Subj : HVYRAIN: Excessive Rainfall Discussion
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Sun Apr 09 2023 00:33:41

FOUS30 KWBC 090033
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
833 PM EDT Sat Apr 08 2023

Day 1
Valid 01Z Sun Apr 09 2023 - 12Z Sun Apr 09 2023

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

Taylor


Day 2
Valid 12Z Sun Apr 09 2023 - 12Z Mon Apr 10 2023

....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE PACIFIC NORTHWEST...

21Z... The latest guidance has trended the QPF higher over central
portions of the Cascade Range with the onshore flow, with
consensus showing 1 to 3 inches reaching further inland. In
coordination with the local forecast offices the Marginal Risk
area for excessive rainfall was expanded east to include parts of
Lewis, Skamania, Clark and Cowlitz Counties. There may be isolated
areas where flash flooding arises.

Campbell

After a relative lull on Saturday...another round of rain should
be ramping up on Sunday as on-shore flow of deep-layered moisture
develops ahead of a low pressure system over the Gulf of
Alaska/eastern North Pacific ocean.  Instability is modest...at
best...but models still show onshore flow of 30 to 45 kts
developing behind a cold front.  The magnitude of the moisture
transport results in rainfall amounts of 1.75 to 3.0 inches or so
in the coastal ranges...most of that being focused in a 12 to 15
hour period.  For this reason...feel there is a low-end risk of
flooding focused in this area.  Concern would be higher if there
was more instability to support higher rainfall rates or a greater
magnitude of moisture transport into the complex terrain.

Bann


Day 3
Valid 12Z Mon Apr 10 2023 - 12Z Tue Apr 11 2023

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

Campbell






Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go=
v/qpf/94epoints.txt__;!!DZ3fjg!7UV3rgPKtl8sSHN1bs_Eb-_9RFSMvtNgNzyaWIK6UdXj=
OSwZasgA9vR7QZskPNPuOykaJUBOH2CeOEPjzRdwHeA0axg$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go=
v/qpf/98epoints.txt__;!!DZ3fjg!7UV3rgPKtl8sSHN1bs_Eb-_9RFSMvtNgNzyaWIK6UdXj=
OSwZasgA9vR7QZskPNPuOykaJUBOH2CeOEPjzRdwSxQ3Nqk$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go=
v/qpf/99epoints.txt__;!!DZ3fjg!7UV3rgPKtl8sSHN1bs_Eb-_9RFSMvtNgNzyaWIK6UdXj=
OSwZasgA9vR7QZskPNPuOykaJUBOH2CeOEPjzRdw5AMkGD8$=20


$$



=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email
Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.14-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

.