913  
FXUS66 KOTX 180912  
AFDOTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SPOKANE WA  
212 AM PDT THU APR 18 2024  
   
SYNOPSIS
 
 
COOL AND SHOWERY CONDITIONS CONTINUE TODAY, BEFORE DRYING OUT AND  
BECOMING BREEZY FRIDAY. SHOWERS RETURN FOR SATURDAY EVENING  
THROUGH SUNDAY. MILD AND DRY WEATHER RETURNS FOR THE START OF  
WORK WEEK WHILE SHOWERS ARRIVE BY MID WEEK.  
 

 
   
DISCUSSION
 
 
TODAY THROUGH SATURDAY AFTERNOON: WINDS ARE LIGHT ACROSS THE REGION  
TONIGHT WITH COOL TEMPERATURES. THE LIKELIHOOD OF FROST THIS MORNING  
REMAINS OVER THE WESTERN COLUMBIA BASIN AND WENATCHEE AREA AS CLOUDS  
HAVE ERODED. A WEAK SHORTWAVE WILL MOVE THROUGH THE AREA, USHERING  
IN ANOTHER BOUT OF SHOWERS TO NORTHEAST WA (PERHAPS EVEN THUNDER - A  
15% CHANCE) AND THE ID PANHANDLE. MEANWHILE, EASTERN AND CENTRAL  
WASHINGTON CAN EXPECT PARTLY TO MOSTLY SUNNY AND DRY CONDITIONS,  
THOUGH TEMPERATURES WILL REMAIN COOL IN THE 50S. SHOWERS AND WINDS  
WILL TAPER OFF IN THE EVENING.  
 
MOVING INTO FRIDAY, AN UPPER-LEVEL LOW WILL TRAVERSE THE REGION,  
TIGHTENING THE PRESSURE GRADIENT AND RESULTING IN GUSTY WINDS ACROSS  
THE COLUMBIA BASIN. NORTHEAST WINDS WILL GUST UP TO 35 MPH IN THE  
AFTERNOON BEFORE EASING OFF OVERNIGHT. DESPITE THE WINDY CONDITIONS,  
TEMPERATURES WILL SLIGHTLY WARM UP AND THE REGION WILL EXPERIENCE  
SUNNY WEATHER. DRY AND GUSTY CONDITIONS WILL LEAD TO AN ELEVATED  
FIRE WEATHER RISK IN DEAD GRASSES IN THE COLUMBIA BASIN.  
 
LOOKING AHEAD TO SATURDAY, A RIDGE OF HIGH PRESSURE WILL BRING MORE  
SUNNY SKIES IN THE MORNING AND TEMPERATURES IN THE 60S. AN OVERCAST  
CLOUD DECK WILL MOVE IN SATURDAY AFTERNOON BRINGING A 15% CHANCE OF  
SHOWERS TO STEVENS PASS SATURDAY AFTERNOON. WINDS WILL BE BREEZY,  
GUSTING UP TO 30 MPH ACROSS THE REGION. /BUTLER  
 
SATURDAY NIGHT THROUGH SUNDAY NIGHT: THERE IS GOOD AGREEMENT OF A  
NEGATIVELY TILTED UPPER LEVEL TROUGH PIVOTING ACROSS THE PACIFIC  
NW THIS WEEKEND. MOISTURE SPREAD EAST OF THE CASCADES SATURDAY  
EVENING AS A COLD FRONT MARCHES ACROSS EASTERN WA INTO NORTH ID  
DURING THE OVERNIGHT HOURS WITH CHANCE OF SHOWERS. SNOW LEVELS  
START HIGH BUT LOWER TO 3-4K FT BY SUNDAY MORNING WITH LIGHT  
MOUNTAIN SNOW ACCUMULATIONS. BREEZY WINDS ACCOMPANY THE FRONT  
SATURDAY NIGHT WITH WIND GUSTS OF 20-30 MPH ESPECIALLY ACROSS THE  
COLUMBIA BASIN AND PALOUSE. IN THE WAKE OF THE FRONT, SURFACE  
BASED INSTABILITY WILL PROMOTE AFTERNOON CONVECTION ESPECIALLY  
ACROSS NORTHEAST WA AND THE ID PANHANDLE WITH A SMALL CHANCE OF A  
THUNDERSTORM NEAR THE BC BORDER. SUNDAY WILL BE A COOL AND BRISK  
DAY. THE WESTERLY WINDS REMAIN GUSTY ACROSS THE PALOUSE INTO NORTH  
ID SUNDAY AFTERNOON. THE SHOWERS AND WINDS GRADUALLY DISSIPATE  
SUNDAY EVENING.  
 
