Current Conditions at Sanborn Field

 

 

Thursday Night: Cloudy. Scattered showers possible. Low: 65

 

Friday: Mostly cloudy. Scattered afternoon thunderstorms possible.  High: 82

 

Friday Night: Overcast with showers and thunderstorms likely. Low: 65

Saturday: Cloudy with showers and thunderstorms throughout the day. High: 79

 

 

Saturday Night: Overcast. Showers and thunderstorms likely with decreasing potential past midnight. Low: 66

 

 

 

 

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Discussion:  

Current thunderstorms will continue into Thursday night with a low of 65. Chances for rain will clear into Friday morning, with chances increasing again in the afternoon. Temperatures will reach a high of 75. Clouds and rain will continue into the night on Friday. As a cold front approaches Saturday, chances for rain will increase and continue throughout the day. If you're planning on going to the Mizzou Football game, umbrellas and ponchos are recommended. Saturday night will be overcast with decreasing chances for thunderstorms towards daybreak. Total rainfall expected for through the rest of the week is around 1"-1.5".

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Forecasters: Heienickle, Meyer, Orr

Date Issued: 09/30/21 5:30 PM CST

Technical discussion:  

    This forecast was created using the 12Z run of both the NAM and GFS. Both models were performing extremely poorly, both with inaccurate initial conditions and a poor handling of the current rain showers in Columbia. SREF and GEFS plumes were also used to aid in forecasting temperatures, and overlaid soundings of the GFS and NAM were used to help forecast rainfall and thunderstorm potential. 

    At 250-mb, plots of heights, winds, and divergence depict meridional flow over the United States. A large ridge over Missouri moves east around 00Z Saturday, and a large trough soon makes its way over Missouri. Higher amounts of divergence associated with this trough pass over the forecast area Friday night near 06Z and Saturday night around 21Z, with a short break in between. The trough becomes negatively tilted by 03Z Sunday as it continues to pass over the state. 

     500-mb plots of heights and vorticity support PVA as the trough makes its way toward Missouri. By 03Z Saturday, small circulations begin to make their way into Mid-Missouri. Higher amounts of vorticity associated with the base of the trough move in Sunday at 00Z, providing another chance for thunderstorm development. 

    700-mb plots of heights and relative humidity show varying amounts of humidity over Missouri for the entirety of the forecast period. Friday morning sees a brief break in the higher amount of RH, but Missouri will return to saturated conditions soon after. The highest amounts of RH enter the region Saturday at 06Z and remain until around 06Z Sunday. Favorable amounts of moisture are present throughout the entirety of the forecast period, especially during the times when conditions at upper levels are also favorable. 

     Heights, winds, and temperatures at 850-mb reveal the source of the abundant moisture for the next few days. Winds are disorganized, but southerly until around Friday at 06Z, when winds shift to a stronger, more organized southerly direction. This is the formation of the LLJ, which will provide the moisture for on and off rainfall seen for the entirety of the forecast period. These southerly winds also keep temperatures slightly warmer than average for this time of year. A cold front will make its way into northwest Missouri by 09Z Sunday. Future forecasters should watch for its impact of the central Missouri region. 

    At the surface, MSLP, thickness, and winds continue to support what was seen at upper levels. Winds remain in a southerly direction for the next few days, providing more support for the warmer temperatures. Sunday's cold front is visible in MSLP as well. 

    GFS and NAM soundings were overlaid on each other to help establish timing of rainfall and the potential for storms. The two were used in conjunction due to the poor model performance and overall lack of consensus. On-again off-again rainfall is what dominates this forecast. When the soundings weren't saturated enough for rainfall, there will still be enough saturation for decent cloud cover. Varying amounts of CAPE and UVM are present Friday and Friday night, creating the potential for scattered thunderstorms. The highest potential for thunderstorms occurs on Saturday afternoon and evening, with very negative Omega values and an MUCAPE range of 1100-1500 J/kg between the two models. Total PW values for the forecast period range from 1" to 1.6" inches.

