Virginia Weather: 12/27/16

Yesterday was cool, still, and mostly cloudy.

This morning in Jersey, VA, has been mild, partly cloudy and still.  The warm front moved through last night, meaning the temperature rose from the upper 40’s to the mid-50’s overnight- I woke up to a warmer temperature than when I went to bed.

The National Weather Service (NWS) in Sterling, VA, forecasts a cloudy morning, with a 50% chance of showers before 10 am.  The day will become gradually sunny, with a high temperature of 71 F. The winds will be 7-11 mph from the west.  This evening will be mostly clear, with a low temperature of 36 F.  Winds will be from the northwest at around 6 mph.

The visible satellite imagery is unavailable at this time.

The enhanced infrared satellite imagery shows some thicker clouds over the state so far this morning.  These clouds are clustered ahead of the cold front.

The water vapor imagery confirms the location of cold front through the Appalachian Mountains this morning.

The 12Z sounding from Sterling, VA, shows a humid sounding, with a nearly saturated atmosphere throughout the entire column.  There was 1.16 inches of precipitable water present. There was no Convective Available Potential Energy (CAPE) and no Convective Inhibition (CINH).  There was a moderate, deep thermal inversion near the surface, and the 0-3 km average lapse rate was 3.7 C/km.

The hodograph shows 40 kts of low-level shear (mostly directional changes) and 62 kts of deep-layer shear (mostly speed changes).

The surface observations (from the SPC Mesoscale Analysis Map) show mild temperatures, cloudy to partly cloudy skies, high humidity (as shown by low surface dewpoint depressions) and light southwesterly winds.  Behind the cold front, the winds shift such that they are out of the west or northwest, and the temperature drops.  The Doppler Radar overlay shows a long, thick band of precipitation just ahead of the cold front.

The surface pressure chart shows a slight pressure gradient from north to south across the state this morning, though the winds are not strong.  Notice the bends in the isobars marking the location of the cold front.  The RAP shows the front stalling, not moving very far from the Appalachians over the next six hours.  There are no strong pressure gradients expected as the front remains nearly stationary.

Synoptically speaking, the 300 mb NAM chart (from Unisys) shows strong zonal flow over the state.

The 500 mb NAM chart shows no major vorticity advection over the state today.  This chart has been excluded from today’s post.

The 700 mb NAM chart shows some no rapidly-rising air over the state today.  This chart has been excluded from today’s post.

The 850 mb NAM chart shows strong Cold Air Advection (CAA) moving into the western part of the state by 0Z as the cold front begins to move out of the Appalachians.  Notice the winds blowing directly across the steep thermal gradient.

The Precipitation chart shows some rain over the western part of the state by 0Z.  This is due to the precipitation band that has stalled with the frontal boundary.

Today will be quite pleasant.  I almost wished I went for a run this morning, based on the 57 F temperature here at my parents’ house so far this morning.  It will cool down this evening though, as the cold front approaches.

I will be headed to MD/PA/DE tonight.  I’m not sure where I will stay, but it will be somewhere in one of these three states, depending on how and when I visit my relatives in MD and DE.

Thank you for reading my forecast.

The upper air soundings and mesoscale analysis plots are from the Storm Prediction Center website.
The forecasted upper air soundings are from TwisterData.com.
The surface observation and upper level charts are from Unisys Weather.
The satellite data is from NASA – MSFC

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About highplainschasing

This blog is about my tales in storm chasing. My name is Seth Price and I am an instrumentation instructor at New Mexico Tech. My amateur radio call sign is N3MRA.
This entry was posted in Local WX, Practicing Concepts, Predictions, Radar Imagery, Satellite Imagery and tagged , , , , , , , , . Bookmark the permalink.

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