648 FXUS63 KGLD 101117 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 517 AM MDT Wed Oct 10 2018 .SHORT TERM...(Today through Friday night) Issued at 429 AM MDT Wed Oct 10 2018 Forecast concerns will be how cold it gets tonight, and chances of precipitation through the period. Satellite showing a highly amplified pattern from the Pacific into the western Atlantic. Slow moving trough currently is near the four corners region. Today/tonight...Am letting the current freeze warning and frost advisory continue but conditions are only marginal at this time. Not confident on the high temperature forecast. I do not think cloud cover is going to completely erode. A left front quadrant of the jet starts impacting my area late this morning into the afternoon hours. At the very least this should thicken up cloud cover. That combined with cold advection should keep temperatures from warming up too much. I did warm high temperatures but kept it below guidance. Jet axis moves across the area with the right rear quadrant affecting the northern portion of my area during the evening and early portion of the overnight hours. Also a rather strong and compact shortwave trough moves through the same area during the evening hours. There is a lot cold air aloft, a strong baroclinic zone and associated frontogenesis with this wave. Theta-e lapse are near/slightly above zero. Look to have a quick shot of light snow and/or flurries. For tonight, after that the clouds clear out as the surface ridge noses into the northeast two thirds of the area. There appears to be some cloud cover, probably some stratus as the day shift mentioned in my southern and western fringes. However vast majority of the area should have little cloud cover and little to no wind. Based on the above and collaboration, lowered the low temperatures into the mid and upper 20s across most of the area. As a result of the above and collaboration, I have issued a Hard Freeze Warning form my northern 3 tiers of counties. Since I am unsure about the cloud cover in my south, I have those six counties in a Hard Freeze Watch. Thursday/Thursday night...Freeze highlights continue through 16z. Will have a cold start to the day. Also cloud cover will increase at multiple levels through the day with light upslope winds in place. This is a recipe for not warming up much. So I lowered the high temperatures for most of the area. Rather strong shortwave trough starts affecting the western portion of the area later in the afternoon. The main affects of this shortwave trough and jet lift from a strong southern jet will be felt during the night. The high pops the forecast builder looks reasonable and kept or slightly adjusted up. Friday/Friday night...Above mentioned lift and precipitation affect the area during the morning. Dry conditions are expected in the afternoon. High temperatures for the day look fine at this time. However, am a little concerned that some low level cloud cover could make things cooler in the east. The next shortwave trough moves in during the later half of the night and affects the southern portion of the area. The pops the forecast builder gave me looks reasonable. .LONG TERM...(Saturday through Tuesday) Issued at 355 AM MDT Wed Oct 10 2018 The orientation of the jet stream over the weekend and into the middle of next week remains extremely meridional with upper-level winds diving southward out of Canada into the Plains states inviting with it unseasonably cold air. The flow reflects down into the mid- levels and is such that a deep longwave trough remains to our west, producing and ejecting multiple disturbances throughout the period with two well-defined cold frontal systems expected to pass...one Saturday evening into Sunday morning and another Tuesday evening into Wednesday morning. Coldest temperatures will occur on Sunday behind the stronger of the two cold fronts, with max temps topping out in the upper 30s across most of the region and subsequent low temperatures in the lower 20s. Temperatures were adjusted downward form the initial output of the Superblend considering the extend of the mid-level CAA with very tight packing of almost 10 degrees at 850 mb according to the GFS and winds out of the due north averaging 30 kt as the front passes over NW Kansas. Moisture is also quite extensive, thus leading to steady snow showers over almost an entire 24 hour period. Current snowfall amounts for Sunday are estimated to be somewhere in the neighborhood of half of an inch to an inch. Subsequent model runs will provide a better prediction of the finer details related to this front such as timing, placement with reference to timing, duration and severity of snow showers as well as more accurate temperature fluctuations. The ECMWF also displays a roughly 10 degree temperature differential at 850 mb behind the front and is several degrees colder than the GFS. The ECMWF is considerably more moist also and was the model of choice among neighboring offices during collaboration discussions. The second frontal passage expected to occur Tuesday night into Wednesday morning is considerably weaker with a much less-defined thermal gradient, thus not much of an impact on temperatures is expected to occur behind that front. Most precipitation chances associated with this front will remain confined to the eastern sector and generally below 40%. With respect to the other elements of this forecast period, no significant precipitation is expected aside front the rainshowers which give way to snow showers as the front progresses southeastward across the area on Sunday as well as the 40% chances for Wednesday in the eastern sector. Temperatures remain fairly steady with the exception of Sunday. Max temps in the mid-to-upper 50s are expected for all other days with a gradual warming trend from Monday through Wednesday. Hopefully as the jet pattern shifts downstream and brings a longwave ridge into the area, we will see temps rise again and break out of the 50s and possibly into the upper 60s by Friday of next week. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 512 AM MDT Wed Oct 10 2018 For Kgld, until 17z mvfr conditions and northwest winds near 13 knots are expected. From 17z to the end of the period, vfr conditions are expected. From 17z to 04z, north winds of 12 knots will prevail. At 04z, northwest winds of 6 knots will be in place and then become light and variable around 09z. For Kmck, until 17z mvfr conditions and northwest winds near 15 knots are expected. At 17z, vfr conditions return for the rest of the period. From 17z to 02z, northwest winds will start out near 13 knots and decrease to 7 knots around 02z. At 05z those northwest winds become light and variable. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Hard Freeze Warning from 11 PM MDT /midnight CDT/ this evening to 10 AM MDT /11 AM CDT/ Thursday for KSZ001>004-013>016. Freeze Warning until 10 AM MDT /11 AM CDT/ this morning for KSZ001-002-013-014-027-028-041-042. Frost Advisory until 11 AM CDT this morning for KSZ003-004-015- 016-029. Hard Freeze Watch from this evening through Thursday morning for KSZ027>029-041-042. CO...Hard Freeze Warning from 11 PM this evening to 10 AM MDT Thursday for COZ090-091. Freeze Warning until 10 AM MDT this morning for COZ090>092. Hard Freeze Watch from this evening through Thursday morning for COZ092. NE...Hard Freeze Warning from 11 PM MDT /midnight CDT/ this evening to 10 AM MDT /11 AM CDT/ Thursday for NEZ079>081. Freeze Warning until 10 AM MDT /11 AM CDT/ this morning for NEZ079-080. Frost Advisory until 11 AM CDT this morning for NEZ081. && $$ SHORT TERM...BULLER LONG TERM...SANDERSON AVIATION...BULLER