     

 

 

Current Conditions at Sanborn Field

 

 

Thursday: Increasing cloudiness with spotty t-storms developing during the afternoon. High: 83

 

 

Thursday Night: Partly cloudy. Patchy fog possible by morning.
Low: 68

 

 

Friday: Mostly cloudy with scattered showers and thunderstorms possible (mainly during the late afternoon). High: 80

Friday Night: Considerable cloudiness with showers and thunderstorms likely (especially after midnight). Low: 66

 

 

Saturday: Periods of showers and thunderstorms. High: 78

 

 

 

 

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Discussion:  

Increasing clouds throughout today will lead to the chance for scattered showers and storms to develop, though the probability of rain decreases considerably into the overnight hours. An approaching trough from the Rockies will move toward our region throughout Friday into Saturday, with southerly winds increasing moisture content and increasing cloud cover even more. Temperatures will remain in the upper 70s to low 80s over this period, with chances of rain increasing with each successive day. Rain will be scattered at the beginning of this forecast period, becoming more organized and concise as we enter the weekend.

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Forecasters: McDonald, VanUnnik, Aldrich

Date Issued: 09/30/21 9:30 AM CST

Technical discussion: 

The 06Z GFS model run was used in the forecast today because it handled the movement of the low-pressure system over the Rockies and the temperature pattern better than the NAM.  GFS soundings were used to evaluate moisture, instability, and temperatures as well as timing for precipitation.

The 250-mb plots of heights, winds, and divergence show a long-wave ridge dominating the central United States at the start of the forecasting period that starts to move out of the area quickly over the next 24 hours. Divergence aloft continues to increase around the area as the low approaches by late Friday and into Saturday. With no indication of any jet streaks or stong wind speeds aloft, the general flow remains meridional flow with southerly winds until the area of low-pressure moves into our region by late on Saturday
.

Vorticity plotted against heights at 500-mb shows Missouri under the influence of an area of PVA starting late Friday and into the day on Saturday. This circulation of vorticity and area of low-pressure will strengthen over the next 24-36 hours bringing an increasing amount of cloud cover and chances for showers and thunderstorms - especially by late Friday and into the day on Saturday.

At 700-mb, moisture continues to move into the region ahead of the area of low-pressure moving in from the west. Omega and RH levels continue to increase throughout the day on Friday, into Friday night, and during the day on Saturday. This would indicate a good opportunity for periods of showers and thunderstorms throughout the forecast period.

 

The 850-mb plots of heights, winds, and temperatures show that the region will be in a favorable position to warm into the upper 70s and low 80s due to the placement of the high-pressure system off to our southeast, and the arrival of the area of low-pressure moving in from the Rockies. Winds from the south will advect moisture into the region from the Gulf of Mexico, allowing for considerable cloudiness and the increasing change for showers and thunderstorms from Friday night into the day on Saturday.

 

The GFS soundings show the atmosphere becoming more and more saturated throughout the rest of the forecast period. Instability parameters look relatively low (CAPE values reaching almost 800 J/kg and the LI at -3 by Saturday afternoon), so while there could be some convection, severe weather appears to be very low.

Future forecast shifts will need to monitor the potential for fog late tonight and into tomorrow, as well as the chances of convection ahead of the vorticity maximum approaching the region late Friday night and into the day on Saturday/

 

Current Conditions at Sanborn Field

 

 

Wednesday Night: Cloudy. Chance for light showers. Low: 68

 

 

Thursday: Rain throughout the day. High: 79

 

 

Thursday Night: Mostly cloudy with scattered showers. Low: 65

Friday: Rain throughout the day. Chance of thunderstorms in the late afternoon. High: 80

 

 

Friday Night: Rainy. Low: 66

 

 

 

 

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Discussion:  

Starting tonight, winds from the Gulf of Mexico will bring moisture into the area. Developing clouds pair with extra moisture from an approaching low pressure system transition into rain tonight. Significant cloud cover and rain will lower our temperatures slightly over the next few days. Late Friday afternoon, there is a chance of thunderstorms for Columbia. Rainfall totals through Friday night are expected to be about 0.75 inches. 

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Forecasters: McMullen, Noblitt, Cochran

Date Issued: 09/29/21 5:00 PM CST

Technical discussion: 

The 12Z GFS model run was used in the forecast today because it handled the movement of the LPS over South Dakota and it's associated front with more accuracy than the NAM. GEFS and SREF plumes were referenced for temperatures and hourly and total QPF values. Lastly, GFS soundings were used to evaluate CAPE and LI values as well as timing for precipitation.

The 250-mb plots of heights, winds, and divergence show a long-wave ridge dominating the central United States at the start of the forecasting period until Saturday around 15Z. This keeps the area in meridional flow with southerly winds until an approaching LPS shifts our winds to the SW Saturday afternoon.

