Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
040 FXUS65 KBOU 081033 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 433 AM MDT Mon Jul 8 2024 .KEY MESSAGES... - Drier starting today with a prolonged warming trend kicking off. - A heat wave is expected to bring temperatures into the triple digits across the urban corridor and plains Friday through Sunday. Heat related highlights will likely be needed during this stretch. && .SHORT TERM /Through tonight/... Issued at 430 AM MDT Mon Jul 8 2024 Drier and more stable air is moving into the area from the northwest. With the drying and a little warming aloft, most of the area should be capped or have such weak instability that we`ll only have a few cumulus clouds. With a little more moisture lingering over the central mountains, there`s still a chance of a few weak showers or storms over the mountains around Park county in the late afternoon and evening. We`ve further backed off the PoPs and cloud cover, but left a little in that area. Forecast temperatures near or a little above guidance look good. && .LONG TERM /Tuesday through Sunday/... Issued at 430 AM MDT Mon Jul 8 2024 Northwesterly flow aloft will continue to be over Colorado on Tuesday. There will be a subtle shortwave within this flow which may provide very weak QG ascent over our forecast area. At the surface, there will be light northerly flow and the majority of the moisture that has been in our area for a couple days will be pushed out. Dew points will be in the 30s which will limit shower and storm activity to the mountains and foothills. The plains will be dry as high temperatures return to normal. 500 mb heights will rise on Wednesday as northwest winds persist. Temperatures will warm to the low 90s across the plains as there will continue to be limited moisture. A few isolated showers and storms may form over the mountains and foothills but the lack of instability across the plains will keep conditions dry there. The dreaded summer heat wave will then be upon Thursday through Sunday. A 500 mb ridge that is currently over California creating all-time record high temperatures in spots will move over Utah on Thursday. High temperatures will reach the mid to upper 90s across the plains with plenty of sunshine. By Friday through Sunday, the ridge will be directly situated over Colorado. Some global models have 500 mb heights reaching above 600 dm in western Colorado. The ECMWF ensembles have a mean 500 mb height of 5980 m on Sunday over KDEN which equals the daily max on the SPC sounding climatology page. The subsident flow under this ridge will keep conditions dry and mostly sunny and 700 mb temperatures will increase to around 22-23 C across the I-25 corridor. Those 700 mb temperatures would equate to surface temperatures of around 100 F. Given low to mid level winds will be from the north across the plains, any convective cloud development will likely stay focused on the higher terrain. This means sunshine will be maximized on the plains. At the same time, the northerly winds are not adding a downslope component to the flow and that aspect of the forecast may end up keeping Denver from hitting the all-time record high of 105. Nonetheless, highs in the 100s are expected across the urban corridor and plains Friday through Sunday. It was hard to argue with the NBM high temperatures that were loaded into the forecast grids so they were left as is. The high temperature forecast for Denver is 101 on Friday and 100 on Saturday and Sunday. Interestingly, all three of those values are the record highs for the date. Ensemble forecasts show that a high of 103 or 104 is well within reason in Denver. In fact, if temperatures made a run on Sunday at the all-time high temperature of 105, it wouldn`t surprise me. Regardless of the exact temperatures, this period will have the potential to create significant health impacts if the proper precautions are not taken. Staying hydrated and avoiding strenuous activities during the middle of the day will be important for individuals that will be outside. To our partners in the emergency management field, now is the time to start making preparations for opening cooling shelters. Heat related highlights will likely be needed for the high population areas Friday through Sunday. && .AVIATION /12Z TAFS through 12Z Tuesday/... Issued at 430 AM MDT Mon Jul 8 2024 VFR through tonight. Light southwest winds will become easterly by 18z, then back to southwest by 06z. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Gimmestad LONG TERM...Danielson AVIATION...Gimmestad