Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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546 FXUS65 KBOU 280313 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 913 PM MDT Mon May 27 2024 .KEY MESSAGES... - Mostly dry tonight, with just the slightest chance of a shower or storm. - Warm through the week. - Limited late day storm coverage Tuesday, then higher coverage of showers and thunderstorms Wednesday, and potentially into Thursday and Friday. A few severe storms are possible on the plains with the highest threat on Wednesday. && .UPDATE... Issued at 907 PM MDT Mon May 27 2024 A few showers have developed along a broad axis stretching from KDEN to Burlington/Goodland this evening. Most of these aren`t producing measurable precipitation but there have been a few weak downbursts noted off TDEN velocity data. These showers will likely continue for another hour or two with activity diminishing overnight. One last wildcard is an outflow boundary dropping in from southeastern Weld county... but there`s only so much instability/moisture to work with at this point. Elsewhere, it`s a quiet and mild evening with scattered cloud cover. The overnight hours will generally remain quiet across the region. Only notable change this evening was to add PoPs in the aforementioned corridor where showers are ongoing. Otherwise the grids were in good shape. && .SHORT TERM /Through Tuesday/... Issued at 158 PM MDT Mon May 27 2024 Satellite shows some shallow cumulus developing. ACARS show a weakening cap, but little if any MLCAPE is available (less than 200 J/kg). Thus, even if we do reach convective temp, don`t think there`d be much more than virga around at this point. And most of that would be over the Palmer Divide area south of Denver, and the WY/NE border area where water vapor shows a little more moisture availability. For Tuesday, moisture values improve a little further with precipitable water (PW) values coming up another 0.1 (mountains) to 0.2 inch (plains). MLCAPE will also increase, with a few hundred J/kg over the eastern plains. That said, it will take some heating to break the cap, but that should be able to occur by late afternoon across portions of the I-25 Corridor and Palmer Divide area. We don`t think any of these storms would have much if any severe potential given relatively limited instability, but a couple stronger ones late in the day could produce small hail, gusty winds, and brief moderate rainfall. High temperatures will be near readings seen today - about 2-4 degrees above normal. && .LONG TERM /Tuesday night through Monday/... Issued at 158 PM MDT Mon May 27 2024 Not too many changes to the long-term forecast. An active early summer pattern begins Wednesday through Friday with diurnal showers and storms across the Front Range. An upper level trough will push north of our area near the US/Canada border, thus clipping the CWA and increasing mid-level moisture along the foothills and plains Wednesday. Daytime heating and weak instability will likely lead to scattered thunderstorm and shower development Wednesday afternoon. Low level southeasterly winds increase between 20-30kts Wednesday afternoon east of the I-25 corridor. This combined with higher MLCAPE values near 800-1200 J/kg will likely lead to a greater chance of severe storms for the eastern plains through late Wednesday evening especially below I-70 east. These storms could produce hail, wind gusts up to 60 mph and brief heavy rainfall. Coverage for showers and storms decreases Thursday due to moisture exiting the region through northwest flow as an additional shortwave trough is favored to develop southeast of northeastern Colorado. Isolated to scattered chances (10-30%) exist mainly for the foothills and plains through Thursday afternoon. Also, a cold front develops along the Front Range foothills extending into the plains Thursday. There is still some uncertainty in timing of the front but with the potential for the front arriving late Thursday morning, thunderstorm development may become limited. Still, there is higher confidence in weak isolated showers versus thunderstorms Thursday afternoon. Friday, there is lower confidence in precipitation chances along the Front Range as models differ in mid-level moisture back building from the potential shortwave trough southeast. Knowing this pattern is usually not favorable, decided to lower NBM PoPs but still keep isolated to scattered chances. Zonal flow occurs Saturday and diurnal chances of storms and showers should come as no surprise once more favoring the mountains and foothills then decreasing in coverage along the plains. Warmer and drier conditions are expected Sunday through early next week. Above normal temperatures are likely across the entire CWA. This pattern may lead to elevated fire weather conditions depending on fuel status. && .AVIATION /00Z TAFS through 00Z Tuesday/... Issued at 528 PM MDT Mon May 27 2024 VFR through the TAF period. Expect a gradual turn from the current light easterly flow to drainage through 06z. Winds again will turn clockwise through tomorrow morning/early afternoon and eventually settle on an east or northeast direction. Can`t rule out a shower or storm south of APA tomorrow afternoon but not enough confidence in that to include in the TAF. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hiris SHORT TERM...Barjenbruch LONG TERM...AD AVIATION...Hiris