Vorticity plotted against heights at 500 mb shows Missouri under the influence of an area of PVA from the exit of the upper-level ridge. This circulation continues to build as we move later into the week, supporting cloud development for the region. More vorticity approaches with a LPS over Kansas as we move into the beginning of the weekend.

A collection of moisture takes place over Columbia seen on the 500-mb plots of heights, vertical velocity, and relative humidity. The start of the building moisture comes from the Gulf region and meets up with moisture coming from the western LPS. Our area is saturated at this level from Thursday at 12Z until the conclusion of the forecast period. 

 

The 850 mb plots of heights, winds, and temperatures show that the low level jet is prominent for the time period, aiding in moisture advection. However, the 1000mb-500mb thickness and MSLP plot show little to no temperature advection, so no drastic changes in temperatures are expected.

 

The GFS soundings show the atmosphere becoming more and more saturated throughout the rest of the week. They also show the maximum value of CAPE reaching almost 1300 kJ on Friday at 21Z. The LI at this time is -4, suggesting a stormy afternoon. GEFS and SREF plumes suggest the total-QPF for the forecast to fall around 0.75 inches.

Future forecasters should pay attention to the approaching LPS and it's associated moisture and vorticity.

Current Conditions at Sanborn Field

 

 

Wednesday: Cloud cover increasing throughout the day. High: 85

 

 

Wednesday Night: Overcast. Possibility for light rain. Low: 68

 

 

Thursday: Cloudy. Rain in the morning and early afternoon. High: 79

Thursday Night: Cloudy. Light isolated showers possible. Low: 65

 

 

 

Friday: Cloudy. High: 78

 

 

 

 

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Discussion:  

Cloud cover will increase throughout the day today and continue into tonight and for the rest of the forecast period. Winds have shifted to the south providing some moisture needed for cloud development. Our first chance of rain is tonight, although the best chance for rain throughout the forecast period is Thursday. Rainfall totals through Friday afternoon are expected to be between 0.5 inch and 0.75 inch. 

-Macko & Kobielusz

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Forecasters: Macko, Kobielusz, Bongard

Date Issued: 09/29/21 10:00 AM CST

Technical discussion: 

 For this forecast period the 06Z GFS model run was favored over its NAM counterpart due to several factors. First, GFS matched better with initial conditions observed at the surface at the start of the forecast period. Secondly, and more importantly, GFS modeled 500 mb height contours matched more favorably with upper level water vapor satellite imagery associated with the developing mid-lat cyclones to the west of the region over the Rockies. This is significant as mid-Missouri will reside in the warm sector of this MLC for the duration of the forecast period. GFS model soundings were used in accordance with modeled precipitation accumulations to determine timing and amounts of rainfall. Plumes were used as quality checks for both models.

 

250-mb upper level models reveal an extremely amplified meridional flow pattern across the CONUS in a trough-ridge-trough pattern at the start of the period. The ridge over the central CONUS will begin to give way to the oncoming trough out west this evening promoting the deep southerly flow that extends from the surface up through 300 mb on GFS model soundings. This extreme pattern will persist through Friday afternoon. 

 

500 mb vorticity maps show an increase in energy over eastern Kansas beginning this afternoon and persisting through Thursday. This vorticity is associated with positive vorticity advection in the upstream flow of the invading trough that will make its way off the Front Range of the Rockies tonight and enter the Midwest by tomorrow. This vorticity will be the catalyst needed for precipitation development over the region beginning as early as this evening.

 

The low levels are rich with moisture and southerly flow throughout the forecast period at both 700- and 850-mb. PWAT values depicted in GFS model soundings will soar from 1 inch today to 1.75 to 2 inches by 18Z Thursday. Soundings also show a moist profile with some CAPE available for convection though CIN may keep convective development to a minimum. The sounding is very reminiscent of a warm sector sounding. Friday's profile will dry out slightly shutting down rain chances briefly at the end of the period though the column will begin to saturate again by 00Z Saturday as the next cold front approaches. Future forecasters will have to tangle with timing of this frontal passage and associated precipitation.

