822  
FXUS66 KOTX 181117  
AFDOTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SPOKANE WA  
417 AM PDT MON OCT 18 2021  
   
SYNOPSIS
 
 
MOST OF THE REGION WILL REMAIN DRY AND WARM THROUGH TUESDAY, BUT  
LOOK FOR A MIX OF SUN AND CLOUDS. A PERIOD OF LIGHT RAIN IS  
POSSIBLE WEDNESDAY. A WETTER PATTERN IS FORECAST FOR THE INLAND  
NORTHWEST FOR THE END OF THE WEEK INTO NEXT WEEKEND, WITH  
TEMPERATURES COOLING CLOSER TO NORMAL.  
 

 
   
DISCUSSION
 
 
MONDAY AND TUESDAY: EASTERN WASHINGTON AND NORTHERN IDAHO WILL BE  
ON THE NORTHERN FRINGE OF A DEEP TROUGH THAT IS TRACKING THROUGH  
THE GREAT BASIN TODAY. THIS WILL BRING CLOUDS AND ANOTHER MILD,  
SEASONAL TEMPERATURE DAY FOR THE REGION. TUESDAY WILL ACTUALLY  
FEATURE MUCH OF THE SAME WEATHER AS WE BECOME INFLUENCED BY WEAK  
RIDGING BETWEEN WEATHER SYSTEMS AND MAY SEE ONLY THE SLIGHTEST  
CHANGE IN DAYTIME TEMPERATURES FOR LOCATIONS EAST OF THE CASCADES.  
 
WEDNESDAY: OUR NEXT SET OF WEATHER SYSTEMS WILL BEGIN TO TAKE AIM  
AT THE WEST COAST STARTING WEDNESDAY AND WILL REMAIN IN AN  
UNSETTLED PATTERN FOR THE NEXT WEEK OR MORE. THE LONG RANGE  
ENSEMBLE GUIDANCE WOULD SUGGEST SEVERAL SHORTWAVES WILL MOVE  
THROUGH THE NORTHWEST WITH A PARENT TROUGH POSITIONED OFF THE  
COAST OF WASHINGTON STATE/BRITISH COLUMBIA. OUR FIRST TROUGH ON  
WEDNESDAY BECOMES NEGATIVELY TILTED BEFORE IT MOVES INLAND AND THE  
MOISTURE PLUME IS MORE DIRECTED INTO NORTHERN CALIFORNIA AND  
OREGON. BY THE TIME THE ENERGY FROM THE SHORTWAVE TRACKS THROUGH  
NORTH CENTRAL OREGON INTO THE COLUMBIA BASIN AROUND THE CASCADES,  
MUCH OF THE FORCING WILL AIDE IN THE TRACK OF THE WAVE NORTH INTO  
CANADA AND WILL BRING MORE CLOUDS AND SOME LIGHTER PRECIPITATION.  
RIGHT NOW THE FORECAST HAS AROUND 0.10" TO 0.15" OF PRECIP.  
SOUTHERLY WINDS WILL BECOME BREEZY WITH GUSTS AROUND 10 TO 25 MPH.  
THIS IS EXPECTED TO BE A TYPICAL RUN-OF-THE-MILL LIGHT RAIN FALL  
DAY. /DEWEY  
 
THURSDAY: LOOKING MORE AND MORE LIKE A DRY DAY - A BREAK BETWEEN  
PRECIPITATION SYSTEMS. TEMPERATURES WILL RECOVER A LITTLE BIT FROM  
A COOLER WEDNESDAY; ABOUT 5 TO 10 DEGREES ABOVE AVERAGE IN THE 60S  
FOR MOST OF THE AREA. WINDS WILL BE RELATIVELY NORMAL WITH GUSTS  
UP TO 20 MPH POSSIBLE IN THE COLUMBIA BASIN.  
 
THURSDAY NIGHT THROUGH SUNDAY: A WETTER PERIOD WITH WIDESPREAD  
RAIN AND BREEZY WINDS...AND MODELS DIVERGE GREATLY ON TIMING AND  
INTENSITY. MAX TEMPERATURES WILL COOL TO THE 50S FROM THE CLOUD  
COVER/RAINFALL AND WITH THE HELP FROM A COOLER AIRMASS MOVING IN  
FRIDAY. HOWEVER SOUTHWEST FLOW AND WARM ADVECTION (AND THE EFFECTS  
OF OVERNIGHT CLOUD COVER) WILL KEEP US FROM DROPPING TO WIDESPREAD  
LOWS BELOW FREEZING.  
THERE ARE 2 END OF THE WEEK SYSTEMS WE'RE KEEPING AN EYE ON.  
* SYSTEM 1: ROUGHLY FRIDAY...MAY BEGIN THURSDAY NIGHT AND BE OUT  
OF THE AREA FRIDAY AFTERNOON OR ARRIVE LATER AND EXIT SATURDAY  
MORNING. LATEST MODEL RUNS SUPPORT POSSIBLY AROUND A QUARTER OF  
AN INCH IN PARTS OF THE BASIN AND EASTERN WASHINGTON. THIS  
SYSTEM ELONGATES AND WEAKENS WHEN IT REACHES THE COAST, SO IT  
MAY STILL BE A COUPLE OF MODEL RUNS BEFORE THERE IS CONSENSUS ON  
HOW MUCH IT SLOWS DOWN AND HOW MUCH RAINFALL IT CAN PRODUCE.  
* SYSTEM 2: SATURDAY OR SUNDAY...DEPENDING ON WHICH MODEL SOLUTION  
REALITY TILTS TOWARD. MUCH OF THE ENERGY ASSOCIATED WITH THE  
FRIDAY SYSTEM REGROUPS NEAR THE GULF OF ALASKA AND APPROACHES  
DURING THE WEEKEND, POTENTIALLY FROM THE SOUTHWEST INSTEAD OF  
OUR TYPICAL CROSS-CASCADES SYSTEM. SATURDAY HAS A CHANCE AT  
BEING ANOTHER IN-BETWEEN-SYSTEMS DAY, BUT NO PROMISES... RC  
 

 
   
AVIATION
 
 
12Z TAFS: MID AND HIGH CLOUDS WILL FILTER INTO FAR SOUTHEAST WA  
AND THE CENTRAL ID PANHANDLE TODAY. LIGHT DIURNALLY DRIVEN WINDS  
AROUND 10 KTS OR LESS AND VFR CONDITIONS ARE EXPECTED THE NEXT 24  
HOURS FOR AREA AIRFIELDS. /DEWEY  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
SPOKANE 66 36 64 41 60 39 / 0 0 0 0 40 10  
COEUR D'ALENE 65 37 63 40 58 39 / 0 0 0 0 40 10  
PULLMAN 59 33 63 41 59 37 / 0 0 0 0 40 10  
LEWISTON 66 42 68 47 65 44 / 0 0 0 0 40 10  
COLVILLE 68 31 65 34 59 33 / 0 0 0 0 50 20  
SANDPOINT 63 36 59 36 55 36 / 0 0 0 0 50 30  
KELLOGG 67 41 63 44 60 39 / 0 0 0 0 40 20  
MOSES LAKE 67 33 63 43 62 38 / 0 0 0 10 40 0  
WENATCHEE 67 42 62 46 59 43 / 0 0 0 10 60 10  
OMAK 68 38 66 43 60 40 / 0 0 0 0 60 10  
 

 
   
OTX WATCHES/WARNINGS/ADVISORIES
 
 
ID...NONE.  
WA...NONE.  
 

 
 

 
 
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