Inauguration Weather 2013: Temperature Exceeds Expectations

January 23 Update: The final daily low was 32° at midnight. The hourly data table and climate summary have been updated.

9 PM Update: The temperature reached 47° at 6 pm to exceed the earlier high. The low of 33° is also likely to be surpassed by midnight. (Hourly data table updated.)

Original post:
The weather for Inauguration 2013 has been much warmer than four years ago. The high of 46° was 16° above that of January 20, 2009, and the average of 40° was +4° relative to normal, vs. -9° last time. The official temperature at noon was 40° with a south wind at 10 mph.

The hourly observations:

Hour	Wind	Weather	Temperature	Dewpoint	Humidity	Wind Chill	Pressure
12:00 AM	NW 23 G 35	Fair and Breezy	32	9	0.38	19	1013.6
11:00 PM	NW 17 G 26	Fair	33	11	0.4	22	1013.6
10:00 PM	NW 8 G 20	Fair	34	14	0.44	27	1013.4
9:00 PM	N 14 G 21	A Few Clouds	35	15	0.44	26	1013
8:00 PM	N 18 G 29	Fair	39	14	0.36	30	1012.1
7:00 PM	N 15	Mostly Cloudy	41	22	0.47	33	1011.5
6:00 PM	NW 5	Overcast	47	25	0.42	45	1009.6
5:00 PM	S 6	Partly Cloudy	45	27	0.49	42	1009.1
4:00 PM	S 8	A Few Clouds	46	27	0.47	42	1010
3:00 PM	S 9	Partly Cloudy	46	25	0.44	41	1011.3
2:00 PM	S 10	Mostly Cloudy	44	23	0.43	39	1012.8
1:00 PM	S 7	Mostly Cloudy	42	20	0.41	38	1014.6
12:00 PM	S 10	Mostly Cloudy	40	21	0.47	34	1016.4
11:00 AM	S 6	Mostly Cloudy	38	19	0.46	33	1018.6
10:00 AM	SE 7	Mostly Cloudy	38	19	0.46	33	1019.3
9:00 AM	E 7	Mostly Cloudy	35	18	0.5	29	1019.5
8:00 AM	SE 6	Mostly Cloudy	34	17	0.5	29	1019.6
7:00 AM	E 6	Mostly Cloudy	33	16	0.49	27	1019.8
6:00 AM	E 7	Overcast	33	15	0.48	27	1019.6
5:00 AM	NE 9	Overcast	35	15	0.44	28	1019.4
4:00 AM	E 8	Overcast	35	16	0.46	28	1019.4
3:00 AM	N 12	Mostly Cloudy	36	14	0.4	28	1019.5
2:00 AM	N 10	Partly Cloudy	37	13	0.37	30	1019.5
1:00 AM	N 13	Mostly Cloudy	38	14	0.37	30	1018.8
12:00 AM	N 8	Mostly Cloudy	39	14	0.36	33	1019

The daily climate summary from the National Weather Service:

..THE WASHINGTON NATIONAL DC CLIMATE SUMMARY FOR JANUARY 21 2013  
  
CLIMATE NORMAL PERIOD 1981 TO 2010  
CLIMATE RECORD PERIOD 1871 TO 2013  
  
WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST       
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR       
                                                  NORMAL                
..............................................................  
  
TEMPERATURE (F)                                                       
 YESTERDAY                                                             
  MAXIMUM         47    553 PM  70    1959  43      4       34         
  MINIMUM         32   1159 PM  -4    1985  28      4       28         
  AVERAGE         40                        36      4       31        
                                                                       
PRECIPITATION (IN)                                                     
  YESTERDAY        0.00          1.41 1902   0.10  -0.10     0.23      
  MONTH TO DATE    1.21                      1.90  -0.69     1.53      
  SINCE DEC 1      4.24                      4.95  -0.71     6.43      
  SINCE JAN 1      1.21                      1.90  -0.69     1.53      
                                                                       
