335 FXUS65 KBOU 220941 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 341 AM MDT Fri May 22 2020 .SHORT TERM...(Today and tonight) Issued at 340 AM MDT Fri May 22 2020 Light winds and residual low level moisture behind last night's convection to the south and east has allowed patchy fog to develop across the plains. Most of this is along and east of a Fort Morgan to Limon line. That will dissipate with daytime heating and light downslope flow just off the deck. Temperatures will warm today with upper level ridging and southwest flow aloft becoming more pronounced. Mid level warm advection will occur, and plenty of sunshine will boost high temperatures into the lower 80s across the plains and into the 60s to lower 70s mountains and high valleys. Mostly dry conditions will persist, but with steep mid level lapse rates and low to mid level moisture advection from the southeast into the evening, can't rule out isolated high based showers and storms. That threat would not start until late in the afternoon or evening. Only light rain/sprinkles and a couple lightning strikes will be possible. Otherwise, mild temperatures will prevail overnight under partly cloudy skies. .LONG TERM...(Saturday through Thursday) Issued at 340 AM MDT Fri May 22 2020 SW flow aloft will increase, on Sat, as an upper level low moves into wrn Wyoming. At the sfc, low pres will intensify over ern CO with a dryline located over the far ern plains. Steep lapse rates combined with just enough moisture may lead to a chc of high based showers and a few storms over the higher terrain in the aftn. Across the plains, MLCAPE will be in the 1500-2000 j/kg range over the far northeast plains near the dryline. At this time, it appears best chc for stg storms will be along and east of a Sterling to Akron line. As for highs, readings will be mainly in the lower to mid 80s over nern CO. Looking ahead to Sun, the upper level low over wrn Wyoming will move northeast as a 2nd piece of energy digs southeast into Colorado. Meanwhile, a cold front will move across the area Sat night into Sun morning, with another stronger surge, late Sun aftn into Sun evening. The combination of the upper level trough moving across Sun aftn into Sun night along with increasing upslope flow behind the 2nd surge, late in the day, should allow for widespread showers and tstms across the area. Temps will be cold enough for snow in the mtns Sun aftn thru Sun night with several inches of wet snow above 10000 feet. As for highs, readings will drop into the 60s over nern CO. On Mon, the upper level trough will move slowly southeast with a gradual decrease in moisture by aftn. However, will still see a good chc of showers especially in the morning across the plains and higher terrain. Highs on Mon will remain in the 60s over nern CO. For Tue into Wed, an elongated upper level trough will extend from the srn plains into Texas with a flat upper level ridge over nrn CO. This will lead to mainly dry conditions with a warming trend. && .AVIATION...(For the 12Z TAFS through 12Z Saturday morning) Issued at 340 AM MDT Fri May 22 2020 VFR conditions will persist through most of the period. There is just a slight risk of a high based shower/storm after 23Z producing variable wind gusts up to 30 knots. That risk should be over by 05Z. We will have to watch return of low level moisture and potential for stratus/fog development toward 12Z Saturday with the development of a Denver Cyclone. Models show most of this staying just north and east of KDEN. Winds will become southeast and gust up to 20-25 knots 20Z-03Z. Otherwise fairly normal wind patterns will persist. && .FIRE WEATHER... Issued at 340 AM MDT Fri May 22 2020 South/southwest winds will increase across the Palmer Divide and South Park. Wind speeds should stay just below criteria. Fire danger will increase on Saturday over South Park and Palmer Divide due to increasing south to southwest winds and low humidity levels. && .BOU WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday afternoon through Saturday evening for COZ214-241-246-247. && $$ SHORT TERM...Barjenbruch LONG TERM...RPK AVIATION...Barjenbruch FIRE WEATHER...RPK