994 FXUS21 KWNC 041936 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EST January 04 2026 SYNOPSIS: At the start of week-2, a tight gradient between high surface pressure over the interior West and low pressure farther south increases the odds for periods of high winds over the Southwest through midweek. Later in the period, surface high pressure is expected over the Canadian Prairies while the southern Rockies see lower pressures downstream from a developing mid-level trough. This is favorable for heavy snow in the east-central and northeastern Rockies and the adjacent High Plains, with upsloping low-level flow enhancing totals. Heavy precipitation is possible farther south in the Southwest, but there is too much uncertainty to post any related hazards there. Farther north, a sharp mid-level trough may bring much below normal temperatures to the western half of Alaska while a potentially potent storm farther south raises the odds for high winds and heavy precipitation over south-central and southeastern Alaska, but there is too much uncertainty to post any hazards in Alaska at this time. HAZARDS Slight risk of high winds in the Southwest from Arizona through southern California, Mon-Thu, Jan 12-15. Slight risk of heavy snow over the east-central and northeastern Rockies and the adjacent High Plains, Fri-Sun, Jan 16-18. DETAILED SUMMARY FOR WEDNESDAY JANUARY 07 - SUNDAY JANUARY 11: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR MONDAY JANUARY 12 - SUNDAY JANUARY 18: Early week-2, the ensemble means favor a moderately amplified pattern with a sharp mid-level trough stretching from western Alaska into the central North Pacific, a downstream mid-level ridge over the western Contiguous United States (CONUS), and a weak mid-level trough across the eastern CONUS. The European ensemble (ECENS) mean is strongest with the western CONUS mid-level ridge while the GEFS mean is the weakest. The Canadian ensemble (CMCE) mean splits the difference but is closer to the more amplified ECENS mean. A compromise of the models is favored, but in any case, these differences would not result in dramatic differences in the resulting sensible weather. This pattern remains in place with some amplification of the eastern CONUS mid-level trough until the middle of the period, when the pattern starts to retrograde. By the end of the period, the ensemble means build a mid-level ridge into the upper North Pacific, which allows mid-level heights to build into Alaska but drop over the western CONUS. This results in a relatively weak positively-tilted mid-level trough stretching from north of the Great Lakes through the interior West. The GEFS mean is stronger than the ECENS and CMCE means over the interior West, but the ECENS and CMCE means show a secondary 500-hPa height minimum from the southern Great Basin through southern California which retrogrades off the West Coast near the end of the period. The CMCE and ECENS means would result in a pattern favoring heavier precipitation over and near the southern Rockies, and to a lesser extent farther north near the central and northern Front Range and adjacent High Plains. Meanwhile, over the eastern half of the CONUS, the mid-level trough should diminish later in the week as a flat mid-level ridge is established from the lower Mississippi Valley, the Southeast, and possibly into the Mid-Atantic region. While the ensemble means are in decent agreement overall, a few deterministic model runs show mid-level features that are more amplified and/or persistent, introducing additional uncertainty into the week-2 Hazards Forecast. At the start of week-2, the mid-level ridge over the interior West should establish a strong surface high pressure system centered over the Rockies. The deterministic European model (ECMWF) is strongest with this feature, showing surface pressures approaching 1050 hPa in a few spots across the central Rockies. The other ensemble means and other deterministic models are not as strong, but all show pressures topping 1040 hPa. Meanwhile, mid-level heights are forecast to be closer to normal farther south toward Mexico and the adjacent Pacific, resulting in lower surface pressures over the Southwest. Most model solutions show surface pressures below 1024 mb in parts of southern Arizona and southern California at the beginning of the period. This results in a tight pressure gradient over portions of the Southwest, increasing the odds for periods of high winds across the region. The probabilistic extremes tool (PET) from the ECENS continues to show elevated odds for sustained winds reaching the top 15 percent of climatology, topping out at over 60 percent in parts of Arizona. The PETs from the GEFS and CMCE are much less impressive, but the CMCE has moved in the direction of the ECENS PET today, supporting an extension of the slight risk of high winds farther to the east to cover southern California, southernmost