MONDAY THROUGH TUESDAY: AN UPPER RIDGE BUILDS INTO WA ON MONDAY  
WHILE THE UPPER LEVEL TROUGH SHIFTS EAST, ALTHOUGH IT STILL  
BRUSHES THE ID PANHANDLE. IT WILL START OFF COOL MONDAY MORNING  
WITH AREAS OF FROST ACROSS THE LOWLANDS OF EASTERN WA.  
TEMPERATURES ON MONDAY WARM TO NEAR SEASONAL LEVELS BY AFTERNOON.  
LINGERING MOISTURE AND SURFACE BASED INSTABILITY LEAD TO THE  
REDEVELOPMENT OF MOUNTAIN SHOWERS OVER NORTH ID. WINDS WILL BE  
LIGHTER AND SHIFT FROM THE EAST AND TEMPERATURES REBOUND TO MORE  
SEASONAL LEVELS. THE UPPER RIDGE SHIFTS INLAND MONDAY NIGHT INTO  
TUESDAY WITH LIGHT EASTERLY WINDS AND DRIER CONDITIONS. DAYTIME  
TEMPERATURES SHOULD MILD ON TUESDAY WITH WIDESPREAD 60S TO LOWER  
70S REGION-WIDE.  
 
TUESDAY NIGHT THROUGH THURSDAY: MODEL GUIDANCE HAS LOWER  
CONFIDENCE WITH THE MID WEEK FORECAST, ESPECIALLY DEALING WITH HOW  
LONG THE UPPER RIDGE REMAINS AND THE TIMING OF THE NEXT PACIFIC  
LOW PUSHING INLAND AND AT WHAT TRAJECTORY. AT LEAST THROUGH  
THURSDAY, THE POSITION OF THE APPROACHING TROUGH REMAIN NEAR THE  
COAST TO OFFSHORE WHICH SHOULD KEEP A MILD SOUTHWEST FLOW INTO THE  
REGION. THE NBM BEGINS TO SPREAD MOISTURE AND A CHANCE OF SHOWERS  
ACROSS THE INLAND NW BY TUESDAY NIGHT AND CONTINUES A LOW CHANCE  
OF SHOWERS THROUGH WEDNESDAY INTO THURSDAY. TEMPERATURES LOOK TO  
REMAIN ON THE MILD SIDE AND JUST ABOVE SEASONAL NORMALS WITH  
LITTLE IN THE WAY THREAT OF FREEZING. /RFOX.  
 

 
   
AVIATION
 
 
06Z TAFS: CONVECTIVE CLOUDS ARE DISSIPATING ACROSS EASTERN WA AND  
NORTH ID. THERE ARE MID LEVEL CLOUDS THAT ARE BLOSSOMING ACROSS  
CENTRAL WA INCLUDING MWH/EAT. THESE CLOUDS WILL LIKELY CONTINUE  
THROUGH THE NIGHT AND THEN CLEAR TOWARDS MID TO LATE MORNING.  
SHOWERS WILL REDEVELOP AGAIN THURSDAY AFTERNOON, BUT CONFIDENCE OF  
THEM GOING OVER ANY PARTICULAR TAF LOCATION IS LOW.  
 
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: THERE IS HIGH  
CONFIDENCE IN VFR CONDITIONS THROUGH THE TAF PERIOD. HREF IS  
SHOWING A 10-20% CHANCE OF MVFR CONDITIONS AT COE FROM 09-16Z. NBM  
HAS ABOUT A 5% CHANCE. CONFIDENCE OF MVFR CONDITIONS DEVELOPING  
IS VERY LOW.  
 
-----------------------  
 
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 54 31 56 33 62 39 / 20 0 0 0 0 30  
COEUR D'ALENE 52 30 54 31 61 38 / 30 10 0 0 0 40  
PULLMAN 53 31 56 33 62 38 / 10 0 0 0 0 40  
LEWISTON 61 34 64 36 69 44 / 10 0 0 0 0 40  
COLVILLE 54 27 57 27 63 35 / 30 10 0 0 0 40  
SANDPOINT 50 30 52 30 60 38 / 30 10 0 0 0 50  
KELLOGG 49 30 51 32 61 40 / 50 20 0 0 0 50  
MOSES LAKE 62 36 64 38 67 41 / 0 0 0 0 0 10  
WENATCHEE 61 37 61 37 63 41 / 0 0 0 0 0 10  
OMAK 59 34 62 34 64 39 / 10 0 0 0 0 30  
 

 
   
OTX WATCHES/WARNINGS/ADVISORIES
 
 
ID...FROST ADVISORY UNTIL 9 AM PDT THIS MORNING FOR LEWISTON AREA.  
 
WA...FROST ADVISORY UNTIL 9 AM PDT THIS MORNING FOR LOWER GARFIELD  
AND ASOTIN COUNTIES-MOSES LAKE AREA-WENATCHEE AREA.  
 

 
 

 
 
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