185 FXUS65 KBOU 181134 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 534 AM MDT Mon Jul 18 2022 .SHORT TERM...(Today and tonight) Issued at 318 AM MDT Mon Jul 18 2022 The main story today will be the heat and record setting high temperatures expected across eastern Colorado. Today will be the hottest day of the week as thermal ridge shifts over Colorado with 700mb temperatures climbing between 20c-21c. This a 2 degree C increase over yesterday which will equate to about 3-5 degrees warming from Sunday's readings. The Denver record today is 99 degrees and this expected to be broken with highs at Denver around 101. A heat advisory has already been issued for much of Northeast Colorado from later this morning through the evening. The only fly in the ointment is impact of increasing cloud cover this afternoon, where clouds could impact temperatures a few degrees pending on cloud arrival. Water vapor showing moisture already on the upswing over western Colorado with ongoing showers and a few storms across southwest Colorado and eastern Utah. The upper high will be sliding southward into Northern New Mexico later today in response upper trof moving across the northern Rockies and northern high plains. The mid level flow will in turn be shifting more westerly and increasing this afternoon. This increase in moisture will result in an increasing chance of showers and thunderstorms over the mountains and higher terrain this afternoon. Precipitable water values will be increasing to close to an inch over the Front Range and plains with .7 to .9 over the mountains. Forecast soundings becoming inverted-v profile with mainly mid level moisture above 500mb and dry low levels. Impacts will be mainly gusty winds with the showers across the plains with DCAPE values close to 1500j/kg. There may be enough flow to steer isolated showers across much of the plains towards the evening hours and will carry at least isolated pops across lower elevations. .LONG TERM...(Tuesday through Sunday) Issued at 318 AM MDT Mon Jul 18 2022 A strong shortwave trough will move from Montana towards Minnesota on Tuesday which will push the ridge over the Four Corners region to the south a little bit. At the surface, a cold front will move across our forecast during the morning. It doesn't feel right calling this feature a cold front because there's not much "cold" associated with it. This front will have moderate northwesterly winds behind it with drier air. Even though high temperatures will be cooler than Monday as a result of this front, the morning could be very warm in a relative sense. Warm temperatures aloft could mix down quickly with the moderate boundary layer winds and Denver could reach 90 shortly after 9 AM. With cooler 700 mb temperatures behind the front, temperatures may not increase very much during the afternoon but highs will still be in the mid to upper 90s across the plains. Other than the warm temperatures, there will be two weather concerns on Tuesday. One will be fire weather as the increased winds along with dry conditions behind the front will lead to elevated to near critical conditions across the plains to the north and east of DIA. The other concern will be gusty winds from showers and storms that form mainly over the higher terrain to the south of I-70 and along the Palmer Ridge. Some gusts could reach 55 mph in the stronger storms due to steep low level lapse rates. The threat for burn area flash flooding looks quite low as areas to the north of I-70 will be rather stable which will limit storm activity. 700 mb temperatures will decrease slightly on Wednesday as a surface high pressure center moves from the panhandle of Nebraska towards Kansas. Light easterly, upslope winds will develop across the plains but the moisture return will be low. The best low level convergence will setup over the Palmer Divide and southern foothills which will lead to the best storm coverage in that area. The plains to the north and east of Denver will again be rather stable and showers and storms will be very minimal there. Wednesday will be one of the cooler days of the week but that's not saying much. Highs will still be in the low to mid 90s across the plains. The upper level ridge will shift slightly eastward on Thursday with low to mid level temperatures increasing slightly. Highs will warm a couple degrees as a result and shower and storm activity will be mostly confined to the higher terrain. Friday looks to be another very hot day with a chance of Denver reaching 100 degrees again. The upper level ridge will move more directly overhead and compressional warming will increase ahead of a trough over the Pacific Northwest. 700 mb temperatures will likely reach 20 C and if conditions end up being sunnier than currently expected, the record high of 102 in Denver could be within reach. However, there is just enough mid level moisture that moves over our forecast area that showers and storms will limit the heating a bit in the afternoon. These storms could produce very gusty winds due to inverted-V soundings. Saturday is the day where forecast guidance really starts to diverge. Some models have a cold front pushing through the plains with more storm activity and cooler temperatures. Other models have Sunday being the hottest day of the week with temperatures well into the 100s across the plains as compressional heating ahead of a shortwave trough increases. It's too early to have much confidence in either solution so the NBM forecast was left mostly unchanged. There's a better chance that Sunday will be cooler with a cold front having moved through the area at some point Saturday or Sunday morning. Ensembles are hinting that a healthy wave of monsoonal moisture may arrive during this period which could lead to burn area flash flooding. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 526 AM MDT Mon Jul 18 2022 Southerly winds will decrease and shift a bit more southwest to west through the mid morning hours then becoming west to northwest by late morning. Increasing moisture will lead to isolated high based showers from 21z-01z with main impacts of gusty winds up to 35kt. && .FIRE WEATHER... Issued at 318 AM MDT Mon Jul 18 2022 Elevated fire danger across the plains this afternoon with hot temperatures, low humidities in the 12-17 percent range and breezy conditions. Wind speeds with areal extent and strength are marginal for red flag conditions so no warnings will be issued. Tuesday through Saturday will have minimum relative humidities in the low teens due to the hot and dry conditions. The only day where the winds will be strong enough to increase the fire danger will be Tuesday. Winds could gust up to 30 mph behind a cold front across the plains to the north and east of DIA. This will lead to elevated to possibly critical fire weather conditions. We will attempt to get updated fuel moisture data during the day today to see if the fuels would meet the red flag criteria. A Red Flag Warning is possible on Tuesday. && .HYDROLOGY... Issued at 318 AM MDT Mon Jul 18 2022 There will be an increase in moisture over the mountains today with a resultant limited risk for flash flooding over the burn scars. Storm motions will be quick enough to keep flood risk more marginal. Conditions will be rather stable and dry on Tuesday so the burn area flash flood threat is very low. A storm or two can't be completely ruled out over the burn areas so the threat is still limited. The chance for flash flooding increases a tad on Wednesday as storm coverage increases slightly. The slow moving nature of the storms could pose a threat that day. The flash flood threat will be low Thursday and Friday but not zero as drier and warmer air moves in. A healthy amount of monsoonal moisture may arrive by late this weekend into the following work week which could increase the risk of flash flooding. && .BOU WATCHES/WARNINGS/ADVISORIES... Heat Advisory from 10 AM this morning to 9 PM MDT this evening for COZ038>040-042>051. && $$ SHORT TERM...Entrekin LONG TERM...Danielson AVIATION...Entrekin FIRE WEATHER...Entrekin/Danielson HYDROLOGY...Entrekin/Danielson