188 FXUS01 KWBC 211855 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 252 PM EDT Tue Apr 21 2026 Valid 00Z Wed Apr 22 2026 - 00Z Fri Apr 24 2026 ...Pacific system will bring lower elevation rain and mountain snows to much of the West through Thursday... ...Gusty winds and warm, very dry conditions will lead to a Critical Risk of fire weather along much of the High Plains Wednesday... ...Severe weather threats increase Thursday for much of the Plains... A deep upper-low and associated surface frontal system will continue to progress eastward over the western U.S. this evening bringing shower and thunderstorm chances across most of the West Coast and into portions of the Great Basin. The heaviest rainfall is expected along the coastal ranges of northern/central California and upslope regions of the Sierra Nevada, where some isolated flooding will be possible. A period of very heavy snow will also be possible for the higher elevations of the Sierra today where totals of 1-2'+ can be expected. Other ranges of northern California, the Cascades, and into the Great Basin may also see some snow but totals should initially remain light. The precipitation focus will shift northward on Wednesday, continuing for the Pacific Northwest and northern Great Basin while expanding into the northern Rockies. Lower elevations will see rain while snow will continue for regional ranges of the Great Basin and spread into higher elevations of the northern Rockies, where locally heavy snow is expected to continue into Thursday as well. Some of the higher valleys in the northern Rockies may begin to see some snow mix in by Wednesday night, though little to no accumulations are expected. As this system emerges into the West and the Plains on Wednesday, a deepening lee low/trough east of the Rockies will bring increasingly gusty winds along the High Plains Wednesday. These downsloping winds will lead to warm, very dry conditions and have prompted a broad Critical Risk of fire weather (level 2/3) from the Storm Prediction Center. The main cold front pushes into the Plains by Thursday, with an increasing risk for severe weather along and ahead of the boundary, with the Storm Prediction Center highlighting a slight risk (level 2/5) for severe thunderstorms from parts of the Central Plains to the Upper Mississippi Valley. Locally heavy rainfall is likely associated with storms as well, but the system should be progressive enough to limit any widespread flash flooding threat. Elsewhere, a frontal system will bring some scattered shower chances from the Great Lakes/Ohio Valley east into the Northeast over the next couple of days. A progressive upper-level pattern will lead to variable temperatures across much of the country through mid-week. A strong upper-level ridge ahead of the noted Pacific system will continue to bring well-above average temperatures across the Interior West east into the northern/central Plains and Midwest this evening. Widespread highs in the 60s to low 80s are forecast, with some mid- to upper-80s possible across portions of the northern/central Plains. However, the incoming Pacific system will bring an eastward expansion of much cooler, below average temperatures. Highs in the 50s and 60s along the West Coast will spread across much of the Interior West Wednesday. A dramatic drop in temperatures will reach portions of the northern Plains by Thursday as highs fall into the 40s. Meanwhile, to the east, temperatures will begin to moderate for many following a cold front passage over the weekend. Highs will return to the 70s and 80s for the Ohio Valley/Southeast today and much of the Mid-Atlantic as well as Texas Wednesday. Cooler temperatures will linger longest for New England as highs remain in the 40s and 50s through mid-week. Santorelli/Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$