Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Mon Oct 02 2023

Day 1
Valid 12Z Mon Oct 02 2023 - 12Z Tue Oct 03 2023

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE SOUTHERN HIGH PLAINS...

...Southern High Plains...

An upper trough propagating through the West will trigger showers
and thunderstorms across the High Plains today. The Southern High
Plains, in particular, will face the threat of excessive rainfall
and flash flooding. PWATs will be between 1-1.5" with decent low
level southerly flow. The instability this afternoon will be over
1000J/Kg meaning storms that initiate could produce efficient rain
rates of over 0.5"/hr over recently saturated soils. The Slight
Risk area, in coordination with ABQ, was expanded northwestward
since the last issuance to account for the especially vulnerable
Hermits Peak Calf Canyon burn scar. The Slight's southwestern
extent was maintained to account for a consistent GFS and HREF
signal for another round of late night/early morning convection
near Pecos and Monahans in west Texas. HREF probabilities are
hitting on high confidence of over 3" in that area tonight.

...Florida...

The Marginal Risk area from the last issuance was curtailed to
encompass only southeastern Florida surrounding the eastern Keys
and the Miami metro. A slow moving surface front is expected to
continue its southward trajectory today. The main threat of flash
flooding will be over the urban corridor where there's moderate
confidence of HREF probabilities reaching over 3".

...Texas Coast...

There's been a persistent signal for some heavy rain to occur
along a convergence zone within southern Gulf Coast of Texas
today. Ample instability around 1500-2000J/Kg and a modest low
level jet will support a few intense rounds of convection this
afternoon. HREF probabilities suggest moderate confidence of over
3" of rainfall. Urban areas such as Corpus Christi will be
susceptible to flash flooding.


Kebede



Day 2

The Day 2 outlook will be updated by 0830Z.


Day 3
Valid 12Z Wed Oct 04 2023 - 12Z Thu Oct 05 2023

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE SOUTHERN PLAINS...

There is growing confidence in a heavy rainfall event unfolding
over much of the Southern Plains of Oklahoma and north-central
Texas on Wednesday. The operational models have been signalling
2-4" (locally higher) for much of the current Slight Risk area
centered over the Red River for the last several runs. The
amplified upper trough swinging through the Great Plains and upper
jet crossing will provide ample forcing of convection over Texas
and Oklahoma. Sufficient instability of over 1000J/Kg will be in
place with low level jet support to allow for higher rain rates.
Further upgrades are possible if confidence continues to grow.


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