How Much Rain?

Here is just a very quick post of the latest official precipitation forecast from HPC and the high resolution models from NCEP (National Center for Environmental Prediction). I will also post the official grid forecast for Harrisburg, PA  First, the QPF map which has been nudged westward by about 50 miles from the last issuance 12 hours ago.

And here are the high resolution graphics from the NAM and the WRF models.  This is basically created by a model depicting how the radar returns will appear for a 48 hour period and then a mosaic of all the time periods are superimposed to create this graphic.  Note the sharp gradient along the spine of the Appalachians through PA.  Here is the NAM.

And here is the WRF.

Lastly, the official text forecast for Harrisburg.  This is the NWS product with which many of you are quite familiar......

Today: Scattered showers. Cloudy, with a high near 78. Northeast wind between 3 and 10 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.

Tonight: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 8pm. Low around 68. Breezy, with a north wind between 16 and 23 mph, with gusts as high as 34 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

Sunday: Showers and possibly a thunderstorm before 11am, then showers likely. High near 76. Windy, with a northwest wind between 23 and 28 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

Sunday Night: Mostly clear, with a low around 56. Northwest wind between 6 and 9 mph.

Monday: Sunny, with a high near 80. Northwest wind between 5 and 8 mph.

But compare this forecast for say my meteorological buddy in Palmyra....a substantial difference!

Today: Scattered showers. Cloudy, with a high near 78. Northeast wind between 3 and 10 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch possible.

Tonight: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 8pm. Low around 68. Windy, with a north wind 16 to 19 mph increasing to between 25 and 28 mph. Winds could gust as high as 39 mph. Chance of precipitation is 100%. New rainfall amounts between 2 and 3 inches possible.
Sunday: Showers and possibly a thunderstorm before 2pm, then a slight chance of showers. High near 75. Windy, with a northwest wind between 25 and 33 mph, with gusts as high as 45 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

Sunday Night: Mostly clear, with a low around 55. Northwest wind between 7 and 10 mph.

Monday: Sunny, with a high near 79. Northwest wind between 5 and 8 mph.

Wind will be an issue, but rainfall will spike the streams like the Swatara for those of you with interests along the Swatty.  Once we get actual precip obs, I'll post some stream forecasts for our immediate area.  It will take a few days for the Susquehanna to spike at Harrisburg as the runoff works its way southward from NE PA and New York state.

Have a great Saturday.....

Smitty

AA:  1-3 inches of rain likely from late Saturday through midday Sunday.  Gusty and damaging winds likely with the saturated ground and full foliage trees.  Uproots will be widespread especially in the eastern sections of our immediate area.