Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
356 PM EDT Mon Oct 03 2022
 
Day 2
Valid 12Z Tue Oct 04 2022 - 12Z Wed Oct 05 2022 

...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL ACROSS PORTIONS 
OF THE SOUTHWEST AND THE SOUTHERN ROCKIES/HIGH PLAINS...

...2030Z Update...

No changes made with this update. The expected precipitation 
across much of NM and small portions of the neighboring states 
remains unchanged.

Across the mid-Atlantic through southern New England, there 
remains significant disagreement among the guidance on rainfall 
locations and intensity. Thus far today, rainfall rates have been 
unimpressive even in the areas getting the heaviest rain, largely 
staying under 1/4 inch per hour. Thus, despite continued large 
differences on where the core of the heaviest rain will be, think 
rainfall rates on the whole will remain under values needed for 
flash flooding. Note that portions in today's MRGL risk (southern 
NJ, northern DE & Philadelphia) have low FFGs, such that rapid 
training may result in an isolated flash flooding risk. Thus, a 
future upgrade to a MRGL in this area may be needed for Tuesday, 
but is not expected at this time.

Wegman 

...Previous Discussion...

The shortwave trough will continue to dip southeast across the 
southwestern U.S., pushing a cold front farther south and east 
into the southern Rockies and High Plains during this period. The 
anomalously moist airmass will remain pooled near the boundary 
which will continue to maintain and support diurnal thunderstorms. 
Some of these storms may reach or exceed 0.50 inch/hr intensities 
which increases the risk for potential flash flooding. A Marginal 
Risk for excessive rainfall remains in effect from southern 
Arizona/New Mexico to central Colorado and the panhandles of 
Oklahoma and Texas.

Campbell
 
Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt