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A few days of cold, then progressively
warmer temps expected by late week
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Long Range Outlook

Important information:

  • Weather Weeklies video, found at http://epawaweather.com/weather-weeklies/ will continue every Sunday throughout the Winter season.
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DatesThreatsSignificanceConfidence
1/13-1/18TemperatureSlightly below averageVery high
1/19TemperatureNear averageHigh
1/20-1/28January thawAbove averageModerately high
1/29-2/4TemperatureSlightly above averageModerately high
2/5-2/11TemperatureNear to slightly below averageModerate
1/13Early AM wintry mix, flash freeze, black iceFriday night’s system brings rain to the region, and with the advance of a rapidly moving Arctic front late at night into early Saturday AM, rain will transition to brief freezing rain, then sleet, and snow for the interior locations well NW of I-95. Flash freezes will occur everywhere Saturday morning as the front moves to the coast, leading to dangerous black ice.Very high
1/16-1/17Snow or snow showersA cut-off upper level low over the eastern Great Lakes will spawn snow showers at a minimum in this time frame, but different handling of this system with various models leaves uncertainty on whether this will be just a few snow showers with very minor accumulations, or coastal redevelopment that brings a moderate or significant snowfall to parts of the region. This remains a system of interest coinciding with the colder air in place, and we will monitor.Moderate
January as a wholeTemperatureSlightly above average (+1.0°F to +2.0°F)Moderately high
January as a wholePrecipitationNear average (-0.5" to +0.5")Moderately high
January as a wholeSnowfallNear averageModerately high
February as a wholeTemperatureNear to slightly above average (+0.0°F to +1.0°F)Moderate
February as a wholePrecipitationAbove average (0.5" to +1.5")Moderate
February as a wholeSnowfallNear to slightly above averageModerate

Outlook table last updated: Friday January 12th, 11:00am.  Next scheduled update: Friday January 19th.

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/my-pocket-meteorologist/ 

*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:

DateAverage Hi/LoEPAWA projection
January 13th40°F/25°FSlightly below average
January 20th40°F/25°FAbove average
January 27th41°F/26°FAbove average
February 3rd41°F/26°FSlightly above average

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.

Long range analysis: 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 rain or severe events, not publicly. To join this discussion and hear our updated thoughts from our team, visit The My Pocket Meteorologist Page by clicking HERE and select the “Premium Weather Forum” option.

Precipitation Discussion:

Precipitation:

Two systems that we are monitoring for precipitation this week, the first of which is ongoing, and will end Saturday early morning with frozen precipitation for the far interior. Weather Alerts has the latest information on this system along with wintry expectations from it, at http://epawaweather.com/weather-alerts/. The biggest takeaway is not the wintry precip as much as it is the flash freezes and resultant black ice that will be a concern for everywhere in our coverage area on Saturday morning. Rapid drop in temperatures from the 60s today and tonight to below freezing in a matter of a few hours will result in any wet surfaces, including road surfaces and walkways, to freeze almost instantly.

The 2nd system comes at a time when cold air is in place, and is a bi-product of a cut-off upper level low spinning over the eastern Great Lakes. Models are handling this feature differently, which presents a wide array of solutions from just a few insignificant snow showers on Tuesday, to something potentially much greater with coastal redevelopment. At this point, a signal identified in last week’s outlook for this period remains intact, but devil’s in the details at this range. Once the Saturday system clears, the eventuality of this Tuesday and/or Wednesday system should become more evident. All options are on the table, but at least this time it is not a guessing game of precipitation type, and will be in the form of snow where it does fall. We will continue to monitor closely over the weekend.

