Friday, December 10, 2021

 


Current Conditions at Sanborn Field




Friday Night:
Showers and thunderstorms, some may be severe. Low: 35




Saturday:
Exiting clouds. High: 47




Saturday Night:
Clear. Low: 32




Sunday
: Sunny. High: 53

 



Sunday Night:
Clear. Low: 35

Thanks to IconArchive.com for the icons! 

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Discussion:  

The weather for the start of the weekend will be quite active as storms are expected to arrive in mid-Missouri early Friday evening. Thunderstorms are likely to appear ahead of an oncoming cold front with some of these storms possibly being severe, particularly before midnight tonight. With that said, be sure to take any severe weather precautions to ensure safety, such as staying indoors, away from windows and on the lowest, most interior part of the building. As a low pressure system and the associated cold front passes through overnight Friday, the remainder of the weekend will remain fairly calm, yet cool. Temperatures should become progressively warmer as the coming week begins.

- Millsap

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Forecasters: Millsap

Date Issued: 12/10/21 05:00 PM CST

Technical discussion:  

Several models were consulted in regards to the guidance of this forecast; both NAM and GFS height contours had a decent handling of the positioning of the deep trough moving through the northern plains. With that said, the GFS picked up on a cold front in New Mexico where the NAM did not necessarily ignore it, but paid less attention to its intensity. After observed surface temperatures were compared with the model outputs, it was then decided to use GFS as the primary guide. RAP was also used as a high-resolution model to help pinpoint the timing and intensity of incoming storms. Soundings were viewed in both GFS and RAP formats.

An amplified trough has been working its way over to the Midwest CONUS. A decent amount of divergence aloft indicates surface-level convergence, which helps encourage vertical lift. This divergence peaks at around 03Z, which is correlated to a burst in 500 mb circulation around the same time. This disturbance already provides evidence of some early evening thunderstorms. Further evidence could be spotted by examining the vertical lift associated with the upper-level divergence - omega values were well below -10 according to the RAP soundings, indicating a strong vertical lift in the mid-altitudes.

Provided with the aforementioned information, the possibility of severe weather Friday night was given closer examination, particularly in regards to modest CAPE values in the GFS of just over 300 j/kg. This was compared to CAPE values in the RAP soundings, which were measured exceeding 1,000 j/kg, which is a sufficient amount for the development of thunderstorms. This, mixed with a veering wind profile throughout the day on Friday and unseasonably warm temperatures, provides a possibility of severe thunderstorms Friday night.

There are some factors that could inhibit the development of this severe weather event. For starters, there is a capping inversion present in the early evening hours on Friday and noticeable CINH values exceeding 150 j/kg at the surface. Although this is a fair amount, it may not be enough the entirely prevent convection. However, persistent cloudiness on Friday will keep temperatures cool enough to keep surface-based convection from occurring. Therefore, the possibility of severe weather is decreased, yet it can not be completely ruled out given the sufficient CAPE values and above-average temperatures.

By Saturday morning, the cold front will have passed and the remainder of the weekend will remain calm. Once the trough makes its exit, upper-level flow will become more zonal, lending way to a more persistence-based outlook. The sky will quickly clear out and is expected to remain so for the rest of the forecast period. Temperatures will decrease back into seasonal averages, particularly on Saturday. CAA will take over behind the cold front, as indicated by a northwesterly flow at the surface. Temperatures may begin to increase once more on Sunday, both as a result of an abundance of sunshine and a progressively southerly flow which will take hold throughout the day.

- Millsap


 

 


Current Conditions at Sanborn Field



Friday:
Overcast with scattered showers. High: 66




Friday Night:
Showers and storms, some possibly severe. Low: 35




Saturday:
Clouds exit early. High: 47




Saturday Night:
Cold and clear. Low: 32




Sunday
: Warming up. High
: 53

 

Thanks to IconArchive.com for the icons! 

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Discussion:  

An active night of weather is in store for Missouri today, as anomalously warm temperatures and a moisture rich atmosphere prime the atmosphere ahead of an approaching low pressure system and accompanying cold front. The front will pass through Columbia tonight around 10-11 p.m., bringing some rain and the distinct possibility for some thunderstorms. Before that though, expect cloudy skies today with progressively warmer temperatures buoyed by a southwesterly breeze. Calmer weather is in store for the rest of the weekend after tonight. Temperatures will drop significantly after frontal passage, as northwesterly winds push colder air into the mid-Missouri region. After a near freezing low temperature Saturday night, a wind shift to the south will bring seasonably mild temperatures to Columbia on Sunday.

