Tornado in Oregon, June 18, 2023

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1036 AM PDT Sun Jun 18 2023

Updated Aviation Discussion

.SYNOPSIS...An upper trough will push across the region today through
Tuesday, with cooler temperatures and plenty of showers. Could even
see a few thunderstorms around, mainly Monday. Will be cool enough to
have spotty light snow on the higher elevations of the Cascades.
Warming back to seasonal levels later in the week.
&&

.SHORT TERM...(Today through Tuesday)...
Key Messages:
 1)  Cooler, with showers today through Tuesday.
 2)  Lots of showers and isolated thunderstorms Monday.
 3)  Some new snow for areas above 4500 feet in Cascades.

Not much change in the current forecasts, as trends continue to
track as earlier expected. A cold front offshore will push onshore
today.May see a band of light rain or steady drizzle along the coast
into the Coast Range is it comes onshore, with spotty drizzle or
brief light rain farther inland this morning. But, front is fairly
anemic, with bulk of precipitation coming in the afternoon as more
unstable air mass aloft shifts into the region. As such, will have
increasing showers for most of the day into this evening.	 Much

cooler today, with temperatures only in the 50s to lower 60s along
the coast, and 60s inland valleys. Likely to only rise up to the 40s
for most of the Cascades. Likewise, cooler tonight and again Monday
night, with upper 30s to mid 40s for most areas, but freezing
temperatures in the higher Cascades. Brrrrr, Junuary anyone?

Main upper trough axis will push over the region on Monday, with
plenty of showers. Appears to be enough instability to support
isolated thunderstorms, some with heavier rain. So, will upgrade
wording to isolated thunderstorms for Mon into Mon evening. Showers
continue into Tuesday as another upper disturbances moves onshore.
Showers will be scattered in nature with some locations receiving
more rain than others, though general QPF for today through Tuesday
indicates anywhere from 0.25 to 1.00 inch across lowlands, with 1 to
perhaps 2 inches over the Cascades and Coast Range.

Additionally, the cold nature of this weather system will drop
snow levels to 4500 to 5000 feet by later today into tonight, and
staying in the range for Monday. Snow levels will rise slowly up to
6000 ft on Tuesday. NBM 4.2 is indicating an 80-95% chance of over 1
inch of snow and 30-80% chance of over 4 inches of snow for tonight
through Tuesday night. Additionally, it is indicating a 20-40% chance
of above 8 inches of snow at the highest elevations of the Cascades,
locally up to a 50-75% chance over Mount Hood and Mount St Helens.
Due to the scattered nature of the snow showers, warmer roads, and
the longer period of daylight hours, the majority of fallen snow is
not expected to stick to roads. However, motorists are encouraged to
use caution while driving during snow as wet roads will still be
slick.

.LONG TERM...Wednesday through Friday...By Wednesday, ensemble
guidance indicates the main upper trough will move northeast
into Canada with weaker troughing remaining over the region.
This will keep occasional shower and thunderstorm chances over
the Cascades into Friday. Temperatures will bounce back to right
around 70 degrees on Wednesday, warming further to the upper
70s to low 80s for late week. -HEC

&&

.AVIATION...18Z TAFs: Widespread showers through the TAF period
with predominately VFR conditions and periods of MVFR that will
likely be associated with showers. Starting around 20Z Sunday,
there will be a slight chance for thunderstorms across the
forecast area through the TAF period. If a thunderstorm does pop
up, the chances for MVFR and IFR conditions increase, along with
the possibility for gusty and erratic winds and small hail.

For detailed Pac NW aviation weather information, go online to:
http://weather.gov/zse

KPDX AND APPROACHES...Widespread showers will result in
predominately VFR conditions and periods of MVFR, that will
likely be associated with showers. Slight chance for thunderstorms
starting around 20Z Sunday. If a thunderstorm does pop up, the
chances for MVFR and IFR conditions increase, along with the
possibility for gusty and erratic winds and small hail. /42

&&

.MARINE...An upper level cutoff low originating in the Gulf of
Alaska will slowly track south along the coastline towards the
Pacific NW into Monday. Due to the track and placement of the
low northwesterly winds will remain off the coast of British
Columbia Sunday and move into Washington Monday. This will
maintain a fresh northwesterly swell around 5 to 7 ft, 10 sec
across the coastal waters into Tuesday. The associated surface
low will migrate offshore from Vancouver Island Monday night and
send a weak front across the waters into early Tuesday morning.
Hires model guidance suggests a weak coastal jet forming over
PZZ252 between Cape Falcon and Cape Foulweather. Wind gusts up to
30 kt are possible for a brief period as the front moves onshore.

Expect a wind driven sea to form during this time with southerly
waves
of 4 to 6 ft around 6 sec to form within the jet. This coupled
with an approaching northwesterly swell of 6 ft at 10 sec will
create confused seas until the winds diminish Tuesday evening.
Seas will remain around 5 ft through midweek.

The new moon Saturday night will produce stronger tidal currents
during the early morning ebb cycle through Tuesday morning. Those
moving in and out of harbors and crossing coastal bars should use
caution. -BMuhlestein

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...None.

&&

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Preliminary Local Storm Report
National Weather Service Portland OR
1116 AM PDT Sun Jun 18 2023

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

0903 AM     Funnel Cloud     1 ESE Camas             45.58N 122.40W
06/18/2023                   Clark              WA   Public

            Social media video shared via Twitter showed
            a funnel cloud with observable rotation. The
            person who recorded the video, was located
            in Camas, WA near SE 2nd Ave and SE Cedar
            St. They were facing south towards the
            Columbia River in at the time. The funnel
            cloud was observed for a few minuets before
            dissipating. No other reports have been
            received at this time. Location is
            approximate.

&&

DAB