SNOWFALL (IN)                                                          
  YESTERDAY        0.0           3.5  1982   0.2   -0.2                
  MONTH TO DATE    T                         3.4   -3.4                
  SINCE JUL 1      0.2                       6.2   -6.0                
  SNOW DEPTH       0                                                   
                                                                       
DEGREE DAYS                                                            
 HEATING                                                               
  YESTERDAY       25                        29     -4       34         
  MONTH TO DATE  473                       609   -136      534         
  SINCE DEC 1   1076                      1395   -319     1147         
  SINCE JUL 1   1787                      2090   -303     1742         
                                                                       
 COOLING                                                               
  YESTERDAY        0                         0      0        0         
  MONTH TO DATE    0                         0      0        0         
  SINCE DEC 1      0                         0      0        0         
  SINCE JAN 1      0                         0      0        0          
..............................................................  
  
WIND (MPH)                                                             
  HIGHEST WIND SPEED    26   HIGHEST WIND DIRECTION    NW (320)        
  HIGHEST GUST SPEED    37   HIGHEST GUST DIRECTION    NW (320)        
  AVERAGE WIND SPEED    10.0                                           
  
                                                                       
SKY COVER                                                              
  POSSIBLE SUNSHINE  MM                                                
  AVERAGE SKY COVER 0.6                                                
  
                                                                       
WEATHER CONDITIONS                                                    
 THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.                          
  NO SIGNIFICANT WEATHER WAS OBSERVED.                                 
  
                                                                       
RELATIVE HUMIDITY (PERCENT)                                            
 HIGHEST    51           800 AM                                       
 LOWEST     34          1200 AM                                       
 AVERAGE    43                                                         
   

Inauguration Weather 2013 Update

	Temperature		Precipitation
Jan. 20	High	Low	Liquid	Snow
2009	30	19	0	0
2010	44	35	0.03	T
2011	44	35	T	T
2012	40	28	0.05	0.5
Jan. 21
2009	34	18	0	0
2010	44	31	0.08	T
2011	39	20	0.01	0.1
2012	34	28	0.23	0.6

Approaching the midpoint of meteorological winter, there have been only 5 days so far with temperatures cooler than average in Washington. As the 2013 inauguration approaches, however, it's likely that colder temperatures will prevail.

The latest extended outlook from the Climate Prediction Center for January 20-26 (click to enlarge) shows a 40% or higher probability of colder than average temperatures for the Mid Atlantic area. Precipitation chances, however, are rated at 40% or higher to be drier than average.

The table above shows that the trend to cooler temperatures has been common at this point in the winter in recent years, as temperatures have tended to be near or below normal on January 20 and 21. The warmest maximum temperature on each of the 2 days for the 4 years beginning with the last inauguration in 2009 was 44°, just 1° above the long-term average. In each of the last 3 years, there has been at least a trace of precipitation. Some of this fell as snow on each occasion, although the largest amount was 0.6" on January 21 last year.

For a more detailed review of the previous inauguration's weather see:
Inauguration Day Weather, 2009

For a temperature and precipitation climatology of inaugurations prior to 2009 see:
Inauguration Temperature Climatology
and
Political Climate: Inauguration Weather

Cold Inauguration Weather In the Deniosphere

Jan. 26 Update:
It's one thing when an openly political organization trashes the science, but a meteorologist who is a Fellow of the American Meteorological Society ought to know better than to cherry-pick the Inauguration Day data.

Original post:
The cold temperatures in Washington on Inauguration Day have excited the anti-global-warming deniosphere over the symbolism: Obama's Inauguration was colder than Bush's! At least the Competitive Enterprise Institute's OpenMarket blog admits it's "not scientifically meaningful" (as if real science means anything to these folks).

Just how random is this irrelevant fact? Instead of only 40 square miles of the District of Columbia, let's look at the 3,537,438 square miles of the entire U.S. (still merely a couple of percent of the entire earth's surface). While 9° below the long-term average, Washington's temperature on January 20 was far from the record low for the date. According to the National Climatic Data Center, out of nearly 6000 stations with at least 30 years of data, 6 new record low temperatures were set for the date, all except one of them in the state of Michigan. How many high temperature records were set? Forty-five, in Alaska, Arizona, California, Colorado, Idaho, Montana, Nebraska, New Mexico, South Dakota, Texas, and Wyoming.

