396  
FXUS66 KOTX 070457  
AFDOTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SPOKANE WA  
957 PM PDT TUE JUN 6 2023  
   
SYNOPSIS
 
 
ABOVE AVERAGE SEASONAL TEMPERATURES WILL CLIMB INTO THE 90S  
THROUGH MID WEEK WITH LITTLE RELIEF OVERNIGHT. CHANCES FOR SLOW  
MOVING THUNDERSTORMS CAPABLE OF HEAVY RAIN AND GUSTY OUTFLOW WINDS  
WILL INCREASE WEDNESDAY AND INTO NEXT WEEKEND. TEMPERATURES WILL  
BE COOLER AND CLOSER TO SEASON AVERAGE FRIDAY INTO SATURDAY.  
 

 
   
DISCUSSION
 
 
TUESDAY THROUGH THURSDAY: TODAY IS A PIVOTAL FORECAST DAY AS WE  
TRANSITION FROM AN ANOMALOUSLY DRY PERIOD TO AN ANOMALOUSLY WET BY  
LATER THIS WEEK. BREEZY NORTH WINDS (20-25 MPH) DOWN THE OKANOGAN  
VALLEY UNDER THE RIDGE OF HIGH PRESSURE WILL BEGIN TO RELAX THIS  
EVENING AS THE PRESSURE GRADIENT ALSO WEAKENS. THE EASTWARD PUSH OF  
DRY AIR WILL SLOWLY ERODE OR MOISTEN UP WEDNESDAY FROM THE SOUTHEAST  
AND CONTINUE THROUGH LATER THIS WEEK. THIS LAYOUT OF HIGH PRESSURE  
TO THE NORTH AND TROUGHING SOUTH WITH A SOUTHEASTERLY ADVECTION OF  
MOISTURE IS SIMILAR TO A MONSOON-TYPE PATTERN, WHICH I'VE SEEN  
BEFORE, JUST NOT IN THIS PART OF THE COUNTRY.  
 
TEMPERATURES WILL TOP OUT WEDNESDAY AND THURSDAY, DEPENDING ON  
SPECIFIC LOCATION AND SHOULD BE THE WARMEST OF THE NEXT WEEK  
AHEAD. WEDNESDAY AFTERNOON WE BEGIN TO GET A PUSH OF MOISTURE FROM  
THE SOUTHEAST INTO CENTRAL IDAHO THANKS TO THE LOW OVER THE  
SOUTHWEST. PRECIPITABLE WATER VALUES WILL CLIMBING TO 180-200% OF  
NORMAL WEDNESDAY INTO THURSDAY. MID LAYER WIND FLOW WILL SHIFT  
FROM SOUTH TO SOUTHEAST WITH SHEAR OF ABOUT 15 KNOTS. THE  
INSTABILITY (CAPE) WILL BE QUITE HIGH (1000 J/KG OR SO) BUT THE  
LOWER LAYERS WILL STILL BE MOISTENING UP. FORECAST SOUNDINGS ARE  
INDICATIVE OF QUICK BUILDING (STEEPER LAPSE RATES) STORMS BUT WITH  
A DRY SUBCLOUD AND BOUNDARY LAYER, GUSTY WINDS AND BRIEF RAIN MAY  
BE THE BIGGEST THREATS WEDNESDAY AFTERNOON AND EVENING.  
 
THURSDAY, WHILE STILL INCREASING THAT LOW-MID LEVEL MOISTURE WE'RE  
NOW LOOKING AT 200-250% PWAT VALUES AND A MODEST BUMP IN  
INSTABILITY (2000-2500 J/KG CAPE) OVER A WIDER AREA FROM THE IDAHO  
PANHANDLE NORTHEAST THROUGH FERRY AND LINCOLN COUNTIES OF CENTRAL  
WASHINGTON. THE STORM POTENTIAL WILL HAVE BETTER SHEAR AND  
CONVECTIVE DEVELOPMENT AS WELL AS MOTION WHILE STILL INCORPORATING  
THE HEAVY MOISTURE PROFILE. THE TEMPERATURES THURSDAY MAY BE  
INHIBITED BY THE EXTENSIVE CLOUD COVER AND CONVECTION. THE INFLUX  
OF MOISTURE WILL CONTINUE THROUGH THE EVENING THURSDAY LENDING TO  
A MORE HUMID YET SLIGHTLY COOLER PERIOD OVERNIGHT INTO FRIDAY.  
THE STORM PREDICTION CENTER HAS PLACED NORTHERN IDAHO AND EASTERN  
WASHINGTON IN A MARGINAL OUTLOOK THURSDAY FOR SEVERE THUNDERSTORMS  
(ABOUT 5% AT THIS TIME) AND LOCALLY WE ARE SEEING A 30-45%  
PROBABILITY OF THUNDERSTORM COVERAGE OVER THE INLAND NORTHWEST. AS  
MENTIONED, ALONG WITH THE THUNDERSTORM THREAT, COMES HEAVY RAIN.  
WE ARE ALSO UNDER AN AREA OF MARGINAL TO SLIGHT RISK FOR EXCESSIVE  
RAINFALL, MEANING THE POTENTIAL FOR HEAVY RAIN WILL EXIST FROM  
THESE STORMS AS THEY TURN TO MORE SHOWERY RAIN. QUITE THE SETUP OF  
HOT AND DRY TO STORMY AND WET, AS I SAID IT'S VERY SIMILAR TO A  
DESERT SOUTHWEST MONSOON SETUP JUST 15 DEGREES FARTHER NORTH  
LATITUDE. /DEWEY  
 
