596  
NOUS46 KSEW 270330 AAA  
PNSSEW  
 
WASHINGTON PRECIPITATION SUMMARY...AMENDED  
NATIONAL WEATHER SERVICE SEATTLE WA  
830 PM PDT TUE MAY 26 2020  
 
THE BELOW NORMAL PRECIPITATION CONTINUED INTO APRIL FOR THE ENTIRE  
STATE OF WASHINGTON. ALL OF EASTERN WASHINGTON AND A FEW REGIONS IN  
WESTERN WASHINGTON DID NOT GET ABOVE 50 PERCENT OF NORMAL FOR THE  
MONTH. AS FOR THE WATER YEAR, MOST OF WESTERN WASHINGTON IS NEAR  
NORMAL EXCEPT FOR THE OLYMPICS AND SOUTHWEST INTERIOR WHICH ARE  
BELOW NORMAL. ALL OF EASTERN WASHINGTON IS BELOW NORMAL FOR THE  
WATER YEAR.  
 
FOR WESTERN WASHINGTON, THE MONTHLY PERCENTAGE OF NORMAL FOR  
PRECIPITATION RANGED FROM 32 PERCENT IN THE OLYMPICS TO 60 PERCENT  
IN THE NORTHWEST INTERIOR. THE GREATEST AMOUNT OF PRECIPITATION AT  
THE CLIMATE STATIONS FOR THE MOUNTAINS, COAST AND INTERIOR LOWLANDS  
WAS 5.19 INCHES AT CEDAR LAKE ON THE WESTERN SLOPES OF THE CASCADES,  
3.56 AT QUILLAYUTE, AND 3.64 INCHES AT VANCOUVER IN THE SOUTHWEST  
INTERIOR.  
 
FOR EASTERN WASHINGTON, THE PERCENTAGE OF NORMAL FOR PRECIPITATION  
RANGED FROM 15 PERCENT IN THE CENTRAL BASIN TO 42 PERCENT IN THE  
PALOUSE AND BLUE MOUNTAINS. THE GREATEST AMOUNT OF PRECIPITATION AT  
THE CLIMATE STATIONS FOR THE MOUNTAINS AND LOWLANDS WAS 0.79 INCHES  
AT STEHEKIN ON THE EASTERN SLOPES OF THE CASCADES, AND 0.54 AT  
NORTHPORT IN THE NORTHEAST REGION.  
 
THE OUTLOOK FOR MAY AND BEYOND FOR WASHINGTON STATE, FOR THE NEXT  
TWO WEEKS THE OUTLOOK IS FOR ABOVE NORMAL PRECIPITATION. THE  
MONTHLY OUTLOOK FOR MAY CALLS FOR EQUAL CHANCES OF ABOVE, BELOW OR  
NEAR NORMAL PRECIPITATION. THE THREE MONTH OUTLOOK FOR MAY THROUGH  
JULY CALLS FOR BELOW NORMAL PRECIPITATION.  
 
THE TABLE BELOW GIVES PRECIPITATION FIGURES AS A PERCENT OF NORMAL  
FOR REGIONS OF WASHINGTON. THE CURRENT WATER YEAR BEGAN 1 OCTOBER  
2019 AND ENDS 30 SEPTEMBER 2020.  
 
APRIL WATER YEAR PAST 3 PAST 12  
2020 TO DATE MONTHS MONTHS  
WESTERN WASHINGTON  
COAST 43 95 73 94  
OLYMPICS 32 84 70 86  
NORTHWEST INTERIOR 60 112 107 109  
PUGET SOUND LOWLANDS 52 97 85 97  
SOUTHWEST INTERIOR 50 83 77 87  
WEST FOOTHILLS CASCA 57 102 104 100  
CASCADES WEST 53 106 105 104  
 
EASTERN WASHINGTON  
EAST SLOPES CASCADES 26 78 62 86  
OKANOGAN 22 59 39 79  
CENTRAL BASIN 15 57 44 69  
NORTHEAST 24 80 40 81  
PALOUSE AND BLUE MTN 42 79 77 81  
 
THE TABLE BELOW EXPRESSES PRECIPITATION IN INCHES AND AS A PERCENT OF  
NORMAL FOR A VARIETY OF LOCATIONS AROUND THE STATE. OCCASIONALLY  
MISSING DATA AT A SITE ARE ESTIMATED USING OBSERVED DATA FROM  
SURROUNDING STATIONS.  
 
APRIL WATER YEAR PAST 12 MONTHS  
INCHES PCT INCHES PCT INCHES PCT  
 
QUILLAYUTE 3.56 45 85.86 104 101.74 102  
HOQUIAM 2.12 42 53.32 91 60.30 89  
BELLINGHAM 1.86 72 28.56 107 37.38 106  
SEATTLE 1.70 63 31.49 102 38.68 103  
OLYMPIA 1.40 40 40.13 94 46.66 93  
LONGVIEW 1.62 43 35.01 91 43.11 90  
 
CONCRETE 3.12 62 59.65 104 70.46 100  
SNOQUALMIE FALL 2.53 53 48.58 98 62.30 100  
RANDLE* 2.36 57 46.78 102 57.52 101  
DIABLO DAM 2.09 43 66.12 101 77.04 100  
STAMPEDE PASS 3.25 62 73.86 111 84.36 104  
PARADISE* 4.32 52 107.60 108 126.82 107  
 
WINTHROP 0.15 20 6.90 64 12.59 85  
STEHEKIN 0.79 50 28.34 89 35.15 97  
LEAVENWORTH 0.21 19 17.98 84 21.78 87  
MOUNT ADAMS 0.29 12 28.53 70 34.79 76  
WENATCHEE 0.08 15 3.03 44 5.80 64  
YAKIMA 0.07 13 2.77 45 4.94 60  
 
COULEE DAM 0.21 24 5.01 69 9.86 91  
LIND 0.25 30 5.59 77 8.38 86  
REPUBLIC 0.18 15 6.81 68 13.68 81  
SPOKANE 0.29 23 9.51 81 14.28 86  
PULLMAN 0.58 75 12.11 85 15.97 78  
DAYTON 0.46 27 10.16 71 15.15 79  
 
* = ESTIMATED  
 

 
GRUB  
VALUES IN TABLES CORRECTED DUE TO CALCULATION ERRORS  
 
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