Want presidential symbolism in the records? Besides the multiple records set in Texas and Wyoming, Mt. Rushmore, SD, broke its previous record in a 46-year history by 4° with a high of 62°. In South Dakota. In January.

Too much cherry-picking to look at just one day? OK, here are the figures for the entire month of January so far: lowest minimum records 399, highest maximum records 846.

Weathercaster-in-Chief: Roker and Obama

Al Roker gets a moment with President Obama on Inauguration Day:

Inauguration Day Weather, 2009

2013 Update: See Inauguration Weather 2013 Update for more recent data.

Jan. 23 Update: Added January daily chart and link to hourly observations for Jan. 20.

January 20 temperatures
High: 30
Low: 19
Departure from average: -9

Precipitation: 0

Noon conditions
Temperature: 28
Wind: NNW at 13 mph, gusting to 23 mph
Sky: Few clouds at 4500 ft, Overcast at 25000 ft. 

Complete hourly weather observations from the National Weather Service are here.

Click here for previous Inauguration Weather posts.

Image (click to enlarge):
CapitalClimate chart of January 2009 observed daily temperatures from NWS data, background image © Kevin Ambrose

Inauguration Weather: PM Update

The occasional snow has now moved out of the Washington area, which received only a minimal accumulation. Total precipitation at the major reporting locations was 0.01" at Dulles and BWI, with only a trace at National Airport. Baltimore Inner Harbor reported a whopping 0.03". Snowfall amounts were a bit higher to the north and west, with some reports of 1-2" in central and northern Maryland.

The outlook for Inauguration Day continues to be cold and dry, with a brisk northwesterly breeze. A few snow flurries are possible (20% chance) in the afternoon. After a morning low in the lower 20s, temperatures will struggle to reach the freezing mark later in the day.

Some snowfall amounts reported by the National Weather Service as of 4 pm:

LOCATION          STORM TOTAL    TIME/DATE    COMMENTS
                     SNOWFALL       OF
                     (INCHES)   MEASUREMENT

MARYLAND

...ALLEGANY COUNTY...
   FROSTBURG              4.0   244 PM  1/19   SPOTTER

...BALTIMORE COUNTY...
   HUNT VALLEY            2.0   230 PM  1/19   WBAL-TV MEDIA
   JACKSONVILLE           1.5   230 PM  1/19   USDA METEOROLOGIST
   OWINGS MILLS           1.3   200 PM  1/19   SPOTTER
   REISTERSTOWN           1.0   125 PM  1/19   SPOTTER
   TOWSON                 1.0  1220 PM  1/19   EMGNCY MNGMT

...CARROLL COUNTY...
   WESTMINISTER           1.3   255 PM  1/19   SPOTTER
   SYKESVILLE             1.2   145 PM  1/19   NOAA/NESDIS EMPLOYEE
   WESTMINSTER 1N         0.9   106 PM  1/19   CO-OP

...HARFORD COUNTY...
   JOPPA                  1.5   200 PM  1/19   SPOTTER

...HOWARD COUNTY...
   ELLICOTT CITY          1.5   330 PM  1/19   MEDIA RPT
   COLUMBIA               1.4   245 PM  1/19   SPOTTER

...MONTGOMERY COUNTY...
   LAYTONSVILLE           1.5   315 PM  1/19   MEDIA RPT
   MONTGOMERY VILLAGE     1.5   330 PM  1/19   NWS NCEP EMPLOYEE
   OLNEY                  1.5   158 PM  1/19   SPOTTER
   BROOKVILLE             0.5  1255 PM  1/19   SPOTTER
   GERMANTOWN             0.3  1125 AM  1/19   MAINLY GRASSY AREAS

