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Excessive Rainfall Discussion
(Caution: Version displayed is not the latest version. - Issued 1528Z Dec 06, 2022)
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Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1028 AM EST Tue Dec 06 2022

Day 1
Valid 16Z Tue Dec 06 2022 - 12Z Wed Dec 07 2022

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


Day 2
Valid 12Z Wed Dec 07 2022 - 12Z Thu Dec 08 2022


...North Texas and Eastern Oklahoma eastward into the western
Tennessee Valley...
Southern stream trough pivoting through the Southwest on Wednesday
move across the central-southern Rockies and High Plains Wednesday
night. As this occurs, the downstream upper level ridging
underneath the broad/deep low centered over north-central Canada
will result in upper level confluence and an eventual jet streak
across the Central Plains and Upper Midwest on Day 2. Increasing
southern-stream forcing (deep-layer Qs convergence), coupled with
the frontogenetic, entrance-region upper jet forcing from the
northern stream (Qn convergence) will make for a favorable
environment for deep layer lift across the outlook areas. Both the
GEFS and SREF show a relatively quick bout of robust low-mid layer
moisture transport, with 8500-700 mb moisture flux anomalies
topping out between +3-3.5. PW values are just as anomalous, with
a stripe of 1.5-1.7" PWs traversing the outlook areas Wed and Wed

The progressive nature of the favorable forcing
(forward-propagating Corfidi or MBE vectors), along with the
relative lack of deep-layer instability (MUCAPEs generally less
than 750 J/Kg) will be the primary inhibitors to the flash flood
risk. In addition, per the latest NASA SPoRT analysis, 0-100cm
soil moisture percentiles are running between 10-30% of normal
across much of the outlook area. Nevertheless, per collaboration
with WFOs TSA, OUN, LZK, and SGF, given the anomalous degree of
deep-layer forcing and moisture, consistent with the 00Z
GEFS-based first-guess fields, will maintain a targeted Slight
Risk across parts of central-eastern OK into northwest-north
central AR and southwest-south central MO, with a surrounding
Marginal Risk from North Texas east-northeast across the western
TN Valley.


Day 3
Valid 12Z Thu Dec 08 2022 - 12Z Fri Dec 09 2022

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


Day 1 threat area:
Day 2 threat area:
Day 3 threat area: