Friday, April 28, 2023

 





 


Friday Night:
Mostly Cloudy. Low: 51


 
 




Saturday:
Partly Cloudy, chance of a trace amount of rain in the morning. High: 66
 
 





Saturday Night:
Partly Cloudy.
 Low: 43







Sunday
: Decreasing Clouds. High: 58
 






Sunday Night: 
Mostly clear. Low: 41

 

 

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Discussion:

A cold front is set to slide over our area tonight into Saturday morning, cooling temperatures down and bringing a slight chance for light rain early Saturday morning. The rest of the weekend looks to be clear with the Sunday high set in the upper 50s.

-Sausen


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

Forecasters: Thomas, Sausen, McGuire

Date Issued: 4/28/2023 4:20PM CDT

Technical Discussion:



A deepening upper level trough is currently centered over the Plains with a positive tilt, with general high pressure in the low levels over the Rockies. Closer to the surface the low becomes cutoff over the OH River valley, with a smaller lobe centered over Texas. WPC analysis places a large stationary front between the Texas Panhandle all the way up into Wisconsin, with light rain and fog reported along most of the frontal boundary. Otherwise, the forecast area remains under the influence of a weak surface ridge.

Our “problem of the day” for this weekend appears to be chances for rain Saturday morning and evening. We went with the GFS, as the NAM’s surface temperatures were significantly (~10degF) warmer than observations were this morning.

The lobe of low pressure over Texas looks to become cut off overnight tonight, and travel due east all the way into Saturday night, becoming absorbed in its’ parent low offshore Sunday night, keeping its’ influence on the forecast area limited at best. The main feature will be a weak cold front moving through the area Saturday morning. Surface dewpoints of 50 degrees, weak but present 700mb vertical velocity values and weak PVA leads me to believe that this front will produce some weaker precipitation. Surface temps in the 50’s should negate any chance for wintry precip, but soundings show a relatively saturated troposphere overall, which should give way to widespread and thick cloud cover tonight into Saturday morning. CAPE values are measly in all measures, and the lid strength index indicates a moderate cap on the forecast area, suggesting slim to zero chance of anything convective. As such, we’ve added trace amounts to the precipitation forecast for Saturday morning. A second shortwave is noted in the evening, though with even less moisture to work with. Similar story to the first wave, this one should also bring a period of thick cloud cover and perhaps some light precip Saturday evening, clearing out by midnight.

By Sunday morning, the main speed max of the main low centered over the Great Lakes should move south, placing the backside of the trough over the forecast area. Some of these winds should mix to the surface, and as such gusty winds seem likely overnight Sunday. Otherwise, large scale ridging over the Rockies should transfer into the Plains, leaving us in a col point between the two systems ensuring peaceful weather. 
-Thomas

 

 





Friday: Partly Cloudy. High: 70



Friday Night:
Mostly Cloudy. Low: 49
 


 

Saturday:
Decreasing Clouds in the afternoon. High: 66

 
 


Saturday Night:
Mostly Clear. Low: 43
 
 
 


Sunday:
Mostly Sunny, breezy. High: 56


 

 

Thanks to IconArchive.com for the icons!


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Discussion:

Hey there Tigers! This weekend is looking like a good time to enjoy the outdoors with high temperatures this Friday and Saturday reaching low-70s and mid-60s  respectively. We will have a mostly sunny sky after Friday night as the atmosphere dries up Saturday afternoon. You may want a jacket on Sunday, though, as highs decrease to the mid-50s and winds reach about 17 mph throughout the day. 
 
-Allen
 =================================================================

Forecasters: Sallot, Allen

Date Issued: 4/28/2023 10:00 AM CDT

Technical Discussion:

The main concern of the forecast period is a cold front passing through the forecast area on Friday night. This front is expected to pass without precipitation, but will bring cooler temperatures. Both the NAM and the GFS were used to construct this forecast as both models had a good handle on current conditions and agreed for most of the forecast period.

At 250mb, the upper level flow is zonal until about Saturday at 18z when the flow becomes meridional and a deep trough extends into northern TX. The main systems of concern this weekend are a strong low pressure system moving from southern OK into northern TX and a second low pressure system moving from southern Canada into the Great Lakes region. However, the positioning of these lows will keep MO out of the areas of active weather. As the southern low continues east, northerly flow takes over in the upper levels, and MO sits under the jet stream for the rest of the forecast period.

At 500 mb, a shortwave passes through the forecast area around Saturday 00z to 06z along with the cold front. This may support precipitation, but a lack of moisture will keep Mid-MO dry, so only some clouds are expected to develop Friday night with the frontal passage.

Additionally, each of the low pressure systems provide ample circulation for rising motion. This circulation bridges the two systems through MO around Saturday 12z before the southern low gets wrapped up into the northern low by Mon 00z. High circulation from the northern low in the Great Lakes reaches Mid-MO early Sunday morning. There is some model disagreement on this timing as the NAM expects this circulation around Sunday 00z to Mon 00z and the GFS expects this circulation around Sunday 12z and extends through the end of the forecast period. Despite this disagreement, a consensus on a lack of moisture will likely prevent any precipitation Saturday night into Sunday.

As the cold front passes around Saturday 00z to 03z and the northern low pressure system over the Great Lakes sits to our north east, north and northwesterly flow will dominate the flow at all levels for the rest of the forecast period. This will drop temperatures into the 60s and 50s on Saturday and Sunday, but a consistent lack of moisture will allow for plenty of insolation. 
 
Sallot

Thursday, April 27, 2023

 




 



Thursday Night:
Mostly Cloudy. Low: 48



Friday:
Partly Cloudy. High: 70
 


 

Friday Night:
Light Showers. Low: 49

 
 


Saturday:
Partly Cloudy. High:68
 
 
 


Saturday Night:
Clearing to Mostly Clear. Low: 43


 

 

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Discussion:

We expect to continue these seasonal temperatures into the weekend with a slight chance of showers Friday night. Besides that, mostly cloudy conditions expected to continue into Saturday.

-Labit
 =================================================================

Forecasters: Labit, Macko

Date Issued: 4/27/2023 5:00 PM CDT

Technical Discussion: 


The primary focus of this forecast is the likelihood of showers overnight Friday as well as how long these seasonal temperatures will be lingering. After comparing both upper-air observation to analysis as well as comparing location and intensity of current precipitation. Both the NAM and GFS have been handling the current and past condition quite well. Additionally, when comparing the two models against each other, they seem to be quite similar. Due to this both models will be used interchangeably during this forecast. 

A shortwave visible at all levels of the atmosphere is positioned over the mid-Mississippi Valley causing divergence aloft. The exact placement of the trough axis remains closer to the Bootheel of Missouri. Combined with circulation and saturation at all levels, moderate rain is expected into early Friday morning. This should only be for areas south of central Missouri because of dry air at the surface preventing any rain that might fall aloft from reaching the ground. 

This shortwave will fall apart as it decays off to the northeast being replaced by a deepening longwave trough Friday evening. However, the mid-lattitude cyclone associated with this shortwave will propagate into the Great Lakes supplying ample moisture at the 850-mb level. This will be the layer to expect most cloud development. In between this transitioning phase, high relative humidities and warm air advection will help support partly cloudy conditions through Friday. Then by early Saturday morning this longwave will bring additional moisture at the 700-mb level. When mixing with the surfaced based moisture, divergence aloft and circulation (which is a bi-product of diverging winds with the jet stream), could result in light showers. After consulting the NBM, accumulations near ~0.10" will be likely.

Continuing into Saturday evening/overnight, the trough at 250mb will continue to deepen creating a closed, upper-level low into the Southern Plains. While this will cause some issues with more active weather in the Southern Plains Saturday evening, central Missouri should only see cloud formation. High relative humidity mixed with warm air advection at 850mb will help influence that, but it'll be too dry aloft and near the surface for any chances of precipitation. 

By late Saturday night into early Sunday morning, the mid-lattitude cyclone located in the Southern Plains continues to drive into the Lower Mississippi River Valley. This, combined with the second midlattitude cyclone over the Great Lakes region, should help wrap the remianing moisture towards the east out of our area.

- Labit




 


Thursday:
Overcast Light Rain Possible. High: 63



Thursday Night: Light Rain. Low: 48
 


 
Friday: Partly Sunny. High: 70

 
 

Friday Night: Light Showers. Low:51
 
 
 

Saturday : Clearing to Mostly Sunny. High: 68

 

 

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Discussion:

Prepare for a chance for rain today, tonight, and overnight Friday. Make sure to bring a raincoat or your trusty umbrella!

-Samson
 =================================================================

Forecasters: Hefner, Macko, Samson

Date Issued: 4/27/2023 10:00 AM CDT

Technical Discussion: 
 
The biggest concerns for this forecasting period (Thursday 12Z to Sunday 00Z) are rain chances Thursday and Thursday night and overnight Friday, potentially into Saturday. The GFS and NAM resolved most features similarly; however, preference was given to the GFS because it has been trusted more over recent forecasts than the NAM.

Beginning at the 250mb level, a shortwave trough is situated over the Oklahoma-Texas panhandle. As this shortwave begins to propagate towards the northeast on Thursday, moving into the Ohio River Valley, upper-level divergence will occur ahead of the shortwave. The upper-level divergence indicates lower-level convergence, which is rising air motion. However, none of this upper-level divergence will occur over Columbia. When the shortwave has passed through, and out of the Columbia area (Friday 09Z), a deepening trough will propagate into Missouri on Saturday at 00Z. This trough will bring upper-level divergence, affecting the Columbia area at 09Z. However, this upper-level divergence only lasts for a short time.
 
Continuing with forcing features at the 500mb level, the shortwave trough noted above, as it propagates to the northeast, slight circulation (spinning air parcels) starting at 12Z Thursday will pass over Columbia with the shortwave’s passing. There will always be very minimal amounts of circulation passing over Columbia. Although as the trough talked about above begins to pass over Columbia, circulation will ramp back up starting at 03Z Saturday and continue until 21Z Saturday. After 21Z Saturday, the circulation associated with the trough will have passed through and no longer affect Columbia.
 
While the circulation is more consistently present at the 500mb level, vertical lift is not as prevalent at the 700mb level. Negative Omega values remain on the lower end until 03Z Saturday with the passage of the longwave trough. At 03Z Saturday, negative Omega values will increase with trough propagating and last until 15Z Saturday. This lift and relative humidity could lead to cloud formation and potential for precipitation if saturation is reached (relative humidity >90%). And Columbia will have consistent moisture support at the 700mb level starting at 15Z Thursday and continuing until 15Z Saturday when the atmosphere will dry out. Since there will be significant negative Omega occurring 03Z Saturday with the moisture support, there is potential for rain.

Moving on to moisture support at the 850 mb level, the GFS is resolving notable relative humidity (values >70%) from 12Z Thursday until 15Z Saturday. A brief dry patch will last until 18Z Saturday when moisture will build back in. The present moisture increases our rain chances today, tonight, and overnight Saturday. The low-level jet will not impact Columbia until 00Z Sunday when a low-level jet will bring cold, moist air into the Columbia area from the north.

Speaking of cold air, at the surface level, there will be cold FROPA between 03Z and 06Z Saturday. This cold FROPA will play a role in our rain chances for Saturday morning.

When diagnosing rain chances for this forecast, GFS forecast soundings were used. Soundings for Thursday at 18Z show upper-level saturation over Columbia from 850mb level to around 700mb, with dry air between the 850mb level and the surface. At this point, it appears to be a coin flip over whether or not rain will happen today. Saturation could evaporate and not hit the surface, or any precipitation that reaches the 850mb level could cause the dry layer to saturate, allowing rain to reach the surface. Rain, however, does seem more certain at 09Z Friday, where the air between the surface and the 850mb level will moisten. However, any rain that will occur seems light due to low negative Omega values. Rain seems more likely overnight Friday starting at 06Z Saturday. This rain could potentially last into the daytime Saturday (12Z). Similar to rain on Thursday, any rain that will happen will be on the lighter side due to weak forcing.

For precipitation amounts and temperature for our forecast, the National Blend of Models and SREF plumes were consulted for guidance. For total precipitation, Columbia could get .10” of rain and, at the very least, 0.02” of rain.

-Samson

 

Wednesday, April 26, 2023

 

Current Conditions at Sanborn Field


 
 
 


Wednesday Night:
Mostly cloudy. Low: 46
 
 
 
 
 
Thursday: Overcast. Rain beginning in afternoon. High: 61



Thursday Night:
Overcast as light rain continues overnight. Low: 48

 
 
 
 
Friday: Overcast. High: 67
 
 


 
Friday Night: Overcast. Low: 47

 

 

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Discussion:

 Temperatures are slowly on the rise. Daytime highs will be in the 60's leading up into this weekend. Light rain also looks likely for Thursday afternoon, lasting until Thursday night. when it is not raining, conditions will be cloudy leading up into the weekend.

-Cook
 =================================================================

Forecasters: Chirpich, Cook

Date Issued: 4/26/2023 5:00 PM CDT

Technical Discussion:
 

After a little bit of a dry spell, we may see some moisture falling from the sky Thursday afternoon. We are expecting to see a little bit of rain, accompanied with lots of clouds leading up into the weekend. The GFS was the main model used for the development of this forecast, along with assistance from the NBM for temperatures and precipitation totals. 

At 250mb, an amplified shortwave is situated over the panhandles of Texas and Oklahoma. This shortwave will trigger divergence ahead of it as it moves off to the east. This divergence is associated with rising air motion, which will allow for the development of showers out ahead of the shortwave. The divergence will be over  our CWA,  will remain weaker, suggesting lighter rain. As the shortwave moves off to the east, it will de-amplify as it is absorbed into the larger long wave trough, leaving our CWA under the long wave trough for the rest of the forecast period. 

At 500mb, the shortwave is still seen. Ahead of the shortwave, upper level air circulations exist ahead of it's general circulation. Those upper level circulations exist over the CWA for most of Thursday, with the strongest circulations being overhead Thursday afternoon into early Friday morning. Couple this with moisture that is seen at 700mb and 850mb on Thursday afternoon/evening, and all the ingredients for precipitation exist for the latter part of Thursday. This is supported by model soundings showing deepened saturation Thursday afternoon that lasts through Thursday night. Soundings for Friday morning shows lower level saturation, suggesting thick cloud cover Mid Missouri. This saturation exists throughout all of daytime Friday. Deep saturation briefly returns Friday night, but quickly leaves, leading to a drying trend for the end of the forecast period.


 -Cook

 

 

Current Conditions at Sanborn Field


 
 
 


Wednesday:
Partly cloudy, building in the afternoon. High: 67
 
 
 



Wednesday Night:
Cloudy. Low: 48





Thursday:
Scattered showers beginning around noon, persist throughout the day into the evening. High: 59

 
 



Thursday Night:
Cloudy with scattered showers. Low: 48.
 
 




Friday
: Partly Sunny. High: 67

 

 

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Discussion:

Missouri will continue its pleasant weather again this Wednesday being partly cloudy and a high in the upper 60s. This is not the case on Thursday as a low pressure system is propagating into the Mississippi Valley. This will being cooler temperatures (upper 50s low 60s) and limited rainfall to mid-Mo. Rain is expected to begin midday Thursday and die down in the evening and night hours with an overall accumulation up to a quarter of an inch. Friday, we go right back to our pleasant weather with a high in the upper 60s, again.

-Ritsema

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

Forecasters: Ritsema, Clark, Cochran

Date Issued: 4/26/2023 10:00 AM CDT

Technical Discussion:
 
This forecast primarily used the GFS due the higher confidence between members, compared to the NAM.


An upper-level shortwave will be propagating from the Great Plains into the Mississippi Valley Region tomorrow, before getting absorbed back into the jet-stream on Friday. This shortwave will be bringing minimal divergence aloft to mid-Missouri as the brunt of this system is situated to the south in TX, OK, and AK. The jet stream will be moderate with winds from the southwest up to 100 knots on Thursday. Zonal flow is initiated, yet again, after the shortwave has passes around 09z on Friday.  

Winds at 500mb remain weak for the entirety of the forecast period, never exceeding 30 knots. Although the winds are weak, circulation due to the shortwave does exist. Circulation is present in mid-MO from Thursday 00z until Friday afternoon, when this system leaves the area. 
 
Moisture in the lower levels are quite inconsistent with each other. 700 mb saturates between Thursday 12z and Friday 12z. At 850, moisture moves in overnight Wednesday at 21z and persists until Saturday 00z, and the surface lags behind the levels above it, where soundings show saturation of the surface saturation occurring around Thursday 18z, with a dry out on Friday at 18z. Due to this inconsistency of moisture between the three lower levels, rain will be likely between Thursday 15z and Friday 15z. Even so, the precipitation will be scattered throughout central Missouri.
 
The low track at the surface differs from that above it, as it takes a southerly track through Texas and Arkansas, into the eastern Great Lake Region. This will limit the forcing in MO, where minimal amounts of Omega correlates to scattered precipitation rather than widespread. Soundings suggest PWAT values between .8-.9 inches from Thursday 15z to Friday 06z with higher values in the early afternoon on Thursday. Accumulations up to a quarter of an inch are expected in mid-Missouri. After low passage, the lower levels dry out and sunshine will warm up and end the day Friday. 

-Ritsema
 

Tuesday, April 25, 2023


 Current Conditions at Sanborn Field




Tuesday Night:
Mostly Cloudy. Low:
46

 

Wednesday:
Partly Cloudy. High: 64


Wednesday Night:
Mostly Cloudy. Low:48
 
 

Thursday:
Mostly Cloudy. Slight chance of a rain shower High:63
 
 

Thursday Night: Mostly Cloudy. Low: 47

 

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Discussion:

Cloud cover will begin to increase as we head further into the week with high temperatures in the mid 60s and overnight lows in the upper 40s. A slight chance of rain is possible late Thursday afternoon, but total accumulation should only be around 0.1".

-McCormack

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

Forecasters: Smitty, Peine, McCormack

Date Issued: 4/25/23

5:00 PM CDT

Technical Discussion:
 

The biggest concern for this week will be a low that is currently over Utah that will eventually become cut-off. The GFS was the model used for this forecast as it is currently handling the upper level flow well. Also, the GFS is handling the surface systems and fronts better than the NAM. 

In the upper levels of the atmosphere, a ridge is currently seated over Missouri. This ridge will remain over Missouri until a cut-off low pushes it out of the area. This low is currently over Utah and it will become cut-off when it moves over the New-Texlahoma region on Wednesday. Missouri will then be under the influence of this cut-off low come Thursday morning. This cut-off low will cause a strong jet streak to form over central Missouri on Thursday at 15Z. However, the majority of the upper-level divergence will stay southeast of central Missouri. 

In the middle levels of the atmosphere, much is the same as at 300mb as there is currently a ridge that is parked over Missouri. As the cut-off low approaches towards Missouri, moderate vorticity advection will occur overnight Wednesday into Thursday giving central Missouri some vorticity. While some vorticity is expected over central Missouri, the vorticity max will stay south of us in Arkansas. The mid levels will remain dry until some moisture advects into the area Thursday morning. Along with this moisture, omega will also build in causing upward motions in the atmosphere. Similar to the vorticity, the greatest areas of moisture and omega will stay south of Missouri into Arkansas.

In the low levels of the atmosphere, Missouri will remain dry until Thursday. On Tuesday and Wednesday, Missouri will be dominated by high pressure which will not allow any moisture to advect into the area. This will cause the moisture to remain in the southern parts of Missouri. A weak 850mb low will move right over Missouri Thursday which will then allow for moisture to build in Thursday morning. While there will be moisture, there will not be enough for storm development and this moisture will only bring clouds into the area, with a stray shower possible. 

At the surface, there is currently a very weak surface low off to the northeast at the border between Missouri, Illinois, and Iowa. While very light precipitation is possible from this surface low, the majority of the precipitation will remain to the northeast. As the week progresses, a strong surface high off to our east will dominate the atmosphere for Tuesday evening into Thursday morning. With this high pressure dominating, a light easterly wind will come into effect Tuesday night. As the week moves on, the surface low associated with the cut-off low will go south of central Missouri. The low is expected to pass through Arkansas Thursday afternoon. While the heaviest precipitation will stay south of Central Missouri, some light precipitation is possible Thursday afternoon in central Missouri. The expected precipitation total will be from a trace to .06''.
 

-Meier

 

 Current Conditions at Sanborn Field



Tuesday:
Increasing Clouds. High: 66



Tuesday Night:
Partly Cloudy. Low: 48


Wednesday:
Mostly Cloudy. High: 64

Wednesday Night:
Mostly Cloudy. Low: 48
 
 

 Thursday: Cloudy with a chance of showers. High: 61

 

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Discussion:

The sun will be out Tuesday so make sure to go out and get some sun. As the week progresses, more cloud cover builds in which will bring the temperatures down. While it will not be cold, the temperatures will be under the seasonal average.

-Meier

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

Forecasters: McCormack, Peine, Smith

Date Issued: 4/25/23

2023 5:00 PM CDT

Technical Discussion:
 


The NAM was picked for this forecast because the GFS over-predicted much of the scattered rain showers seen over western Illinois earlier today. In addition, the NAM had a more accurate representation of showers in the Northeast.


The jet stream stays off to the south and east of MO. A trough has been and will continue to strengthen until 0z Thursday. At this time, it will be located over Kansas and begin to weaken and be absorbed back into the longwave upper level trough throughout the day Friday. This feature will start to weaken as the jet stream begins to strengthen and an area of divergence forms on the leading edge of the low. This area of divergence will stay relatively south of the mid Missouri region. The 500 MB vorticity map shows a circulation associated with the upper level trough but this again will stay to the south of mid Missouri. The vorticity lines up with the area of divergence hinting at the chance for more organized showers further south.


The upper level low is vertically stacked and can be seen lower in the atmosphere. There is an increase in moisture available associated with the low pressure system as seen on the 700 MB relative humidity map. This increase is most significant from 18Z Thursday to 9Z Friday. Also associated with the passage of this aforementioned low is a sharp uptick in lift as seen in the 700 MB omega map. However, the strongest areas of lift will remain off to the south in the Arkansas region. The moisture does not translate into the lower levels as the 850 MB dewpoint map shows relatively dry air in mid Missouri. This is likely due to the complete absence of any kind of low level jet completing shutting off low level moisture transport.


On the surface, a low pressure system starts over the middle of Texas and tracks across Arkansas around Thursday afternoon and into the evening. This system will bring an increased risk for precipitation for the area. However, since this low tracks so far south there will likely be little to no precipitation for mid Missouri. Additionally, if the low tracks more to the north like the GFS predicts, then the chance for rain increases; albeit precipitation totals will still remain low. When looking at soundings, the NAM never shows complete saturation while the GFS is fully saturated at the low levels for 12 hours.


Soundings show a general cloud cover for the length of the forecast regardless of precipitation. As a result, there won't be much in the way of diurnal heating so high temperatures will stay in the mid 60s. Lows will be in the mid 40s.

-Smitty