-Bongard

Current Conditions at Sanborn Field

 

Tuesday Night: Clear. Low: 64

 

 

Wednesday: Cloud cover increasing throughout the day. Showers possible in the afternoon. High: 86

 

 

Wednesday Night: Overcast. Rainy with possible thunderstorms. Low: 67

 

 

Thursday: Cloudy. Rain throughout the day. High: 79

Thursday Night: Cloudy. Scattered showers likely. Low: 65

 

 

 

 

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Discussion:   

Tonight will be clear with increasing clouds throughout the day on Wednesday, and by Wednesday afternoon scattered showers are likely. Potential of rain increases over night, with the possibility of thunderstorms early in the evening. While the chances of thunderstorms diminish by late Thursday morning, rain will persist throughout the day. Keep the umbrella handy as scattered showers will continue into the overnight hours. Despite rain dominating the forecast, temperatures will remain seasonable.

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Forecasters: Duff, Watts, Orr

Date Issued: 09/28/21 5:00 PM CST

Technical discussion: 

    The 12Z run of the GFS was used to create this forecast due to the NAM output having a cold bias and being over-saturated. GEFS and SREF plumes were used to forecast temperatures and GFS soundings were used to assess rain timing and the potential for severe weather. 

    At the 250-mb level, plots of heights, winds, and divergence display very meridional flow dominating over the United States. Missouri is under the influence of a large ridge Tuesday and into early Wednesday. By Wednesday afternoon around 18Z, the ridge moves out of the our region, and the Middle Mississippi Valley falls under the effects of a large trough. Higher amounts of divergence associated with the trough pass through the forecast area
between 21Z Wednesday and 12Z Thursday. Smaller amounts of divergence remain in the area through Thursday and into Friday.

    At 500-mb, plots of heights and vorticity show large amounts of vorticity associated with the incoming trough. As the ridge leaves Missouri, high amounts of vorticity enter the forecast region around 00Z Thursday. Weaker circulations remain in the area until 00Z Friday. Future forecasters should watch for the potential for another wave of vorticity to move through Mid-Missouri on Friday, providing opportunity for storm development.

     700-mb plots of heights and relative humidity support rainfall associated with the vorticity and divergence seen in the upper levels. High RH values begin entering the region around 21Z Wednesday and persist until 00Z Friday. The presence of moisture favors rainy weather for Wednesday afternoon through the rest of the forecast period, with the potential for thunderstorms most prominent Wednesday night and into Thursday morning. 

     At 850-mb, plots of heights, temperatures, and winds depicts the source of the abundant moisture. The LLJ forms late Tuesday around 21Z and funnels in moisture from the Gulf for Wednesday and Thursday's rainfall. These southerly winds are also advecting warmer air into Missouri, providing us with the slightly above seasonable temperatures. The surface level also depicts the steady, southerly winds, further favoring these decent temperatures.

 GFS soundings provide support for Wednesday night's thunderstorms. Negative Omega values, negative LI values, favorable K and TT indexes, and MUCAPE of around 1100 J/kg first appear around 21Z Wednesday and persist to around 09Z Thursday. After this time, favorable thunderstorm conditions slowly taper off. Thunderstorms are most likely in Mid-Missouri during this time frame, and severe conditions are unlikely, but should not be ruled out.

 

Current Conditions at Sanborn Field

 

 

Monday Night: Clear. Low: 64

 

 

Tuesday: Clear. High: 90

 

 

Tuesday Night: Becoming partly cloudy overnight. Low: 66

 

 

Wednesday: Becoming cloudy. High: 86

Wednesday Night: Cloudy. Showers around and after sunset. Low: 67

 

 

 

 

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Discussion:   

Monday nearly broke the record high temperature of 93 that was set in 1897. This heat will carry into tomorrow and keep our temperatures in a summer like state. Tonight the sky is expected to remain clear, cooling the temperatures down to 64. The winds are also expected to die off and remain calmer over the upcoming days. Tuesday is expected to be very similar to Monday, except less wind, with a clear sky and a high temperature of 90. Clouds are expected to begin building in the overnight hours of Tuesday. This cloud cover should help keep the temperatures slightly warmer than the previous night with a low of 66. Going into Wednesday, we will see more cloud cover entering the area and keep our high temperature notably cooler at 86. For Wednesday night, expect showers to begin around sunset and continue throughout most of the night. Precipitation totals for Wednesday night are expected to total .25 inch and the low temperature will be 67 as a low pressure system pass through the area.