-Schneringer

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Forecasters: Splater, Schneringer, Bongard

Date Issued: 12/10/21 10:00 AM CST

Technical discussion:  

A wide blend of models was used for the forecast period due to numerous uncertainties. The GFS, NAM and RAP were all utilized to take multiple scenarios into account. Soundings from each model were also compared to determine specific conditions for the forecast.

A deep trough is expected to impact the region late this evening and bring a slight chance for severe weather to our area. Presently, a diffuse frontal boundary is lifting north across Mid-Missouri and producing fog and light precipitation. As the trough meanders eastward today it will push the front further north and accompanying WAA will lead to near-record level warmth. Dewpoints are also forecast to approach the low 60s as we dwell in the warm sector of a surface low. This will lead to a chance for more showers throughout the day.

By this evening the trough will begin to enter the Mid-Mississippi valley, dragging the surface low and its associated cold front through the region. Fropa is aimed near 03Z tonight as model soundings depict increasing shear (around 75 kts 0-6 km, 45 kts 0-3km) and PWATs approaching 1". This, coupled with modest CAPE values from the low 100s in the GFS and near 1000 J/kg with other models will be sufficient for storms, possible severe.

However, a modest capping inversion in place today may throw a wrench in this forecast. Heavy cloud cover and showers today may also aid in sustaining it. Models depict the cap eroding away by fropa, but if it remains and reduces convection, storms will become much less likely. Additionally, the richer environment for severe storms is centered to our east towards the Ohio Valley. Overall, the threat for severe weather remains conditional for the forecast period.

Behind this system comes much more seasonal conditions for early December. Enhanced northerly flow will drop temperatures near freezing overnight though lingering cloud cover should prevent more frigid conditions. Cold air advection continues through Saturday though temperatures will still manage to stay slightly above average. Clouds exit the region early Saturday and clear conditions continue as a ridge affects the area to end the weekend. This will lead to the return of markedly warm conditions for the season with more above-average temperatures next week.

-Splater

Thursday, December 9, 2021

 


Current Conditions at Sanborn Field




Thursday Night:
Clear. Low: 42





Friday:
Cloudy with chance for rain, breezy. High: 70





Friday Night:
Clouds with continued chance for rain, breezy. Low: 35





Saturday:
Clear. High: 47





Saturday
Night: Clear. Low
: 32

 

Thanks to IconArchive.com for the icons! 

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Discussion: 

Your calendar might say it’s December 9th, but the weather certainly does not feel like it. The low tonight of 42 is only a few degrees shy of the average high for December (around 46). For Friday, the record high of 69 set only a year ago is in jeopardy as temperatures might make it into the 70s. Then a cold front moves through on Friday, dropping temperatures into the middle 30s, where they should be for December. Rain chances stay low with the front passing by, but a quick hit of rain cannot be ruled out. What will be noticeable will be the winds, cranking out of the south around 30mph with gusts approaching 40mph during the day on Friday. Saturday will feel more like winter, with highs in the 40s with a northwesterly wind around 20mph, lows might get near freezing Saturday night.  

- Meyer

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Forecasters: Meyer, Heienickle, Orr

Date Issued: 12/9/21 5:00 PM CST

Technical discussion:  

This forecasting period was analyzed using a blend of the GFS and NAM models. When looking at the two models they both accurately depicted the low pressure system to our North. The NAM under forecasted the temperatures that were currently seen at Sanborn field. These variances from the actual forecast were considered when making this forecast. 

At the top levels, a jet streak moves through Northern Missouri Thursday night. Strong upper level winds push this weather through the CONUS. A strong jet streak will move through central Missouri around 18Z Friday. Missouri will see this jet streak with weaker winds throughout the day Saturday. 

Circulation shown at 500mb does not impact Missouri until Friday at 12Z. This vorticity quickly moves out of the area with another wave of circulation with strengthened values at 19Z Friday. Circulation continues to be present and significant values can be seen around 09Z Saturday. This circulation exits at 21Z Saturday. Small circulations renter at 00Z Sunday for a brief period of time.

High levels of relative humidity are not present Thursday night, giving way to clear conditions. Around Friday at 18Z, high levels of relative humidity enter the area and will remain until 00Z Saturday. This potential for rain is increased with the low pressure system moving through during this time. Late Saturday night increased values of relative humidity are seen.  

At 850mb, weak westerly winds allow for stable conditions Thursday night. Winds begin to shift southerly as a low pressure system forms over Kansas. This low pressure system moves to the East and moves just North of Missouri around Friday afternoon. There will be significant winds blowing in air from the southwest with winds up to 60kts. Around Saturday at 09Z, as a low pressure system to our North moves out, we see cold air move in. Winds shift to the Northerly and significant cold temperatures are seen. Cooler temperatures remain until the remainder of the forecasting period.

