155  
FXUS66 KOTX 212357  
AFDOTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SPOKANE WA  
457 PM PDT THU SEP 21 2017  
   
SYNOPSIS
 
 
DRIER AND WARMER WEATHER STARTS FRIDAY AND PERSISTS INTO NEXT  
WEEK AS HIGH PRESSURE GRADUALLY BUILDS OVER THE REGION.  
 

 
   
DISCUSSION
 
 
TONIGHT THROUGH SATURDAY NIGHT...WATER VAPOR IMAGERY TODAY SHOWED  
A MOIST BOUNDARY PRODUCING A SWATH OF SHOWERS OVER EAST CENTRAL  
WASHINGTON. THIS HAS DISSIPATED AND BEEN REPLACED BY SPOTTY  
CONVECTIVE SHOWERS, MOSTLY OVER THE NORTHERN HALF OF THE AREA,  
WHERE MID LEVEL MOISTURE CONTINUES TO SURGE SOUTHWEST ALONG THE  
POSITIVELY TILTED TROUGH. WITH THE SUN BREAKING THROUGH IN SPOTS  
AND 500 MB TEMPERATURES AROUND -23 C SOME INTENSE SHOWERS CONTINUE  
TO BE POSSIBLE THIS AFTERNOON. NOT ENOUGH INSTABILITY EXISTS,  
THOUGH, TO EXPECT MUCH IN THE WAY OF THUNDERSTORMS. THESE SHOWERS  
WILL DISSIPATE WITH THE LOSS OF DAYTIME HEATING. GUSTY NORTH WINDS  
IN THE OKANOGAN VALLEY WILL REMAIN ELEVATED THROUGH THE EVENING  
AND INTO FRIDAY MORNING. WE'LL ALSO SEE TEMPERATURES DIP INTO THE  
LOWER 30S AND FROST WILL BE POSSIBLE IN SPOTS OVERNIGHT. AS THE  
LOW SLOWLY TRANSITS EAST ON FRIDAY WE FINALLY GET INTO SOME DRIER  
MID LEVEL FLOW WHICH WILL KEEP US DRY ON FRIDAY AND INTO THE  
WEEKEND. WINDS WILL DECREASE BY THE EVENING AS WELL. ON SATURDAY  
THE UPPER LEVEL RIDGE CONTINUES TO EDGE INLAND, BRINGING MOSTLY  
DRY NORTHERLY FLOW FOR INCREASING TEMPERATURES AND THE ONLY  
POSSIBILITY OF SHOWERS OVER THE ID/MT BORDER. /BW  
 
SUNDAY THROUGH THURSDAY...A FLAT RIDGE IS OVER THE REGION  
INITIALLY WITH A PAIR OF WEAK DISTURBANCES MOVING THROUGH THE  
AREA. MOST OF THE MOISTURE FROM THESE WAVES TRACKS NORTH OF THE  
AREA, BUT JUST ENOUGH TO WARRANT A SLIGHT CHANCE OF SHOWERS FOR  
THE NORTHERN MOUNTAINS AND IDAHO PANHANDLE FOR EARLY NEXT WEEK.  
THESE WAVES SHOULD ALSO BRING AN ABUNDANCE OF MID AND HIGH LEVEL  
CLOUD COVER TO THE REGION. THE RIDGE AMPLIFIES OVER THE AREA  
WEDNESDAY AND THURSDAY RESULTING IN MOSTLY CLEAR SKIES AND A  
CONTINUED WARMING TREND. HIGHS THURSDAY MAY REACH THE MID 70S TO  
NEAR 80 WHICH WOULD BE AROUND 5-8 DEGREES ABOVE NORMAL. JW  
 

 
   
AVIATION
 
 
00Z TAFS: WIDELY SCATTERED SHOWERS WILL LINGER THROUGH 02Z THEN  
DRIER AIR BEGINS TO SLOWLY WORK IN FROM THE NORTH. THERE IS A  
SMALL POTENTIAL FOR BRIEF MVFR CIGS THROUGH 05Z ALONG WITH  
POCKETS OF FOG IN THE SHELTERED VALLEYS BUT ANY COVERAGE WILL BE  
PATCHY AND SHALLOW AND INCREASING NORTH TO NORTHEAST WINDS AFTER  
06Z WILL LEAD TO VFR SKIES. /SB  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
SPOKANE 38 60 40 62 42 64 / 10 0 10 10 10 10  
COEUR D'ALENE 36 59 36 62 38 65 / 10 0 10 10 10 10  
PULLMAN 34 58 38 60 39 63 / 10 10 10 10 10 10  
LEWISTON 41 64 42 66 44 69 / 10 10 10 10 10 10  
COLVILLE 36 66 36 68 38 68 / 20 10 10 10 10 10  
SANDPOINT 34 59 34 60 35 63 / 20 0 10 10 10 10  
KELLOGG 33 54 34 57 35 61 / 20 10 10 10 10 10  
MOSES LAKE 40 68 40 69 43 71 / 10 10 10 0 10 10  
WENATCHEE 45 67 46 69 48 71 / 10 10 10 0 10 10  
OMAK 43 67 40 70 42 73 / 10 10 10 0 10 10  
 

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

 
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab WA Page
The Nexlab ID Page Main Text Page