An upper level trough is currently digging south along the west coast, creating southwest flow for the Ozarks in the upper and mid levels. Moisture from the Gulf and even as far west as the Baja is advecting in along the geostrophic jet flow. This pattern is
somewhat stalled for now, allowing lots of moisture to stream in and positioning us perfectly in the left exit region of the jet. Shortwave energy embedded in the trough will therefor be poised to pass through and provide lift for our moist airmass to produce rain and drizzle.
The primary concern for conditions tonight is the potential for reduced visibilities due to fog and/or the low stratus deck. Tulsa has issued a Dense Fog Advisory to our southwest and we are monitoring conditions along the KS/OK and AR borders closely for the
potential need to issue our own Dense Fog Advisory. Though they may not meet advisory criteria yet, it is worth noting that visibilities are reduced in these areas (to about 1 mile currently). Model guidance probabilities of visibilities less than a quarter mile really begin to ramp up around 3-4AM (60-80%) along the KS/OK border and the higher terrain east of Springfield, which tracks given that the stratus deck is so low that you wouldn`t have to climb much elevation to enter it. If visibilities go under 0.25 miles begin to encroach on the area, a Dense Fog Advisory will be issued.
Thankfully, temperatures will remain in the mid-30s through the night, so any drizzle or fog that does develop will not freeze!
Tuesday afternoon rain will begin to move in from the south around mid-afternoon and move north through the evening. Less than half an inch of rain is expected with this round, but given the widespread 1" accumulations yesterday (up to 1.5" east of
Springfield) and the frozen ground (frost depth is 5" in Springfield).
We`ll see temperatures in the mid-40s today and stay warm overnight in the low 40s thanks to cloud cover.
It will rain through the night and some may still see scattered showers by 6AM Wednesday, but the rain will continue to move out through the morning and allow for a break before yet another shortwave trough moves through as that upper level ridge finally begins to lift northeast. This round will be focused on the eastern half of the area toward south central MO with precipitation totals less than a quarter of an inch.
When all is said and done by Thursday afternoon, area rain totals since the first round of precipitation began Sunday night will be 1-2 inches widespread with localized higher amounts, especially in the southeast.
More rain is on the horizon beginning Friday and lasting through the weekend as another upper level wave passes by.
We`ll be a few degrees above normal all week with highs in the upper 40s to mid 50s.
Source: NWS Springfield