Highs for days 3-7:

A bit chilly..............but seasonal for December!

Moderating next weekend.

Lows days 3-7 below:

Freeze line fairly far south but not  unusual for this time of year!

Cold enough for snow in many locations!

https://www.wpc.ncep.noaa.gov/medr/medr_min.shtml

Temperatures compared to Average for days 3-7

Above average N.Plains.  Chilly in the Deep South and East vs average.

https://www.wpc.ncep.noaa.gov/medr/medr_mean.shtml

Surface Weather features days 0-1-2 then days 3-7:

 A couple of snowstorms the next 4 days. 

https://www.cpc.ncep.noaa.gov/products/forecasts/

Days 0-1-2 below:

Days 3-7 below:

Total Snow THIS week from the 12z European Ensemble model from Sunday.

Liquid equivalent precip forecasts for the next 7 days are below.

Northern part of this will be snow!

Day 1 below

http://www.wpc.ncep.noaa.gov/qpf/fill_94qwbg.gif?1526306199054

Day 2 below:

http://www.wpc.ncep.noaa.gov/qpf/fill_98qwbg.gif?1528293750112

Day 3 below

http://www.wpc.ncep.noaa.gov/qpf/fill_99qwbg.gif?1528293842764

Days 4-5 below:

http://www.wpc.ncep.noaa.gov/qpf/95ep48iwbg_fill.gif?1526306162

 Days 6-7 below:

http://www.wpc.ncep.noaa.gov/qpf/97ep48iwbg_fill.gif?1526306162

7 Day Total precipitation below:

https://www.wpc.ncep.noaa.gov/qpf/p168i.gif?1566925971

Excessive rain potential.

None

Mesoscale Precipitation Discussions

Current Day 1 Forecast

Day 1 Threat Area in Text Format  

Current Day 2 Forecast

Day 2 Threat Area in Text Format 

Current Day 3 Forecast

Severe Storm Risk the next 8 days:

Quiet!!

https://www.spc.noaa.gov/

Current Day 1 Outlook
Current Day 2 Outlook
Current Day 3 Outlook	F
Current Day 4-8 Outlook

Current Dew Points

Dry air in place. Gulf of Mexico closed for water vapor transport business to the north.

Latest radar loops

http://www.nws.noaa.gov/radar_tab.php

Go to: Most Recent Image

    You can go to this link to see precipitation totals from recent time periods:

https://water.weather.gov/precip/

                              Go to precipitation, then scroll down to pick a time frame. Hit states to get the borders to see locations better. Under products, you can hit "observed" or "Percent of Normal"

Soilmoisture anomaly:

These maps sometimes take a day to catch up to incorporate the latest data(the bottom map is only updated once a week).

https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/US/Soilmst/Soilmst.shtml#

Drought Monitor maps:

Latest: The first map below is the latest. The 2nd one is from last week.

      https://droughtmonitor.unl.edu/     

The top map is the Canadian ensemble average,  the maps below are the individual members that make up the average at the end of week 2.

+++++++++++++++++++++++++++++++++++++++++

Each member is like the parent, Canadian model operational model.......with a slight tweek/variation in parameters. Since we know the equations to represent the physics of the atmosphere in the models are not perfect, its useful to vary some of the equations that are uncertain(can make a difference) to see if it effects the outcome and how.

The average of all these variations(ensembles) often yields a better tool for forecasting. It's always more consistent. The individual operational model, like each individual ensemble member can vary greatly from run to run.........and represent an extreme end of the spectrum at times. The ensemble average of all the members, because it averages the extremes.............from opposite ends of the spectrum.........changes much less from run to run.

End of week 2.................  Canadian ensembles:

December 13: After the period prior to this of slightly more amplified, meridional, north to south flow, (ridge west/trough east configuration) which will yield several cold days from cold in Canada  getting pushed into the US.........the flow...............at least on this model takes on a more zonal component. The GFS and European models look alot different than this, with modest ridging across the western  1/2 to 2/3rds and weak troughing along the East Coast.

360h GZ 500 forecast valid on Dec 28, 2020 12 UTC

Forecasts for the control (GEM 0) and the 20 ensemble members (global model not available)

++++++++++++++++++++++++++

Individual GFS ensemble solutions for the latest 12z run at 336 hours:

http://mp1.met.psu.edu/~fxg1/ENSHGT_0z/f336.gif

December 13: Take you pick. Mucho differences in solutions. At least half like a ridge west/trough east couplet....... warm west, chilly east solution.

GFS Ensemble mean(average of all the individual solutions above).  The first map is a mid/upper level map. The 2nd one is a temperatures map at around 1 mile above the surface. These are anomalies(difference compared to average).

NCEP Ensemble t = 360 hour forecast

December 13: Tremendous changes in the anomolies in short periods the next 2 weeks. So the one at 168 hours doesn't stick around long. Extreme negative anomaly in blue in Alaska and NW Canada, positive anomaly across the northern tier of the US, cuts off the frigid air in Canada. At 360 hours, we have a weak positive anomaly across the western 2/3rds of the US and a small negative in the Northeast. A new positive from Greenland to the N.Atlantic should be watched for a Greenland block -NAO potential at the end of the month. This is suggesting the coldest place at the end of the month will be the East Coast.

2 weeks out below

                                    ++++++++++

Latest, updated graph/forecast for AO and NAO and PNA here, including an explanation of how to interpret them...............mainly where they stand at the end of 2 weeks

https://www.marketforum.com/forum/t

Previous analysis, with the latest day at the bottom for late week 2 period.

Discussions, starting with the oldest  below.

December 13:  AO is solidly negative and favors cold being flushed from high latitudes to mid latitudes...........more than what model solutions/weather maps show. NAO is slightly negative and a small factor for dialing in extra cold in the East. PNA not a factor at near 0, after it had been anomalously positive recently and help push cold deeply into the South. 

National Weather Service 6-10 day, 8-14 day outlooks.

 Updated daily just after 2pm Central.

Temperature Probability

 Precipitation Probability

the 8-14 day outlooks ArchivesAnalogsLines-Only FormatGIS Data

Temperature Probability

The week 3 and week 4 CFS model  from the previous day

Updating the Sunday weather stuff now!!

@MassachusettsWx

RGEM is pretty dang impressive! Can’t wait till even more mesoscale models come in range!

December 14 update:

—AO and slightly -NAO pose the threat for a much colder pattern later this month.

The GFS is not as cold as the European model and the disparity is tremendous, including the change from run to to run because of the huge temperature gradient.