Mesoscale Precipitation Discussion 0628
NWS Weather Prediction Center College Park MD
505 PM EDT Fri Aug 10 2018

Areas affected...Southwest NM, Central & Southeast AZ

Concerning...Heavy rainfall...Flash flooding POSSIBLE

Valid 102102Z - 110302Z

Summary...Showers and thunderstorms are beginning to develop
across the area.  Hourly rain totals to 2" could lead to issues.

Discussion...Veggie Band Goes-16 imagery shows showers and
thunderstorms developing across central and southeast AZ as a
shortwave slowly pushes south across northern AZ.  The flow at 700
hPa is north-northeast at 10-15 kts, while the 850 hPa flow is
starting to back more west-northwesterly at 10 kts.  Precipitable
water values in the terrain are ~0.75" while southwest AZ has
1.5-2" values per GPS data.  The mean 850-400 hPa flow is quite
weak, around 5 kts.  ML CAPE across the region is 500-2000 J/kg
per SPC mesoanalyses.

With the low-level inflow exceeding the mean wind, heavy rainfall
is a concern within an environment of greater than average
moisture.  There is some concern that activity in southeast AZ may
see greater organization at RAP mass fields show 700 hPa winds
reaching 20 kts by 01z.  The available moisture supports hourly
rain totals to 2" where cells merge and/or train.  Storms are
expected to move generally southwest at 10-15 kts.  The 12z HREF
probabilities of 1"+ an hour suggest activity should maximize in
northwest AZ in 2-3 hours, but could keep going beyond 04z across
central AZ, which would need to be watched.

Roth

ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC...VEF...

ATTN...RFC...CBRFC...WGRFC...

LAT...LON   36881226 35761184 35121144 34771097 34160960
            34140893 33510799 33010782 32270818 31300903
            31140955 31121033 31381148 32561119 32881146
            33671256 34541324 35961334