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

January 13th-January 19th: Slightly below average, watching Tues-Wed for possible accumulating snow

January 20th-January 26th: Slightly above average, likely no snow

January 27th-February 2nd: Near to slightly above average, likely little snow outside of far interior

February 3rd-February 9th: Near average, snow events start coming back into play

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

 

Note:  Any image in the outlook is clickable for larger viewing

The GFS shows the rain ending early Saturday as some wintry precip for the far interior, but the bigger issue will be the flash freezes and resultant black ice that follows Saturday AM as temps plummet below freezing in a matter of hours.

gfs1

The same GFS for next Tuesday shows snow showers and minor accumulations as a result of a cut-off upper level low spinning over the eastern Great Lakes. Some models are more aggressive with moderate snows from coastal redevelopment.

gfs2

Pattern Discussion:

Pattern:

A very cold, and at times brutally cold January pattern prior to this recent warm surge has left many areas with well below average (-6°F to -9°F) temperature departures through yesterday, and current record-high warmth today will chop into that somewhat… but we do have another colder than average period to deal with this week between Saturday and Thursday of next week. This period will average slightly below, and not the brutally cold shot of air that we saw last week. This is climatologically the coldest time of year, so it is relative.

We will then transition from slightly below average to near average on the 19th January, and then we enter into the milder forecast period and January thaw for an extended period that encompasses the period from at least the 20th-28th of January, with the SE ridge having more of an influence on the overall pattern during that time. Many were confused by this current surge of synoptically driven warmth as being the “thaw period” that we were referencing, and it’s not. That still looms. The current warmth is a result of a system cutting to our west, and synoptically driven warmth running out ahead of it. The cold period in between was expected, but we did extend it by a few days to the 18th from last week’s outlook.

Madden-Julian Oscillation (MJO) projections are for the best tropical forcing in the Indian Ocean to transition from the current phase 3 look to the milder period afterward, that coincides with the MJO reaching the Maritime Continent near the 20th and onward. This supports the milder look to the overall pattern, and a return of the SE ridge influence as a more dominant player. As we reach the tail end of January and early February, we will transition to a more typical La Niña look, with cold returning to the northern and northwestern US west of the Great Lakes regions, so we’ll call this the “transition week” with still slightly above average temperatures, and then back to winter from February 5th or so onward. The MJO at this time is projected to be in a more favorable cold and active phase in the western Pacific, and continuing to propagate eastward into the colder and stormier phases from there.

January started off below average, but then some up and down periods this week and the thaw looming thereafter, will likely yield a slightly warmer than average January as a whole. Despite the cold start, we think when the dust settles on the 31st, January will finish slightly above average (+1.0°F to +2.0°F). Aside form the threat of snow Tuesday/Wednesday, the rest of the month with the milder look will be more difficult to produce, but not impossible. Timing of moisture coinciding with cold shots will be key to any snow events during the 2nd half of January, and favors interior locations over the coast.

We did adjust February in a big way from last week and abandoned our winter outlook projection of a torchy/warm February. That no longer looks to be the case as I write this outlook today. A look at the latest climate models for February now suggest temperatures will be relatively close to average, but an active precipitation track over our region with a temperature gradient close by. There will be a lot of ups and downs in February with temperature, and both rain and snow events, but snow events carry bigger potential with the above average precipitation forecast as a whole for the the entire month of February. Winter is far from over…

Note:  Any image in the outlook is clickable for larger viewing

The GEFS shows the cold expected to arrive Saturday to hang around for much of the upcoming week, and then moderation occurs after Thursday-Friday. Until then, the January thaw will have to wait, but it is still looming beyond.

gefs2

The Madden-Julian Oscillation using the Euro EPS weeklies shows the steady propagation from the Indian Ocean and phase 3, then milder risks are more prevalent afterwards as tropical forcing returns to the Maritime Continent.

mjo2

Next 3 weeks of US temperature departures

Images below are clickable for better viewing

Days 1-5 outlook – confidence VERY HIGH:

1-5

Days 6-10 outlook – confidence HIGH:

6-10

Days 11-15 outlook – confidence MODERATELY HIGH:

11-15

Days 16-20 outlook – confidence MODERATE:

16-20

Current U.S. Soil Moisture Anomaly

Below is a look at the latest snow cover propagation across Canada and the Contiguous United States.

This image will automatically update daily.

My Pocket Meteorologist

The My Pocket Meteorologist text alert program is gearing up for the upcoming Winter season. Seasonal options are now available. Click on the image below for more information.

mpm3

Forecaster: EPAWA Meteorologist Bobby Martrich
Discussion last updated:  Friday January 12th, 11:00am