Thursday night, at the surface, will see average temperatures with weak warm air advection over Missouri. Strong southerly flow is seen just before it is interrupted Friday at 18Z from a low pressure system moving from Kansas to Northern Missouri. Significant warm air advection can be seen as the Low moves through. These warm temperatures exit with the low. Cold air and winds from the North are seen late Friday and into Saturday. Saturday will see cooler and more seasonable temperatures. 

The soundings for this forecasting period indicate multiple periods where rain could be a potential. 18Z Friday, when the low pressure moves through, sees potential for precipitation. Veering winds are present just before indicating there is warm air advection. There is moisture at the surface and aloft, but there is a dry layer around 850mb. This dry layer could be from the increasing southwest winds Missouri is receiving, but will prevent any significant rainfall. Later in the evening, 00Z Saturday, the NAM remains dry, while the GFS forecasts a slight potential for a thunderstorm with increased CAPE values and southwesterly winds.

- Heienickle

 

Current Conditions at Sanborn Field





Thursday:
 Sunny. High: 64





Thursday Night:
Mostly Clear. Low: 42





Friday:
 Cloudy with rain possible late in the afternoon. High: 70





Friday Night :
  Scattered Clouds. Low: 37





Saturday
: Abundant Sunshine
. High: 47

 

Thanks to IconArchive.com for the icons! 

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Discussion: 

    Temperatures will begin to recover from the cool weather pattern at the start of the week. A strong southerly wind Thursday and Friday will keep temperatures well above average for this time of year. Clouds will begin to increase ahead of a low pressure system and cold front on Friday, so expect an overcast but warm Reading day as you prepare for finals. The region could see the possibility for showers late Friday afternoon, but rain totals are minimal to none. The rest of the weekend looks to be cooler and drier. 

-Duff

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Forecasters: Aldrich, Duff, McDonald

The 06z GFS was used for our forecast today, as it held a slight advantage over the NAM in terms of temperature initialization


In the upper levels of 250 mb Missouri is just barely outside the path of multiple strong jet streaks, missing the state to the northeast as they flow into Iowa and Wisconsin. The advancement of a trough towards the state at 00z Saturday lines Missouri directly in a section of divergence on the lower right side, indicating an active weather threat Friday night into Saturday morning. Jet streaks look to be stronger at this point, but their magnitude appears to decrease into the later hours of Saturday past 21z. While rain cannot be determined solely from this level, there is reason to believe our sharpest pattern change will occur that day. 


Vorticity is initialized as being active, but will remain quiet at 500 mb until Friday night. At Saturday 06z, vorticity associated with the aforementioned trough will begin to compact and wrap into Kansas and Missouri, covering a large swath of both states. Just slightly ahead of the west moving trough, at least some precipitation would be expected over that timeframe. Winds continue to diverge at this level, indicating that the stacking of the system is fairly even and building confidence in the model output. 


Even as warm air increases, humidity levels at 700 mb will remain low aside from Friday night into Saturday morning. A large swath of humidity will approach alongside the trough’s center to our northwest, situating us on the active side of the system. However, the peak of this humidity does not align with the peaks of vorticity and divergence, indicating that weather produced will contain lighter amounts of rain to generally overcast conditions. Omega values supplement this trend, as values are low during the periods of greatest moisture content in the atmosphere. 


850 mb paints a better picture for temperatures, showing hot air from the southwest extending far into the midwest, keeping the region warm for the next few days. Continuous southwest winds will warm up the region until the trough arrives, where winds shift back to the northwest at 15z Saturday once it departs. The drop in temperature from this strong shift could be substantial, as the model indicates warm air almost immediately receding into the southwest. 


GFS soundings display considerable moisture content increasing each day into Saturday, where heavy cloud cover is certain and rain is a possibility. At the very least, the weekend will feel much more humid and wet in comparison to this past week. 


Future forecasters should pay attention to another trough behind the one anticipated on Satuday, as it looks to bring similar active weather to the mountain west and great plains on Sunday. 


- McDonald

Wednesday, December 8, 2021

 

Current Conditions at Sanborn Field



Wednesday Night:
Partly cloudy. Low: 39



Thursday:
Sky clearing through the morning. High: 60



Thursday Night:
Moonlit sky. Low: 42



Friday:
Cloudy with scattered light rain. High:65



Friday Night:
Scattering
clouds through the night. Low: 37

 

Thanks to IconArchive.com for the icons! 

