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Area forecast discussion 
National Weather Service Spokane Washington
332 PM PST Wednesday Mar 4 2015

mild high pressure will build over the inland northwest the next
few days bringing a prolonged period of dry weather. Any meaningful
precipitation is not expected until Tuesday or Wednesday next
week. A warming trend is expected over the next few days. By
Friday, most areas will be about 10 degrees above average, and the
mild weather is expected to carry into early next week.


tonight through Fri nt...under a building upper ridge, light
winds and mostly clear skies, expect another cold night with low
temps below normal. There are two subtle waves that will produce
increasing cloud cover over the thur and the other Fri.
Both of these have warm advection/modest isentropic ascent as the
main synoptic-scale forcing for ascent as the low-level flow backs
to southwesterly with wave passage. However, due to the lack of deep
ascent, a stable environment, and dry air below about 700mb, any
light pcpn should be limited to the mtns close to the British Columbia border
and possibly as far south as the cntrl Idaho Panhandle.Bz

Saturday through wednesday: dry conditions continue through at
least Monday, with mild temperatures, before the next opportunity
for precipitation returns. Through at least Monday the jet stream
remains north of the Canadian border, lifting as far north as
northern British Columbia/ab by Sunday. This directs the Pacific shortwaves away
from our region. Aside from some middle to high clouds, the
weather looks dry. The only potential exception skims by the
northeast Washington/north Idaho border with British Columbia Saturday afternoon when the
tail end of a shortwave passes. A few models show an isolated
shower threat here. The threat is too small to put in forecast,
but it will be monitored.

Between Monday night and Wednesday models attempt to bring a
system in from the Pacific. Precisely how this will evolve is not
clear as there is a fair amount of model disagreement. Most
recently the GFS trended quicker, bringing a system in from the
Gulf of Alaska Monday night and Tuesday. The European model (ecmwf) keeps that system
entirely north and instead carries a system from the central
Pacific inland Tuesday night or Wednesday. The dgex is more in
line with the GFS, but slower. The Canadian model is more in line
with the European model (ecmwf). Depictions are likely to waver over the next
several days. However the GFS seems like the biggest outlier.
Based on recent performance and in comparison to other models, the
GFS seems to bring the precipitation in too quick. What is more
starkly different at this time is the temperature and snow level
difference between the GFS and European model (ecmwf). Next Wednesday the GFS was
showing snow levels near 0 and the European model (ecmwf) was showing snow levels
near 7000 feet. The GFS will be monitored, but it was largely not
used for the latter part of the forecast. Either way look for
some increasing threat of precipitation across the region Tuesday
and Wednesday. Confidence is highest across the Cascades and
northern mountains.

As for temperatures, milder air surges in. Regional 850mb
temperatures will be on the rise through the end of week, leveling
in the lower to middle single digits c. This correlates to surface
highs reaching 10 to 15 degrees above normal. Confidence is
reasonably high through Monday. Thereafter confidence drops some.
The quicker solutions push highs back down toward seasonal norms
by Tuesday. Slower models push temperatures up even more. Again
trending away from the GFS, I keep things mild through Tuesday,
then offer a relative cool down Wednesday. /J. Cote'


00z tafs: under strengthening upper ridging...expect generally clear
skies and light, terrain-driven/diurnal winds to prevail at the
taf sites in eastern Washington and north Idaho through thurs.Bz


Preliminary point temps/pops...
Spokane 22 49 30 54 33 56 / 0 0 0 0 0 0
Coeur D'Alene 20 49 28 54 30 55 / 0 0 0 10 0 0
Pullman 25 52 29 56 34 57 / 0 0 0 0 0 0
Lewiston 26 57 33 58 36 61 / 0 0 0 0 0 0
Colville 19 52 28 55 30 57 / 0 0 0 10 0 10
Sandpoint 18 45 26 48 28 51 / 0 0 0 10 10 10
Kellogg 19 46 30 50 31 52 / 0 0 0 10 0 10
Moses Lake 21 54 29 59 34 61 / 0 0 0 0 0 0
Wenatchee 29 53 36 58 38 62 / 0 0 0 0 0 0
Omak 23 53 30 54 33 61 / 0 0 0 0 0 0


Otx watches/warnings/advisories...


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