The Weather Wire
November 2008 Volume 16 Number 11
Avg High - 66.2
Avg Low - 37.9
Snow - Trace
Season Snow - Trace
Precipitation - 1.44"
Avg High - 51.5
Avg Low - 23.5
Avg Snow - 10.7"
Avg Precip - 0.98"
Watches and Warnings
It is that time of year again for everybody to become well versed in the winter weather watches and warnings that will issued by NWS once the snow begins to fly. All of our clients are updated to these watches and warnings, so it is important to know what each means and how it may be relevant to you and your business. Below are definitions of commonly used winter weather watches and warnings:
�A WINTER STORM WATCH IS ISSUED WHEN WINTER STORM CONDITIONS ARE POSSIBLE WITHIN THE NEXT 12 TO 36 HOURS, BUT THE TIMING...INTENSITY...OR OCCURRENCE MAY STILL BE UNCERTAIN.
�A WINTER STORM WARNING IS ISSUED WHEN HEAVY SNOW IS OCCURRING OR WILL DEVELOP IN THE NEXT 18 HOURS. THE HEAVY SNOW WILL BE ACCOMPANIED BY WIND GREATER THAN 15 MPH AND BLOWING SNOW.
�A HEAVY SNOW WARNING IS ISSUED WHEN HEAVY SNOW IS OCCURRING OR WILL DEVELOP WITHIN THE NEXT 18 HOURS. WINDS ARE EXPECTED TO BE LESS THAN 15 MPH DURING A HEAVY SNOW WARNING.
�A BLIZZARD WATCH IS ISSUED WHEN BLIZZARD CONDITIONS ARE POSSIBLE IN THE NEXT 12-18 HOURS.
�A BLIZZARD WARNING IS ISSUED WHEN THE FOLLOWING CONDITIONS ARE EXPECTED FOR AT LEAST 3 HOURS: SUSTAINED WINDS OF 35 MPH OR GREATER CONSIDERABLE FALLING AND/OR DRIFTING SNOW LOWERING VISIBILITIES TO LESS THAN 1/4 MILE.
�A WIND CHILL WATCH IS ISSUED WHEN WIND CHILL WARNING CRITERIA ARE POSSIBLE IN THE NEXT 12 TO 18 HOURS.
�A WIND CHILL WARNING IS ISSUED FOR WIND CHILLS OF AT LEAST -25 DEGREES ON THE PLAINS, AND -35 DEGREES IN THE MOUNTAINS.
�A SNOW ADVISORY IS ISSUED WHEN GENERAL SNOW ACCUMULATIONS ARE EXPECTED:
�BETWEEN 4 AND 8 INCHES IN 12 HOURS IN THE MOUNTAINS...AND BETWEEN 3 AND 6 INCHES IN 12 HOURS AT LOWER ELEVATIONS.
�A SNOW AND BLOWING SNOW ADVISORY IS ISSUED WHEN FALLING SNOW IS ACCOMPANIED BY BLOWING SNOW TO CAUSE TRAVEL PROBLEMS DUE TO LOWER VISIBILITIES AND DRIFTING SNOW.
�A BLOWING SNOW ADVISORY IS ISSUED WHEN WIND BLOWN SNOW WILL OCCASIONALLY REDUCE VISIBILITIES AND CREATE A HAZARD FOR TRAVELERS.
�A DENSE FOG ADVISORY IS ISSUED WHEN WIDESPREAD FOG WILL REDUCE VISIBILITIES TO 1/4 MILE OR LESS.
�A WINTER WEATHER ADVISORY IS ISSUED FOR FREEZING DRIZZLE OR A MIX OF PRECIPITATION TYPES (SUCH AS SNOW AND SLEET) THAT WILL IMPACT TRAVEL CONDITIONS.
�A WIND CHILL ADVISORY IS ISSUED WHEN WIND AND TEMPERATURE COMBINE TO PRODUCE WIND CHILL VALUES OF 18 DEGREES BELOW ZERO TO 25 DEGREES BELOW ZERO.
�THERE ARE OTHER NWS ADVISORIES, BUT THEY ARE RARELY USED HERE IN COLORADO. TO SEE ALL THE WINTER WEATHER WATCHES, WARNINGS, AND ADVISORIES VISIT:
Areas of drought are spreading across much of eastern Colorado as a result of our precipitation deficit year to date. Far northwestern Colorado has seen an increase in drought conditions as well.
The map below shows forecasted temperature deviances for November 2008. As can be seen, it is expected that all of Colorado to have normal temperatures for the month of November 2008.
The map below shows forecasted precipitation deviances for November 2008. Normal precipitation is anticipated for all of Colorado.
Drought conditions are expected to improve across southeastern Colorado over the next 3 months, with no change expected other area of the state.
October of 2008 was above normal in precipitation for a change and near normal in temperatures. In the middle of the month there was a cold spell that promised to bring some snow to Denver, but never did. The end of the month could not have been any nicer with well above normal temperatures and abundant sunshine. As a whole the monthly mean temperature was 52.1 degrees which is about 1 degree above normal. Thankfully the month ended up with above normal precipitation with 1.44" compared to 0.99" normally. This will help cut into the deficit, but we are still 3.89" below average for the year. Without any snow so far this fall in Denver we are already behind more than 6" for the season.
The start of the snow season for the Denver Metro area will be upon us this month. November is typically the 2nd snowiest month in Denver with 10.7" on average. I think it is safe to say that Denver will experience its first snow of the season this month as the weather pattern is becoming much more active after the tranquil weather we had during the last part of October and the early part of November. There can be periods of warm weather, but it is usually short lived and even the warmest days stay in the 70s. Sunshine is less abundant as there is on average only 64% sunshine which is tied with May for the lowest of any month during the year. Get the snow shovels ready it is about time for some real snow!
Sunrise/Sunset (Jul - December Denver area)
October 2008 to April 2009