234 FXUS65 KPUB 161022 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 422 AM MDT Mon Mar 16 2020 .SHORT TERM...(Today and tonight) Issued at 416 AM MDT Mon Mar 16 2020 Main forecast issue in the short term will be a return of low clouds, fog, and precipitation chances overnight tonight across the plains as a cold front moves through the region. Current satellite imagery is indicating that low clouds and fog are blanketing areas across the plains east of a line from about Ordway to Rocky Ford to Springfield, although most stations are reporting fairly good visibility. However, some of the webcams indicate there is some patchy areas of more limited visibility, but the lowest visibilities are being reported to the north and east of our forecast area. Surface observations indicate that temperatures are mainly in the 20s and 30s at this hour, with a few 40s being reported under the aforementioned low clouds and along the lee slopes of the eastern mountains. In general, winds have become more westerly across the region, which has kept locations along the I-25 corridor mainly free of low clouds or fog. Today...The low clouds and fog are expected to continue eroding from west to east this morning as westerly surface flow continues drying things out. An embedded shortwave within the northern stream of the upper-level flow is expected to send a dry cold front through the plains late this morning, but temperatures should not be affected all that much. Afternoon highs are expected to reach the 50s and 60s for most areas today. Locations near the Kansas border may take a little longer to warm up depending on how long it takes for the low clouds to dissipate. Tonight...The aforementioned cold front is anticipated to continue sagging south and west into eastern Colorado. In addition, surface high pressure building over the northern Great Plains will help to induce easterly winds at the surface, bringing a return of moisture to the plains. The added moisture is expected to bring back low clouds, fog, and drizzle to areas along and east of the I-25 corridor by Tuesday morning. There is once again potential for locally dense fog to develop late tonight into Tuesday morning for a few locations. The front is anticipated to provide enough lift for scattered showers to develop, but only lighter amounts of precipitation are expected. As of now, temperatures are expected to remain above freezing through the short-term period, keeping roads mainly just wet. That said, temperatures are forecast to drop below freezing in some locations in El Paso and Kiowa Counties just after this period. If that colder air arrives just a bit sooner, some slick spots could develop in the aforementioned locations. Elsewhere, dry conditions are expected for the mountains and high valleys as the front will not affect those areas. Lows tonight should dip down to the 20s and 30s for most lower elevation locations. .LONG TERM...(Tuesday through Sunday) Issued at 416 AM MDT Mon Mar 16 2020 Tue morning it looks like there will be widespread low cloud cover across southeast CO, with area of fog and the potential for drizzle. There could even be some freezing drizzle over portions of El Paso County, depending on surface temps. The GFS shows the low cloud cover dissipating over all but some of the far southeast plains during the afternoon hours. The NAM show the low cloud cover dissipating in the afternoon over the southern I-25 corridor, but remaining over the far southeast plains, and from about northern Pueblo County and northward through El Paso County, with the potential for some light drizzle. Guidance forecast high temps are quite different, with the NAM being the coldest. Areas that keep the low cloud cover thru the day Tue should be on the cold side. The southern I-25 corridor (Walsenburg/Trinidad areas) will likely see the warmest temps in southeast CO on Tue, as these locations are expected to see southwest winds develop in the afternoon with the low clouds expected to clear out. The rest of the forecast area will be dry on Tue, with the exception of some showers moving across the central mtns in the afternoon. Temps in the high valleys, should be above average with mid 50s to around 60 in the San Luis Valley, and in the 50s in the Upper Arkansas River Valley. Tue night, there will be areas of low clouds over the southeast plains at least thru midnight, but then as westerly winds develop over the area, much of the low cloud cover will dissipate. Some showers are expected to move into the southwest mtns Tue night, but the rest of the area is expected to be dry. On Wed an upper low moves into southern NV, and the south to southwest flow aloft ahead of this system will bring increasing moisture to the area with increasing precip chances, especially over the mtns and high valleys. The upper trof moves over CO Wed night, with most of the precip confined to the mtns and high valleys, with a dry slot and breezy south to southwest winds over the southeast plains. There are still model differences as to where the upper low gets wrapped up on Thu. The NAM has the upper low centered over the far northeast corner of CO by 18Z Thu, the GFS shows it over the east central CO border, and the ECMWF shows it over eastern Adams and Morgan Counties in CO. They all move the low farther east thru the rest of the day, with gusty north winds behind it. Most of the precip thru the day Thu remains over the mtns and high valleys, and over the Palmer Divide, but in the afternoon, depending on how far south the upper system ends up, chances for precip may increase over the southeast plains, but the better chances should be mostly from about the Highway 50 corridor and northward. Snow amounts in the mtns along the Continental Divide Wed night through Thu will probably be enough to warrant some kind of winter weather highlight, but it is too early at this time to issue anything. Thu night a trailing upper low is forecast to be somewhere over the Great Basin, with chances for precip continuing over CO. Fri there is still some uncertainty as to what will happen with that upper system, but it looks like it will weaken, but there will still be some precip over the CO mtns. Model differences for the Sat and Sun time-frame are too great to have much confidence in the forecast, but it could be a bit unsettled for additional mtn snows. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 416 AM MDT Mon Mar 16 2020 t KALS, VFR conditions are expected over the next 24 hours, with winds reach 10-15 kts for a few hours this afternoon. At KCOS and KPUB, VFR conditions are expected to persist into tonight with breezy winds of 10-15 kts this afternoon. Then, low stratus and fog are anticipated to develop, reaching LIFR to VLIFR CIGs late in the period, with occasional drizzle or a passing shower possible. There is potential for the fog to become dense at KCOS late in the period as well. && .PUB WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 AM MDT this morning for COZ095-096. && $$ SHORT TERM...CARLBERG LONG TERM...28 AVIATION...CARLBERG