Current Conditions at Sanborn Field

 

 

Monday: Mostly clear. High:70

 

 

Monday Night: Mostly cloudy. Low: 36

Tuesday: Increasing clouds. High: 52

 Tuesday Night:  Chance for showers. Low:39

 

 
 

Wednesday:  Rain showers. High: 47

 

 

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Discussion:

The beginning part of the week will continue warmer than average temperatures for the month of February. Monday will have a high of 68 before a cold front moves through dropping temperatures down to the lower 50s and upper 40s for highs. Wednesday will bring rain showers starting in the early morning lasting throughout the day.


-Jones

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Forecasters:Herion, Jones, Aldrich

Date Issued: 03/06/2023 10:00 AM CST

Technical Discussion:

 

After comparing both the GFS and NAM, we decided to follow the NAM today due to its grasp of initial conditions and the placement of the weak low over mid-Missouri. The NBM and SREF were consulted for temperature readings. Our focus of this forecast shift is the potential for overnight showers on Tuesday and decreasing temperatures after an unseasonably warm Monday.

At the upper levels, ridging continues for much of the forecast period. As the sub-tropic jet stays above mid-Missouri. This will bring above average temperatures for the CWA for Monday. This ridging pattern will continue through Tuesday before a shortwave trough passes through late Tuesday evening and into Wednesday afternoon.

At the mid-levels, the shortwave becomes more prevalent. Ridging continues into Monday but a wave of vorticity begins to push through Tuesday evening. This will stick around until the end of our forecasting period. Moisture levels are low for Monday and will not increase until Tuesday evening. The arrival of the moisture coincides with the vorticity levels. However, we will be near de-saturation into Wednesday evening.

At the 700 MB level, omega is low for Monday but then increases in conjunction with the arrival of upper level moisture. With both present, we think Wednesday 12Z to 21Z would be the best time for rain in the CWA. However, this could change if the SW moves northward. Along the Missouri and Arkansas border, there are higher levels of omega. The movement of this system could change the amount of rainfall mid-Missouri receives. Moisture levels are low for Monday but increase significantly late Tuesday evening. This will also stick around till the end of our forecast period.

Near the surface, there is Cold Air Advection following a cold front that will pass through Monday evening. This front will bring an end to our brief warming trend from the past weekend. This will bring more seasonable temperatures for the rest of the week. This front is associated with a low pressure system that is moving through the upper great lakes region. We do not expect any rainfall with this particular front due to the lack of moisture. As the CAA moves in, before the passing of our shortwave on Tuesday, Warm Air Advection occurs due to the change of winds from coming out of the North to the South. Moisture begins to arrive by 12Z Wednesday and stays until the end of our forecast period.

At the surface, low pressure continues to move out of mid-Missouri through much of Monday as a cold front passes through tonight. This will bring back seasonable temperatures for the rest of the week. The shortwave then arrives late into Tuesday evening and will pass through mid-Missouri by the end of our forecast period. Model soundings show upper levels beginning to saturate by 0Z Wednesday. However, there is a wide dry pocket that stays between 700 MB and 925 MB. As the evening progresses, these levels will slowly saturate before becoming close to fully saturated by 12Z. This continues through the end of our forecast period. SREF plume readings agree with model soundings with the beginning of the showers occurring early Wednesday morning. Model runs show totals between .25-.5 inches of rain with the SREF and NBM forecasting totals slightly closer to the half inch total. We predict rainfall in the range of .25-.5 inches for totals.

-Herion

 Current Conditions at Sanborn Field

 

Friday Night: Mostly clear. Low: 33

 

 

Saturday: Mostly cloudy. High: 60

Saturday Night: Increasing clouds. Low: 38

Sunday Decreasing clouds and gusty. High: 64

 

 

Sunday Night: Mostly clear. Low: 53

 

 

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Discussion:

With Friday morning's system exiting the area, temps look to climb for the next few days, with intermittent periods of clouds and sun, and some gusty winds Sunday. Highs in the 60's and lows moving up from the 30's all the way to the lower 50's by Sunday night should make for some pleasant early spring outside weather.


