039 FXUS63 KGLD 092341 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 541 PM MDT Tue Oct 9 2018 .UPDATE... Issued at 500 PM MDT Tue Oct 9 2018 Main change to the forecast was to increase precipitation chances in the west under the band of snow and reduce them in the east where lift is lacking. Frontogenesis in the 700-500mb layer over East Central Colorado seems to be responsible for the band of snow there. Am expecting the frontogenesis to shift northeast somewhat quickly over the next few hours, taking the band of snow with it. Snowfall will be highest over East Central Colorado where the snow band has lingered the longest. May see amounts approach 3 inches on elevated or grassy surfaces. So far none has accumulated on the highways. The frontogenesis will exit the forecast area before midnight, bringing the snow to and end by or not long after midnight. Meanwhile the small area of higher reflectivity over the now central part of the forecast area may maintain its intensity due to it riding the gradient of lower stability as it moves north. && .SHORT TERM...(This evening through Wednesday) Issued at 307 PM MDT Tue Oct 9 2018 Inverted trough will lift to the northeast and move out of our area overnight tonight. This will allow us to clear out and help our temperatures to drop even further. Issued a Freeze Warning tonight as a result for counties along and west of Highway 25. For all counties east of Highway 25, issued a Frost Advisory. Confidence on the Freeze Warning is high, while the confidence of the Frost Advisory is medium. Depending on cloud cover tonight, and gusty northwest winds it may prevent widespread frost from developing. Dryer conditions expected on Wednesday, and with clearing skies and reduced winds, confident we will drop further and have to issue additional frost/freeze headlines. Prevented doing so this forecast period to prevent confusion. .LONG TERM...(Thursday through Tuesday) Issued at 120 PM MDT Tue Oct 9 2018 Thursday...southeast surface winds return during the day and with it the likelihood of extensive low cloudiness...best chance across the western 1/2 of the area. Models have backed off on precipitation but I couldnt totally rule out a few flurries early in the morning and some sprinkles a little later as temperatures warm above freezing. High temperatures will be challenging and certainly subject to change, especially across the western 1/2 of the area where low clouds may prevent much in the way of warming. Have tweaked highs down a degree or two across the west with upper 30s to low 40s while across the east we should see mid 40s to perhaps 50 degrees. For the overnight hours an upper level trough with plenty of low and mid level moisture moves across the area. The left front quad of a 120+kt upper jet moves in from the southwest for much of the night aiding in lift and looks to support the rather high precipitation chances. With low temperatures currently forecast to drop into the 33 to 38 degree range precipitation type should be mainly rain. 850mb temperatures are also a few degrees above zero so that should help prevent any changeover despite the surface temperatures. Friday...predominately liquid precipitation in the morning quickly ends by noon as Thursdays system quickly moves east-southeast. Clouds will also decrease slowly from west to east. Afternoon temperatures look to warm into the low to mid 50s. Nudged highs up a few degrees across the western 1/2 of the area where more sunshine expected and blend of better performing bias corrected grids match 850mb temperatures. For the overnight hours models are pretty excited about a weather disturbance moving in from the south- southwest after midnight with moisture generally below 700mb. With low temperatures currently forecast to be in the mid 30s to low 40s primary precipitation type will be light rain showers. Saturday...Friday nights weather disturbance continues to move northeast through the morning and afternoon with best chance of precipitation across the far northeast through southern parts of the area. Surface and 850mb temperatures are plenty warm so rain will be the precipitation type. High temperatures generally in the mid to upper 50s. For Saturday night a cold front moves through with breezy north winds. Low temperatures fall into the mid 20s west and low 30s east. A strong weather disturbance with good moisture in the 850- 500mb layer moves through from the northwest bringing a good chance of rain quickly changing over to snow after midnight. Light snow accumulations are currently expected generally along and west of the CO/KS border. Sunday...snow is expected for the entire area in the morning with a changeover to rain in the afternoon as current models show surface temperatures warming above freezing. I do have some concern with this given GFS/ECMWF 850mb temperatures a few degrees above zero in the afternoon and model forecasts of cloud cover and precipitation ongoing. If this verifies the change over to rain may take longer. Additional light snowfall accumulations are expected. For Sunday night models are currently in good agreement pushing precipitation out of the area shortly after sunset with dry conditions after midnight. Low temperatures look to reach the low to mid 20s which would produce a hard freeze across the entire area. Monday...we should see lots of sunshine with afternoon temperatures in the upper 40s to low 50s. Some mid and/or high clouds are possible during the night approaching from the north. Low temperatures in the upper 20s to low 30s. Tuesday... dry weather is expected with a sunny to mostly sunny sky. 850mb temperatures warm a few degrees supporting highs in the mid to upper 50s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 537 PM MDT Tue Oct 9 2018 VFR to IFR conditions forecast for the TAFs. Currently expecting the precipitation to generally shift to the northeast through the evening. Visibility at KGLD may fall some as short bursts of heavier snow move through. Overall conditions should not improve to MVFR until the overnight hours behind the exiting precipitation. Based on the trend of IFR and MVFR conditions the past couple nights, confidence is moderate regarding the TAF for tonight. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Freeze Warning from midnight MDT /1 AM CDT/ tonight to 10 AM MDT /11 AM CDT/ Wednesday for KSZ001-002-013-014-027-028-041- 042. Frost Advisory from 1 AM to 11 AM CDT Wednesday for KSZ003-004- 015-016-029. CO...Freeze Warning from midnight tonight to 10 AM MDT Wednesday for COZ090>092. NE...Freeze Warning from midnight MDT /1 AM CDT/ tonight to 10 AM MDT /11 AM CDT/ Wednesday for NEZ079-080. Frost Advisory from 1 AM to 11 AM CDT Wednesday for NEZ081. && $$ UPDATE...JTL SHORT TERM...EV LONG TERM...99 AVIATION...JTL