WCO issues Area Hydrological Discussion (AHD) at Sep 12, 6:26 AM CDT518
AGUS74 KWCO 121134
AHDNWC
Area Hydrological Discussion #261 - EXPERIMENTAL
NWS National Water Center - Tuscaloosa, AL
626 AM CDT Thu Sep 12 2024
WHAT: Significant flash, urban, and small stream flooding
WHERE: Mississippi and western Alabama
WHEN: Into the afternoon
FORECAST RAINFALL AND ANTECEDENT CONDITIONS:
QPF: 2 - 4", locally higher possible (HRRR, WPC)
QPE: Up to 2" (MRMS, past 12 hours)
Rates: Up to 1.5"/hr (HRRR/WPC)
Soils: Varies from nearly saturated to 40-60% RSM (0 - 10 cm soil
layer, NASA SPoRT)
DISCUSSION...
Significant flash, urban, and small stream flooding is possible
across the area of concern into the afternoon hours as Tropical Storm
Francine barrels inland. Areas further from the coast have received
little to no rainfall, and antecedent conditions are dry, with
topsoils in northern MS as low as 10% RSM and streamflows running
below seasonal norms. Down along the southern edge of the area of
concern, up to 2" of rainfall has already fallen, and
topsoils/streamflows are responding accordingly, with topsoils at 50
- 80% RSM and streamflow rising above season norms. These drier
antecedent conditions are helping to mitigate the threat of small
stream flooding, but the threat cannot be entirely ruled out. Flash
and urban flooding are currently the primary threats.
The NWM SRF continues to signal high probabilities (25 - 75%) for
rapid-onset flooding (ROF) across the area of concern through the
next 12 hours. The magnitude of signals from the high flow magnitude
service have decreased over recent runs and are currently showing
only isolated stream reaches crossing the 50% annual exceedance
probability (AEP) threshold. This supports the notion of small stream
flooding impacts being mitigated by the dry antecedent conditions.
GRAPHICAL REPRESENTATION weather.gov/owp/operations-ahd
Additional National Water Center products are available at
weather.gov/owp/operations
//Bliss
ATTN...WFO...JAN...MEG...BMX...MOB
ATTN...RFC...ORN...ALR...WPC
Source:
WCO issues Area Hydrological Discussion (AHD) at Sep 12, 6:26 AM CDT---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
