Current Conditions at Sanborn Field
After a dry Wednesday and Wednesday night, rain will re-enter the forecast starting Thursday morning. A low pressure system will slide by to our south Thursday afternoon, giving mid-MO a very good chance of widespread soaking rain starting mid to late morning Thursday. Breezy conditions are also possible as the rain moves through. Rain and clouds will keep highs on Thursday down in the upper 40s to lower 50s. Rain will move out Thursday evening, leaving us dry for Friday. Clouds will still hang around for Friday and Saturday, however, and there's an outside chance of a few light rain showers Friday evening. The good news? Temperatures will trend warmer as we head into the weekend, with readings near 70 possible by Saturday.
==================================================================
After a brief reprieve from the wet weather on Wednesday, another round of widespread rain is expected in mid-MO late tonight into Thursday.
WPC surface analysis places an occluded surface low over the upper Midwest. This system was responsible for the wet weather in mid-MO on Tuesday. As this low pushes northeast, another sfc low is projected to develop and undergo rapid cyclogenesis across the lower Midwest through Thursday afternoon. The GFS and NAM both concur in placing mid-MO in an ideal place for the strengthening of a surface low, with ample divergence at 250-mb by 18 UTC Thursday courtesy of coupled jet streaks.
Overnight, skies will remain overcast ahead of the developing surface cyclone. GEFS and SREF means, along with the 18 UTC HRRR, have lows only falling into the middle 40s. Moist flow should begin to establish itself in the lower levels of the atmosphere by daybreak Thursday, though significant lift will not arrive until the developing closed low slides into Missouri around the late morning to early afternoon hours.
For Thursday, rain looks to start in earnest around or shortly after 15 UTC (10 AM CDT). The shortwave aloft will support a deepening closed circulation at the surface by midday, with the track of the surface low likely falling around 100 miles southeast of Columbia. This will support a small deformation zone on the backside of the cyclone, placing COU in an ideal location to receive some fairly significant rainfall amounts despite a lack of instability. The deterministic GFS, NAM, HRRR, and the GEFS all support a period of moderate to occasionally-heavy rain Thursday afternoon, with the heaviest precipitation likely to occur between 12 PM and 8 PM CDT. The HRRR and SREF means both peg QPF around 0.5", whereas the GFS, GEFS, and NAM are significantly more bullish, showing around an inch. Given the rapidly-deepening nature of the storm system and PWATs near 1 inch, it's likely that Columbia sees anywere from 0.5 - 1 inch of rain out of this system. Additionally, the pressure gradient on the backside of the surface low will intensify Thursday afternoon, so breezy conditions are likely along with this rain.
Precipitation looks to clear out Thursday evening. Clouds should hang around through at least the first half of the night before breaks of clear sky are possible towards Friday morning. Given modest CAA and the potential for some clearing, lows Thursday night should be rather chilly: near 40 degrees.
Sensible weather looks to be quieter on Friday, though the longwave trough will still be to our west. That will encourage the development of yet another surface low on the lee side of the Rockies, which could spread more cloud cover over mid-MO during the day on Friday. Nevertheless, I think the majority of the cloudiness will pass just north of Columbia. That, along with modest WAA, will lead to highs in the lower to middle 60s.
Saturday looks similar, though the aforementioned surface low will be skirting by just to the north. It appears moisture-starved at this time but ensemble models do indicate low POPs Friday night into Saturday. Interested parties should monitor the forecast for a rain potential during that time. Additionally, despite decent WAA ahead of an associated cold front on Saturday, cloud cover (or lack thereof) in association with the low will determine whether or not highs will break 70 degrees. Right now, cloud cover and the timing of the front seem to advocate for highs in the middle 60s to near 70. If the forecast trends sunnier, these highs may need to be raised.
No comments:
Post a Comment