029
CXUS55 KBOI 011758 AAA
CLMBOI
CLIMATE REPORT...CORRECTED TO ADD NARRATIVE
NATIONAL WEATHER SERVICE BOISE ID
1035 AM MST FRI DEC 01 2023
NOVEMBER 2023
THE TEMPERATURE AVERAGED 2.6 DEGREES ABOVE NORMAL. IT WAS THE
SEVENTH CONSECUTIVE WARMER-THAN-NORMAL MONTH.
PRECIPITATION WAS ONLY .01 INCH ABOVE NORMAL. SNOWFALL INCLUDED A
TRACE ON THE 6TH AND 0.1 INCH ON THE 30TH. THE 30-YEAR AVERAGE (1991-
2020) FOR NOVEMBER IS 2 INCHES.
THERE WERE NO RECORD TEMPERATURES OR PRECIPITATION AMOUNTS.
DISTURBANCES EMBEDDED IN MOIST WESTERLY FLOW ALOFT BROUGHT DAILY
PRECIPITATION FROM THE 2ND THROUGH THE 6TH.
DRY WEATHER PREVAILED FROM THE 7TH THROUGH THE 17TH. PACIFIC WEATHER
SYSTEMS MOVED INLAND EITHER WELL NORTH OR WELL SOUTH OF OUR AREA
FROM THE 7TH THROUGH THE 11TH.
FROM THE 12TH THROUGH THE 15TH, WE WERE UNDER DRY SOUTHWEST FLOW
ALOFT ON THE EAST FLANK OF A LOW PRESSURE TROUGH MOVING SOUTH FROM
THE GULF OF ALASKA TO OFF THE CALIFORNIA COAST.
BY THE 16TH, A "REX BLOCK" HAD FORMED, WITH A HIGH PRESSURE RIDGE
OVER THE PACIFIC NORTHWEST, DIRECTLY NORTH OF THE CALIFORNIA TROUGH.
FINALLY, ON THE 18TH, A TROUGH FROM THE ALEUTIANS JOINED FORCED WITH
THE CALIFORNIA TROUGH, AND BOTH MOVED INLAND. THE HALF INCH OF RAIN
ON THE 19TH WAS THE HEAVIEST ONE-DAY PRECIPITATION OF THE MONTH.
TEMPERATURES HAD BEEN ABOVE NORMAL FROM THE 10TH THROUGH THE 19TH.
BUT NORTHERLY FLOW AT THE SURFACE AND ALOFT BEHIND A COLD FRONT KEPT
TEMPERATURES NEAR NORMAL FROM THE 20TH THROUGH THE 24TH.
ON THE 23RD AND 24TH, A TROUGH FROM WESTERN CANADA PLUNGED SOUTH
OVER THE GREAT BASIN. NORTHEAST FLOW OVER THE NORTHERN ROCKIES
ALLOWED COLD AIR TO TRICKLE OVER THE CONTINENTAL DIVIDE INTO CENTRAL
AND EASTERN IDAHO. BY THE 25TH, SURFACE WINDS FROM THE SOUTHEAST HAD
TRANSPORTED THE COLD AIR DOWN THE SNAKE RIVER VALLEY.
THE TROUGH BROUGHT SNOW TO AREAS SOUTH AND EAST OF BOISE. SNOW-
COVERED GROUND IN THE UPPER SNAKE RIVER VALLEY, THE MAGIC VALLEY,
AND THE HIGH TERRAIN SOUTH OF THE VALLEY REINFORCED THE COLD AIR
DURING THE LONG NIGHTTIME HOURS.
MEANWHILE, A HIGH PRESSURE RIDGE OVER THE PACIFIC NORTHWEST BROUGHT
WARMER AIR ALOFT, FORMING A TEMPERATURE INVERSION AS IT TRAPPED THE
COLD AIR AT LOWER ELEVATIONS. FROM THE 25TH THROUGH THE END OF THE
MONTH, BOISE'S TEMPERATURES AVERAGED 5-10 DEGREES BELOW NORMAL IN
THE STAGNANT AIR UNDER THE INVERSION. ALTHOUGH NIGHTS WERE COLD,
MOSTLY SUNNY SKIES ALLOWED AFTERNOON TEMPERATURES TO REACH THE UPPER
30S AND LOWER 40S.
ON THE 30TH, STRONG WESTERLY FLOW ALOFT ACROSS THE NORTH PACIFIC
CARRIED A WEATHER SYSTEM INLAND OVER OUR AREA. LIGHT SNOW BEGAN LATE
IN THE EVENING AS MOIST AND RELATIVELY WARM AIR MOVED OVER THE COLD
AIR IN THE VALLEY.
...............................
..THE BOISE ID CLIMATE SUMMARY FOR THE MONTH OF NOVEMBER 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 67 11/15
LOWEST 19 11/25
11/27
11/29
AVG. MAXIMUM 52.1 48.8 3.3
AVG. MINIMUM 33.7 31.7 2.0
MEAN 42.9 40.3 2.6
DAYS MAX >= 90 0
DAYS MAX <= 32 0
DAYS MIN <= 32 13
DAYS MIN <= 0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 4.43 1874
TOTALS 1.19 1.18 0.01
DAYS >= .01 9
DAYS >= .10 4
DAYS >= .50 1
DAYS >= 1.00 0
GREATEST
24 HR. TOTAL 0.52 11/18 TO 11/19
SNOWFALL (INCHES)
TOTALS 0.1
SINCE 7/1 0.1
GREATEST
SNOW DEPTH 0
24 HR TOTAL MM
DEGREE DAYS
HEATING TOTAL 657 742 -85 918
SINCE 7/1 987 1212 -225
COOLING TOTAL 0 0 0 0
SINCE 1/1 1342 1044 298
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 5.6
HIGHEST WIND SPEED/DIRECTION 32/310 DATE 11/19
HIGHEST GUST SPEED/DIRECTION 46/310 DATE 11/19
AVERAGE RH (PERCENT) 64
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
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