Red Flag Warning issued July 20 at 9:21PM PDT until July 21 at 10:00PM PDT by NWS Pendleton OR
…HOT, DRY, AND UNSTABLE CONDITIONS EXPECTED THROUGH SUNDAY…
…ISOLATED TO SCATTERED THUNDERSTORMS SUNDAY AFTERNOON AND
EVENING…
A strong ridge of high pressure will remain over the area into
Sunday bringing hot dry and unstable conditions especially to
eastern portions of central Oregon. A weak weather disturbance
will move along the west side of the ridge and help to trigger
isolated to scattered thunderstorms in central Oregon Sunday
afternoon and evening.
* AFFECTED AREA…Fire Weather Zones 611 Deschutes National
Forest -minus Sisters Ranger District and 640 Central
Mountains of Oregon.
* TIMING…Noon to 10 PM Sunday.
* RELATIVE HUMIDITY…As low as 12 percent.
* TEMPERATURES…Up to 99.
* THUNDERSTORMS…Isolated to widely scattered. Lightning
activity level of 2 to 3.
* OUTFLOW WINDS…35 to 45 mph. Thunderstorm outflow winds may
result in erratic fire spread.
* IMPACTS…Any lightning strikes combined with hot and dry
conditions could cause new fire starts.
A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.