VIRGINIA

...CITY OF HARRISONBURG...
   HARRISONBURG           1.0  1128 AM  1/19   WSVA RADIO STN

...CITY OF MANASSAS...
   MANASSAS               0.5   235 PM  1/19   SPOTTER

...CITY OF WINCHESTER...
   WINCHESTER             1.5   350 PM  1/19
   WINCHESTER             0.5  1115 AM  1/19   NWS EMPLOYEE
   WINCHESTER             0.4  1156 AM  1/19   SPOTTER-ROADS COVERED

...FAIRFAX COUNTY...
   HERNDON                0.3   115 PM  1/19   NWS EMPLOYEE
   RESTON                   T   220 PM  1/19   SPOTTER

...FREDERICK COUNTY...
   GRAVEL SPRINGS         2.5   312 PM  1/19   NWS EMPLOYEE
   STEPHENS CITY 2E       2.0   130 PM  1/19   SPOTTER
   MIDDLETOWN             0.7  1205 PM  1/19   SPOTTER
   CROSS JUNCTION         0.5   953 AM  1/19   SPOTTER

...LOUDOUN COUNTY...
   STERLING NWS/WFO       1.0  1245 PM  1/19
   STERLING               0.3  1225 PM  1/19

...RAPPAHANNOCK COUNTY...
   SPERRYVILLE            1.5  1111 AM  1/19   SPOTTER-EST 1/4 MI VSBY  

Inauguration Weather Update: Light Snow Develops

Noon update: BWI with 0.01" is the only one of the three major airports in the region to report measurable precipitation so far.

Original post:
Twenty-four hours before the Presidential Inauguration, intermittent light snow, punctuated with breaks of sunshine, has developed over portions of the Washington metro area. While nowhere near the magnitude of the Taft Inauguration storm of 100 years ago, the expected snowfall of up to an inch could lend a wintry appearance to pre-Inaugural activities.

Temperatures will reach the mid 30s this afternoon, but will fall tonight to the mid 20s on northwesterly winds. On Inauguration Day, winds gusting up to 25 mph will make the temperatures in the high 20s to near 30° feel even colder.

Image: Washington, DC area radar shortly before noon today from The Weather Channel

Inauguration Weather Forecast Update: Some Scattered Snow Showers Sunday

Temperatures have moderated significantly overnight, rising above freezing for the first time since Wednesday, when the high was 35°. Radar is showing light snow and mixed frozen precipitation over much of the Washington metro area, but surface reports indicate that little, if any, is reaching the ground.

The computer models have continued to disagree through this morning's runs, but the main storm development in the next couple of days is likely to be south and east of Washington. Some occasional light snow and/or sleet is still probable through Monday, with colder, but not extreme, temperatures returning by Inauguration Day.

Inauguration Day Outlook:
High 29-32
Low 20-22
Chance of precipitation: less than 20%

Image (click to enlarge):
CapitalClimate chart of January 2009 observed and forecast daily temperatures from NWS data, background image © Kevin Ambrose

Inauguration Weather Forecast Update: Weakened Weekend Snow Chances

5:30 pm Update: This afternoon's model runs confirm the earlier trend away from late Sunday/early Monday precipitation, although it can't be completely ruled out.

Original post:
The computer models have continued to disagree overnight over the prospects of snow Sunday night/Monday morning, but each of the major U.S. models has remained consistent with its own previous snow vs. no-snow forecasts. The lack of consistency between models at the 36-hour range weakens the pro-precipitation case, however, so the chances of a wintry event are diminishing. The main effect on the Inauguration of such an event would be to reduce temperatures on Tuesday, increasing the likelihood that readings would remain below freezing.

Inauguration Weather Forecast Update: Weekend Snow Threat Still Evolving

As noted here this morning, one of the major U.S. weather models (known as GFS) has been suggesting the development of a storm system over the Southeast which could bring some snow to the Washington area late Sunday and into Monday. As of the afternoon runs based on 1 pm data, this is not being confirmed by the shorter-range, higher-resolution model (NAM) or the earlier European medium-range model (ECMWF). The afternoon GFS model output, which is still being generated, is generally consistent with that model's earlier results, however.

