498
FXUS66 KOTX 060223
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
723 PM PDT Sun May 5 2024

.SYNOPSIS...
Rain showers will continue across the PacNW into Monday. As the
low slides east, conditions will remain cool and showery and
breezy. Warmer and drier weather will arrive late next week. Next
weekend has the potential to deliver our warmest temperatures of
the spring so far.

&&

.DISCUSSION...
Evening update to make adjustments to the precipitation forecast
for the rest of tonight. Nothing too drastic with the band on the
backside of the low that is pulling away. I did reduce the PRISM
influence and this had the effect of lowering precipitation
amounts a little bit over the mountains. I also removed a
significant area of where we had thunderstorms in the forecast
over northeast portions of Washington into the central and
northern portions of Idaho. Model sounding profiles show a
distinct cap between the 12 kft to 15 kft layer to the convection
tomorrow afternoon that will make it difficult for these areas to
see enough charge separation for lightning. Better chances will
be over the far southeast portion of the forecast area from the
Northeast Blue Mountains to the southern Idaho Panhandle.
Otherwise, the forecast remains on track. Winds will be picking up
tonight precipitation decreases from west to east. Stevens Pass,
Washington Pass, and Lookout Pass will see the potential for
light snow, but any accumulations are expected to be light and
below advisory criteria thresholds. /SVH

&&

.AVIATION...
00Z TAFS: The rain band extending from Sandpoint to Spokane to Tri
Cities will pivot to the west this afternoon. That should bring
several hours of ceiling and visibility improvements to Spokane,
Coeur d`Alene, Pullman and Sandpoint. Radar trends and 12z model
runs limit the westward progress to about Moses Lake and Grand
Coulee. With drier downslope west winds in central WA, confidence
is high that Wenatchee, Chelan, and Omak will remain VFR with
little to no precipitation. Moses Lake and Ephrata will get some
light rain, but may experience enough drying from the west to keep
prevailing VFR until the rain band moves eastward this evening.
Spokane, Coeur d`Alene, Pullman, and Lewiston can expect ceilings
to lower as the band returns in the 00z-05z time frame before it
moves east and gusty winds help to break up low ceilings after
06z. /GKoch

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Confidence in ceilings and visibility within the band of rain is
low. We are dealing with an axis of mid and low level moisture
convergence favoring localized ceiling reductions to 1500 ft or
less, but it is a relatively narrow band with a good deal of dry
being advected from the west. With a good deal of variability in
the MOS and HREF guidance, frequent amendments are anticipated to
keep up with the changing conditions. /GKoch

-----------------------

Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https://www.weather.gov/otx/avndashboard

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  57  35  59  37  63 / 100  50  20  10   0   0
Coeur d`Alene  42  54  35  55  37  60 / 100  70  40  30  10   0
Pullman        40  52  34  52  35  56 / 100  60  40  20   0   0
Lewiston       45  61  41  59  41  63 / 100  60  40  30  10   0
Colville       41  59  32  59  36  67 / 100  40  40  20   0   0
Sandpoint      42  53  36  53  38  58 / 100  80  50  50  10  10
Kellogg        39  49  36  48  37  54 / 100  80  70  70  20  20
Moses Lake     44  63  38  64  37  71 / 100  20   0   0   0   0
Wenatchee      44  59  41  59  40  69 /  10  20   0   0   0   0
Omak           43  64  36  64  38  72 /  80  20  10   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$