- Thomas

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Forecasters: Thomas, Sausen, McGuire

Date Issued: 03/03/2023 04:15 AM CST

Technical Discussion:

 

Starting off with satellite observations, mid-Missouri is currently in a return flow from the cutoff low that passed over last night. Two layers of clouds remain over the CWA, giving partly cloudy to overcast conditions. This forecast is utilizing the 12Z run of the GFS due to its superior temperature plots over the NAM. The focus of this forecast is on the rising temperatures and windy conditions for Sunday afternoon into Monday.

At 250mb, the passing of a negatively-tilted longwave trough leaves the CWA in a zonal flow. Polar jet stream positions itself overhead and fluctuates south to north through the forecast period. The right exit region of a horizontal jet streak will position itself over the CWA starting Monday at 03Z, which will provide some upper-level divergence.

500mb winds remain in a zonal flow pattern throughout the forecast period. Wind speeds maximize at 75-80kts due to the polar jet being positioned above. A couple spots of high vorticity make their way over the CWA on Saturday 12-18Z following the cutoff low.

AT 700mb, a secondary wave of moisture arrives Saturday 15-21Z providing some cloud cover, but lacks any significant lifting mechanism to support precipitation. Winds are of a west-northwesterly component at the beginning of the forecast period. They then shift to a southwesterly component with the passage of a ridge on Sunday 09Z.

800mb winds switch to a westerly component from Saturday 06Z to Sunday 06Z. Winds then shift to a southerly flow with a LLJ with maximum winds of 60kts, bringing WAA over the CWA for the rest of the forecast period through Monday 12Z. RH values of 90-95% approach from the south Monday 00-03Z. Surface winds remain relatively calm until they shift south Sunday 18Z, where wind speeds lay consistently in the 15-20kt range. Solenoid formation at the surface in combination with the aggressive southerly wind further supports WAA over the region through the rest of the forecast period.

There is significant spread on the NBM for this forecast period, so we decided to use the median NBM temperatures in combination with the deterministic GFS output to decide on high and low temperatures. NBM output was used to forecast cloud cover.

-Sausen

Current Conditions at Sanborn Field

 

Friday: Overcast and rainy. High: 44

 

 

Friday Night: Decreasing clouds. Low: 33

Saturday: Mostly sunny. High: 60

Saturday Night: Mostly clear. Low: 40

 

 

Sunday: Cloudy, then mostly sunny. High: 66

 

 

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Discussion:

Friday will be rainy and overcast throughout the day, clearing up by the evening. Temperatures will remain in the 40s Friday with a low in the low 30s Friday night. The rest of the weekend will be warm and dry as the sun comes out Saturday and winds from the south bring warm air on Sunday. Expect highs in the 60s on Saturday and Sunday! Enjoy the weekend tigers!


- Sallot

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Forecasters: Allen, Sallot, McGuire

Date Issued: 03/03/2023 10:00 AM CST

Technical Discussion:

 

The main weather activity we’re looking at this weekend is the rainy conditions that first appeared Thursday evening and will continue into Friday afternoon. There is a Wind Advisory to the east of Boone County from Montgomery and Gasconade into St. Louis, and Flood Warnings to our south starting Laclede and Texas county. In Boone County we have Hazardous Weather Outlook, meaning the storm on Friday is expected to produce heavy rainfall before the afternoon ends. This forecast was mostly created using the NAM as it corresponded with the RAP more than the GFS did. Something to make note of is that the storm that is affecting the MO and the southern states moves out from MO a little faster in the NAM than in the GFS. Due to the speed of the system, we are not concerned out the Hazardous Weather Outlook in Boone County.

At 250mb there is a negatively tilted trough that moves across MO throughout Friday morning. High values of wind divergence move ahead of a low-pressure system that enters MO from the west at 15z and is centered over our region at 18z. The low will move out of our forecast region at about Saturday 00z. For the rest of the forecast period, we see zonal flow with a ridge forming over MO Sunday 00z. The jetstream is over MO for almost all of our forecast period, with the exception of when the low-pressure system in over MO on Friday.

