Wednesday, April 6, 2022

 

Current Conditions at Sanborn Field



Wednesday Night:
Partly cloudy. Low: 39



Thursday:
Partly cloudy. High: 50



Thursday Night:
Overcast with drizzle possible. Low: 34

 


Friday:
Overcast with drizzle ending by noon. High: 46



Friday Night:
A few clouds. Frost possible. Low: 30

 

 

Thanks to IconArchive.com for the icons! 

====================================================================

Discussion:

Windy conditions continue Wednesday due to strong northwesterly winds up to 30mph. A low pressure system to the North of Missouri and resulting cold front will drops temperatures Thursday and Friday. With increased moisture in the atmosphere, Thursday night will likely see light rain. A lack of instability will prevent the rain from becoming any heavier than a drizzle. As temperatures will be near freezing, do not be surprised if a few flurries are mixed with the drizzle Friday morning. No snow accumulation is expected and precipitation will amount to around 0.1 inches. Gusty conditions are expected throughout the day Friday due to strong northwest winds. As Friday night’s temperature dips below freezing, there may be a layer of frost in the early morning. Cover any spring flowers and crops left outside. 

- Heienickle 

=================================================================

Forecasters: Meyer, Heienickle, Orr

Date Issued: 04/06/2022 5:00PM CDT


Technical Discussion: 
 
For this forecast, the main interests for the next several days are the possibility of light precipitation Thursday night into Friday morning as well as cooling temperatures leading to the potential of frost Friday night. To forecast, the NAM was used over the GFS. Both models were accurate when it came to current temperatures and cloud cover. Where they differed was on current dewpoint, with the GFS noticeably higher than the current dewpoint. 

For the rest of the forecast period, the main feature at the 250-mb level is the large trough over the central and eastern United States. This feature deepens but does not move much over the next several days. As the trough deepens, winds over Missouri slowly back from westerly flow to northerly flow until the end of the forecast period. By Friday, the trough begins to shift eastward but does not move away from Missouri until after the forecast period. 

At 21Z Wednesday, a large amount of circulation is present over Missouri which is in the process of exiting as per 500-mb analysis. After a period of low circulation, enhanced vorticity returns to Missouri beginning 14Z Friday and lasts to the end of the forecast period. 

Higher RH values are overhead on the 700-mb level in central Missouri beginning at 21Z Wednesday. This is supported by satellite showing clouds moving in from the north. Higher RH values move east by 08Z Thursday, suggesting a break in the cloud cover before RH values return by 18Z Thursday. 
 
Although there is sufficient moisture Thursday into Friday morning. Omega values remain close to 0, meaning there is little lifting to get precipitation going. This is supported by soundings from the NAM, suggesting some negative omega values near the surface Thursday night into Friday morning. This suggests the possibility of some light precipitation falling, likely in the form of drizzle. 

Temperatures by Friday morning fall into the lower 30s according to NAM soundings. With the rest of the atmosphere below freezing, a few flurries mixing in with the drizzle are possible. None of the flurries are expected to accumulate as ground temperatures will stay above freezing. Any liquid precipitation amounts will be light, generally less than 0.1". 

As the trough deepens, colder air will begin to spill in from the north into Missouri. Strong winds at the 850-level upwards of 40kts and surface winds up to 20kts will help bring the colder air southwards. With the 20-kt surface winds continuing into Thursday, breezy conditions will continue. However, there is a lack of CAA on Thursday meaning temperatures will still make it to a touch below the climatological average for early April. 

There will exist a brief period of CAA beginning at 21Z Thursday and lasting until 03Z Friday as per the surface guidance. With clouds clearing out and winds calming down, temperatures will fall below freezing for lows on Friday. This will lead to the possibility of frost by Saturday morning. Climatologically, the last frost for Columbia is on April 10, so the frost expected Saturday morning is not unusual. 

-Meyer

No comments:

Post a Comment