000 FXUS65 KPUB 210557 AFDPUB
Area Forecast Discussion National Weather Service Pueblo CO 1157 PM MDT Fri Apr 20 2018
.UPDATE... Issued at 935 PM MDT Fri Apr 20 2018
Intense convective snow showers have developed over eastern Fremont, northwest Pueblo, El Paso and Teller counties. Web cams and social media video has been showing a mix of rain/snow and ice pellets with the more intense showers with road surfaces quickly becoming slushy and snow packed. The heavy wet spring snows are always a challenge to forecast as quick accumulations can occur even with temperatures right around or slightly above freezing. Have updated to lower snow levels and temps, and increase snow amounts into the 2-3" range. Some melting will occur as snow lightens up, so am hesitant to go out with any short fused advisories at this point, but that may become necessary if intensities maintain. -KT
UPDATE Issued at 714 PM MDT Fri Apr 20 2018
Storm is weakening as it moves across the state, and snowfall amounts have been lighter than originally anticipated, so decided to downgrade all of the Winter Storm Warning areas to a Winter Weather Advisory. End times for the highlights remain the same. Moore
UPDATE Issued at 602 PM MDT Fri Apr 20 2018
Update for expiration of the winter weather advisory for the Southern Sangres. Incorporated latest obs data, and added areas of fog across the eastern plains tonight through early tomorrow morning. Moore
.SHORT TERM...(This evening through Saturday) Issued at 259 PM MDT Fri Apr 20 2018
At 2 pm, scattered showers with embedded thunder was noted over a good part of the region. Most of the precip was over the central mtns, Pikes peak region, the s mtns and the far eastern plains. Temps across the plains varied considerably, with 60s in the Pueblo area while temps were in the 40s most of the rest of the plains. Over the valleys temps were in the 30s and 20s in the mtns. A brisk se sfc wind was occurring over most of the plains with lighter winds over the higher elevations.
The main mid level circulation was over SW colorado, vicinity Montrose. The surface circulation was just south of Pueblo.
Rest of today and into tonight...
Best chance of precip in the short term (rest of this afternoon) will be over the far eastern plains, Pikes Peak region and central mtn areas. With flow now from a westerly component over the s mtns, San Luis Valley and sw mtns, these areas will see the least amount of precip. For this reason have cancelled the winter wx hilites these regions.
For tonight, the 500 mb circulation will move generally east. Flow will come around to a northerly component later this evening and this will favor the Palmer Divide region/Pike`s peak and the central mtns for precip this evening and into tonight. Areas typically south of this region will see little if any precip. Winter weather hilites for these regions will continue, with several additional inches of snow for the c mtns and Pike Peak expected. N El Paso should see 1- 2" of snow, mainly on grassy areas. COS proper should see a trace to 1" on grassy surfaces.
Min temps tonight should reach into the 20s and lower 30s over the divides while lower ark rvr valley will be in the 30s. Mtns and valleys should be in the teens and 20s.
Closed circulation should be over the CO/KS border, general vcnty of Goodland KS. Precip will be favored over the central mtns/Pikes Peak/N El Paso county in the morning. Some wrap around precip may work its way south down the far eastern plains tomorrow afternoon as circulation wobbles over the KS/CO/NE region tomorrow afternoon. Breezy north to northeast winds are expected over the plains tomorrow with max temps reaching into the U40s to M50s across the lower elevations. 50s should be felt in the valleys with 30s and 40s in the mtns. Quite a bit of clouds will linger tomorrow. /Hodanish
.LONG TERM...(Saturday night through Friday) Issued at 259 PM MDT Fri Apr 20 2018
Saturday night through Monday...The upper low will be located just east of Colorado Sat night, with just some light showers tapering off through the evening hours. A transitional ridge moves in for Sun into Mon, providing for warmer temps as well as some drying at least through the first half of Sun. Isolated snow showers will return to the higher terrain Sun night into Mon, then as the next upper disturbance approaches pcpn will spread across the mts to the adjacent plains Mon aftn and eve. Sfc winds will become southerly and increase for Mon, helping to boost temps. Expect high temps in the 60s for Sun, then 60s for the high valleys and mid 60s to mid 70s for the plains on Mon.
Tuesday...The upper shortwave crosses the Rockies late Mon night through Tue, pushing a cold front south across eastern CO after midnight Mon night. This will cool max temps on Tue across the plains by about 10 to 15 degrees from the previous day. Some showers are expected across the forecast area, but will mainly affect the higher terrain and eastern slopes of the southern Front Range. Look for highs in the 60s for the high valleys, then cooler across the plains with highs in the mid 40s and 50s.
Wednesday through Friday...Unsettled northwest flow aloft settles in across the state for the rest of the work week, keeping the threat of isolated showers for the mts and at times for the plains. Pcpn for the plains will be very hit and miss though, and confidence is low. Temps are forecast to gradually warm through the week however, with highs in the 60s most areas on Wed, then 60s for the high valleys and 60s to lower 70s for the plains both Thu and Fri. Moore