FRIDAY THROUGH TUESDAY: FORECAST IS CHANGING A BIT FOR THE  
EXTENDED PART OF THE FORECAST. FIRST, WE'LL START OFF WITH THE WET  
WEATHER AT THE END OF THE WEEK. THE DETERMINISTICS AND ENSEMBLES  
ARE NOW IN RATHER GOOD AGREEMENT ON THE UPCOMING WEATHER SYSTEM.  
RATHER THAN A ROUND OF AFTERNOON/EVENING CONVECTIVE EVENT FOR  
FRIDAY, THE MODELS ARE NOW SIDING WITH A SCENARIO WHERE THE  
MOISTURE/PRECIPITATION THAT DEVELOPS IN THE SOUTHERN PANHANDLE ON  
THURSDAY AFTERNOON WOULD SPREAD OVER THE REST OF THE AREA ON  
THURSDAY NIGHT. THIS MAKES FOR A CLOUDIER, COOLER FRIDAY (HIGHS IN  
THE 70S) WHICH IS NOT AS CONDUCIVE TO CONVECTIVE WEATHER. THERE  
WILL STILL BE THUNDERSTORMS IN THE FORECAST, BUT THE 700-500MB  
LAPSE RATES ON THURSDAY OF AROUND 7C/KM WILL BE REPLACE BY 5-6C/KM  
ON FRIDAY. IT'S WORTH NOTING THAT THE ECMWF ENSEMBLE SHOWS  
MINIMAL CHANCES OF EVEN 500 J/KG CAPE ON FRIDAY, WHILE THE  
CANADIAN HAS 60-80% ODDS OF 1000 J/KG IN THE PANHANDLE, WITH THE  
GFS SOMEWHERE IN BETWEEN. SO NOT A SLAM-DUNK FORECAST FOR STRONG  
THUNDERSTORMS FOR FRIDAY.  
 
PRECIPITABLE WATER WILL STILL BE OVER AN INCH, SO HEAVY RAIN IS  
STILL A THREAT ON FRIDAY. THE EASTERLY FLOW AT 700MB ACTUALLY  
FAVORS THE HEAVIEST RAIN POTENTIAL FOR CHELAN AND OKANOGAN  
COUNTIES, WHICH ALSO HAVE SEVERAL BURN SCARS THAT WILL NEED  
MONITORING.  
 
FOR THE WEEKEND, THE LOW PRESSURE SYSTEM THAT WAS RESPONSIBLE FOR  
ALL THIS MAYHEM LINGERS OVER OUR AREA WITH ALL OF ITS MOISTURE.  
THE RESULT WILL BE SEASONABLY NORMAL TEMPERATURES (70S) WITH  
AFTERNOON/EVENING SHOWERS AND STORMS. THIS ACTIVITY WILL BE FAIRLY  
WIDESPREAD ON SATURDAY, BUT MAINLY OVER THE NORTHERN/EASTERN  
SECTIONS ON SUNDAY THROUGH TUESDAY. TEMPERATURES WILL VERY SLOWLY  
WARM FROM THE COOL FRIDAY, BUT NOT ALARMINGLY SO. AN OVERALL  
PATTERN CHANGE SHOULD KEEP TEMPERATURES A LITTLE MORE MODERATE,  
ALBEIT STILL ABOVE NORMAL. IN OTHER WORDS, THE HOT TEMPERATURES  
OF TODAY AND TOMORROW WON'T LIKELY BE REPEATED ANYTIME BEFORE  
FATHER'S DAY.  
 

 
   
AVIATION
 
 
06Z TAFS: VFR CONDITIONS WILL CONTINUE TO PREVAIL THE NEXT 24  
HOURS. INCREASING MID AND HIGH CLOUDS FROM CENTRAL IDAHO AND  
SOUTHEAST WASHINGTON GOING INTO WEDNESDAY WILL KEEP CLOUD BASES  
ABOVE 10K FEET.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
SPOKANE 58 91 63 88 63 76 / 0 0 10 40 60 80  
COEUR D'ALENE 58 90 61 85 63 78 / 0 0 10 50 70 80  
PULLMAN 57 87 61 83 59 74 / 0 10 10 50 60 70  
LEWISTON 65 95 67 88 67 82 / 0 10 20 60 60 60  
COLVILLE 51 91 57 88 59 77 / 0 0 0 40 60 80  
SANDPOINT 57 89 61 84 62 77 / 0 0 10 50 60 80  
KELLOGG 61 87 64 84 64 75 / 0 20 20 70 70 90  
MOSES LAKE 54 95 61 90 62 76 / 0 0 0 20 50 50  
WENATCHEE 63 94 68 92 66 74 / 0 0 0 10 30 50  
OMAK 57 95 62 92 65 78 / 0 0 0 10 40 70  
 

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

 
 

 
 
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