629 FXUS63 KTOP 061038 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 538 AM CDT Wed Oct 6 2021 ...Update to aviation forecast discussion... .DISCUSSION... Issued at 356 AM CDT Wed Oct 6 2021 Quiet morning currently across the area. A weak upper low is currently spinning over Arkansas, while high pressure sits over the Great Lakes. The resulting easterly flow in between has pushed some moisture into east-central Kansas, bumping dewpoints up into the low 60s. With light winds in place, breaks in the mid-level clouds could allow patchy fog to develop through sunrise, though so far the clouds have kept any fog at bay. Farther west, dewpoints are about 5- 10 degrees lower, and clearer skies have allowed temperatures to drop into the 50s. Throughout the rest of the day, the upper low over Arkansas will only drift northward. Can't completely rule out a sprinkle or two over far eastern Kansas, but for the most part the only impacts over our area will be continued mid-level cloud cover. These clouds will keep highs in the 70s. The quiet pattern will continue into the beginning of the weekend. Our upper low will gradually move north and east, allowing ridging to build back over the region. This will result in a notable warming trend through Saturday. Saturday does appear to be the warmest day, as the first in a series of upper troughs moves from the West Coast towards the Plains. Strong WAA ahead of this trough and its associated cold front will boost temperatures to around 90 - near record highs for this time of year. The tightening pressure gradient will also keep a gusty SSW wind in place ahead of the front Saturday. The front should begin to pass through the area sometime Saturday night, though things should stay mainly dry to start as moisture is initially limited. Sunday into Monday, the front should stall somewhere near the forecast area as the initial shortwave trough lifts off to the northeast and a secondary shortwave approaches. DCVA from this second trough will allow surface low pressure to develop along the stalled baroclinic zone. This low will likely have a better connection to the deeper Gulf moisture. Recent guidance has generally trended slower, stronger, and farther west with the low as it lifts northeast. As a result, shower and thunderstorm chances should increase as this occurs Sunday PM into Monday AM. A few strong to severe thunderstorms could even occur with the stronger and farther west solutions, given plenty of shear and at least some instability in the warm sector of the low. However for now, there has not been quite enough run-to-run consistency in model guidance to put much weight into any one solution. By the end of the period, sometime around mid-week, an even deeper trough over the western CONUS will eject eastward over the Plains. A strong surface cyclone should develop in response to the lee of the Rockies, allowing moisture to surge northward ahead of it. Will need to keep an eye on this system given its strength, but details such as timing and track remain fuzzy at this time. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 538 AM CDT Wed Oct 6 2021 Current shallow fog at KMHK and KTOP should be largely gone by 12z. After this, VFR ceilings and light east winds should prevail throughout the period. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Reese AVIATION...Reese