At 500mb vorticity is advected into and out of MO from the beginning of our forecast period at Friday 12z to Saturday 6z as it moves with the low-pressure system. At Saturday 15z there is some vorticity that moves across our region. After this, there is no vorticity entering MO until after our forecast period at Monday 3z.

At 700mb increased moisture covers MO from Friday 12z to Saturday 00z. We also see some moisture at Saturday 15z to Sunday 6z across Mid-MO, which is the same time we see increased that vorticity at 500mb.

At the surface there is a trough moving through MO which ushers in the rain we will see until about 0z on Saturday. There is a high-pressure system that moves into MO from AR Saturday 3z-18z. When this system moves east on Sunday it works together with the low-pressure system in ND and SD to give our region a southerly return flow which will help increase our high for Sunday afternoon.  ­

-Allen

 

 Current Conditions at Sanborn Field

 

 Thursday Night: Partly cloudy. Low: 38
 

 

Friday: Mostly cloudy. High: 42

 

 

Friday Night: Heavy rainfall for majority of the day. Low: 33

Saturday: Mostly clear. High: 56

Saturday Night: Mostly sunny. Low: 36

 

 

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Discussion:

Rain will move into our area overnight Thursday. These showers will linger until Friday afternoon with a clearing sky. Temperatures will warm after as we get into the weekend!

- Labit

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Forecasters: Hefner, Macko, Samson

Date Issued: 03/01/2023 5:00 PM CST

Technical Discussion:

 

After taking observations and comparing to the NAM and GFS, we agreed more with the GFS due to its accuracy with tracking the low-pressure system over the southwestern United States. Furthermore, the timing of precipitation occurring and the amount are closer to the SREF mean than the NAM.

Our main concern during this forecast period is the progression of a low-pressure system which will be impacting central Missouri overnight Thursday into Friday afternoon. Currently, the trough is positively tilted over New Mexico but as it moves northeast into Friday between 09z-12z it becomes more negatively tilted. This along with having the greatest values of divergence aloft and vorticity in central Missouri could result in our heaviest rainfall. While this means that there is circulation in the atmosphere, our chances of thunderstorms are low because of the small temperature gradient involved with the passage of the low. 

Both upper- and mid-level moisture builds into our region by Friday 00z turning conditions overcast. By Friday 09z, the low pressure is positioned over the extreme southeast corner of Oklahoma influencing high moisture transport vectors. Conditions begin to clear due to zonal flow building into the region with moisture  decreasing with the northeastern movement of the low.

While the southern United States is expected to experience stronger and more severe storms, areas in southern Missouri are projected to have significant rainfall totals with flood warnings already in effect. While the greatest concern is to the south, areas north of I-70 could also see considerable precipitation. SREF ensembles have high confidence of rain totals between 1.5" - 2" of liquid precipitation. Chances of snowfall are low with the GFS track, however if temperatures get cold enough we could see mixed precipitation as the low moves out of our area by Friday 12z. If mixed precipitation does occur, it'll be brief, associated with the wrap around moisture.

- Labit

 

 Current Conditions at Sanborn Field

Thursday: Partly cloudy. High: 54
 

Thursday Night: Mostly cloudy. Low: 38

 

 

Friday: Heavy rainfall for majority of the day. High: 42

Friday Night: Mostly clear. Low: 31

Saturday: Mostly sunny. High: 54

 

 

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Discussion:

Make sure to make the most of theses lovely above average temperatures for today as washout conditions are expected for tomorrow. All day rain on Friday can bring as much as 2 inches of precipitation for Columbia. As a result, flash flooding in flood plains may occur. Thankfully this rainy weather won't last too long as warm temperatures and sunny skies will return this weekend.

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Forecasters: Hefner, Macko, Samson

Date Issued: 03/01/2023 5:00 PM CST

Technical Discussion:

 

For this forecast period we decided to use the GFS20 due to it more accurately tracking the location of the low-pressure system currently centered in the southwestern United States. Additionally, GFS generated soundings and SREF ensembles were reviewed to examine both  the timing and amount of expected rainfall.

