134 FXUS21 KWNC 032027 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EST March 03 2026 SYNOPSIS: Multiple model ensembles depict low pressure at mid-levels and the surface over the central Contiguous U.S. (CONUS) at the outset of week-2, along with strong high pressure at the surface and mid-levels centered off both coasts. This setup is favored to bring potentially heavy precipitation to much of the eastern CONUS, along with high winds across most areas east of the Rockies. Flooding is also possible for portions of the Southern Plains, Mississippi, Tennessee, and Ohio Valleys as a result of this heavy precipitation potential. Further flooding is possible for portions of the Northeast and Lower Great Lakes region as anomalously warm temperatures begin to melt snow pack accumulated over the winter. Strong pressure gradients across the western CONUS are favored to enhance winds along central portions of the West Coast and over much of the Great Basin and Rocky Mountains. Surface low pressure over the Gulf of Alaska is favored to bring Pacific moisture into the northwestern CONUS favoring the potential for heavy snow for the Northern Rockies. Over southern and southwestern portions of Alaska, hazards are posted for much below-normal temperatures and high winds. HAZARDS Moderate risk of heavy precipitation from the Central Gulf Coast region northeastward to the Lower Great Lakes region and New York state, Wed-Thu, Mar 11-12. Slight risk of heavy precipitation for most of the Eastern CONUS, Wed-Fri, Mar 11-13. Slight risk of heavy snow over the Northern Rockies, Wed-Fri, Mar 11-13. Slight risk of much below-normal temperatures over much of southern and southwestern Alaska, including the Seward Peninsula, Wed-Fri, Mar 11-13. Slight risk of high winds along the West Coast from Monterey Bay northward to southwestern Oregon, Wed-Thu, Mar 11-12. Slight risk of high winds over most areas east of the Rockies, Wed-Fri, Mar 11-13. Slight risk of high winds over the southern coast of Alaska, Wed-Sun, Mar 11-15. Slight risk of high winds over much of the Interior West, Rockies, and southern High Plains, Wed-Tue, Mar 11-17. Possible flooding for portions of the Southern Plains, Lower and Middle Mississippi, Tennessee, and Ohio Valleys to the Lower Great Lakes region and Northeast. DETAILED SUMMARY FOR FRIDAY MARCH 06 - TUESDAY MARCH 10: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR WEDNESDAY MARCH 11 - TUESDAY MARCH 17: Multiple model ensemble solutions for 500-hPa height anomalies over North America depict an amplified synoptic pattern at the outset of week-2, with a full latitude trough over the Great Plains bookended by amplified ridges situated near both coasts. This setup strongly favors cyclogenesis in the lee of the Rockies as well as enhanced baroclinicity across the East, increasing the potential for heavy precipitation across most of the eastern half of the Lower 48 states. Model ensemble daily MSLP forecasts indicate two possible rounds of cyclogenesis during the week-1 period, with the second event forecast late in week-1 and into the first few days of week-2. Uncalibrated probabilities from the GEFS and ECENS both indicate at least a 30% chance of 3-day precipitation accumulations exceeding 1 inch from the Lower Mississippi Valley northeastward to the Lower Great Lakes region Precipitation accumulations may reach 2 inches during this event over the Tennessee/Ohio Valleys. A moderate risk of heavy precipitation is posted from the Central Gulf Coast region northeastward to the Lower Great Lakes region and New York state, Wed-Thu, Mar 11-12. A somewhat larger slight risk area of heavy precipitation is indicated for most of the eastern CONUS, Wed-Fri, Mar 11-13. Combined precipitation accumulations from the week-1 and week-2 systems results in a two-week total of more than 5 inches likely in many highlighted locations. This quantity of water is not easily accommodated by river systems, and river, stream, and urban flash flooding are all possible as a result. A large area is highlighted for possible flooding during week-2 over portions of the Southern Plains, Middle and Lower Mississippi, Ohio, and Tennessee Valleys, Lower Great Lakes region, and Northeast. Flooding including flash flooding are also possible beyond these regions, particularly in low-lying areas. Additionally, temperatures are expected to increase dramatically during week-1 and into week-2. Many areas of upstate New York and the mountains of New Hampshire and Vermont have over 5 inches of liquid equivalent in accumulated snow pack, and much of this is favored to melt away during the coming weeks, once again potentially overwhelming water systems in the area, further exacerbating flood conditions in those areas. Multiple model solutions depict strong surface low pressure development and sharp pressure gradients with these cyclogenesis events, resulting in the potential for high winds across much of the eastern CONUS. Ensemble mean actual wind speeds from the ECENS and GEFS both exceed 20mph across much of the central and eastern CONUS as surface low pressure tracks eastward during the first half of week-2, warranting a broad area highlighted with a slight risk of high winds across the region for Mar 11-13. Multiple model ensembles maintain surface low pressure over the Gulf of Alaska and moist onshore flow over western North America, although strong surface high pressure over the North Pacific generally limits the southern extent of this moist inflow to Washington state. Uncalibrated probabilities from the GEFS and ECENS show a strong signal of 3-day snow accumulations exceeding 6 inches for the northern Cascades early in week-2, and the bullish ECENS indicates at least a 40% chance of accumulations exceeding 12 inches. With strong cyclogenesis likely over the Great Plains, models favor good penetration of the moisture farther into the West. Both the ECENS and GEFS indicate at least a 20% chance of 3-day snow accumulations exceeding 6 inches across the Northern Rockies, and once again with the ECENS indicating higher chances than the GEFS. A slight risk of heavy snow is posted for the Northern Rockies valid Mar 11-13. No hazard for heavy snow is indicated for the Northern Cascades, although locally heavy accumulations remain possible. High winds are also possible across the West associated with this pattern. Ensemble mean wind speeds over 20-25 mph are widespread across the Pacific Northwest and Interior West through the middle of week-2, and wind speeds exceeding 30mph are indicated by the models for portions of the Rockies. Therefore, a slight risk of high winds is posted for much of the Great Basin and Rocky Mountains, valid for all of week-2. 0z GEFS and ECENS model wind guidance forecasts 10-meter wind gusts ranging between 20-33 mph along the central Pacific Coast from Monterey, CA to southwestern OR (Coos Bay). Surface low pressure over the Gulf of Alaska is also favored to enhance winds along the southern coast of Alaska, as well as maintain cold easterly flow over the Interior. Though wind speeds are predicted to remain slightly below hazardous thresholds, the hazard is being extended in large part due to the expectation of freezing spray continuing over this area. This pattern is favored to bring extremely cold temperatures into much of the state during week-1. A slight risk of much below-normal temperatures remains posted for much of the southern and southwestern Mainland of Alaska (including the Seward Peninsula), valid Mar 11-13. The Probabilistic Extremes Tools (PETs) for minimum temperatures from the GEFS and ECENS both indicate at least a 20% chance of minimum temperatures falling below the 15th climatological percentile along the western and southern coast of the state throughout most of the week-2 period. FORECASTER: Anthony Artusa $$