The West Sizzles & Our Mild Weather About To Fizzle

***Watch WISN 12 News for the latest weather information!***

Thank you for stopping by the Weather Watch 12 Blog!  This is Milwaukee’s top source for the inside scoop on the weather, and best of all you can interact with the weather team at any time!  In today’s entry we will look at the extreme heat in the West, and the cold weather headed toward the Midwest.

Let’s start with the heat out West.  High temperatures well above 100 degrees smashed daily and all-time records in southern California on Monday.  Below are just a few of the records broken.  The most significant being the all-time record high in Los Angeles, a scorching 113 degrees!  

                                                                 HIGH        RECORD               ALL 
                                                                TODAY      FOR THE             TIME
                                                                                   DATE (YEAR)    RECORD (DATE)
                                                                       —–   ———–    —————-

DOWNTOWN LOS ANGELES     113**   106 (1963)     112  ( 6/26/1990)    
LONG BEACH AIRPORT               111**   109 (1963)     111  (10/15/1961)
BURBANK AIRPORT                       110*    104 (1963)      113  ( 9/12/1971)
WOODLAND HILLS                         111*    107 (1993)       119  ( 7/22/2006)
LOS ANGELES AIRPORT             105*    105 (1963)     110  ( 9/26/1963)

In order for temperatures to get this hot in southern California in non-desert locations, the weather conditions at the surface and aloft must be perfect.  The ingredients needed to achieve this type of warmth include an offshore wind, an upper level ridge, and compressional warming.

The map below is a 500mb map from Monday at 1 p.m.  Notice the ‘H’ over the Great Basin?  This is an upper level ridge of high pressure.  With a clockwise flow around the ridge the winds will blowing from from east to west.  This meant an offshore wind was present over southern California.  The wind barbs clearly show this wind flow.  Just click on the map to enlarge.

With the flow around the ridge moving the air from east to west, the air flow ascends the mountains just east of Los Angeles, and then flows down the mountainside.  This downsloping wind causes compressional warming.  A warming wind is known as a Chinook Wind.

The diagram shows the upper level wind, and also the warming that is taking place as the air flows down the hillside.  For our sake, just pretend that Los Angeles is located where it says clear and dry.

As the air decends down the slope it warms at about 5.4F per 1,000ft.  So the net result of all factors coming together in L.A. on Monday was a record breaking hot day!

While the West is sizzling, our weather was cool this past weekend and on Monday.  A couple of seasonal days are in store before a big push of cool/cold air moves in the for the weekend.  Below is a forecast temperature map for Saturday at 7 p.m.  Notice that this has Milwaukee in the 50-55 degree range, but some inland locations will be in the 40s! 

A widespread frost/freeze is likely by Sunday morning.  Even lakeshore locations could be in the 30s.  Inland locations could even drop into the upper 20s IF skies are clear and winds are light.  This is something we will watch very closely over the next several days. 

Make sure to watch WISN 12 News for special graphics on the cold weather headed our way, and we will update the 7 day forecast when the latest data rolls in.  So who’s ready for the cold?

Have a great day!

Jeremy Nelson

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12 Responses

  1. Jeremy, You asked who was ready for the cold. I vote a NO on that. Would rather be enjoying the toasty temps of southern CA…well, maybe a few degrees cooler than they have. The frost we had yesterday morning up here in NE Dodge was a rude reminder of what’s to come. Have a good one.

    • Cliff,

      I’ll take heat over the cold any day. Get ready for this weekend, widespread frost looks likely. Highs may be in the low 50s in spots…brrrr.

      Jeremy

  2. That’s still better than last October. We didn’t even get a high that reached 60 until the 19th and there were 9 straight 40s in there. A couple of low to mid 50s isn’t a big deal.

  3. Jeremy, the NWS forecast for September had our area with above average temps and above average precip, oops. They have above average temps also for the 90 day period, why do I get the feeling that they are wrong about that as well?

    • Last year’s well below average October yielded one of the warmest Novembers ever, so anything is possible. I’ll bet this October will definitely be warmer than last year at the least.

    • Bryan,

      September will end up almost right at average, so the NWS forecast wasn’t too far off. The rainfall total will end below average though. I won’t make a long range forecast again until sometime in November. Remember, the pattern is just beginning to form. It will be fun to show everyone how to identify the pattern, and then use it to make a long range forecast.

      Jeremy

  4. I notice that the airport tied their all-time record, while downtown broke the previous record by 7 degrees. Is there more of an island heat effect than there was in 1968?

    Here in British Columbia, the central coast and inland areas have had the wettest Sept on record with flooding not seen since 1968.

    I hope we aren’t in for a repeat of 1968 winter conditions because that was the mother of all winters in these parts.

    • Glacier,

      I’m guessing the city has expanded quite a bit in the past 40 years, so the urban heat island could add a degree or two to temps. The overall setup on Monday in L.A. was the biggest factor in the high heat.

      How did you find our blog here in Wisconsin? Welcome and please stop back!

      Jeremy

      • Jeremy,

        I found your blog when searching for La Nina and ways to predict the coming winter. The page that came up was this one: //…2010/03/23/the-weather-pattern-continues-to-repeat/

        For sure, I’ll visit again!

        P.S. I was in Wisconsin last October for a wedding. Enjoyed the fall colors despite the unseasonably cold weather.

      • Glacier,

        Great to have you on board. The blog will focus much more on the pattern in the coming weeks. I would suggest reading some past blog entries on lrcweather.com. That site is run by the founder of the LRC. Jeremy

        T

  5. Nice blog – J

    Certainly this must be a preview of things to come.

    • The long range GFS keeps the ridge out West. If that persists I may need to book some trips to warm locations this winter;)

      Jeremy

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