Soil Moisture & Forecasting

The ground is wet for sure and soil moisture values will increase the next few days with an unsettled weather pattern.  From this mornings NWS discussion:

- Showery activity will continue today and transition to low
  clouds and drizzle tonight into early Wednesday.

- Showers and thunderstorms are expected north of I-96 and west of
  US-131 Wednesday afternoon and evening with small hail and
  locally heavy rain possible.

- Another round of showers and storms is expected Thursday
  afternoon and evening with locally heavy rainfall as the main
  threat.

- A marginal threat for excessive rainfall exists west of US-131
  from Wednesday afternoon to Thursday due to repeated rounds of
  showers and storms over increasingly saturated ground.

 

Soil moisture is important to forecasting. When the soil is saturated, evaporation from the earth’s surface and transpiration from trees will modify the weather. During the day, the evaporation and transpiration cause the air to be cooler than it otherwise would have been BUT also adds moisture to the air.

In warm climates, the added moisture can more than offset the cooling from evaporation when it comes to how comfortable the air feels. A temperature of 95 with a dewpoint of 75 feels much more uncomfortable than a temperature of 100 with a dewpoint of 50.  Of course the terminology of uncomfortable is different from person to person.  For me anything over 75° is uncomfortable regardless of the humidity levels.

Saturated soils increase the likelihood for dew and frost, especially on clear nights with light wind. The soil moisture increases the dewpoint, which in turn causes the air above the surface to be closer to saturation. Soil moisture is also important to instability.

The addition of moisture from evaporation and transpiration add moisture to the air which can increase the likelihood of rain when a front or another trigger mechanism moves through. An extended period of dry weather will cause soil moisture values to be below normal. This has an effect of reducing rainfall (less evapotranspiration results in less moisture for fronts to lift and less thermodynamic instability).


There has been a debate whether our summer will be cool or hot this year, or just right.  Below are the anomaly graphics from the CPC for this summer which would make one think we would have a cooler and wetter season.  I would take this with a grain of salt as weather dynamics tend to change day to day and week to week.


There is a lot of physics and math (algebra, calculus and statistics)  which goes into the study of meteorology along with geography, knowing the effect of the terrains effect on the weather.  I won’t get into the math part because even though I am still studying much of it is beyond my understanding.  I used a lot of statistical math in my job before I retired however the calculus gave me a headache and brought out my ignorance of the symbology of those things.

I hope this series is helpful for all of you – when I am done I will create a page with a downloadable PDF book covering the whole thing….


 

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Sandy (Hudsonville)Andy WINDYMr. NegativeBarry in Zeeland Recent comment authors
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Sandy (Hudsonville)
Sandy (Hudsonville)

Nice Spring day today!! My daffodils recovered from the snow on the weekend and now they are all blooming. Before we know it so will the tulips.

INDY
INDY

Wood tv 8 had 70* degrees last night for Thursday now 66* degrees interesting…I’m thinking still hard for them to transition into Spring also lol.. Is it May yet? INDY!

Mr. Negative
Mr. Negative

A “non-tropical” 71 in Clearwater this morning 🙁

Rocky (Rockford)
Rocky (Rockford)

Another great Spring day for Barry to work outside and Andy to go golfing?

Barry in Zeeland
Barry in Zeeland

Ran some errands earlier while it was raining, now I’m home and how about that, the sun is out. So you are correct. Turning out to be a perfect day outside today. Bravo.

Barry in Zeeland
Barry in Zeeland

And the temp is 50 with winds out of the SE at 0 to 5mph. Absolutely stellar!

https://www.wunderground.com/dashboard/pws/KMIZEELA26

Andy W
Andy W

Yep love it!!! I don’t golf during the week, it’s not cold and snowing and this weather is perfect to get the morel mushrooms popping!! BRING IT!!

Rocky (Rockford)
Rocky (Rockford)

Give me snow over this cool wet weather any day and all year!

Mark (East Lansing)
Mark (East Lansing)

April showers this week. My lawn is really greening up.

Rocky (Rockford)
Rocky (Rockford)

I still have tons of snow on the ground and piles where I shoveled! What an absolutely incredible winter it has been!

Barry in Zeeland
Barry in Zeeland

Interesting since all the Rockford webcams seem to suggest otherwise:

https://www.rockford.mi.us/Community/ABOUTROCKFORD/RockfordWebcams/tabid/11670

Slim

We are now half way thru April so now is a good time to see where the major reporting stations stand so far. Grand Rapids the mean temp 44.7° (-0.3) total precip 2.50” (1.56 is average) snow fall 4.8” (1.4” would be average) the highest so far this month is 74 and the lowest 19. For other Michigan locations. Departures or averages are in ( ) Muskegon Mean 43.8 (+0.1) precip 1.86” (1.45) snow fall 7.8” (1.9) Lansing mean 44.5 (+0.3) precip 1.34” (1.52) snow fall 1.5” (1.4) Detroit mean 47.5 (+1.1) precip 1.34 (1.43) snow fall trace (1.3) Flint… Read more »

Rocky (Rockford)
Rocky (Rockford)

If you like temps in the 50’s and 60’s with rain and wind then are going to love the rest of this week and beyond!

Slim

MV brought up a very good point today and that peoples comfort level is different for each person. While MV and Barry like it on the cool side I like it on the warmer side. For me the ideal temperature would be in the low 80’s with a touch of humidly in the air. For me anything above the upper 80’s with high humidly would become unconformable. On the cool side it depends once again as to how humid it is. 60 with a low dewpoint can feel very cool in the summer time so I would use that as… Read more »

Rocky (Rockford)
Rocky (Rockford)

Give me 70’s all summer long!