Flash Flood Warning 3, NWS Boise, ID

229 
WGUS75 KBOI 262329
FFSBOI

Flash Flood Statement
National Weather Service Boise ID
529 PM MDT WED JUL 26 2017

IDC073-270015-
/O.CON.KBOI.FF.W.0003.000000T0000Z-170727T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Owyhee ID-
529 PM MDT WED JUL 26 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MDT FOR
CENTRAL OWYHEE COUNTY...

At 525 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Radar indicates 1 to 1.5 inches of rain 
has already fallen. Heavy rain has fallen on Idaho State highway 51 
southwest of Bruneau.

Some locations that will experience flooding include...
The Hat and Big Horse Basin Gap. 

Additional rainfall amounts of a half inch are possible in the 
warned area. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 4257 11626 4272 11624 4282 11585 4260 11585

$$

LC

Area Forecast Discussion
National Weather Service Boise ID
225 PM MDT Wed Jul 26 2017

.SHORT TERM...Tonight through Friday...The upper level trough which
was centered over the northern California coast yesterday has
migrated slowly eastward and is currently inland over northern
California. Models take it northeast over our CWA tonight and
Thursday. This afternoon thunderstorms have developed over northern
Nevada and southern Malheur County Oregon in response to surface
heating and upper level dynamics ahead of the trough. Isentropic
forecasts show another batch of monsoon moisture being drawn into
the system this evening, but the airmass is already moist, with
dewpoints in the 50s at most lower valley locations. PW forecasts
are in the 80 to 90 percentile range through Thursday, so local
heavy rain showers are possible. Support appears to be adequate for
isolated to scattered thunderstorms to persist overnight. Coverage
should decrease somewhat by Thursday morning, then increase during
the afternoon. With drier more stable air moving in from the
southwest behind the weakening trough, showers and thunderstorms
should end Thursday evening. Skies are expected to be mostly sunny
on Friday. Temperatures will remain a few degrees above normal.

.LONG TERM...Friday night through Wednesday. High pressure begins to
build back over the four corners region. Models are still in
disagreement with where this high will set up. Monsoonal moisture
can be seen on both the GFS and ECMWF making its way back up into
our CWA through the extended, however the timing and placement do
not align between these models. Left a mention of slight chances of
precipitation each day with thunderstorm development in the
afternoon hours. Temperatures will remain above normal throughout
the forecast.

&&

.AVIATION...VFR. Showers/thunderstorms have begun to develop
close to the ID/NV border and will slowly track north through this
evening. Surface winds, variable 10-15 kts with gusts in and around
thunderstorms up to 35 kts. Winds aloft to 10k feet MSL, variable 10-
15 kts becoming SW early Thursday morning

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

www.weather.gov/Boise
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www.twitter.com/NWSBoise

SHORT TERM...JT
LONG TERM....JC/WH
AVIATION.....JC