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< Day 1 Outlook Valid Through 12Z Today
Day 2 Outlook >
WPC Day 1 Excessive Rainfall Outlook Risk of 1 to 6 hour rainfall exceeding flash flood guidance at a point
Updated: 0058 UTC Fri Jan 22, 2021
Valid: 01 UTC Jan 22, 2021 - 12 UTC Jan 22, 2021
Forecast Discussion
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
801 PM EST Thu Jan 21 2021
Day 1
Valid 01Z Fri Jan 22 2021 - 12Z Fri Jan 22 2021
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE LOWER MISSISSIPPI VALLEY...
...Central Louisiana through southern Mississippi and into
southwestern Alabama...
Areas of moderate rain have developed this evening along a
stationary front over central LA and south-central MS. Ample
moisture is converging on this front with precipitable water
values of 1.6 to 1.8 inches which is about 2.5 standard
deviations above normal and near climatological max values for
late January. However, limiting factors include a lack of
instability (MUCAPE around 250 J/Kg) and rather dry antecedent
conditions (7-day rainfall totals are near zero and soil
saturation only about 50% per the HRRR). So this will mainly be a
beneficial rain, but should repeating activity late tonight go
over areas that receive around 2 inches per the 23Z HRRR, there
may be localized runoff issues. Narrowed the Marginal Risk area a
little on the north side given regional radar trends and 12hr QPF
overnight from recent CAMs.
Jackson
Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt
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