EPAWA's Long Range Outlook

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

Long range outlook most recently updated Friday June 13th, 10:00 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) had been steadily improving over the past month or so, and there remains NO drought areas noted within our Pennsylvania, New Jersey, or Delaware locales. One moderate drought area remains over Baltimore and Harford Counties in Maryland, otherwise much of Maryland has also improved significantly. This is largely due to quite an impressive month of May with a top 5 rainfall month all-time in some locations, and generally near average precipitation continuing thus far in June. We maintained projections for June this week to a near average (-0.5" to +0.5") precipitation departure for the month as a whole. Most areas are generally near average currently for the month, and a few chances at thunderstorms over the final week of the month should allow most places to maintain near average precipitation. The month of July projections were also maintained this week for a near to slightly above average (+0.0" to +1.0") precipitation departure for the month as a whole. with a wetter 2nd half of the month vs. the first half. 

Shorter term, strong upper-air ridging will be moving in over the weekend, and maintains through at least early next week, leading to dry and very hot conditions. As the ridge begins to break down midweek and shift to the SW, the extreme heat will abate some and it will invite diurnally-driven thunderstorm activity into the region Wednesday and Thursday afternoons along a surface trough around the outer periphery of the retreating ridge. Aside from isolated thunderstorms in between, the next organized activity will likely follow at the end of the month with scattered thunderstorms ahead of a cold front. 

June projections were maintained this week to a near average (-0.5" to +0.5") precipitation departure for the month as a whole, with the expectation of drier conditions until midweek, then isolated to scattered and diurnally-driven thunderstorm activity for the remainder of June. The month of July projections were also maintained this week for a near to slightly above average (+0.0" to +1.0") precipitation departure, using longer term climate models as well as seasonal trends. We expect a near average (overall) first half of the month, then slightly wetter than average during the 2nd half of July presently.  

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

June 21st - June 27th: Below average

June 28th - July 4th: Near to slightly above average

July 5th - July 11th: Near average

July 12th - July 18th: Near average

July 19th - July 25th: Near to slightly above average

July 26th - August 1st: 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 June projections were maintained this week for a near to slightly above average (0.0°F to +2.0°F) temperature departure for the month as a whole. This will largely be the result of strong upper-air ridging moving into the region this weekend and continuing through midweek next week with very high temperatures and warm nighttime lows. Through June 19th, some of our interior climate sites across the region have yet to reach the 90°F threshold, but that will most certainly change this week. Most areas are currently at near to slightly below average temperature levels to this point of the month, and the expected heatwave will push all areas to the warmer side of average by month's end. The month of July projections were slightly adjusted this week for a slightly above average (+1.0°F to +3.0°F) temperature departure for the month as a whole, using long term climate guidance and seasonal/global observation trends. 

• The overall pattern through at least mid-July will generally favor warmer than average conditions for most of that stretch, but there indications that during the 2nd half of the month a wetter pattern will develop. This may also have an effect on temperatures at that time, and generally near average temperatures that likely continues into at least early August. This progression is a result of high pressure and broad upper-air ridging retreating SW after midweek next week, but will remain close enough to keep warmer than average conditions in place in our area, even if slightly so. During the last half of July, the expectation is for this upper-air ridging to retreat even farther SW to the 4 corners region (UT/CO/AZ/NM) which will place our area in a NW flow aloft... and keeps temperatures closer to seasonal average in this configuration with increased precipitation chances. 
  
  
• The Madden-Julian Oscillation (MJO) is currently in the Circle of Death (COD) or NULL phase, and is largely expected to remain in the COD through at least late July. Since tropical forcing is weak, it becomes a non-factor in driving the pattern. Other forces like ridge placement will be key to our temperature patterns, and ridge position suggests warmer than average conditions in most cases through mid-July. The aforementioned ridging retreating to the SW US later in the month may lead to a stagnant NW flow aloft locally and a temperate pattern overall.
  
  
• A composite average of the SST departures in the ENSO regions places it in ENSO neutral territory as it has been for the past 2 months. The Niño 1+2 region (eastern Pacific near Peru) and Niño 4 region (Central Pacific) are the warmest of the 4 ENSO regions at +0.2°C, whereas the other regions (Niño 3 and 3.4) are near -0.2°C, placing the entire Pacific basin solidly in ENSO neutral territory. The expectation is for ENSO neutral to remain throughout the Summer months, which typically favors near to slightly above average temps in the June/July/August 3-month period. Near to leaning slightly above 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 81-85 °F range from north to south across our coverage region, which is about 2°F higher than at this point last week. Average high and low temperatures will continue to increase incrementally over the next few weeks, and then peaks and reaches annual climatological maximums by mid-July. 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 to well above average temperatures listed for the June 22nd-26th period generally features highs well into the 90s, coming at a time when average highs are typically in the mid-80s. Use the average highs/lows chart below providing a point of reference and transparency for what average temperatures are at each corresponding location through August 1st.

The month of June projections were maintained this week for a near to slightly above average (0.0°F to +2.0°F) temperature departure for the month as a whole, and July projections were slightly adjusted this week to a slightly above average (+1.0°F to +3.0°F) temperature departure for the month as a whole, using long term climate guidance and seasonal/global observation trends. 

Note:  Any image below is clickable for larger viewing

Long Range Outlook Table

Climatology

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)