Friday, October 27th – Morning Forecast
Friday: An isolated shower or two. High: 68
Friday Night: Mostly cloudy. Low: 42
Saturday: Cloudy. High: 50
Saturday Night: Rain. Low: 40
Sunday: Continuing rain throughout the day. High: 40
=================================================================================
DISCUSSION:
A cold front will push through central MO today, bringing an isolated shower or two across the state. South of I-70 and along the I-44 corridor is expected to see more precipitation today. Throughout the weekend, temperatures continue to drop into the 40s as NW winds brings in cool air. Rain is expected Saturday night into Sunday, with a continuing decline in temperatures into next week.
-Casserly, Ebert
=================================================================================
Forecasters: Casserly, Ebert, Simmons
Date Issued: 10/27/2023 10:00AM CDT
Technical Discussion:
Current radar reflectivity shows a thin line of precipitation moving into Central MO as the cold front progresses into the state. The front is expected to reach Columbia by midday 15Z-18Z and into St. Louis by early afternoon. Along with this, cooler temperatures are expected and we cannot rule out a shower or two today in central MO, but the main precipitation focus is in southern MO. Overnight tonight will remain dry continuing into Saturday. However, by the evening tomorrow, rain is likely (80%) over most of the state. By Sunday, the temperatures will dip into the 40s and continue to decrease along with continuing rain later in the day.
An upper-level trough sinks through the central CONUS today, with a strong jet streak over the Midwest. A cold front ahead of the trough is pushing into MO today, bringing light precipitation with it. Central MO is not expected to see significant rain, as most of the instability and moisture are south of I-70. RH values and dew points also indicate lighter precipitation. Temperatures today will be the warmest of the upcoming weekend, as NW winds bring cooler air into the area behind the front. A difference of almost 25 degrees is likely from this morning into this evening. Throughout today into tonight, clouds will be dominate in the sky behind the front as the upper air pattern stagnates for the next couple days.
On Saturday, the day will be mostly quiet, with rain chances increasing into the afternoon and evening. There is some lift and instability associated with this more active weather, but little forcing will prevent any severity. The main focus of this weekend is overnight Saturday, with rain expected over most of the state. RH values climb to 90-100% and remain high into Sunday. Rain totals will likely not exceed 0.5″ in total ending on Sunday, but spread in ensemble models shows uncertainty with this total. Current thinking looks to lean more toward the stationary front setting up to our south which would indicate the heaviest rain to our southeast. Temperatures will decrease overnight Saturday with the rain cooling temperatures steadily to the low 40s.
Sunday, the jet streak prevails over the upper Midwest, with the right entrance region centered over Missouri, leading to divergence aloft and convergence at the surface encouraging upward motion. This is coupled with a stationary front that drapes itself across southern Missouri. Moisture along this front can be seen from 700 mb all the way down to the surface and even up to 500 mb into Sunday afternoon. This moisture paired with the upward motion indicated showers for Sunday morning but mainly Sunday afternoon along and south of I70. The heaviest rain appears to be Sunday afternoon where the moisture profile is most impressive .In the afternoon this stationary front will sag farther south as time goes on so temperatures will drop slowly on Sunday and the heaviest rain will be along the I-44 corridor. The next forecast group should monitor the colder air behind the system to see if any moisture comes to fruition. If there is any appreciable moisture later this week, winter weather could be a talking point, but most indications lead to a dry period next week.
-Casserly, Ebert, Simmons