Upper Low Brings Wx Woe

Just a very brief discussion this morning concerning the 500 mb level in the troposphere...up about 18,000' or so.  You see, the altitude varies due to a number of reasons, temperature being a major factor.  When the 500 mb heights are low, the air is colder and more dense dropping the 500 mb constant pressure level closer to the surface of the earth.  The converse of this statement is also true.  With that said, when the upper air is colder than normal, often clouds and precipitation result at the surface of the earth.  Well, this Easter weekend 2019 sees one heckuva trough (low heights) digging into the old, deep south and lifting and dying right over PA through Monday.  The jet stream which can often move these pools of cool aloft is well displaced to our north...I'll let the maps do the remainder of the discussion.  I will display the 500 mb level every 12 hours beginning Good Friday morning...

Good Friday evening...this is when we will likely see our heaviest precip into early Saturday morning as a strong surface low and cold front slowly push across the state...

 

Saturday sunrise...

 Saturday evening...

 Easter sunrise...note the jet running parallel to the USA-O Canada border with the isobars closely packed together...winter cold across northern O Canada; spring warmth across the US except under the dying trough...

 Easter evening...

Easter Monday am...again the jet is zonal running west to east just north of US 2; really looking forward to driving that glorious route across the north country (Maine to Washington) in the not so distant future!

As for the rain Friday night into Saturday morning in these KMDT parts, well, the global models are consistent with ~1.0-1.5" of rain whereas the short-range regional models are indicating much less than that in the Harrisburg area with the heaviest rains falling both to our NW and to our east...here; take a look...

Either way...Happy Easter y'all.  I'll leave you with this very timely & poignant negro spiritual number performed nicely by Willie...

I'm out...

Smitty

AA:  The goods (rains) being delivered for grass growing season! (see crop soil moisture map below...) A bit more sun next week and it will be off to the races for you and others trying to keep pace with the lawn farmers!  Ample soil moisture, mild days and cool nights make for a tired Timmy and an irritable one when those BoSox keep losing!