FOUS11 KWBC 050849

QPFHSD



Probabilistic Heavy Snow and Icing Discussion

NWS Weather Prediction Center College Park MD

449 AM EDT Tue May 5 2026



Valid 12Z Tue May 05 2026 - 12Z Fri May 08 2026



...Central/Southern Rockies and Adjacent High Plains... 

Days 1-2...



Confidence continues to increase for impactful snow through the

Denver Metro in addition to CO Rockies.



A post-frontal low level convergence zone near the WY/CO border 

merely drifts south through tonight before picking up some 

southward speed Wednesday with the passage of a southern stream 

shortwave trough currently over SoCal and a northern stream 

reinforcing trough. A tight baroclinic zone through this low-level

boundary shifts south over CO and banks on the lee-side of the 

Front Range today. This brings snow down to the I-25 corridor 

tonight. Precip intensity increases today as left exit dynamics 

strengthen from a SWly jet over NM to the central Plains and 

upslope easterly flow becomes more pronounced as high pressure 

builds down the Plains in the wake of the cold front.



Snow levels reach 6000ft late this afternoon from the Palmer 

Divide and north before dropping below a mile high during the 

evening hours. Moderate precip rates occur late tonight through 

Wednesday morning from Denver through the Front Range with quick

bursts of wet snow. The focus for the snow will shift to the 

Sangre De Cristo and San Juans Wednesday afternoon as snowfall 

rates gradually diminish north of the Palmer Divide. Snow rates

quickly drop off Wednesday evening as the northern stream shortwave

trough pushes onto the central Plains.



Day 1 snow probs for additional >6" are 50-80% for the Wind River, 

Bighorns, Laramie, and Medicine Bow Mtns in WY. Day 1.5 snow probs

for >6" are 40-70% from Cheyenne down I-25 through the greater

Denver metro and on the Palmer Divide. Meanwhile, probs for >12"

are >80% for the Front Range and Park Range. Day 2 snow probs for

>6" are 50-80% for the Sangre de Cristos/San Juans and 40-70% for 

the Raton Mesa.



This winter storm will produce much needed precip in the drought- 

stricken Central Rockies and High Plains. However, unlike last 

week's event which had less snowfall and was confined to the higher

elevations, this event is more significant and will have notable

impacts. The latest WSSI highlights widespread Moderate Impacts 

for the I-25 corridor from Cheyenne through Denver and the Palmer 

Divide and Major Impacts for the Front Range including Rocky 

Mountain NP. The heavy/wet nature of the snow on trees fully 

leafed out/in bloom and on power lines could result in tree damage 

and power outages.





The probability for significant icing over one-tenth of an inch is

less than 10 percent across the CONUS. 





Jackson







$$