283 FXUS66 KOTX 230941 AFDOTX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 241 AM PDT Sun Jun 23 2013 .SYNOPSIS... The weather today will be warm and dry with just a few mountain showers. Clouds will increase in the afternoon as another Pacific weather system moves into the area. Cool and wet weather will persist through mid week. The weather pattern will then change dramatically with much warmer and drier weather for the end of the week. Temperatures by next Saturday could be the hottest of the year so far. && .DISCUSSION... Today through Monday...The next Pacific weather system to affect the Inland Northwest is on our doorstep. Satellite water vapor imagery shows the stream of moisture ahead of the trough pushing into the region. The trough has a tap into a nice plume of moisture with Pwat content of an inch to an inch and a half. This translates locally to 125 to 175 percent of normal. The moisture is presenting itself as a mid level cloud shield over the western half of the forecast area. Regional radar mosaic shows some light returns over western and north central Oregon that will spread to the Cascades and possibly into south central Washington by daybreak. We also have some isolated shower activity over extreme NE WA, courtesy of the very slowly departing low over central Alberta. This will likely persist through mid-morning while moving slowly east into North Idaho. Today we will start the transition to a much more active weather pattern as a couple of shortwave impulses affect the region. The first wave will arrive as an occluded front that will bring a few showers to the higher elevations this afternoon but the main surge of moisture will come this evening and into the overnight hours. The timing of the front will keep thunder threat quite low. The second wave will arrive during the day Monday as the negatively tilted trough axis sweeps through the Inland Northwest. This is a favorable pattern for thunder across the area, especially considering the timing and that there may be some breaks in the cloud cover behind the first wave that will allow more surface heating. Without taking any heavy rain from thunderstorms into consideration, the general range of qpf through Monday night will be from a tenth or two in the deep basin...to a third an inch over the rising terrain of the east basin...to a half inch in the valleys north and east of the basin...and three quarters of an inch or more in the mountains. This precipitation is likely to impact small stream levels later in the week and will need to be monitored closely. High temperatures today will be in the mid 70s to low 80s, then will cool about 10 degrees or so Monday under extensive cloud cover and precipitation. /Kelch Monday night through Wednesday: Models are in good agreement of pieces of energy from the parent low sitting in the eastern Pacific ejecting and moving through the Inland Northwest. One will move through Tuesday and another Wednesday. Chance of showers will prevail in the forecast. The stronger of the waves is Tuesday where there will be enough instability, moisture from recent rains, and the wave moving through to provide a slight chance of thunderstorms to most locations. Wed the chance of showers will continue as the last wave moves through the area. Have lowered max temperatures a few degrees. Think the fairly extensive cloud cover will keep temps 5-10 degrees below average Tuesday. A 3-6 degree temperature increase is expected Wed, but sadly will still be below average. Min temps will be around average for this time of the year. Thursday through Sunday: The models have come more in line with the idea of a ridge building over the intermountain west starting Thursday. Have kept with the previous forecast and have no mention of precipitation in the extended forecast. Models do disagree starting late Friday afternoon with some moisture moving in and some possible showers developing. Right now I am siding with the more persistent GFS that we have been following the last few days. The GFS would suggest we will be dry through at least early Saturday and then the possibility of the ridge moving slightly to the east allowing for a more moist southwest flow that would be conducive of showers and thunderstorms in the late afternoon/evening hours. But for now have not made any changes. Models will likely continue to flip flop back and forth over the placement of the closed low in the eastern Pacific and how close it will move to the west coast to bring a weather feature through the area. Temperatures Thursday will be around average for this time of the year. By Friday they warm to above average readings. As to how warm we will get, there are still some uncertainties. 00Z runs of the GFS and ECMWF have come in a few degrees cooler at 850 mb. Have lowered temps a degree or two for Saturday and went a bit lower than that for Sunday. But, temperatures will still be about 10 degrees above average for this time of the year. /Nisbet && .AVIATION... 00Z TAFS: The skies are beginning to clear over the region, allowing for afternoon/early evening showers to develop over the higher terrain of northern Washington into the Idaho panhandle. These showers, however, will likely not affect any of the TAF sites. Otherwise, a quiet night is in store site-wide, before clouds begin to increase from the southwest on Sunday. Right now, any shower or possible thunderstorm activity at any site will occur after the 24/00z time frame. ty && .PRELIMINARY POINT TEMPS/POPS... Spokane 76 55 68 53 68 53 / 0 60 70 70 50 40 Coeur d'Alene 76 55 68 54 68 53 / 0 60 80 70 60 40 Pullman 76 52 68 52 68 52 / 0 60 70 60 50 40 Lewiston 84 59 75 56 76 57 / 0 60 70 70 50 50 Colville 80 54 73 55 72 52 / 10 60 90 70 60 50 Sandpoint 76 53 69 54 68 50 / 20 60 90 80 70 40 Kellogg 74 53 65 52 66 51 / 10 50 80 80 60 40 Moses Lake 80 58 74 56 75 56 / 10 60 60 40 20 10 Wenatchee 77 60 74 56 73 56 / 20 60 60 40 20 10 Omak 81 58 74 57 73 53 / 10 70 70 50 40 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$