This afternoon's forecast discussion from the local National Weather Service office notes:

WHAT HAPPENS BEYOND SATURDAY AFTERNOON IS MUCH MORE INTERESTING AND CHALLENGING. 12Z GFS DEVELOPS LOW PRESSURE ACROSS THE SOUTHEAST STATES ON SUNDAY AND TREKS IT NORTHEAST ALONG THE MID ATLANTIC COAST THROUGH MONDAY MORNING AND UP THE NORTHEAST COAST MONDAY AFTERNOON. THIS SOLUTION WOULD BRING INCREASED CHANCES OF SNOW ACROSS THE CWA ESPECIALLY AREAS EAST OF THE BLUE RIDGE SUNDAY NIGHT INTO MONDAY MORNING. THERE/S SOME SUPPORT FROM THE 09Z SREF AND GFS ENSEMBLES IN THIS SOLUTION. HOWEVER...THE 00Z AND 12Z ECMWF DOES NOT SUPPORT THIS SOLUTION AND HAS LITTLE OR NO PRECIPITATION CHANCES SUNDAY NIGHT INTO MONDAY MORNING EXCEPT FOR UPSLOPE AREAS OF THE HIGHLANDS. THE 12Z NAM IS IN THE SAME CAMP AS THE ECMWF. THE DIVERGING SOLUTIONS ADD TO THE UNCERTAINTY OF THIS FORECAST. AFTER MUCH CONSIDERATION AND COLLABORATION...WE HAVE DECIDED TO INCREASE CHANCES OF SNOW ACROSS THE CWA IN LIGHT OF THE GFS/GFS ENSEMBLE/SREF FORECASTS. IF THEY ARE CORRECT...SOME SNOW ACCUMULATION IS LIKELY. ON THE FLIP SIDE...IF THE ECMWF/NAM SOLUTIONS WIN OUT...THEN LITTLE OR NO SNOW MAY OCCUR. WE WILL NEED TO KEEP A CLOSE WATCH ON THIS SYSTEM AND ADJUST DETAILS AS MODEL GUIDANCE BECOMES IN BETTER AGREEMENT.

Meanwhile, bitterly cold air is entrenched in the area. After a morning low of 11° at 8:23 am, the high has made it up to only 18°. This makes it the coldest daily high since it was 17° on Feb. 4, 1996. Tonight promises to be the coldest of the current spell, with lows around 8°.

Click here for previous Inauguration Weather posts.

Image (click to enlarge): GFS model sea level map of pressure and precipitation, 7 am, Monday, January 19, 2009, from NCEP/NWS/NOAA

Pre-Inauguration Snow Threat Possible

After days of showing relatively dry conditions through Inauguration Day, the last couple of model forecasts have been hinting at a storm developing off the Southeast coast on Monday and becoming a classic nor'easter off New England by Monday night.

The most recent model run, made from this morning's 7 am observations, is just now generating its output, and it shows a particularly strong development. Since this is within the 72-hour range for which model forecasts have some positive skill, the situation bears further watching. As shown in the current model output, the heaviest snow (green shading) would be to the south and east of Washington, but several inches of snow in the immediate area would still be possible. The strong northwesterly flow behind such a storm development would also bring much colder temperatures to the Washington area on Tuesday.

Stay tuned for further developments (and remember where you saw it first :)).

Click here for previous Inauguration Weather posts.

Image (click to enlarge): GFS model sea level map of pressure and precipitation, 7 am, January 19, 2009, from NCEP/NWS/NOAA

Inauguration Weather Forecast Update: Numb or Number?

Following on the heels of a very light dusting of snow around dawn this morning (all 3 major airports reported a trace), northwesterly winds gusting as high as 38 mph are bringing an Arctic chill to the Nation's Capital area. Temperatures which have remained in the 20s all day are expected to drop to the mid teens tonight.

Below-average temperatures will persist through the weekend and into Inauguration Week, but the coldest readings are likely Friday into early Saturday, with a high in the low 20s and a low Friday night in the upper single digits.

