056
CXUS55 KBOI 011744
CLMBOI
CLIMATE REPORT
NATIONAL WEATHER SERVICE BOISE ID
1144 AM MDT MON MAY 01 2023
TYPICAL OF EARLY SPRING, FEBRUARY WEATHER ALTERNATED WITH JUNE
WEATHER AS WINDS ALOFT SHIFTED BACK AND FORTH FROM NORTHWESTERLY TO
SOUTHWESTERLY.
TEMPERATURES AVERAGED 3.2 DEGREES BELOW NORMAL FROM THE 1ST THROUGH
THE 25TH, BUT WARM WEATHER DURING THE LAST FIVE DAYS OF THE MONTH
BROUGHT THE DEPARTURE FROM NORMAL UP TO -1.3 DEGREES FOR THE MONTH.
THE 82 ON THE 10TH AND THE 90 ON THE 30TH SET NEW RECORDS FOR THOSE
DATES.
PRECIPITATION WAS A BIT LESS THAN HALF OF NORMAL.
THE TOTAL SNOWFALL OF 2.0 INCHES EXCEEDED THE 30-YEAR AVERAGE OF .1
INCH (1991-2020). BOTH SNOWFALL AND SNOW DEPTH OF 1 INCH ON THE 13TH
SET NEW RECORDS FOR THE DATE.
ON THE 1ST, A WEAK UPPER LEVEL TROUGH EMBEDDED IN WESTERLY FLOW
ALOFT PROVIDED .18 INCH OF RAIN.
FOLLOWING THIS SYSTEM, NORTHWEST FLOW ALOFT ALL THE WAY FROM SIBERIA
CARRIED A MUCH DEEPER TROUGH INLAND OVER THE INTERMOUNTAIN REGION ON
THE 3RD. THE TROUGH RAPIDLY AMPLIFIED, CARRYING MOST OF ITS ENERGY
SOUTH TO THE DESERT SOUTHWEST, SO BOISE RECEIVED ONLY LIGHT
SNOWFALLS FROM THE 2ND THROUGH THE 4TH.
A WEAK TROUGH FOLLOWED, PROVIDING ONLY A TRACE OF RAIN.
A STRONG UPPER LEVEL RIDGE BUILT OVER THE INTERMOUNTAIN REGION ON
THE 9TH AND 10TH, TREATING US TO A BRIEF HINT OF SPRING AS IT
TRANSPORTED WARM DRY AIR NORTH. THE 82 ON THE 10TH WAS THE FIRST 80-
DEGREE READING SINCE OCTOBER 8.
A PACIFIC COLD FRONT ON THE 11TH WAS FOLLOWED BY A STRONGER COLD
FRONT ON THE 12TH, PLUNGING US BACK INTO WINTER. THE SECOND FRONT
USHERED IN A TROUGH WHICH ORIGINATED OVER THE CHUKCHI SEA NORTHWEST
OF ALASKA. THE 1 INCH SNOW COVER ON THE MORNING OF THE 13TH SET A
RECORD FOR THE DATE.
A WEAK RIDGE BROUGHT ANOTHER SMALL SAMPLE OF SPRING ON THE 15TH AND
16TH.
THE NEXT TROUGH, THIS TIME FROM MAINLAND ALASKA, MOVED SOUTH OVER
THE GULF OF ALASKA ON THE 14TH.
A MINOR BUT UNSEASONABLY COLD TROUGH, KICKED INLAND BY THE MAIN
TROUGH OVER THE GULF OF ALASKA, FOLLOWED A COLD FRONT WHICH PASSED
BOISE ON THE EVENING OF THE 17TH. NEARLY AN INCH OF SNOW FELL
OVERNIGHT. AS SKIES CLEARED, TEMPERATURES PLUMMETED INTO THE 20S
DURING THE EARLY MORNING HOURS OF THE 19TH AND 20TH.
THE MAIN TROUGH MOVED INLAND AND WEAKENED OVER WESTERN CANADA ON THE
20TH. IT GENERATED NEARLY A TENTH OF AN INCH OF RAIN AT BOISE ON THE
21ST.
TEMPERATURES WERE ON THE WAY UP ON THE 22ND, BUT STILL BELOW NORMAL,
AS A RIDGE BEGAN TO BUILD.
THE RIDGE WAS INTERRUPTED BY A TROUGH WHICH CROSSED OUR AREA ON THE
24TH, BUT BY THE 25TH THE RIDGE HAD GAINED THE UPPER HAND.
AS THE RIDGE CONTINUED TO BUILD, TEMPERATURES ROSE TO SUMMERTIME
LEVELS, WITH HIGHS FOR THE LAST TWO DAYS OF THE MONTH TYPICAL OF
LATE JUNE OR EARLY JULY.
...............................
..THE BOISE ID CLIMATE SUMMARY FOR THE MONTH OF APRIL 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 90 04/30
LOWEST 24 04/05
AVG. MAXIMUM 61.4 62.3 -0.9
AVG. MINIMUM 37.8 39.6 -1.8
MEAN 49.6 50.9 -1.3
DAYS MAX >= 90 1
DAYS MAX <= 32 0
DAYS MIN <= 32 8
DAYS MIN <= 0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 4.73 1869
TOTALS 0.61 1.23 -0.62
DAYS >= .01 9
DAYS >= .10 2
DAYS >= .50 0
DAYS >= 1.00 0
GREATEST
24 HR. TOTAL 0.18 04/01 TO 04/01
SNOWFALL (INCHES)
TOTALS 2.0R
SINCE 7/1 31.2
GREATEST
SNOW DEPTH 1R 04/13
24 HR TOTAL MM
DEGREE DAYS
HEATING TOTAL 466 424 42 544
SINCE 7/1 5350 5057 293
COOLING TOTAL 9 3 6 0
SINCE 1/1 9 3 6
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 9.6
HIGHEST WIND SPEED/DIRECTION 31/140 DATE 04/10
HIGHEST GUST SPEED/DIRECTION 43/300 DATE 04/03
AVERAGE RH (PERCENT) 49
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
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