423 FXUS63 KTOP 212316 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 616 PM CDT Thu Mar 21 2019 ...Update to aviation forecast discussion... .SHORT TERM...(This evening through Friday) Issued at 329 PM CDT Thu Mar 21 2019 20Z water vapor imagery showed a high amplitude upper ridge over the Great Plains with a closed low over southern NV and a deeper upper level low moving into the Gulf of Alaska. At the surface, a broad area of high pressure was noted over the central plains with the deeper moisture confined to the Rio Grand river valley and south TX. For tonight and Friday, dry weather should continue as ridging aloft gradually weakens and moisture return is slow to develop. Lows tonight are forecast to be in the lower and middle 30s due to clear skies and relatively dry air aiding in radiational cooling. There may be some isolated ground fog, but with afternoon dewpoints in the upper 20s and lower 30s, there doesn't appear to be much water vapor in the boundary layer for saturation. Although winds are likely to be weaker tonight than they were this morning. Highs Friday should make it into the 60s with increasing low level warm air advection and only some high cirrus overspreading the area. .LONG TERM...(Friday night through Thursday) Issued at 329 PM CDT Thu Mar 21 2019 There remains good agreement among the models for the upper low out west to lift across the central plains Saturday and Saturday night. Increasing moisture advection through the day increasings confidence in the chances for showers and even some thunderstorms. There is some signs from the NAM and GFS of elevated instability developing just ahead of the upper low moving through north central KS. The magnitude of the instability remains rather modest so chances for severe weather look to be somewhat low. The bigger changes to the forecast was to lower precip chances for Sunday and into Monday. The second piece of energy that had been expected to move through is much less defined in the model solutions and as a result forcing for precip looks much less organized. Temps Saturday and Sunday look to remain mild with cloud cover holding highs in the 50s on Saturday and low level warm air advection bumping them up into the lower and mid 60s for Sunday. Lows through the weekend are expected to be in the 40s. Monday and Tuesday are looking dry as a surface ridge move into the plains with mid level shortwave ridging overhead. Highs Monday are expected to be in the mid 50s with weak cold air advection forecast. Return flow is expected to redevelop by Tuesday with highs in the mid and upper 50s for Tuesday. With a surface ridge axis moving over the forecast area Tuesday morning, lows are expected to fall into the mid 30s. Tuesday night through Thursday looks to be more of a spring time pattern as the GFS indicates some modified gulf moisture moving into the plains by Thursday. There are some signs for elevated convection Tuesday night although confidence is marginal as forecast soundings show an impressive EML advecting into the central plains. Have some small POPs going Tuesday night through Thursday to account for the potential convection. The pattern should also favor temps warming into the 70s by Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 616 PM CDT Thu Mar 21 2019 VFR conditions. Lower-level winds will be light for this forecast period, but concern for nocturnal BR development is low with crossover temperatures a few to several degrees below expected low temps. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Wolters LONG TERM...Wolters AVIATION...65