Wasatch Weather Weenies

The primary tool for forecasting smoke in the United States is a modeling system known as HRRR-Smoke. HRRR stands for the High Resolution Rapid Refresh, a high resolution developed by the NOAA Earth System Research Laboratories in Boulder Colorado.  The HRRR is actually based on the Weather Research and Forecasting model (WRF), which was developed by the National Center for Atmospheric Research.  Yes, I know this gets confusing.  I can't keep up with it either.   HRRR-Smoke is based a version of the WRF model that includes coupled air chemistry, known as WRF-Chem, in order to simulate smoke emissions and transport.  It also allows for the effects of smoke particles and other aerosols to be considered for the models precipitation processes.  This is known as "aerosol aware microphysics parameterization."   HRRR-Smoke forecasts can be accessed at many web sites and on many apps including OpenSnow.  They can also bee accessed through NOAA a...

I spent last week in Boise attending the 2024 American Meteorological Society Mountain Meteorology Conference.  When we arrived on Sunday afternoon, it was 108˚F with smoke filled skies.  The locals did their best to maintain a sense of humor. Wednesday afternoon is typically a recreation period for attendees.  We decided to drive up to Banks and go for a swim in the Payette River, which was thankfully cold.  On the way home, just outside of Boise, we noticed a column of black smoke set against the bronze sky from fires in Oregon.  After cresting a hill, we noticed a relatively new Ford Expedition engulfed in flames and a lot of people standing around looking at it in horror.  With little to do to help, we drove on.  Ultimately, thunderstorm outflow fanned the vehicle fire into the grass and 1500 acres apparently went up quickly before it rained and they got it under control.  Good times.  Today (Saturday), I'm back in Salt Lake and it's been...

Recent weather has left me with little to say.  Hot, dry, smoky July doldrums with some afternoon convection.  For all intents and purposes, the pattern doesn't change much over the next several days.  The ridge wobbles around, but there are no big changes.  The best we can hope for is a little thunderstorm activity to at least break up the monotony.  Perhaps you felt some drops and wind last night.  Sadly, I didn't. The National Weather Service National Blend of Models forecast for the Salt Lake City International Airport shows the situation well.  Forecast highs near 100 each day.  Perhaps a slight cool down late next week when a trough passes to our north and the ridge weakens just a bit.   Sad.  

Yesterday's maximum at the Salt Lake City International Airport was 106°F, a record for the day and just a degree short of the all-time high (107°F).  The airport measurement site has been much maligned by some as being "jacked" (i.e., too high) or unrepresentative by some.  This is a subject that we've discussed previously in this blog (see What's Up @ KSLC  and Records Falling ).  What I have noticed in social media is that there is a tendency to assume that the airport site is wrong and the other sites are right.  There is also a tendency to assume that the differences in maximum temperature at the various sites are due to either calibration issues or local siting characteristics.  In reality, there are many many factors that affect maximum (and minimum) temperature readings.   There are tens of thousands of weather sensors in the United States providing data to the internet.  The MesoWest project at the University of Utah (https://mesowes...

Northern Utah has so far been sheltered from the southwest heat wave, but that will be changing this week.   All-time records set over the weekend include 120F in Las Vegas (old record 117F) and 124F in Palm Springs (old record 123).  Bishop, Barstow-Daggett, and Desert Rock tied their all-time highs.   The Salt Lake City International Airport has been "blissfully cool" so far this July with temperatures maxing out in the 80s from July 1-4 and then in the low-to-mid 90s from July 5-7.  Minimum temperatures have been in the 50s and 60s.   Temperatures, however, will be climbing during the first part of the work week and are forecast to reach the triple digits from Wednesday through Sunday. Those forecast highs are close to, but not above records (104 for Tuesday, Wednesday, and Thursday; 105 for Friday; 107 for Saturday; 104 for Sunday), but they are close enough that one can't rule out a record being tied or falling.   For kicks and gigg...

Enjoy the "cool" weather this week because I just looked at the forecast and hell is coming.   One of my rules of thumb is the 20/20 rule for temperature.  Anything below -20C or above 20C at 700 mb (about 10,000 feet) is exceptional for northern Utah.   The latest GFS forecast for 0000 UTC 12 July (6 PM MDT Thursday) have us in the 20–22C range. And the latest NBM forecast for the Salt Lake International Airport shows a gradual warming trend after tomorrow well into the triple digits by next Thursday with highs into the triple digits.  Of the forecasts used for the NBM, the median high is 104. The upper 25% are 108 or greater.   Source: https://apps.gsl.noaa.gov/nbmviewer The NWS is already messaging the potential for dangerous, record-breaking heat.   Source: NWS, obtained 3 July 2024 A cruel reminder that July is a four-letter word.

With high temperatures this past weekend of 100 and 101 at the Salt Lake City International Airport, today's "cool change" is greatly appreciated.  As I write this at about 3:10 PM, the temperature at the airport is only 81 and it is looking likely that we won't even eclipse 90 today.   Those long in the tooth might remember that Cool Change was a 70's hit for the Little River Band. The Little River Band was from Australia, where the Cool Change is an actual meteorological phenomenon that produces dramatic temperature falls from oppressive summertime heat in southeast Australia.   The current drop in temperature is perhaps not as large or dramatic as the Australian Cool Change, but we'll take it.  I addition, the extended forecast is actually a good one for early July, with persistent ridging upstream along the Pacific coast (e.g., GFS forecast valid 0000 UTC 7 July below) putting northern Utah in northwesterly flow.   That's much better than the ...