Climatological Report (Monthly)
Issued by NWS Boise, ID
Issued by NWS Boise, ID
000 CXUS55 KBOI 020503 CCA CLMBOI CLIMATE REPORT...CORRECTED TO ADD NARRATIVE NATIONAL WEATHER SERVICE BOISE ID 1104 PM MDT THU JUN 01 2023 THE AVERAGE TEMPERATURE OF 65.0 IS 5.1 DEGREES ABOVE NORMAL. THE LOWS OF 57 ON THE 1ST AND 60 ON THE 20TH WERE RECORDS FOR THE DATES. THE HIGH OF 92 ON THE 21ST WAS ALSO A RECORD FOR THE DATE. THE TOTAL PRECIPITATION OF 1.43 INCH IS .02 INCH BELOW NORMAL. AN UPPER LEVEL TROUGH CENTERED JUST OFFSHORE NEAR THE WASHINGTON COAST ON THE 1ST PUT US UNDER SOUTHERLY FLOW AS IT DRIFTED SOUTH ALONG THE COAST, KEEPING TEMPERATURES 10-15 DEGREES ABOVE NORMAL FROM THE 1ST THROUGH THE 3RD. BY THE 4TH THE TROUGH WAS CENTERED OVER THE CALIFORNIA COAST, POISED TO LIFT NORTH AS ANOTHER TROUGH DEEPENED OFF THE WASHINGTON-OREGON COAST. AS THE CALIFORNIA TROUGH MOVED NORTH, IT DROPPED TEMPERATURES TO A FEW DEGREES BELOW NORMAL AND GENERATED SHOWERS FROM THE 5TH THROUGH THE 9TH AS A SERIES OF SECONDARY TROUGHS ROTATED THROUGH THE MAIN TROUGH. PRECIPITATION FOR THAT PERIOD TOTALED 1.00 INCH. THE .41 INCH ON THE 7TH WAS BY FAR THE HIGHEST DAILY TOTAL. THE HIGH OF 59 THAT DAY WAS THE COOLEST MAX OF THE MONTH. AN UPPER LEVEL RIDGE BOUGHT DRY AND WARMER WEATHER FROM THE 10TH THROUGH THE 12TH. ON THE 13TH A WEAK TROUGH BEGAN TO IMPINGE ON THE RIDGE FROM THE SOUTHEAST. BY THE 14TH THE TROUGH HAD REPLACED A PORTION OF THE RIDGE SOUTH OF THE CANADIAN BORDER. SUFFICIENT MOISTURE AND INSTABILITY RESULTED IN MEASURABLE RAIN ON THE 14TH AND 15TH, WITH A QUARTER INCH FALLING IN A THUNDERSTORM ON THE 15TH. THE STORM ALSO PRODUCED SMALL HAIL AND A WIND GUST OF 44 MPH FROM THE SOUTH. BY THE 19TH THE RIDGE OVER THE INTERMOUNTAIN REGION HAD RECOVERED, BRINGING BOISE THE FIRST 90 DEGREE HIGHS OF THE SEASON FROM THE 19TH THROUGH THE 21ST. THE 92 ON THE 20TH WAS THE MONTH`S HIGH. SMOKE FROM WILDFIRES IN WESTERN CANADA ACCOMPANIED THE HEAD. DURING THE NIGHT OF THE 21ST A PACIFIC COLD FRONT PASSED BOISE, WITH LIGHT PRECIPITATION BUT MAJOR COOLING ON THE 22ND AS AN UPPER LEVEL TROUGH FOLLOWED THE FRONT INLAND. A GUST OF 51 MPH ACCOMPANIED THE FRONTAL PASSAGE. THE HIGH OF 91 AHEAD OF THE FRONT ON THE 21ST WAS FOLLOWED BY A HIGH OF ONLY 74 ON THE 22ND. TROUGHINESS PERSISTED WEST OF THE ROCKIES FOR THE REST OF THE MONTH, WITH NEARLY DAILY SHOWERS IN THE MOIST UNSTABLE AIR. THE BOISE AIRPORT MISSED OUT ON THE HEAVIER SHOWERS, WITH ONLY .01 INCH ON THE 24TH AND .08 INCH ON THE 30TH. ON THE 30TH A ROGUE THUNDERSTORM DEVELOPED OVER THE OWYHEES AND ROLLED ACROSS THE VALLEY. PRECIPITATION AMOUNTS WERE QUITE VARIABLE. THE AIRPORT WAS ON THE EDGE OF THE STORM AND RECEIVED LITTLE PRECIPITATION. BUT THE STORM`S ABUNDANT MOISTURE AND SLOW MOVEMENT GUARANTEED THAT LOCATIONS UNDER ITS CORE WOULD BE DRENCHED WITH HEAVY RAIN, RESULTING IN LOCAL URBAN FLOODING. IN FACT THERE WERE A COUPLE OF REPORTS OF AROUND HALF AN INCH OF STORM TOTAL RAINFALL IN TOWN, AND SOCIAL MEDIA POSTS OF STREET AND SIDEWALK FLOODING. ON THE 31ST SHOWER AND THUNDERSTORMS DEVELOPED ALONG A PACIFIC COLD FRONT. ONLY .05 INCH OF RAIN WAS MEASURED AT THE AIRPORT. THE THUNDERSTORMS GAINED STRENGTH AS THE FRONT CONTINUED EASTWARD, WITH SOME STORMS REACHING SEVERE INTENSITY IN SOUTH CENTRAL IDAHO. ................................... ...THE BOISE ID CLIMATE SUMMARY FOR THE MONTH OF MAY 2023... CLIMATE NORMAL PERIOD 1991 TO 2020 CLIMATE RECORD PERIOD 1875 TO 2023 WEATHER OBSERVED NORMAL DEPART LAST YEAR`S VALUE DATE(S) VALUE FROM VALUE NORMAL .............................................................. TEMPERATURE (F) HIGHEST 92 05/20 LOWEST 41 05/10 AVG. MAXIMUM 77.5 72.3 5.2 AVG. MINIMUM 52.5 47.5 5.0 MEAN 65.0 59.9 5.1 DAYS MAX >= 90 3 DAYS MAX <= 32 0 DAYS MIN <= 32 0 DAYS MIN <= 0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 4.90 1890 TOTALS 1.05 1.45 -0.40 DAYS >= .01 8 DAYS >= .10 5 DAYS >= .50 0 DAYS >= 1.00 0 GREATEST 24 HR. TOTAL 0.39 05/08 TO 05/09 SNOWFALL (INCHES) TOTALS T SINCE 7/1 31.2 GREATEST SNOW DEPTH 0 24 HR TOTAL MM DEGREE DAYS HEATING TOTAL 81 200 -119 300 SINCE 7/1 5431 5258 173 COOLING TOTAL 86 42 44 14 SINCE 1/1 95 45 50 .............................................................. WIND (MPH) AVERAGE WIND SPEED 7.3 HIGHEST WIND SPEED/DIRECTION 35/260 DATE 05/21 HIGHEST GUST SPEED/DIRECTION 51/270 DATE 05/21 AVERAGE RH (PERCENT) 49 - INDICATES NEGATIVE NUMBERS. R INDICATES RECORD WAS SET OR TIED. MM INDICATES DATA IS MISSING. T INDICATES TRACE AMOUNT. $$