Unsettled late week and to begin the
weekend, along with cooler temps…

Technical discussion below will feature two (2) subcategories: Precipitation, and Pattern Discussion. Storm possibilities will be discussed exclusively in the Premium Forum with intense model analysis leading up to any major snow, ice, or rain events, not publicly. To join this discussion and hear the updated thoughts from our team, visit The My Pocket Meteorologist Page by clicking HERE and select the “Premium Weather Forum” option.

Precipitation:

OVERVIEW:  The month of March we project a near average precipitation departure (-0.5″ to +0.5″) for the month as a whole, which was maintained as the projection from last week with a generally unsettled pattern…but not overwhelmingly so in terms of quantitative precipitation during the final week of the month. It is also likely that snow and wintry precipitation is largely done for this season everywhere, with the exception of a few arbitrary flakes in northern areas still possible. The month of April we also maintained near to slightly above average precipitation for the month as a whole with near average snowfall or none at all, but snowfall in April at all climate locations are generally under an inch.

Shorter term, low pressure cutting through the Great Lakes Friday night will drag a warm front northward through our region with showers, then as a secondary low pressure develops SE of the region Saturday, additional showers are likely during the day, wrapping up Saturday evening. A couple of weak shortwaves will move though the region early to mid next week with showers, but not occurring during that entire period. The next organized system will be similar in nature to the Saturday 3/25 system with a cutting primary low into the Great Lakes with secondary low development, and brings the threat of rain at the end of next week in the Friday-Saturday time frame.

The month of March’s projection is for a near average (-0.5″  to +0.5″) precipitation departure for the month as a whole, with snowfall likely already having occurred this month. The last week of March will be unsettled on several occasions, but precipitation appears to be generally near average during that week as a whole. Our projection for the month of April was maintained this week for a near to slightly above average (+0.0″  to +1.0″) precipitation departure for the month as a whole, using longer term climate models and global observation trends.

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Breakdown of precipitation departures from normal over the next several weeks:

March 25th  – March 31st: Near average

April 1st – April 7th: Near to slightly above average

April 8th – April 14th: Near to slightly below average

April 15th – April 21st: Near average

April 22nd – April 28th: Near to slightly above average

April 29th – May 5th: Near to slightly above average

Public/free available maps will be updated when a threat is imminent for significant weather on the weather alerts page throughout the year:  http://epawaweather.com/weather-alerts/

 

Note:  Any image below is clickable for larger viewing  

After a warm front pushes through the region late Friday night, scattered showers are likely during the day Saturday as secondary low pressure forms SE of the region, and wraps up Saturday evening.

A series of weak waves will affect the region in the Monday through Wednesday time frame, and light showers can occur at different points within that window, but not during the entire period.

Pattern:

OVERVIEW: The temperature projection for the month of March was raised slightly this week to a near average (-0.5°F to +0.5°F) temperature departure. This is mostly due to recent milder periods skewing the mean temperature for the month thus far, and will keep the earlier projections of solidly below average from occurring most likely. Average highs/lows are coming up fairly quickly, so although the chart looks “chilly” with a lot of blue/near to slightly below average periods listed in April, it doesn’t mean the same thing in March and April as it does in January or even February, and is relative to time of year. As we reach April, temperatures relative to average will moderate as climatology shows normal highs getting into the 60s week 2 of April and beyond…which means 50s on occasion yet if we are slightly below at that time. Despite the pattern suggesting near to slightly below average temperatures at times in transient periods largely doesn’t support snow or wintry precipitation through early Spring.

The Madden-Julian Oscillation (MJO) best forcing currently resides in a weaker phase 2 signal, and is expected to collapse into the Circle of Death (COD) over the weekend. Beyond that, extended climate guidance suggests it will remain in the COD through at least the first week of April, and perhaps reaching phase 7 in the Western Pacific week 2 of the month as suggested by the GEFS-EXT. With this transition it suggests transient cooler periods at times, but any wintry/snow chances become much more difficult beyond the vernal equinox. Not impossible…but more rare and difficult to achieve. We feel there are no credible or foreseeable surprise events on the horizon, and most likely Winter is essentially over for this region in terms of wintry precipitation aside from perhaps arbitrary flakes in northern areas of elevation.

Average high temperatures are currently in the 51-56°F range from north to south across our coverage region, which is about 3° higher than this time last week. Temperatures are gradually rising each week, and will continue to do so going forward. Any above or below average stretches listed in the outlook will be relative to seasonal norms at that time, and it is important to note that cooler/warmer periods will be relative to the time of year we are talking about. For example, the slightly below average temperatures listed in the March 29th-31st time frame will generally feature highs in the lower 50s in spots for most of that stretch. Use the average highs/lows chart below that provides a point of reference for what average is for each corresponding date, with the examples used for the Philadelphia region, which is one of our warmest climate sites.

The month of  March projection is for a near average (-0.5°F to +0.5°F) temperature departure for the month as a whole, with up and down temperatures expected for the last full week of the month. The projection for April was maintained this week for a near to slightly below average (-0.0°F to -2.0°F) temperature departure for the month as a whole, using longer term climate guidance and seasonal observation trends.

Note:  Any image below is clickable for larger viewing

Generally slightly milder than average conditions will be seen late this weekend, but cooler temperatures relative to average will settle in next week to end the month of March on a cooler note.

Average snowfall drops off in March compared to February, followed by less than 1″ on average in April. Average snowfall at each location is the mean snowfall for the 1991-2020 climate period.

Outlook table last updated: Friday March 24th, 11:05 AM. Next scheduled update: Friday March 31st.

This is a weekly updated public long range guidance product from EPAWA. For daily long range updates and more detailed updates M-F, please join the EPAWA forum. More information/sign-up at: http://epawaweather.com/mpm/ 

*Indications of above or below average temperatures in the table above are relative to what is considered “normal” using data collected over the long term for a particular date. This is collected and maintained by the National Climatic Data Center in conjunction with the National Weather Service actual data from previous years collected at official ASOS/climatology stations across our coverage area. Also note that as time moves forward into a different period as shown above, average temperatures for those dates will also change. See the example below using Philadelphia, PA as the climo station:

The departure from normal uses the average temperature for the date, averaging temps over 24 hours for any given location, using both high and low temperatures hourly during any particular day. This outlook determines warm vs. cool periods relative to normal temperatures.

Images below are clickable for better viewing

Days 1-5 – confidence VERY HIGH

Days 6-10 – confidence HIGH

Days 11-15 – confidence MODERATELY HIGH

Days 16-20 – confidence MODERATE

Below is a look at the latest Soil Moisture Anomaly for the Contiguous United States. This is used by NOAA/CPC for the purpose of drought monitoring and drought outlooks.

This image will automatically update daily.

Forecaster: EPAWA Meteorologist Bobby Martrich
Discussion last updated: Friday March 24th, 11:05 AM