The focus of this forecasting period is the low-pressure system arriving over mid-Missouri on Friday morning which is expected to bring high amounts of precipitation over our area.  Currently at the 250mb-level rests a positively tilted trough centered over the Santa Ana region. This trough will progress west across the southwestern United States before transitioning to negatively tilted over the Texarkana region on Friday at 12Z. At this time period, intense circulation will be present over the same region with a vort. max located roughly over central Arkansas. Mid-Missouri will experience some circulation but less compared to the intense values expected in the south.

At the 700mb-level, upper level moisture begins to appear over our area on Friday at 00Z. High moisture values persist until Saturday 00Z until progressing west, leaving dry conditions over Columbia for the remainder of the forecast period. At the 850mb-level, high amount of moisture transport from the Gulf suggests an impact of a low level jet. Due to the combination of all of the factors associated with this low pressure system (negatively tilted trough, intense circulation, moisture transport, and wind shear) the Storm Prevention Center currently lists Texarkana region under moderate risk for severe weather. Thankfully, we are not expecting severe weather to occur over Columbia, in part due to a minimal temperature gradient leading to a lack of instability.

While severe weather is not expected with this low-pressure system, however, intense amounts of precipitation is. SREF ensembles resolve a high confidence in 1.5" to 2" inches of liquid precipitation. GFS generated soundings suggest saturation will be achieved Friday at 06Z. Furthermore the highest negative Omega values will occur from Friday 09Z-12Z which will result in the most intense rainfall during that time period. It is important to note these high amounts of precipitation may result in flash floods in flood plains. While most of this liquid precipitation will occur as rainfall, a chance of snowfall can not be ruled out. Temperatures are expected to decrease to 32 degrees Fahrenheit Friday 21Z. In the event snowfall occurs, ground temperatures will be above the freezing mark resulting in melting any would be accumulation. All liquid precipitation will stop by Saturday 00Z as the upper atmosphere begins to dry out as well as be cut off from negative Omega.

The low pressure system affecting our local area is expected to push out Saturday 06Z leaving zonal flow as less active weather to follow. Future forecasting shifts should pay attention to the low over the Pacific Northwest Coast and track future impacts it may hold over our local region.

 

-Hefner 

 

 Current Conditions at Sanborn Field

 

 

 

Wednesday Night: Partly cloudy, decreasing clouds. Low: 34

 

 

Thursday: Partly cloudy. High: 54
 

Thursday Night: Mostly cloudy. Low: 38

 

 

Friday: Rain. High: 42

Friday Night: Mostly clear. Low: 33

 

 

 

 

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Discussion:

Thursday starts a cooling trend for the end of the week with highs in the middle 50s. Cloud cover increases that night as rain chances begin early Friday morning. Expect rain all day on Friday until the early evening, where we might get to see a few flurries. However, no accumulation is expected as the surface stays above freezing. Conditions dry out quickly, and precipitation will finish by dinnertime.

-Chirpich

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Forecasters: Chirpich, Cook, Travis

Date Issued: 03/01/2023 5:00 PM CST

Technical Discussion:

 

The 12Z run of the GFS was chosen for this forecast, as it forecast the observed high temperature for Wednesday better than other models. The problem of the day for this forecast period is the low-pressure system currently located near California that is expected to bring precipitation to mid-Missouri late Thursday night.

The focus of the forecast will be the track of the aforementioned low-pressure system as it moves east. The trough formed by the low is currently positively-tilted as it sits over the western CONUS. However, the low-pressure system moves southeast, traveling through New Mexico and Texas before turning into a negatively-tilted trough by the time it reaches Missouri. The center of the low is expected to pass through the Missouri bootheel around 15Z on Friday. It will bring increased upper-level divergence, allowing for low-level convergence. While the low moves to the southeast of the forecast area, the wrap-around moisture associated with the southerly flow will allow for plenty of precipitation for the Midwest. Missouri will start to see increased dewpoints and cloud cover by 06Z on Friday. 

