Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 307 PM EST Tue Feb 26 2019 Valid 00Z Wed Feb 27 2019 - 00Z Fri Mar 01 2019 ...Heavy to excessive lower elevation rains likely over Central to Northern California..while very heavy snows accumulate through the Sierra... ...Lighter snows likely to spread from the Upper Mississippi Valley...through the Great Lakes...much of NY State into central New England... ...Wet weather expected along the Central to Eastern Gulf coast/Lower Mississippi Valley into the Southeast... ...Much below average temperatures to continue over the Northern to Central Plains with a reinforcing shot of arctic air likely by the end of the week... The mid to upper level flow is expected to remain highly blocked from Alaska to off the Pacific Northwest Coast this period...with a closed upper high over the Gulf of Alaska and a closed low off the Washington/Oregon coasts. This pattern will support widespread heavy precipitation across central to northern California where anomalous moist onshore flow will persist for most of this forecast period. Lower elevation heavy rains and potential flooding possible across central to northern California...while very heavy snow...measured in feet...likely through the Sierra and southern Cascades. While the heaviest precipitation is expected to be centered over central to northern California...the above large scale pattern will also support heavy snows through portions of the Northern Rockies from northwest Wyoming into central to far eastern Idaho. A relatively weak area of low pressure forecast to move eastward from the Mid Mississippi Valley and to the south of the Lower Great Lakes this period. Enhanced vertical velocities to the north of this low will support a fairly broad region of moderate to locally heavy snows from the Upper Mississippi Valley...across much of the Great Lakes region.....Western to Northern New York State and into Central New England. While snowy weather dominates the northeastern tier of the nation...wet weather will persist this period across the southeastern tier of the nation from the Central to Eastern Gulf Coast/Lower Mississippi Valley...into the southeast. This wet weather is focusing to the north of a west to east oriented frontal zone along the Gulf Coast into Central Florida. Moisture values along and and to the north of this front are expected to remain above average through the forecast period...supporting the potential for widespread moderate to locally heavy rainfall amounts. Arctic air is expected to remain entrenched this forecast period across the Northern to Central Plains where arctic high pressure will persist. Much below average temperatures likely across these areas over the next 2 days...with morning lows Wednesday morning likely in the -25 to -30 degree range over the Northern High Plains...while day time highs struggle here to reach 10 above. Temperatures expected to moderate some by mid week across this region..before a reinforcing shot of arctic air plunges southward late in the week as a strong upper vortex sinks south into South-Central Canada on the eastern side of the aforementioned blocking pattern from Alaska to off the Pacific Northwest coast. Oravec Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php