The outlook for Inauguration Day is for somewhat less numbing conditions, but with a high near or a little above freezing, spectators will definitely feel a chill:

High: 31-36°
Low: 18-23°
Chance of precipitation: 20%

Other forecasts:
National Weather Service
Partly sunny, with a high near 34.
The Weather Channel
More clouds than sun. Highs in the mid 30s and lows in the upper 20s.
AccuWeather
High: 32 °F, Mostly cloudy and cold

Click here for previous Inauguration Weather posts.

Images, top to bottom (click to enlarge):
CapitalClimate chart of January 2009 observed and forecast daily temperatures from NWS data, background image © Kevin Ambrose;
GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA

Inauguration Weather Update: Cold and Dry Still on the Program

January 20 is now moving out of the extended forecast range, but the latest 6-10 day forecast, for Jan. 20-24, continues to call for significantly colder than average temperatures. The probability of below-average readings in the Washington area is over 50%. Relatively dry conditions are also still likely, with a 40%+ chance of below-average precipitation.

Looking at the shorter term, Washington is moving into one of its most intense cold waves in several winters. The National Weather Service notes that Friday's expected high is near the 21° recorded on Jan. 10, 2004. The record low maximum for Jan. 16, however, was 15° in 1893.

Today's high was 36° at midnight, but daytime temperatures have remained below freezing. Some light snow was reported on radar, but little, if any, reached the ground.

A low pressure area moving eastward from the Ohio Valley will help usher in some even colder Arctic air for the next several days. High temperatures on Thursday will again have a hard time reaching the freezing mark, and highs on Friday will be in the low 20s. Temperatures are likely to remain below freezing through much of the weekend, but with some moderation late Sunday and Monday.

The outlook for Inauguration Day:
High: 33-37°
Low: 20-25°
Chance of precipitation: 20%

Click here for previous Inauguration Weather posts.

Images, top to bottom (click to enlarge):
CapitalClimate chart of January 2009 observed and forecast daily temperatures from NWS data, background image © Kevin Ambrose;
6-10 day temperature,
6-10 day precipitation forecasts from Climate Prediction Center/National Weather Service/NOAA;
GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA

Inauguration Weather Update: Cold, Mainly Dry

The latest extended outlook from the Climate Prediction Center, for the 6-10 day period Jan. 19-23, continues to call for cold temperatures in the Washington, DC area. Probabilities are 50%+ for below-average temperatures through nearly the entire East Coast.

Precipitation chances are 33-40% for below-average amounts.

Cold Arctic air making its way toward the East Coast on Wednesday will persist at least through the weekend before Inauguration Day. After highs in the low 30s tomorrow, temperatures are likely to remain below freezing through Saturday, with only a little moderation into the early part of next week. This means that highs on Inauguration Day are likely to be in the low to mid 30s.

Current indications are that the chance of precipitation will be low, less than 30%, on January 20.

Today's temperatures (preliminary):
High 38
Low 29
Departure from average: -1
Month to date: +0.6

Precipitation:
Today 0"
Month to date 2.02"
Departure from average +0.65"
Days with measurable accumulation: 4 out of 13

Click here for all Inauguration Weather posts.

Images, top to bottom (click to enlarge):
6-10 day temperature,
6-10 day precipitation forecasts from Climate Prediction Center/National Weather Service/NOAA;
GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA

Inauguration Prognostication: Forecast Favors Dry, Cool DC Weather

Once again, as they have ever since January 20 moved within the target date window, the latest 6-10 and 8-14 day extended range forecasts are indicating cooler and drier than average weather for the period leading up to and through the Inauguration. The 5-day interval centered on Inauguration Day (Jan. 18-22) is expected to be colder than average with at least a 60% probability. Conditions are likely to moderate toward the end of the period, with chances of cooler than average temperatures lowered to 40% or more for the 7 days of Jan. 20-26.

For precipitation, the chances of drier than average conditions are about 50% for Jan. 18-22 and 40% or higher for Jan. 20-26.

The specific daily model forecast (read the caveats!) continues to imply a moderating temperature trend beginning around Jan. 20.

Today's temperatures (preliminary):
High 40
Low 27
Departure from average: -1
Month to date: +0.7

Precipitation:
Today 0"
Month to date 2.02"
Departure from average +0.76"
Days with measurable accumulation: 4 out of 12

Click here for all Inauguration Weather posts.