It is also important to note that the 1000-5000MB thickness values stay above 5400m around the low-pressure system. This is a hint that winter precipitation might not be likely. However, soundings were consulted to give a deeper look into the possible precipitation type. The upper atmosphere begins to saturate at 03Z on Friday, with a pronounced dry layer seen at the surface. By 09Z, the zipper effect allows for the lower levels to become saturated. At this time, there is saturation at -10 degrees Celsius with a prominent warm nose and surface temperatures well above freezing, so precipitation will begin as rain. High negative omega values at 500MB and the surface were also seen at 09Z, leading to the heaviest rain expected early Friday morning. Rain will continue throughout the day on Friday until around 20Z, when the column begins to cool to just above 0 degrees Celsius. As the temperatures in the lower levels hover around freezing, it is possible that the area could see a switch to snow. However, as surface temperatures stay above the middle 30s, any snow that does fall will melt either before or as it hits the ground. This will not contribute any hazardous impacts for the event as no snow is expected to accumulate. Also, the atmosphere dries up by 21Z, quickly ending any possible snow or rain. Expected rain accumulation for the entire event will range between 0.5" to 1" of liquid precipitation, most of which will fall as rain.

No travel impacts are expected for the event, aside from wet roadways and possible reduced visibility in the early morning when the rain is heaviest. As conditions dry out, Friday night will be left with minimal cloud cover.

-Chirpich

 

 

 Current Conditions at Sanborn Field

 

 

 

Wednesday: Overcast. High: 47

 

 

Wednesday Night: Overcast. Low: 39
 

Thursday: Rain. High: 47

 

Thursday Night: Rain. Low: 34

Friday: Partly cloudy. High: 47

 

 

 

 

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Discussion:

A weak rainstorm is scheduled to pass through mid-Missouri on Thursday. Due to low moisture content within the atmosphere, expect accumulation between a quarter to a half an inch. The heaviest rain will be falling Thursday morning into the early afternoon, then transitioning into light rain and drizzle overnight.

In addition,

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Forecasters: Ritsema, Clark, Cochran

Date Issued: 03/08/2023 10:00 AM CST

Technical Discussion:

 

The GFS model was mainly used in this forecast due to the consistency and accuracy of storm tracks in recent weeks. Again this week, NAM's surface low track is considerably different than the GFS with the center of the low 100-200 miles to the east when passing over Missouri. 

Wednesday morning, leftovers from last nights active weather are lingering in the area. Vorticity and moisture at the 700 and 850mb levels will continue to move out Wednesday morning, clearing fully by midday(18z). Low level moisture will persist, though, leaving overcast skies throughout the day Wednesday. 

Thursday, a shortwave trough is set to influence mid-Missouri. On the surface, the low tracks from Oklahoma into mid-Missouri, eventually making its way into Illinois and out east.  Although unimpressive, the trough still brings along upper level forcing with divergence at the 300mb level between 12z and 18z. Raised levels of vorticity at 500mb exists for a short amount of time on Thursday between 06z and 18z, and the last ingredient for forcing is the weak, but widespread, omega throughout Missouri between 12z-21z. 

When looking at soundings, near-saturation exists at all levels beginning at 12z on Thursday. By 18z, the mid-levels of the atmosphere begin to dry out quickly. At 00z Friday, moisture only exists at 700mb and below and continues to dry out overnight. By 9z Friday, most of the moisture will have moved out of Missouri. 

The coupling of forcing and moisture present on Thursday will allow for rain to fall throughout the day Thursday. Heaviest rainfall will occur when forcing is present which is Thursday between 12z and 18z, transitioning to light rain and a drizzle overnight Thursday. Rain is expected to stop around 9z Friday. 12 hour QPFs from the NBM suggest around a quarter of an inch of rain throughout the day Thursday with less than a tenth of an inch overnight into Friday.

On Friday, the backside of the shortwave trough will be over mid-Missouri flushing in cooler dry air. Moisture is close to the surface which will produce low-level clouds.After the rain ceases, a low-level jet of 40kts from the northwest will influence stronger surface winds. Expect gusty conditions at the surface until 18z on Friday. 

-Ritsema