Hot temperatures in the 90s
for most of the region Friday…

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 big story in May was the absence of precipitation, and in some areas the previous month finished with record low rainfall, and between 2.5″ and 3.5″ below average as a composite average of the major climate locations within our coverage area. The first half of June also likely starts out drier than average as an extension of the very dry May. but ensembles continue to suggest the 2nd half of June will begin to turn wetter…albeit “near normal” precipitation. The combination of a dry first half of June and slightly wetter finish should allow precipitation to finish near to slightly below average (0.0″ to -1.0″) for the month as a whole, and not enough certainly to offset the very dry May and reestablished year-to-date deficits. We are optimistic that July turns a bit wetter relative to average, but this may be more related to thunderstorms in the expected hotter and more humid environment. Our opening bid for July is near to slightly above average (0.0″ to +1.0″) rainfall.

Shorter term, a backdoor cold front crosses the region Saturday, but unfortunately there is not much precipitation associated with it. Some isolated and spotty light hit-or-miss showers will be possible mainly in parts of Central and Northern PA, and mainly dry elsewhere. An upper level low situated to our north across New England midweek could bring a few showers rotating around it in the Wednesday-Thursday time frame, but more likely Wednesday as afternoon instability pop-ups. The next opportunity will come with a cold front the following Monday, and scattered showers and thunderstorms will be possible with that frontal passage.

Our projection for the month of June as a whole was adjusted this week to near to slightly below average (0.0″ to -1.0″) as a generally dry first half of the month is expected and near average during the back half of June. The opening bid for the month of July as a whole is a bit more optimistic, with near to slightly above average (0.0″ to +1.0″) projected currently. With the expected hotter and more humid temperatures relative to average in July, this could be mostly tied to an increased amount of convection.

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

June 3rd – June 9th: Slightly below average

June 10th – June 16th: Near to slightly below average

June 17th – June 23rd: Near to slightly above average

June 24th – June 30th: Near to slightly above average

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

July 8th – July 14th: 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  

A backdoor cold front moves through the region Saturday, and may touch off a shower/storm in mostly Central PA, which will be rather isolated and not helping alleviate drought concerns much.

An upper level low situated off to our north across New England midweek could spawn a few showers for parts of our region most notably on Wednesday, but this too looks to be rather insignificant.

Pattern:

OVERVIEW: After finishing the month of May slightly below average overall across the region, early June has started off very summerlike, but generally near average as overnight lows have been cooler than normal with dry conditions present. A trough arrives Saturday, then generally slightly below average conditions will be present through next Thursday. During this time, high temperatures will dominate in the 70s at a time where either side of 80° is normal. We’ll likely see a brief return to slightly above average temperatures next weekend until a cold front arrives the following Monday, and more near to slightly below average temperatures follow for several days. The 2nd half of June sees a gradual moderation in temperatures relative to average, followed by a warmer turn toward the end of the month. That trend continues further in at least the first half of July where slightly above average temperatures are expected more consistently. Average highs and lows continue to increase rapidly as June progresses, and temperatures will be relative to time of year. Use the image below for a point of reference in comparison to this week’s long range chart for what average temperatures are going forward at select major climate sites within our region. The month of June projection was adjusted this week to a near to slightly below average (0.0°F to -2.0°F) temperature departure projection for the month as a whole, mostly due to the dominant slightly below average periods earlier in the month post June 2nd. Our projection for the month of July was introduced this week for a slightly above average (+1.0°F to +3.0°F) temperature departure for the month as a whole.

The Madden-Julian Oscillation (MJO) best forcing currently resides in a weak phase 8/1 signal, and likely collapses into the Circle of Death (COD) by early next week and remains there for the foreseeable future. Once the MJO reaches the COD, it will have less of an influence on the overall pattern, and outside forces other than tropical convection will be largely running the show. A COD dominance during the summer months is very typical when trade winds are generally weaker.

Average high temperatures are currently in the 76-79°F range from north to south across our coverage region, which is about 2° higher than at this time last week. Temperatures are gradually rising each week, and will continue to do so going forward through mid-July when it reaches the annual climatological peak. 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 first week of June will generally feature highs in the lower to middle 70s at a time when average highs are in the upper 70s to near 80°. 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 June projection is for a near to slightly below average (0.0°F to -2.0°F) temperature departure for the month as a whole, thanks in large part to the dominant cooler stretches expected at times before the Summer solstice. This will be offset somewhat by the warmer finish to June expected. The opening projection for the month of July was introduced this week for a slightly above average (+1.0°F to +3.0°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

After a hot summerlike day Friday, a backdoor cold front drops down from New England Saturday and brings a series of troughs and cooler temperatures to our region through the end of next week.

Average highs and lows across the region continue to increase at a +1-2°F per week pace, and this chart was created to use as a point of reference comparing to the long range chart for transparency. 

Outlook table last updated: Friday June 2nd, 10:25 AM. Next scheduled update: Friday June 9th.

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.

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

CPC 6-10 day temperature outlook

CPC 6-10 day precipitation outlook

CPC 8-14 day temperature outlook

CPC 8-14 day precipitation outlook

CPC weeks 3-4 temperature outlook

CPC weeks 3-4 precipitation outlook

CPC next 3 months temperature outlook

CPC next 3 months precipitation outlook

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 June 2nd, 10:25 AM