Images, top to bottom (click to enlarge):
6-10 day temperature,
8-14 day temperature,
6-10 day precipitation forecasts from Climate Prediction Center/National Weather Service/NOAA;
GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA

Inauguration Weather Forecast Update: Cold Week Coming Up, Some Moderation Possible

With Inauguration Day 9 days away, it's still too early for a specific daily forecast, but a pattern is emerging for a cold pre-Inaugural week. Some moderation is possible by January 20, but the exact timing is not yet definite.

Today's extended range forecasts continue to show below-average temperatures for the Washington, DC region in both the 6-10 and 8-14 day periods. For Jan. 17-21, temperatures are forecast to be below average along the entire East Coast with a 40%+ probability. Likewise, Jan. 19-25 is also projected colder than average, with the chances for the Mid Atlantic area closer to 50% than 40%.

Precipitation probabilities continue to favor below-average amounts: 33-40% for Jan. 17-21 and 50%+ for Jan. 19-25.

Looking at the day-to-day pattern evolution (read the caveats!), a series of Arctic airmass outbreaks across the eastern U.S. is forecast through the upcoming pre-Inauguration week and into next weekend. As of now, however, there is at least the suggestion of some moderation by the day of the event.

Today's temperatures (final):
High 40
Low 28
Departure from average: -1
Month to date: +0.8

Precipitation:
Today 0.10"
Month to date 2.02"
Departure from average +0.87"
Days with measurable accumulation: 4 out of 11

Click here for all Inauguration Weather posts.

Images, top to bottom (click to enlarge):
6-10 day temperature,
8-14 day temperature,
8-14 day precipitation forecasts from Climate Prediction Center/National Weather Service/NOAA;
GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA ;
CapitalClimate chart of January 2009 observed and forecast daily temperatures from NWS data, background image © Kevin Ambrose

Inauguration Weather Forecast Update: DC Still Looking Dry, Cool

Today's extended forecasts from the Climate Prediction Center continue to indicate cool and dry weather on average for the week leading up to and including Inauguration Day. January 20 is now included in the 6-10 day forecast, which calls for a 40-50% chance of below-average temperatures Jan. 16-20. In the longer range, the prediction for the 8-14 day interval Jan. 18-24 has the Mid Atlantic region well within a 50%+ area of below-average temperatures.

For precipitation, the shorter-range forecast (Jan. 16-20, not shown) has near equal chances of above, near, or below-average precipitation. The longer range (Jan. 18-24) has at least a 40% probability of below-average precipitation.

The individual 10-day model forecast for January 20 (read the caveats!) shows a warming trend following a strong cold outbreak in preceding days.

Today's temperatures (preliminary):
High 40
Low 32
Departure from average: +1
Month to date: +1.0

Precipitation:
Today 0.06"
Month to date 1.84"
Departure from average +0.80"
Days with measurable accumulation: 3 out of 10

Click here for all Inauguration Weather posts.

Images (click to enlarge): 6-10 day temperature, 8-14 day temperature, and 8-14 day precipitation forecasts from Climate Prediction Center/National Weather Service/NOAA; GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA

Inauguration Weather Forecast Update: Cold Chances Continue Climbing

If you're thinking about what to pack for a trip to the Inauguration in Washington, you might want to start looking for Click and Clack's proverbial Bronco Nagurski long underwear. January 20 is now smack dab in the middle of the 8-14 day extended forecast range. The latest forecast from the Climate Prediction Center, for the week of Jan. 17-23, shows an intensifying Arctic outbreak across the Mid Atlantic and Northeast. Although the core of the coldest air is forecast to remain to the north, from northeastern Pennsylvania across New York and into New England, the Washington region is expected to have a 50-60% chance of below average temperatures for the 7 days centered on Inauguration Day.

For precipitation, probabilities are still 40%+ for drier than average conditions.

For what it's worth, and not to be taken literally (read the caveats), the 11-day model forecast specifically for January 20 (bottom map on the right) shows a very cold air mass extending from eastern Canada southward along much of the East Coast.

