Hail in Oregon, July 18, 2016

Area Forecast Discussion
National Weather Service Pendleton OR
240 PM PDT MON JUL 18 2016

.SHORT TERM...Tonight through Thursday afternoon...A low pressure
system near the wa/or coast will continue to spin disturbances
across our area into tonight. The disturbances will combine with
daytime heating to produce thunderstorms across the two state area
and some of the storms may become strong and produce gusty
winds...hail...frequent lightning with the greatest chances of this
occurring is southeast of a line from Madras Oregon to Walla Walla
Washington. The convective activity should decrease tonight but with
an upper level jet overhead some showers should persist into Tuesday
morning mainly over the southern and eastern sections of our area
along with the area mountains. As the low pressure remains nearly
stationary over the pacnw several disturbances will continue
drifting across our region and another round of developing
thunderstorms is forecast Tuesday afternoon and again Wednesday
afternoon before decreasing in coverage and intensity overnight.
While the low pressure remains along the wa/or coast the moisture
lessens over the region and the showers should be limited to the
area mountains over the eastern third of the area including the east
slopes of the wa cascades on Thursday afternoon. Temperatures
through the period should remain near normal.

.LONG TERM...Thursday night through Monday night...A mi/upper
level trough will be on the coast Thursday evening and introduce mid
level moisture and marginal instability Thursday evening for a
slight chance of Evening thunderstorms in central and NE Oregon as
well as far SE Washington. The trough moves across forecast area
over night and Friday morning for a chance of showers in the Blue,
Elkhorn and Wallowa Mountains and a slight chance of showers along
the foothills of the Blue Mountains. Flat zonal westerly flow aloft
takes over Friday afternoon for dry conditions. A mid/upper level
ridge of high pressure  then builds over the region and continues
through Saturday night. Models differ on whether or not a mid/upper
level short wave moving through the forecast area on Sunday will
produce any showers during the day on Sunday. As such I decided to
keep a dry forecast due to uncertainty. Sunday night through Monday
night a dry SW flow aloft continues for dry conditions Sunday night
through Monday night.  Polan

&&

.AVIATION...18Z TAFS...VFR conditions are expected to predominate
for the next 24 hours. However, visibility and/or ceiling could
deteriorate briefly to MVFR/IFR in showers and thunderstorms
especially at KRDM, KBDN, KPDT and KALW this afternoon/evening.
Winds will be light except for gusty and erratic winds near showers
or thunderstorms. Isolated strong to severe thunderstorms this
afternoon and evening in east central and NE Oregon and in SE
Washington (Walla Walla County eastward). The strongest thunderstorm
cells may produce gusty winds and hail to 1.00 inch in diameter.
Polan

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  56  81  57  85 /  30  20  20  10
ALW  59  82  61  86 /  30  20  20  10
PSC  60  86  61  90 /  30  10  10  10
YKM  56  84  56  87 /  30  10  10  10
HRI  59  84  60  89 /  30  10  10  10
ELN  56  80  55  82 /  40  10  10  10
RDM  46  77  45  83 /  40  30  20  10
LGD  53  80  54  80 /  40  20  20  20
GCD  51  81  52  85 /  30  20  20  10
DLS  59  81  61  85 /  30  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

97/99/99

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
1035 AM PDT MON JUL 18 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0954 AM     HEAVY RAIN       1 N PRINEVILLE          44.32N 120.84W
07/18/2016  M0.65 INCH       CROOK              OR   TRAINED SPOTTER

            0.65 INCHES OF RAIN SINCE 730 AM PDT.

&&

JAS