aforementioned zone, capable of localized
flood potential within any small towns or urban corridors near
Omaha/Lincoln. As of now, have added a MRGL risk encompassing the
Quad state area across northeast KS, northern MO, central and
southern IA, as well as eastern NE. Recent drought will likely
limit some significant impacts within the above corridor, but hard
soils from the lack of precip this winter and the threat of
training within generated cold pools in the convective area of
interest may lead to isolated flash flood returns, especially in
any storms that exceed 1.5"/hr or greater.

Kleebauer



Day 3

The Day 3 outlook will be updated by 2030Z.


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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