The 500mb jet stream level chart shows a “noisy” flow of disjointed incoherent vorticity max and min advection.
Therefore, unfortunately it will be difficult more than a few hours ahead of time, to give a timeline for rain this weekend. That’s due to the complicated pattern with a slow moving frontal low pressure system, difficult to time upper level disturbances (aforementioned vorticity), large scale assent but varying surface instability and unknown low level outflow boundaries.
I’ve often pointed out over the years that thunderstorm forecasts, unlike regular rain or snow forecasts many times must be updated ever two hours or so.
So it’s impossible to give specific start and stop times for any given place in this type pattern but neither day should rain all the time.
Bottom line for the weekend is have an umbrella available on stand-by and have a plan B if planning outdoor activities.
It should not be a constant rain either day and coverage and intensity should max out afternoons and evenings, however, there will be a chance of rain in the mornings as well.
Remember even if it’s not raining on you “When thunder roars go indoors”, if you hear thunder or see lightning even at a distance you are at risk of being struck.
Heavy downpours at times and rain accumulation over time could lead to some flooding of low-lying areas and the usual suspect creeks and streams. An isolated strong or severe thunderstorm with damaging wind will be possible. No widespread severe weather expected as of now, but that could change so monitor forecast updates ahead.
TODAY the chance of rain is estimated to start 2pm, goes up after 4pm but it looks much more hit and miss compared to late yesterday with rain amounts a tenth to a quarter of an inch on average and isolated 1 in totals possible.
Weekend rain amounts a quarter to half an inch each day on average with isolated 2-4 inch totals possible by the time it all ends.
Looks like it will be diminishing Sunday evening. It turns cooler than normal Sunday into next Wednesday with highs in the 70s and lows in the upper 40s to low and mid 50s along with low humidity early next week.
Most if not all of next week looks dry, and maybe just maybe next weekend as well.
RAINFALL ESTIMATE FOR FRIDAY/FRIDAY NIGHT:
ESTIMATED AVERAGE RAINFALL TOTALS BETWEEN NOW AND LATE SUNDAY NIGHT:
EXCESSIVE RAINFALL OUTLOOK NEXT 3 DAYS:
SEVERE WEATHER RISK LEVELS SATURDAY AND SUNDAY:
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