Nevada, and much of Arizona. As the mid-level pattern begins to retrograde toward the middle of week-2, the surface high pressure over the Rockies begins to lift northward and dissipate, relaxing the pressure gradient over the Southwest and reducing the odds for high winds thereafter. Later week-2, 500-hPa heights begin to build a flat ridge over the south-central and southeastern CONUS, pushing the eastern CONUS mid-level trough northward to southern Canada. At the same time, the mid-level ridge initially over the western CONUS begins to retrograde, building toward the central North Pacific and into Alaska. This results in lowering 500-hPa heights over the western CONUS, establishing an positively-tilted anomalous mid-level trough with an axis reaching from southern Canada through much of the western CONUS. Additionally, the CMCE and ECENS means show a secondary 500-hPa height minimum forming over the far southwestern CONUS later week-2 which retrogrades slightly as the period ends. These mid-level features engender relatively high surface pressures above the trough axis in the Canadian Prairies, and lower surface pressures upstream from the southwestern CONUS mid-level trough across the southern Rockies. If these features evolve as forecast, the odds for heavy snow increase along the Front Range of the central and northern Rockies and the adjacent High Plains due to the combination of cyclonically-curved mid-level flow and lower-level upsloping winds. The deterministic model and ensemble mean snowfall forecasts are not particularly heavy at this time, but the GEFS PET shows increased odds for snow water equivalent totals among the top 15 percent of the climatological envelope for the last few days of week-2. There are no snow water equivalent PETs derived from either the ECENS or CMCE, but the pattern forecast by their ensemble means would be more favorable for heavy snow in the region than the GEFS mean, boosting forecast confidence somewhat. Farther south, closer to the southwestern CONUS mid-level trough, the PETs and some deterministic models show increased potential for heavy precipitation over the southern Rockies and some adjacent areas at the same time, but there is too much uncertainty to post any related hazards in the Southwest at this time. There are no hazards posted for Alaska again today, but some guidance shows the potential for a few hazards to affect different parts of the state. However, there is a great deal of model spread and the preponderance of the tools keep conditions below hazards thresholds. A sharp mid-level trough initially along the western tier of the state could result in much below normal temperatures over some of the central and western sections of the Mainland. Early week-2, most deterministic models and ensemble means depict temperatures ranging from 10 to 30 deg. F below normal over at least some portion of the central, west-central, and southwestern parts of the state. A few solutions show temperatures reaching as much as 45 deg. F below normal, but these are minority outliers at this time, and there have been other recent model runs showing temperatures not significantly below normal. Similarly, a few deterministic runs have shown temperatures dropping to as low as -55 deg. F in sports, but the preponderance of the models, including the ensemble means, keep readings above -40 deg. F. Given the wide range of model solutions, no hazards are posted at this time, although the situation will continue to be monitored. There is also uncertainty regarding the potential for a potent storm system to affect some of the southern parts of the state. Most model solutions have low surface pressure starting the week over or near the Gulf of Alaska with higher surface pressures across the interior of Alaska and western Canada, but the strength and location of any storm system that forms and the high surface pressures to the north and east are highly uncertain. The 0z deterministic ECMWF depicts a 969 hPa low pressure center in the Gulf of Alaska early week-2 while surface pressures approach 1020 hPa in far southeastern Alaska. This pattern would engender high winds and heavy precipitation across south-central and southeastern Alaska, along with heavy snowfall away from the immediate coast. In contrast, the ensemble means all keep the surface low pressure center above 990 mb, and both the deterministic Canadian and CMCE mean place a relatively weak low pressure center inland over the southeastern Mainland, which results in less unsettled weather. The PETs derived from the ECENS and CMCE show enhanced odds for winds reaching the 15th percentile of the climatological envelope, but the raw wind forecasts from the ensemble means and most deterministic models keep precipitation and winds below hazards thresholds. Given the broad array of model solutions, no wind or precipitation hazards are posted in Alaska at this time. FORECASTER: Rich Tinker $$