396 FXUS21 KWNC 071918 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EST February 07 2026 SYNOPSIS: A transition to a wetter and more active weather pattern remains favored across much of the western contiguous U.S. (CONUS) starting later next week. Early in week-2, a strengthening area of mid-level low pressure is expected to bring an elevated risk of heavy precipitation, high elevation heavy snow, and high wind hazards during the period. As this area of mid-level low pressure shifts eastward across the Interior West, surface low development is favored in the lee of the Rockies, which is favored to bring accumulating, and possibly heavy snowfall across the Upper Midwest and Great Lakes towards the middle of week-2. HAZARDS High risk of heavy snow for the higher elevations of the Sierra Nevada Mountains, Sun-Mon, Feb 15-16. Moderate risk of heavy snow for the Sierra Nevada, Klamath Mountains, lower Cascades, Sun-Tue, Feb 15-17. Moderate risk of heavy precipitation for coastal California and southwestern Oregon, Sun-Mon, Feb 15-16. Moderate risk of heavy snow for the higher elevations of the Desert Southwest, adjacent parts of the Great Basin and Southern Rockies, Sun-Tue, Feb 15-17. Moderate risk of high winds for portions of the lower Four Corners, Central and Southern High Plains, Sun-Tue, Feb 15-17. Slight risk of heavy precipitation for the West Coast, and portions of the Desert Southwest and lower Four Corners, Sun-Sat, Feb 15-21. Slight risk of heavy snow for the Cascades, Klamath, and Sierra Nevada Mountains and surrounding areas of the Great Basin, Sun-Sat, Feb 15-21. Slight risk of heavy snow for the higher elevations of the Desert Southwest, Rockies, Northern Intermountain West, and Great Basin, Sun-Sat, Feb 15-21. Slight risk of high winds for much of the central and western CONUS, Sun-Thu, Feb 15-19. Slight risk of heavy snow for portions of the Central and Northern Plains, Upper Mississippi Valley, and Great Lakes, Mon-Wed, Feb 16-18. DETAILED SUMMARY FOR TUESDAY FEBRUARY 10 - SATURDAY FEBRUARY 14: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR SUNDAY FEBRUARY 15 - SATURDAY FEBRUARY 21: The week-2 hazards perspective remains on track throughout the CONUS, which continues to highlight a transition to a wetter and more active weather pattern across the West, with warmer conditions prevailing east of the Rockies during week-2. By late next week, there is good model agreement among the ensemble mean 500-hPa height forecasts featuring an amplifying trough digging over the West Coast and shifting into the Interior West through the middle of week-2. Relative to yesterday, this mid-level feature has become more amplified and deeper in both the GEFS and ECMWF ensembles, resulting in overall stronger surface responses in the raw and calibrated tools. For precipitation, the uncalibrated GEFS and ECMWF both now indicate greater than 40% chances for 3-day precipitation amounts exceeding an inch from southwestern Oregon southward along the California coast to the Mexico border, with Probabilistic Extreme Tools (PETs) depicting elevated (>30%) chances of these amounts exceeding the 90th climatological percentile. Although Integrated Vapor Transport Tools (IVT) remain fairly tenuous with Atmospheric River (AR) potential (maintaining low chances for IVT values exceeding 250 kg/m/s), the substantial uptick in precipitation signals in these other tools supports the addition of a moderate risk of heavy precipitation for the California Coast and portions of the Oregon Coast for Feb 15-16. The increased precipitation favored may trigger urban and/or small stream flooding from the Bay Area to southern California. By day 10 (Feb 17), ensemble guidance points to a northward retreat of the heavy precipitation potential across the Pacific Northwest by the middle of the period. This is best reflected by the ECMWF PET depicting growing signals over portions of southwestern Washington and western Oregon with 30% chances for amounts exceeding the 85th percentile. However, uncalibrated tools are not quite supportive of a higher hazard designation at this time. The weak probabilities for amounts exceeding 2 inches over the Pacific Northwest is likely tied to the mean trough gradually deamplifying with time, but this potential will continue to be monitored in upcoming outlooks. To capture this evolution, a slight risk of heavy precipitation remains posted for the entire West Coast for week-2, with coverage extended into the Desert Southwest and Lower Four Corners based on increased signals for amounts exceeding 1 inch early in the period. Colder temperatures are expected to overspread much of the West Coast as the trough axis shifts inland, however actual minimum temperatures are expected to remain above hazard thresholds. With increased tropospheric moisture associated with more northern stream shortwave activity, this also supports a higher risk of snow related hazards across the higher elevations of the West. Consistent with the precipitation tools, substantial increases are evident among a number of snow tools where the uncalibrated ECMWF, in particular, indicates 60-70% chances for 3-day amounts exceeding a foot across the higher elevations of California early in week-2, resulting in the addition of a high risk of heavy snow posted for the higher elevations of the Sierra Nevada mountains for Feb 15-16. Based on the increases in the precipitation and snow signals further north along the West Coast, a moderate risk of high elevation snow remains posted over the Sierra Nevadas (Feb 15-17) and is expanded northward to cover the Klamath Mountains and the southern Cascades. As the mid-level troughing shifts eastward, there is better tool support for the addition of a moderate risk of heavy snow focused Mogollon Rim of Arizona and adjacent ranges of the Great Basin and Southern Rockies (Feb 15-17), where the GEFS based Snow Water Equivalent (SWE) PET shows 30% chances for values exceeding the 85th percentile in the region. A slight risk of high elevation snow remains issued for much of the Interior West, valid for all of week-2, with additional coverage over Nevada in the updated outlook. Due to stronger troughing favored in updated guidance, the slight risk of high winds remains posted (Feb 15-19) and is broadened to include much of the western and central CONUS at the base and ahead of the mean amplified troughing aloft, and where ensembles also favor stronger surface pressure gradients through mid week-2. Based on the PETs, as well as the ECMWF ensemble depicting 40-70% for wind gusts exceeding 40mph over the lower Four Corners and into the Central and Southern High Plains, a moderate risk of high winds is issued for Feb 15-17. This elevated wind risk is tied to lee cyclogenesis favored, with both the GEFS and ECMWF ensembles featuring an expansive 999-hPa mean low on day 9 (Feb 16) over the High Plains. As this surface low is expected to generally track northeastward, accumulating and possibly heavy snowfall is possible on the backside of the surface low despite warmer than normal temperatures being favored. Ensembles show 20-30% chances for snowfall exceeding 4 inches with the GEFS SWE PET maintaining 20% chances for values exceeding the 85th percentile over the north-central CONUS to support the addition of a slight risk of lower elevation heavy snow for Feb 16-18. Across the eastern CONUS, the slight risk of heavy snow over the Northeast is discontinued in the updated outlook, as tools have become less supportive of this risk early in week-2. While both the GEFS and ECWMF ensembles do show the return of potentially heavy snowfall over the Northeast associated with the aforementioned surface low later in week-2, disagreement in the timing and uncertainties in details of the storm track location preclude any snow related hazards over the eastern U.S. at this time. No hazards are issued over Alaska. While colder than normal temperatures are favored tied to a strong mid-level ridge over the North Pacific, actual minimum temperatures are expected to remain above hazard thresholds. Stronger cold signals in the PETs do emerge as ridging extends northward into the Bering Sea later in week-2, and this potential will be reassessed in upcoming outlooks. Over Hawaii, there is some ensemble support for troughing to redevelop underneath the North Pacific ridge favorable for Kona Low development. PETs show increased chances for precipitation amounts exceeding the 85th percentile over much of the island chain, but keep the highest amounts (> 1 inch) off to the west in these tools. FORECASTER: Nick Novella $$