Today's temperatures (preliminary):
High 39
Low 27
Departure from average: -2
Month to date: +1.4

Precipitation:
Today 0
Month to date 1.78"
Departure from average +0.85"
Days with measurable accumulation: 2

Click here for all Inauguration Weather posts.

Images (click to enlarge): 8-14 day temperature and precipitation forecasts from Climate Prediction Center/National Weather Service/NOAA; GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA

Inauguration Weather Forecast Update: Trending Colder

Today's extended outlook for the 8-14 day interval including Inauguration Day reverses a slight recent trend toward more seasonable temperatures. For the week Jan. 18-22, the predicted area of below-average temperatures has expanded to cover nearly the entire U.S. east of the Mississippi. Northern Virginia, the District of Columbia, and Maryland are now in the southern portion of an area with 50% or greater probability for temperatures below the climatological average.

For precipitation, chances are still 40%+ for below-average amounts.

Following up on yesterday's discussion of model limitations, this morning's 12-day model forecast for 7 am on January 20 shows a stunningly severe cold wave extending as far south as the Gulf Coast and northern Florida, along with frozen precipitation over much of the East Coast. This is a dramatic change from the much less intense cold outbreak and generally dry conditions over the Mid Atlantic area in the forecast from data collected just 24 hours earlier.

As far as the model forecasts for the specific day are concerned, Climate Capitalists should humbly recall the immortal words of the late Louis Rukeyser, "At least some of them will be wrong." See the excellent comments by site visitor SteveT on why even the average range of model predictability is likely to be too optimistic in this case.

Today's temperatures (final):
High 42
Low 30
Departure from average: +1
Month to date: +1.4

Precipitation:
Today trace
Month to date 1.78"
Departure from average +0.96"
Days with measurable accumulation: 2
Note: Yesterday's 1.26" of rain was just 0.07" short of the record for the date set in 1908.

Click here for all Inauguration Weather posts.

Images (click to enlarge): 8-14 day temperature and precipitation forecasts from Climate Prediction Center/National Weather Service/NOAA; GFS model output map for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA

Why Don't We Have a Specific Forecast for Inauguration Day?

You may have noticed that the discussion of the Inauguration Day weather outlook, at least so far, has been expressed only in terms of average probabilities for an entire week including the day of interest. If climate predictions can be made with some confidence well into the remainder of the century, why can't we make an accurate weather forecast less than 2 weeks ahead?

Early last year, we posted an analysis of the limits of daily weather forecasting. The upper chart to the right shows that there has been a steady increase in the skill of computer weather models, but there is essentially no value in a forecast beyond about 8 days. In spite of this, some current forecast models are routinely run out as far as 16 days. Is this just a waste of computer resources at taxpayer expense? No, it serves to generate a base of experience from which the models can continue to be improved in the future.

Because the model output is available, however, snow freaks looking for the next school cancellation, commercial weather services looking to make a quick buck, and corporate media attempting to capture more eyeballs for their pop-up, animated, cycle-sucking advertising continue to peddle the notion that a forecast for a specific day at a particular location 2 weeks or more in advance makes sense. This is not only foolish, it's also unprofessional on the part of those meteorologists who enable such activity (despite their disclaimers and caveats), and it confuses a public already being bombarded by misinformation and even deliberate disinformation on the relationships among weather, climate, and policy issues.

As an example, the 4 maps to the right are the computer model predictions for 7 am, January 20, 2009 made on each of the last 4 days (most recent at the top, oldest at the bottom). If you're not familiar with reading weather maps, the solid lines are surface air pressure, the green and blue shaded areas are precipitation, and the dashed red and blue lines are an indirect representation of temperature. You don't need to be a weatherman, however, to see that these are very different patterns.

Images (click to enlarge): Weather model skill as a function of year, from The Emergence of Numerical Weather Prediction, Peter Lynch, Cambridge University Press, 2006. Chart © ECMWF. GFS model output maps for sea level pressure, 1000-500 mb thickness, and precipitation, 7 am, January 20, 2009, from NCEP/NWS/NOAA.