Friday Night - Clear. Low: 38-42
Saturday - Clear skies. High: 62-66
Saturday Night - Brief partly cloudiness. Then becoming clear. Low: 36-40
Sunday - Clear. High: 46-50
Friday - Clear skies. High: 52-56
The main focus of this forecast period is how interactions between the a cut-off, upper-level low and the remnants of Hurricane Zeta will impact chances for precip going into Wednesday night. A blend of the GFS and NAM was used with emphasis on the GEFS and SREF ensembles for temperatures and precip amounts.
Disturbed, upper-level flow dominates over much of the CONUS according to Wednesday's RAP analysis of 250-hPa height and wind. A cutoff low currently sits over the NM - TX border and puts Missouri in the inflection point between the associated amplified trough and weaker ridging over the far SE CONUS. GFS prognostics of 250, 500, and 700-hPa heights and winds keep the Midwest in southwesterly flow until the upper-level low gets pulled off to the northeast by the remnants of Zeta. As the wave propagates to the NE, it will bring with it ample dynamic support for precipitation Wednesday night and into Thursday morning. GFS plots of both 250-hPa divergence and 500-hPa vorticity show increased divergence overhead and increased circulation accompanying. 700-hPa RH shows Zeta will help bring in plenty of moisture to work with at least in the mid levels of the atmosphere. A look at both GFS and NAM soundings show that this moisture exists throughout the entire column. Soundings also back up the dynamic support as decent UVM is present as well. Rain will likely begin by 00z Thursday and continue until 12z at the latest.
Both GFS and NAM soundings show a drying out of the column by 09z starting at the upper and mid-levels, but keeping the lower levels relatively saturated. Rain will most likely taper off by 12z when both models' soundings show that the entire column has sufficiently dried out. Clouds will exit the region with the precipitation and Columbia will likely see mostly clear to clear skies by late afternoon.
Behind the exiting longwave trough, GFS 500-hPa heights show that the upper-level flow turns zonal by Thursday night and continues into Saturday. This is reflected by lower level and surface high pressure building in from the northwest on Friday. GFS and NAM show low level flow shifting out of the southwest by Friday resulting in a couple days dominated by moderate WAA. This will result in a clear warming trend that will allow our temperatures to reach the middle 60s by Saturday before the next system approaches by Sunday. Future shifts should pay close attention to the strength of WAA and adjust temperatures accordingly.
This forecast was put together using the 06ZGFS and SREF plumes for temperatures. The main focus for this forecast period will be the low pressure system moving toward us from the southwest.
High values of relative humidity at the 700mb and 850mb levels point to overcast conditions today. As the low moves toward us from the southwest, winds will shift to the south, causing moisture advection and WAA from the Gulf. There are high values of vorticity associated with the low at the 500 mb level, paired with negative omega at 700mb. Increased vorticity and negative omega values will be present over Columbia tonight and through Thursday afternoon, which will cause rain totalling about an eighth of an inch. Chances for flash flooding will remain to our south since the heaviest rain will occur south of Columbia.
By Thursday afternoon, relative humidity will decrease as the low moves to our southeast. This will allow the rain to end and clouds to decrease. Relative humidity remains low through Friday and the flow aloft becomes zonal. The skies will remain clear and allow for warmer temperatures than we experienced earlier in the week.
This forecast was generated from the 12Z NAM & GFS, supplemented by the SREF. The main focus for this forecast period is the track and intensity of the cutoff low currently detaching itself from a positively tilted trough over the western CONUS.
Satellite imagery indicates a thick cloud deck over a large portion of the central and eastern CONUS. This broadband of clouds has provided us with a lot of moisture and precipitation that we are still seeing right now and will continue to see into the early parts of tonight. At 250mb, there is a prominent positively tilted trough with a large & strong jet streak that extends from the SW to the NE CONUS. The trough is expected to collapse on itself while the low pressure system is still very apparent across the Southern Plains. This vertically-stacked cutoff low is associated with a lot of vorticity.
