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

Long range outlook last updated: Friday April 18th, 2025, 10:25 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 a portion of the region under a moderate to severe drought, but this has been steadily improving over the past few weeks with recent rainfall contributing to overall abatement. 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 slightly adjusted this week to a near average (-0.5" to +0.5") precipitation departure, down from near to slightly above average last week. We also maintained the below average snowfall projection outside of elevations, but this has already occurred this month and nothing further is expected. We maintained projections for May this week for a near to slightly above average (0.0" to +0.5") precipitation departure, and snowfall no longer becomes a listed metric in the chart going forward until next November.

Shorter term, a cold front will approach Saturday, but more than likely for most areas will hold off any shower activity until the evening...which will be found closest to the best forcing in mainly the northern half of our region. The same frontal boundary will stall south of our region Sunday, and then returns northward as a warm front on Monday. This will quickly be followed by another weak cold front Monday night, and a few showers are possible as it moves through. The next chance for rain arrives next weekend, however there is a wide variance in timing of the cold front and showers. It is uncertain of Saturday during the day is affected or if it holds off until the late day or evening/overnight period. 

The projection for the month of April was slightly adjusted this week to a near average (-0.5" to +0.5") precipitation departure for the month as a whole. We also maintained below average snowfall outside of elevation areas. but this has likely already occurred and no further snow accumulation is expected. May projections were maintained this week for a near to slightly above average (0.0" 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 19th - April 25th: Slightly below average

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 to slightly above average

May 24th - May 30th: 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  

Pattern Discussion

OVERVIEW:  The month of April projections were slightly adjusted this week to a near average (-1.0°F to +1.0°F) temperature departure with temperatures currently running slightly below average, or about 2-3°F below average month to date. With the expected milder push dominating much of the remainder of April sans a transient slightly cooler period around the 27th/28th, temperatures should balance a bit and finish closer to normal by month's end. The month of May projections were 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. With our 5-6 week outlook now in range for most of May, it appears that temps for much of the month will favor the slightly cooler side of average, most notably on either side of mid-month, but this is relative to normal highs/lows at this time and not cold per se.

• The Madden-Julian Oscillation (MJO) is currently in the Circle of Death (COD) or NULL phase, and tropical forcing is expected to move into a weaker phase 7 look in the Western Pacific over the weekend or early next week, and remains there through early May. Afterwards is still a bit uncertain, but forcing could very well collapse back into the COD after the first few days of May. Since phase 7 forcing is rather weak, it should favor more seasonable temperatures for the most part going forward, and less in the way of abrupt colder shots. It appears we have finally turned the corner toward a more springlike pattern. 
• A sudden stratospheric warming event (SSW) over the polar regions that occurred in March connected with the lower troposphere, and allowed cooler temperatures to be forced farther south and into the lower latitudes. This time-delayed process led to cooler than average temperature risks during the first half of the month, but the effects of this SSW is gradually wearing off... and natural climate cycles and climatology appear to be taking over finally.
• 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 this past Monday. Any lingering La Niña background effects are continuing to wane as we move into May. The Niño 1+2 region (eastern Pacific) remains the warmest of the 4 ENSO regions at +0.6°C this week, and the ENSO 3.4 and ENSO 4 regions are currently the coldest between -0.2°C and -0.3°C respectively. The ENSO 3 region is at +0.1°C , and all observed SSTA data is current as of April 16th.

Average high temperatures are currently in the 63-66 °F range from north to south across our coverage region, which is about 3°F higher than at this point last week. Average high and low temperature increases will continue at a 2-3°F gain per week throughout April, then slows the upward pace a bit in May. 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 for April 27th/28th generally features highs in the lower 60s, coming at a time when average highs are typically in the 65-70° range. Use the average highs/lows chart below providing a point of reference for what average is at each corresponding location through June 1st.

The month of April projection was slightly adjusted this week to a near average (-1.0°F to +1.0°F) temperature departure, largely due to the warmer than average temperature pattern expected for most of the remainder of the month. Aside from a transient slightly below average period April 27th/28th,  the overall theme will be above average temperatures dominating the pattern through the end of April. The month of May projections were 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.

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)