Snow no cause for panic. Yet.
Today's snow should be notable only because it will likely be the first measureable snowfall of the season, and because it's cold enough to make it an all-snow event... and because we'll all be watching it from work, wondering how bad the commute home will be, and itching to get started. The National Weather Service forecasters say the disturbance will move quickly, and it's not a very wet system, which will hold accumulations down. An inch or two.
Much more interesting is the weekend forecast. Still cold, more moisture. More snow. Slower to move through. Here's what the NWS discussion (edited for jargon and abbreviations) is saying about today's snow:
"A PERIOD OF LIGHT SNOW IS EXPECTED TO MOVE ACROSS
THE (FORECAST AREA) TODAY. TEMPERATURES (PREDICTED)BY ALL MODELS ARE PLENTY COLD AND BELOW FREEZING, TO KEEP (PRECIPITATION)TYPE ALL SNOW. HOWEVER WITH THIS CLIPPER, SNOWFALL AMOUNTS WILL BE LIMITED BY MOISTURE AND DURATION. PREVIOUS FORECASTS CALLED FOR AROUND AN INCH OF SNOW FOR THIS CLIPPER EVENT THOUGH IT DOES NOT HAVE MUCH MOISTURE WITH IT. (WE) THINK LIQUID SNOW EQUIVALENT WILL RANGE IN 1:15 RANGE FOR THIS EVENT. THIS WOULD PRODUCE AMOUNTS IN THE 1-2" RANGE...WITH AMOUNTS HIGHER ALONG THE FAR WESTERN TIER OF COUNTIES ALONG THE WESTERN-FACING RANGE... I AM NOT EXPECTING ANY INCREASE IN MOISTURE TO BE PICKED UP BY THIS SYSTEM BEFORE IT CROSSES THE AREA.
"WE THINK THE BEST THE TIME FOR ACCUMULATING SNOWS RANGES FROM LATE MORNING THROUGH MID AFTERNOON... A LITTLE EARLIER IN WESTERN SECTIONS...LATER IN THE EAST. WE CAN EXPECT ABOUT A 2-4 HOUR PERIOD DURING THIS TIME RANGE OF LIGHT SNOW...BEFORE THE SYSTEM PASSES EAST OF THE AREA BY (7 P.M.) IT ALSO LOOKS LIKE BEST AREA FOR REACHING OUR ADVSRY CRITERIA OF 2" WOULD BE OVER MOSTLY THE NORTHERN 2/3RDS OF THE (FORECAST AREA). HENCE FOR THIS PACKAGE, WILL ISSUE A SNOW ADVISORY FOR THE AFOREMENTIONED AREAS, WHICH INCLUDE THE DC AND BALTIMORE METRO AREAS."
Here's what they're saying about the weekend:
"FRIDAY HAS SURFACE HIGH PRESSURE BUILDING DOWN FROM ONTARIO WTH INVERTED RIDGE, WHICH WILL GIVE US A COLD BUT SUNNY DAY ACROSS THE REGION. THIS COLD WILL CONTINUE FRIDAY NIGHT WITH LOWS ABOUT 10 DEG BELOW NORMAL.
"...PATTERN THEN BECOMES ENERGIZED WITH A SIGNIFICANT SHORTWAVE MOVING ACROSS THE MID ATLANTIC SATURDAY NIGHT INTO SUNDAY NIGHT. SURFACE LOW CLIPPER GETS ENERGY INFLUX AS IT MOVES EAST ACROSS THE APPALACHIANS AS ... SHORT WAVE DROPS OUT OF MANITOBA AND INVIGORATES IT...DEEPENING AS IT MOVES OFF THE CAROLINA COAST. (MODEL) SOLUTION PROVIDES A LONG LASTING WEEKEND SNOW EVENT FOR OUR (FORECAST AREA) IF IT PANS OUT. WILL INCREASE PROBABILITY OF PRECIPITATION TO GOOD CHANCE FOR NOW...AND ISSUE WINTER STORM OUTLOOK (LATER)."
Here's the full discussion, with abbreviations.