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Discussion: 

    To recover from the cool weather earlier this week, some warmer temperatures are in store for the remainder of the week! A clear sky is expected as temperatures climb, reaching into the mid-60s on Friday. However, the week will end sour with the passage of a cold front Friday evening, bringing cold temperatures and a slight chance of rain. Hopefully, we can make use of this melancholy Reading Day by prepping for Finals Week. Trace amounts of precipitation are expected for the rest of the week.

-McMullen

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Forecasters: McMullen, Noblitt, Cochran

Date Issued: 12/8/21 5:00 PM CST

Technical discussion: 

    For our forecasting period, both the NAM40 and GFS20 were compared to the current surface map produced by the NWS. Both models followed fairly well with the pressure contours as well as the locations of the two highs to our north and a low near the Gulf Coast of Texas. However, both models had difficulties with the pressure contours and pressure systems on the West Coast. In addition, both the SREF and GEFS plumes were consulted for the current surface temperatures, and both ran colder than the actual temperature at Sanborn. So, we ultimately decided to observe data from both models to see where they agreed and where some uncertainty lies. Satellite imagery was used to observe current regional cloud cover and both the NAM and GFS soundings were also utilized to forecast sky conditions.

    Starting with the 250-mb plot of heights, winds, and divergence, a ridge is passing over at 21Z Wednesday. This ridge eventually gives way to strong zonal flow around 9Z Thursday, allowing a jet streak to spread to our north. Around 18Z Friday, a strong trough begins to move across the CONUS from the Rockies, forcing the downstream portion of the jet streak into the Mississippi Valley. This creates some divergence over Missouri Friday evening all the way through Saturday at 12Z, when the trough is directly over the Mid-Missouri.

    As we look towards the 500-mb plot of heights and vorticity, some circulation can be anticipated as the previously mentioned ridge continues to the east. The accompanying zonal flow keeps the air calm, however some spotty circulation ahead of the incoming trough begins to push through Missouri. This culminates in strong circulation aloft as the trough from the Rockies enters the Middle Mississippi Valley around 10Z Saturday.

    Following up with the 700-mb plot of heights, omega, and RH, no saturation is present over or around Missouri until 21Z Friday. During this time, a LPS and it's correlating trough moves moisture from the West Coast/Rockies across the northern Plains which saturates the northern half of the Mississippi Valley. This moisture will be crucial for cloud development and possible precipitation through the rest of the forecasting period.

    Finally, the 850-mb plot of heights, winds, and temperature shows a westerly wind shift south as the noted ridge treks on. This southerly wind begins to rotate clockwise until the LPS and its trough move closer, forcing our winds to shift southwest. At around 6Z Saturday, the LPS and a cold front extending to the SW have passed far enough to our NE that the winds come clockwise to westerly before settling into northwesterly at the end of the week. WAA can be seen on the MSLP and 1000-mb to 500-mb thickness over our area until 18Z Thursday, helping to warm up our surface temperatures. The next batch of WAA, starting 9Z Friday, continues to warm us up thanks to the incoming LPS. However, with its overhead passage, some CAA could bring cooler temperatures for the rest of Friday.

    Soundings indicated a slight chance of precipitation Friday. With KI in the 20s, nothing significant is expected. Since the QPF from both the GEFS and SREF plumes had quite a bit of uncertainty between their ensemble members and each other, a conservative trace amount of rain could occur Friday.

    Future forecasters should be aware of the uncertainty in the models, as well as the cooler projections of both models. Pay close attention to the trough to our west Saturday as future models may provide better insight.

- Noblitt

 

 

Current Conditions at Sanborn Field





Wednesday:
Increasing clouds. High: 48


 


Wednesday Night:
Cloudy. Low: 37


 


Thursday:
Clearing sky throughout the day. High: 60         

 

Thursday Night:
Clear. Low: 42


 


Friday:
Building clouds. High: 68

 

 

Thanks to IconArchive.com for the icons! 

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Discussion: 

If all you want for Christmas is some warmer weather, fear not--we'll be leaving some of these chilly temperatures behind later this week. Despite some cloudiness Wednesday night, sunshine is to be expected on Wednesday and Thursday, but the sky will turn overcast early Friday. Don't be surprised if you feel a raindrop or two when leaving campus on Friday afternoon! This will be the best chance of rain this week, although only trace accumulations are expected.
 
