527 FXUS21 KWNC 141912 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT March 14 2026 SYNOPSIS: Strong mid-level high pressure is forecast across the west-central CONUS at the outset of week-2 leading to widespread unseasonably warm weather across portions of the Great Basin, Southwest, and into the Central and Southern Plains. The level of heat is forecast to diminish compared to the late week-1 period, with positive temperature anomalies decreasing. The early-season warmth is likely to accelerate spring snowmelt where seasonal snowpack has been well below normal. Continued frontal activity across the Northeast favors increased winds and relatively cooler temperatures. Persistent mid-level high pressure over the western Aleutians favors colder than normal temperatures across Alaska, with surface low pressure over the Gulf of Alaska leading to enhanced winds along the southern coastal Mainland and Southeast Alaska. HAZARDS Moderate risk of much above normal temperatures for portions of the Central Great Basin, southern California, Desert Southwest, and the Central and Southern Rockies and Plains, Sun, Mar 22. Slight risk of much above normal temperatures from much of the western CONUS into the Central and Southern Plains, Sun-Tue, Mar 22-24. Slight risk of high winds across the Northeast and northern Mid-Atlantic, Sun-Mon, Mar 22-23. Slight risk of much below normal temperatures over much of central and southern Mainland Alaska, Sun-Tue, Mar 22-24. Slight risk of high winds over portions of coastal southern Mainland Alaska and Southeast Alaska, Sun-Tue, Mar 22-24. DETAILED SUMMARY FOR TUESDAY MARCH 17 - SATURDAY MARCH 21: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR SUNDAY MARCH 22 - SATURDAY MARCH 28: Dynamical models remain in very good agreement regarding a period of exceptionally warm temperatures developing across the western and central CONUS during week-1. The warmth is forecast to peak late in week-1 tied to an anomalously strong mid-level ridge axis over the Four Corners, with latest Weather Prediction Center forecast indicating widespread positive maximum temperature anomalies of +20 to +30 deg F on days 6 and 7 (Mar 20-21) over the western CONUS into the Great Plains. By day-8 (Mar 22), the GEFS and ECMWF ensembles depict decreasing positive temperature anomalies, a sign that that most substantial warmth is beginning to wane. The moderate risk for much above normal temperatures remains posted across portions of the Central Great Basin, southern California, Desert Southwest, and the Central and Southern Rockies and Plains for Mar 22 as there is still a strong signal in the National Blend of Models (NBM) for daily record high temperatures over these regions. In addition, both the GEFS and ECMWF Probabilistic Extremes Tools (PETs) depict some areas with a 40-70 percent chance maximum temperatures exceed the 98th climatological percentile. Actual temperatures range from the 70s to 80s deg F across the Great Basin to the 90s deg F over the Southwest and southern High Plains. Triple digit temperatures are possible across some of the climatologically hottest areas of the Desert Southwest. By day-9 (Mar 23), there is a notable drop in the PET percentile probabilities and a further reduction in positive temperature anomalies in the GEFS and ECMWF ensembles. Therefore, the moderate risk is discontinued with a slight risk for much above normal temperatures remaining in place over much of the western CONUS into the central and southern Plains through Mar 24. Later in week-2, the 0z GEFS shifts troughing from the Gulf of Alaska to closer to the northwestern CONUS. However, the 0z ECMWF and Canadian ensembles are instead weaker with any troughing and increase positive 500-hPa anomalies across the Southwest later in week-2. While the GEFS solution would favor colder conditions extending along the West Coast, and increased chances for precipitation, the ECMWF and Canadian outcomes would favor relatively warmer and drier conditions persisting throughout the period. There are also elevated signals for increased wind speeds in the GEFS and ECMWF PETs and uncalibrated guidance along the West Coast tied to increasing onshore flow. However, model uncertainty regarding the pattern evolution beyond the middle of week-2, precludes any additional hazards across the West. While the western and central CONUS are predicted to experience very warm temperatures, a relatively colder pattern is anticipated across the northeastern U.S. tied to a trough centered over southeastern Canada and the northwest Atlantic, along with a blocking ridge developing near Greenland. This emerging pattern resembles a negative phase of the North Atlantic Oscillation (-NAO), which would favor a greater likelihood of below normal temperatures during week-2 over portions of the Northeast and northern Mid-Atlantic. The 0z GEFS, ECMWF, and Canadian ensembles all depict surface low pressure developing along the trough axis across the Canadian Maritimes, with a tightening pressure gradient extending into the Northeast at the start of the period. With added support from both the GEFS and ECMWF wind PETs which depict at least a 20 percent chance wind speeds exceed the 85th climatological percentile and 20-mph, a slight risk for high winds is posted across the Northeast and northern Mid-Atlantic, Mar 22-23. Ridging and positive 500-hPa height anomalies to the west of Alaska combined with troughing and surface low pressure over the Gulf of Alaska favor increased probabilities for below normal temperatures over much of Alaska. Given the time of year, it is becoming harder to reach hazardous cold temperatures across the state. However, the GEFS and ECMWF PETs continue to depict portions of central and southern Alaska having probabilities of at least 20 percent for temperatures falling below the 10th climatological percentile early in the period, with the highest probabilities (greater than 40 percent) focused farther to the south and southwest where the corresponding uncalibrated guidance indicates temperatures 15-25 deg F below normal. These signals support a continued slight risk of much below normal temperatures across central and southern Mainland Alaska into the Alaska Peninsula, Mar 22-24. Southeast Alaska is removed from the slight risk given increasing onshore flow reducing the magnitude of the negative temperature anomalies relative to the Interior. Surface low pressure over the Gulf of Alaska results in a tight pressure gradient extending from Southeast Alaska across the southern coastal Mainland, with the PETs supporting a slight risk of high winds, Mar 22-24. While this system favors increased precipitation across Southeast Alaska, amounts are forecast to remain below hazards thresholds. Following a Kona low event ongoing over the Central Pacific that looks to bring heavy rains, high winds and flooding to Hawaii, ensembles depict some potential for the mid-level trough to reload temporarily to the west of the state by early week-2, which may induce additional heavy precipitation. The ECENS and GEFS PETs continue to highlight 20 to 50 percent chances for 3-day precipitation amounts exceeding the 85th climatological percentile over much of the island chain during the first half of week-2. If it materializes as expected, the additional rainfall will exacerbate any flooding ongoing at the start of the period. FORECASTER: Thomas Collow $$