Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, 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
342 FXUS65 KPUB 281034 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 434 AM MDT Tue May 28 2024 .KEY MESSAGES... - Strong to severe storms are possible (40-60% chance) for today, especially for our southeastern plains. - Daily thunderstorm chances (40-60% chance) will continue across the southeast mountains/plains through the week, with strong to severe storms possible along and east of I-25. - Slow drying and warming trend starts late weekend into early next week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 322 AM MDT Tue May 28 2024 Currently.. Satellite imagery depicts troughing over the northeastern and northwestern conus, with broad ridging overhead. Temperatures are still in the 40s and 50s across the plains as of 3am this morning, with dew points in the 30s and 40s. Other than a bit of lingering mid-level cloud cover on our far eastern plains, sky conditions are mostly clear. Light northerly winds are in place over the I-25 corridor. Today and Tonight.. High res models bring a bout of shortwave energy and easterly surface winds through the area this afternoon, which will help to bring in additional moisture and instability. Our mountains will see weak general thunderstorms develop by around noon, with main risks for the high country today being gusty winds and lighting. Forecast soundings across our far eastern and southern plains however, show anywhere from 2500 to 3000 J/kg of CAPE this afternoon, especially for eastern Las Animas and Baca counties. These areas are also looking at 35 to 45kt of 0 to 6km bulk shear, and are outlooked as Slight Risk for damaging winds and hail for this afternoon as well. CAMs show the potential for to severe storms over Kiowa, Bent, and Prowers counties also, and the SPC has included much of the plains in their marginal outlook, though it does look like the western extent of moisture and instability will be limited at least somewhat this afternoon. Most high res model guidance develops storms over the southern plains by around 1pm this afternoon. These storms look to become strong to severe as they push through eastern Las Animas and Baca county after 3pm this afternoon, where main threats will be large hail up to 2 inches and winds gusting to 60 mph. Another round of storms looks to develop over the Pikes Peak region after 2pm. Chances for storms becoming severe over El Paso and Pueblo County today are low due less instability and less moisture further west this afternoon, but as storms push eastward into Kiowa, Bent, and Prowers counties, some storms may become strong to severe later this afternoon and this evening, with main threats being large hail up to 2 inches and 60 mph winds. Daytime highs today will be near to just slightly above normal, with most of our plains warming into the mid 80s, 70s for mountain valleys and El Paso County, and 50s and 60s for higher terrain locations. Storms look to weaken and push into Kansas by around 10 or 11pm at the latest this evening, with mild temperatures and continued moist southeasterly flow persisting through the overnight hours into Wednesday morning. Continued southeasterly winds and potential moist outflows will help to set the stage for potentially more available moisture and a possible higher risk for strong to severe storms on Wednesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 322 AM MDT Tue May 28 2024 Low amplitude upper ridge will slide east into the plains on Wed, as moderate w-sw flow aloft continues. At the surface, expect Tue evening/overnight convection to our southeast to send some sort of outflow westward across the plains, potentially pushing deeper low level moisture all the way west to I-25 by Wed morning. It may then take much of the day for instability to build over the plains given rather cool/stable air mass initially in place, but by late afternoon/early evening, most models show CAPE of 1000-2000 J/KG over the plains east of I-25. Model scenarios point to late (around 00z) convection firing near the Palmer Divide and Raton Mesa, with strong storms then pushing eastward toward the KS border in the evening. Main negative factors for Wed convection include lack of a strong s/w trigger (best upper energy ejects fairly far to the north) and rather weak 0-6km shear values (around 30 kts) due to pronounced weakness in the wind field from the surface through about 3km AGL. SWODY2 has most of the plains in a marginal severe risk, with the southern end of the slight into Kiowa County, which looks reasonable as stronger forcing is to the north. Farther west over the mountains and interior valleys, surface air mass is rather dry, with any convection likely staying high based and weak. Thursday is setting up to potentially be a rather active convective day across the plains, though numerous hard to time mesoscale details will play a major role in storm formation/evolution. Fairly strong upper wave will move through the state in the afternoon, providing enhanced upward motion to all of srn Colorado in the afternoon/evening. Surface pattern is rather messy on the plains early in the day, with outflow enhanced cold front (and accompanying north winds) dropping south through the plains in the morning, following by increasing easterly surface winds and westward moisture advection in the afternoon as surface low pressure spins up over nern NM. Progged CAPE over the plains approaches 3000 J/KG over the far east, with values in the 1000-2000 J/KG range all the way west to I-25. Again, 0-6km shear isn`t particularly strong (30-35 kts), but if forecast deep instability develops, shear/instability combo will likely be sufficient for widespread severe storms, potentially all the way back to the I-25 corridor. Set-up again looks like convection forms over the higher terrain mid-afternoon, then strengthens late afternoon/evening as it encounters deeper instability on the plains. Main negative factor for storms would be if post-frontal air mass ends up cooler/more stable than currently forecast due to potential large cold pool from Wed night convection to our north, but tough to forecast that at this time range (48+ hours out). SWODY3 reflects the increased chance of severe storms Thu, with slight risk covering almost all of the plains from I-25 eastward. Would lean toward strong/damaging winds being the greatest risk Thu, though CAPE may be large enough to overcome weak shear and thus storms could produce large hail as well. Mountains and interior valleys may see an uptick in convective coverage Thu afternoon/evening with better forcing, but low level moisture remains lacking, so widespread wetting rains look unlikely. Thunderstorm pattern remains in place Fri on the plains, with moderate wly flow aloft and residual low level moisture lingering, though convective outflows from Thu night convection will play a major role in the evolution of the surface air mass and resultant instability. Forecast at this point has scattered pops for much of the area, which looks fine for now. Trend toward drier weather then develops over the weekend into early next week, as upper flow turns slightly more swly and increases by Sunday, drawing some drier air into the region, especially Sun/Mon. Temps for the Wed-Fri period will end up roughly near to slightly above seasonal averages, before warmer weather arrives over the weekend into early next week. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 322 AM MDT Tue May 28 2024 VFR conditions are expected at all three TAF sites, KCOS, KPUB, and KALS for the next 24 hours. A few showers/thunderstorms may be possible across the San Luis Valley near KALS this afternoon, which could produce gusty winds if they pass near the terminal. Better potential for showers/thunderstorms at KCOS from mid afternoon into this evening. Gusty winds could accompany any storms that move across KCOS. CIGS look to lower at KCOS behind a frontal boundary by late evening. KPUB looks to remain dry, with CIGS lowering late this evening. && .PUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...EHR LONG TERM...PETERSEN AVIATION...EHR