As the low continues to travel towards us from the west, the counterclockwise winds associated with the cyclone will begin to funnel in southerly winds, thus beginning WAA. Moisture is present in the lower 300mb of the atmosphere with this system, but no forcing is expected to allow for rain to reach the ground until Wednesday night. Instability should stay on the SW portion of the low, so no thunderstorm activity is expected. Sufficient moisture and omega values will continue to drop rain across Mid-MO until midday Thursday, when this system moves eastward. Moisture will go with it and sunny skies across Columbia will allow temperatures to warm into the mid 50s on Friday.
Future forecasters should monitor the track of the low to our south and how it could influence Hurricane Zeta, as its landfall is scheduled for late Wednesday. Since the low is expected to advect moisture into Mid-MO, it could potentially take moisture and energy from Zeta. It will be interesting to see how those two interact with each other.
This forecast was generated using the 06z GFS. The main focus for this forecast period is an increase in chances of rain throughout most of the forecast period and temperature trends.
Currently, satellites and radars show a dry area located over the majority of central and western Missouri. A weak high pressure system is located over central northern Missouri leading in a break in rain over central Missouri. The upper level jet is currently positioned over Northern Missouri positioning Central Missouri in the left divergence region which will influence our rainfall possibilities later today. We should remain dry until late afternoon hours where warm air advection begins to occur leading to the possibility of showers into this Tuesday evening fueled by low level flow originating from the Gulf of Mexico.
West of Missouri located over southern Kansas and northern Oklahoma, a deepening trough is beginning to develop which will begin to push west tracking along the Missouri/ Arkansas border. The upper level jet max remains situated northeast of Missouri over the Great Lake region. This will continue to keep us located in the left divergence area leading to continuous rainfall for much of Wednesday. The southwesterly flow Wednesday morning will lead to an increase in temperatures Wednesday. Along with warmer temperatures, this southwestern flow will bring with it moisture in the lower levels originating from the Gulf of Mexico. As we head into Wednesday afternoon, the deepening low-pressure system moving west from the Oklahoma/ Kansas border moves south of the CWA and sets up along the central portion of the Missouri/Arkansas border. Fueled heavily by the moist low-level jet high amounts of heavy rainfall will be seen the further south of the I-70 corridor you go. Chances of thunderstorms have begin to diminish as predicted wind shear and CAPE values have decreased throughout much of the forecast time.
This forecast was generated by a general model blend from the 18Z NAM, GFS, HRRR, and RAP, supplemented by the SREF and GEFS. We tried to look at the latest model runs of many models to see if there is continuity between them during the wet week ahead expected for Mid-MO. The main focus for this forecast period is the continuation of winter weather through the night and a few more rain chances expected in the next couple of days.
Winter weather made its first appearance of the season today. In Columbia, rain transitioned to sleet around 15Z and that transitioned to snow before 18Z today. It recently just transitioned back to sleet. Temperatures have dropped about 10 degrees F since midnight as a dominant high pressure system sitting over the central Great Plains funnels in a cold air mass to the Midwest. Northerly winds have gusted up to 20mph as we sit under a jet streak and to the east of a pronounced negatively tilted trough at 250mb. This is forecast to become a cutoff low within the next 24 hours and will likely impact our weather over the next few days. All of the models we looked at this afternoon had sufficient continuity for this system.
Soundings indicate saturation throughout the lower half of the troposphere all night long with temperatures straddling the freezing line. We are expected to dry up near sunrise tomorrow morning, but the surface temperature and dew point temperature will be so close together that this could create freezing fog/drizzle when the morning low is achieved tomorrow. Temperatures are expected to warm into the 40s in the afternoon where saturation could be reached again, creating a chance for rain. This low-level cloud deck is expected to stay around through Tuesday and Wednesday, even when precipitation is not likely to reach the ground.
A warm front is forecast to approach us on Wednesday, bring a warm & moist air mass with it. This could provide enough lift and instability to create weak thunderstorms. As this cold and warm air mass collide, the biggest threat would be hail forming in the updrafts up the supercooled air within these storms. We also have to monitor the track of the cutoff low from the west and Hurricane Zeta in the Gulf of Mexico. The cutoff low is expected to impact our rain chances on Wednesday and Thursday, but future forecasters should watch for the impacts that could be created if/when Zeta and the cutoff low merge. These are both likely to keep moisture in Mid-MO during the middle of this week but probably not by the upcoming weekend.