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Forecasters: Gromada, Alexander, Gotsch

Date Issued: 09/27/21 5:00 PM CST

Technical discussion:  

 

    This forecast was generated with the use of the 12z GFS model run. The current GFS model guidance aligns with the current conditions better than the NAM. The main focus for this forecast period will be the above average temperatures and the possibility of showers Wednesday evening into the overnight hours.

 Currently the Mid-Mississippi Valley is under a ridge that extends into Canada. This leads to clearer skies and the higher temperatures. The WAA will cause above average temperatures for the Mid-Mississippi Valley region on Tuesday. Going into Tuesday night the LLJ will provide enough moisture to cause clouds to begin forming and will inhibit radiation cooling in the overnight hours keeping the low temperatures higher than the night before. The cloud cover that began forming Tuesday night will increase during the day on Wednesday slowing the daily heating, causing the high to be closer to the seasonal averages. As the ridge and subsequent high pressure system move further to the east, WAA and moisture advection will become more prominent into the Mid-Mississippi Valley region. This advection will eventually cause showers to develop Wednesday evening and night as the moisture begins hitting the backside of the dry line that was created from the ridge. QPF totals around .25 inch are to be expected.

The next forecasters main area of concern will be with the upper-level ridge leaving the Mid-Mississippi Valley region which could alter the amount of WAA and moisture advection into the Columbia area altering the timing and intensity of the showers on Wednesday.

 

Current Conditions at Sanborn Field

 

Monday: Clear skies. High: 91

 

 

Monday Night: Clear. Low: 66

 

 

Tuesday: Clear. High: 90

 

 

Tuesday Night: Becoming partly cloudy overnight. Low: 66

 

 

Wednesday: Becoming cloudy. High: 86

 

 

 

 

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Discussion:   

Summer-like temperatures will stick around for the first part of the week. High temperatures Monday will approach a Columbia record of 93 for September 27. High pressure will keep our skies clear with winds out of the southwest, bringing in warmer air. Temperatures overnight will stay above average in the mid 60s. Clouds finally move in Tuesday night into early Wednesday morning out ahead of a low pressure system. Isolated showers can not be ruled out Wednesday evening, but the bulk of the rain should hold off until overnight Wednesday into Thursday.

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Forecasters: Cade, Baker, Travis

Date Issued: 09/27/21 10:00 AM CST

Technical discussion: 

A return of summer is in full swing here in mid-Missouri with daytime highs Monday and Tuesday approaching record highs. The main concern for this period is the approach an upper-level low that will bring an abrupt end to hot and sunny conditions. Both the GFS and NAM had excellent consensus in the upper-level setup when compared with GOES upper-level WV imagery. As such, went primarily with GFS guidance, but consulted the NAM for narrowing down timing of precipitation. 

Models' handling of the upper-level setup lines up well with each other and with what GOES WV imagery shows. One would hope so, since there is not much up there at the time of forecasting. Model 250-hPa height and wind and 500-hPa height and absolute vorticity depict zonal flow across much of the CONUS with a pesky cut-off low over the Four Corners region. Deamplified flow has kept and will keep low-level high pressure in place over the SE allowing southwesterly flow at the surface to facilitate WAA. This will change by the end of the forecast period. GFS 500-hPa height and vorticity shows an amplifying longwave trough digging far south from the Pacific NW Tuesday into Wednesday. This will finally overtake the cut-off low and carry it to the NE where it will become the Midwest's problem.

GFS 700-hPa RH and UVM depict a heavy increase in mid-level saturation ahead of the system Wednesday morning into early afternoon. A lack of a LLJ seen at 850 hPa over Missouri would suggest precip will hold off until the overnight hours when the nocturnal LLJ develops. 

Of note at the surface is a prominent boundary that will sit over northern MO Tuesday into Wednesday. Winds to the south will remain westerly, turning southwesterly further south in the state. Winds to the north change rapidly (<50 miles) by 180 to be out of the east. The boundary, believed to be a weak stationary front, will linger in Northern Missouri until the approach of the next system Wednesday night. Though unlikely with little horizontal forcing, if this boundary were to sag further south than models are anticipating, daytime highs could be knocked down by ~5 degrees. 

As far as precipitation goes, the bulk of the rain looks to hold off until the overnight hours Wednesday into Thursday thus making it future shifts' "problem of the day," but as GFS soundings begin to saturate from the top on down, the slight chance of isolated showers beginning in the afternoon cannot be ruled out right now.