- Macko

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Forecasters: Kobielusz, Macko, Bongard

Date Issued: 12/8/21 10:00 AM CDT

Technical discussion: 

Meridional flow is dominating the entirety of the CONUS placing a trough to Missouri’s east and west and a ridge moving west into Missouri as Wednesday progresses. Flow changes to become zonal overnight and continue into Thursday when a strong jet will entrench itself just north of Missouri. Winds on Friday shift back to meridional as a well defined trough forms in the Dakotas.

Vorticity builds overnight Wednesday in Kansas which will make its way into Missouri by early Thursday morning. This vorticity continues to push east as the day progresses and by Thursday night, central Missouri is clear of vorticity until Friday when vorticity builds throughout the day to the end of the forecast period.

Missouri will be considerably dry until Friday when upper level moisture from Kansas begins to make its way into Missouri.

Winds near the surface will be out of the west on Wednesday but will shift to the southwest overnight bringing dry, warmer air into Thursday morning. Friday an area of low pressure from Nebraska makes its way into the Mississippi Valley, which will shift winds back to a westerly component during the evening hours on Friday.

A deep moisture profile overnight on Wednesday indicates that there will be the presence of clouds but those clouds should begin to clear during the day on Thursday. Low clouds begin to develop early Friday morning. If moisture prevails, there could be trace amounts of rain early Friday morning. Future forecast shifts should keep an eye on this.

Since the last forecast shift used the NAM and the NAM was running considerably cold, a decision was made to bump up Thursdays high by 10 degrees despite the rule of four. Timing of cloud cover and a shift in winds also made it more likely that the temperature would be warmer. Future forecast shifts may want to bump up Thursdays high more.

-Kobielusz

Tuesday, December 7, 2021

 

 

Current Conditions at Sanborn Field



Tuesday Night:
Cloudy with possible snow flurries. Low: 26



Wednesday:
Cloudy.High: 44

 


Wednesday Night:
Clear. Low: 33



Thursday:
Clear. High: 50



Thursday Night
:
Clear . Low: 46

 

Thanks to IconArchive.com for the icons! 

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Discussion: It would be wise to wear a coat this week, as cold winds are going to blow through Missouri Tuesday and Wednesday night. Tuesday night will be the coldest temperature seen this week, that being in the upper 20s due to the cold westerly winds of 10-20 mph. The weather pattern will begin shifting this week that will bring about southerly flow and thus, warmer weather.

-Watts


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Forecasters: Watts, VanUnnik, Bongard

Date Issued: 12/06/21 5:00 AM CST

Technical Discussion:  

The 12Z run of NAM40 was used for this forecast. The NAM and GFS both reached temperatures that remained accurate with what was observed at Sanborn Field, yet the NAM seemed to have better placement of the trough-ridge-trough pattern. During this forecast period, a very meridional flow takes stage across the CONUS, leading to variable weather over the next few days.
A positively tilted trough axis drapes over mid-Missouri on Tuesday night, as displayed at 300mb. This causes a wind shift from westerly to northwesterly on Wednesday morning, before a ridge pushes the trough out east and takes its place by afternoon. Yet another trough follows behind, making its way to the Midwest on Thursday, this time being a negatively tilted shortwave. Again, the pattern offers a wind shift, and southwest winds bring warmer air to Missouri on Thursday night.
The aforementioned trough on Tuesday night is seen again at 500mb, deepening off to Missouri's east. This is followed by a ridge on Wednesday, meaning fair (but still cold) weather remains. Vorticity advects into the area on Thursday morning, but quickly pushes out to the northeast.
Moisture follows along the current trough at 700mb over northern Missouri, making its way southeast Tuesday night into Wednesday morning. The ridge on Wednesday brings positive Omega values on Thursday, followed by a southwesterly flow.
850mb shows more of the same, again broadcasting the ridge over Missouri on Wednesday. An LLJ along with the backside of the ridge brings a strong southerly flow to Missouri on Thursday night.
Solenoids are seen on the surface analysis as cold air advects into the area on Tuesday. Columbia, and most of Missouri, remains on the cold side of the 540 line until Wednesday morning. There is a slight chance for snow flurries overnight. WAA brushes into Missouri late Thursday night, coming from both the south and the west. Due to the timing of it, the WAA brings a halt to the nighttime cooling, and temperatures will remain steady until sunrise brings with it a significant warm-up.
NAM Soundings aided cloud and temperature forecasting, and temperatures showed on the 12Z run had a significant warming trend in comparison to previous Campus Weather Forecasts. The temperatures on this forecast show quite a jump due to the model that we used, and its accuracy for temperatures seen today.

Future forecasters should keep an eye out for a chance of rain Friday morning.

 -VanUnnik