textproduct: Topeka

KEY MESSAGES

- Low clouds, fog, and patchy drizzle will continue into Friday. Highs will only reach the upper 30s to mid 40s.

- Saturday and Sunday will be warmer with highs in the 50s, may be around 60 degrees on Sunday across the southern counties.

- There will be a chance that rain may mix with snow before ending Monday evening across northern KS. No accumulations are expected at this time.

DISCUSSION

Issued at 309 AM CST Thu Dec 26 2024

Early this morning a southern stream upper level trough was located along the NM/TX border. An upper trough was approaching the Pacific Northwest coastline.

At the surface, a ridge of high pressure extended from the upper Great Lakes southwest into eastern NE/KS. Low stratus and areas of fog were observed across the CWA.

Today through Friday night:

The southern stream H5 trough will shift east across north TX. The richer moisture will remain south of the area across eastern TX and southeast OK. Residual moisture return and weak isentropic lift will keep low clouds, drizzle and areas of fog through the day. Any dense fog that develops this morning should lift to 1 to 5 miles by Noon Today. The upper trough across the Pacific Northwest will dig southeast across central Rockies Tonight, then across the Plains on Friday. Once again the more amplified section of the upper trough will move across north TX. But weak isentropic lift and residual moisture will keep the low clouds, fog, and periods of drizzle in place through Friday. Friday night, Isentropic downglide on the west side of the departing H5 trough may scatter out the low cloud cover. There is a chance with clear skies and light wind, that patchy ground fog may develop before daybreak on Saturday. If any ground fog develops, it should mix out by 9 AM Saturday morning.

Saturday through Monday: The GFS and ECMWF show a quick moving southern stream H5 trough shifting east across OK. Both models show there may be enough ascent for a few shows across our southeast counties during the late morning and early afternoon hours. But temperatures should warm into the 50s with afternoon insolation.

Sunday, will probably be our warmest day of the forecast period. Light southerly winds and mostly sunny skies will allow afternoon highs to reach the mid 50 north to the upper 50s to around 60 degrees south.

Monday, a quick moving H5 trough across the central Rockies into the central Plains will develop surface low across northwest KS, that will track southeast across the area during the afternoon hours. Most of the day areas south of I-70 will be in the warm sector but a surface front will push southeast across the northern counties of the CWA to about I-70 through the afternoon hours. There may be a few to scattered rain showers along the north of the surface front as DCVA increase ahead of the H5 trough tracking southeast across western NE into western MO by 00Z TUE. Highs on Sunday will be warm across the southern counties ahead of the surface front, with highs in the upper 50s. The northern counties may only reach the lower 50s, before the front moves through with steady temperatures through the remainder of the afternoon hours.

Monday night into Tuesday:

The H5 trough will amplify across MO Tuesday evening, then move southeast across the mid MS River valley by 12Z TUE. The ECMWF model solution continues to develop a TROWAL across the eastern and northern counties of the CWA Monday evening. This may allow enough cold air to advect into northeast KS for the light rain to mix with snow before ending around midnight. The GFS and Canadian model solutions continue to be a bit farther north and only clips the far northeast counties of the CWA with precipitation Monday evening.

Tuesday looks drier and cooler behind the surface front. Highs on Tuesday will only reach around 40 degrees north, to the mid 40s south. At this time, New Years Eve looks dry with no travel problems. There may be some accumulating snow across southeast CO ahead of another H5 trough digging southeast across the central Rockies.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 540 AM CST Thu Dec 26 2024

Low stratus with LIFR ceilings and visibilities will continue through the next 24 hours. In areas of heavier drizzle visibilities may drop at times down to 1/2 SM to 1 SM and ceilings down to 100 feet. If denser fog develops this evening the visibilities may drop below 1/2 SM at times, with VV001.

TOP WATCHES/WARNINGS/ADVISORIES

Dense Fog Advisory until noon CST today for KSZ008-KSZ009- KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026- KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055- KSZ056-KSZ058-KSZ059.