EPAWA's long range outlook is updated weekly every Friday morning before noon

Long range outlook last updated: Friday April 25th, 2025, 10:15 AM

Technical discussion is below for advanced readers:

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 Discussion

OVERVIEW: The US drought monitor (photo toward the bottom of this outlook) has largely remained unchanged from the the previous week. The most notable areas of moderate to severe drought are found across NW and far Southern New Jersey through East Central and Southeast PA, and extending into Western and Central Maryland. Although these areas have been shrinking a bit with recent rainfall, it hasn't been enough to offset the rainfall deficits that have been largely common since the Fall of 2024. The outlook for the remainder of April is looking less favorable for seeing above average precipitation anomalies as we'll largely be dealing with quicker-moving frontal passages with limited quantitative precipitation. As such, the April projections were maintained this week at a near to slightly below average (0.00" to -1.0") precipitation departure, and is likely to end that way in a few days. We also maintained the below average snowfall projection outside of elevations, but this has already occurred this month and nothing further is expected. We slightly adjusted projections for May this week to a near average (-0.5" to +0.5") precipitation departure, and snowfall no longer becomes a listed metric in the chart going forward until next November.

Shorter term, a series of fronts will affect the region in the upcoming week. The first is a warm front that brings showers Friday evening through Saturday morning, then after a short break, the cold front follows Saturday afternoon with more isolated showers or perhaps garden-variety thunderstorms. The next cold front arrives Tuesday night and crosses on Wednesday of next week, with the bulk of the showers with that front expected Tuesday night. Another warm front and cold front combination will affect the region late in the week, centered around Friday with showers through Friday evening.

The projection for the month of April was maintained this week to a near to slightly below average (0.0" to -1.0") precipitation departure for the month as a whole, with only a few frontal boundaries with limited overall precipitation to contend with through end of month. We also maintained below average snowfall outside of elevation areas. but this has already occurred and no further snow accumulation is expected. May projections were slightly adjusted this week for a near average (-0.5" to +0.5") precipitation departure for the month using longer term climate models as well as seasonal trends. 

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

April 26th - May 2nd: Near to slightly above average

May 3rd - May 9th: Near to slightly below average

May 10th - May 16th: Near average

May 17th - May 23rd: Near average

May 24th - May 30th: Near to slightly above average

June 1st - June 7th: Near 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  

Pattern Discussion

OVERVIEW:  The month of April projections were maintained this week to a near average (-1.0°F to +1.0°F) temperature departure with temperatures currently running very slightly below average through April 24th, and the outlook over the remaining days of the month balancing the monthly mean temperature to near average. The month of May projections were also maintained this week for a near to slightly below average (0.0°F to -2.0°F) temperature departure as a whole, using longer term climate guidance and global observation trends. Although most of the month will be on brand and seasonal for May, it appears that temps on either side of the middle of the month will favor the slightly cooler side of average, but this is relative to normal highs/lows at this time and not cold. For example, if at that time "normal" highs are in the lower 70s, highs may be capped at near 70° instead. No notable warm or cool extreme periods are currently expected.

• The Madden-Julian Oscillation (MJO) is currently straddling the Circle of Death (COD) or NULL phase, and phase 7 in the Western Pacific. Tropical forcing is largely expected to remain in that general vicinity through much of May. Since tropical forcing is rather weak, it should favor more seasonable temperatures for the most part going forward, and less in the way of abrupt colder...or warmer extremes. This likely sets the pattern for May to be quite seasonable.
• A composite average of the SST departures in the ENSO regions places it in ENSO neutral territory, and the Climate Prediction Center (CPC) has officially acknowledged that this week by issuing a final La Niña advisory two weeks ago. Any lingering La Niña background effects are continuing to wane as we move into May. The Niño 1+2 region (eastern Pacific) has been the warmest of the 4 ENSO regions, but all regions are now between 0.0°C and -1.0°C and solidly in ENSO neutral territory. The expectation is for ENSO neutral to remain throughout the Summer months, which typically favors slightly above average temperatures in the June/July/August 3-month period. Near average precipitation is typical of June and July - with a historically wetter than average month of August during ENSO neutral Summers within the past decade. 

Average high temperatures are currently in the 66-68 °F range from north to south across our coverage region, which is about 2-3°F higher than at this point last week. Average high and low temperature increases will continue at about a 2.0°F gain per week throughout May and the first half of June. 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 above average temperatures listed for April 29th-30th generally features highs in the lower 80s, coming at a time when average highs are typically in the upper 60s to near 70 degrees. Use the average highs/lows chart below providing a point of reference and transparency for what average temperatures are at each corresponding location through June 15th.

The month of April projection was maintained this week to a near average (-1.0°F to +1.0°F) temperature departure, with temperatures favoring the warmer side of average over much of the remainder of the month sans a cooler day this Sunday. The month of May projections were also maintained this week for a near to slightly below average (0.0°F to -2.0°F) temperature departure as a whole, using longer term climate guidance and global observation trends. June projections will be included in next week's long range outlook once April is behind us. 

Note:  Any image below is clickable for larger viewing

Long Range Outlook Table

Climatology

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.

Climate Prediction Center (CPC) Graphical Products

These products are from the NOAA Climate Prediction Center (CPC) and do not necessarily reflect the EPAWA forecast which is detailed above. All images below update automatically as the CPC releases new graphical products

U.S. Soil Moisture Anomaly

US drought monitor (NE US)