Jody James
Warning Coordination
Meteorologist
National Weather Service
Lubbock TX
National Weather Service
Lubbock Office
• 24 Staff Members
• 15 Meteorologists
• Open Round the Clock
Weather Operations Center
NWS Lubbock’s Main Focus
Spring/Early Summer
Severe Weather
Definition of Severe
1 inch+ Hail
58+ mph
wind gusts
Tornadoes
There are four basic forecasting methods:
1. Persistence forecasts: based on current conditions.
2. Climatological forecasts: based on long-term averages.
3. Analog approach: based on current conditions and similar
well-studied patterns from the past.
4. Numerical weather forecasting: based on computer
programs that mimic the behavior of the atmosphere.
• Skill of 1-day forecast
doubled since 1965
Our success at forecasting
1” rainfall events
• 2-day forecast skill has
quadrupled over that
time
• Our 7-day forecast is
about as accurate as a
3-day forecast a decade
ago
courtesy Pearson Education 2014
NOT VERY
Chaos is a condition that occurs in
physical systems that makes it impossible
to precisely predict how a system will
appear in some future time.
Forecast
#1 w/ IC1
Forecast
#2 w/ IC2
Forecast
#3 w/ IC3
Forecast skill naturally drops off with time because the end result
is highly sensitive to the initial conditions.
• Precipitation forecasts are
generally less skillful than
temperature (for all forecasts
times)
• For strong El Nino/La Nina
precipitation skill can be as
high as temperature skill for
cool season
• Forecast skill for temperature
peaks in late winter/late
summer – lowest skill in late
spring/late fall
Forecasts are expressed as
Probabilities of the observed
averages temperature (total
precipitation) falling
- either above – near – or
below normal
HUMANS add
about 30%
to the overall forecast skill
of the models.
9,
10,
5, 2014
2013
2011
2012
Drought
Extreme Improving
Drought July 8,
La Nina (Cooler Waters)
El Nino (Warmer Waters)
El Nino and La Nina (ENSO)
“normal” state
• Ocean-atmosphere is naturally linked
through the “Walker Cell”
• Trade winds move warm water
westward
• Cold water upwelling replaces warm
water
o Warm water → low
pressure/storminess
o Cold water → high pressure/sinking
air
•
•
•
•
“El Nino” (warm phase)
Trade winds weaken or reverse
Warm water sloshes eastward
Flip-flop in pressure systems
Change in distribution of rainfall
and ultimately the path of jet
streams
L
H
H
L
H
El Nino Conditions
July 2015
This image shows the July 13-19, 2015 sea surface temperature departure from the 1981-2010
average. In addition to the warmer than normal waters generated by the El Niño conditions,
the Pacific Decadal Oscillation is also creating persistently higher than normal sea surface
temperatures in the northeastern Pacific. From NOAA Environmental Visualization Laboratory.
El Nino
What does this mean
for us?
El Nino Notes/Stats…
(Stats for Lubbock, TX)
Correlation (its effect on Temps/Precip) is mainly
during the cool season (18 Total), (2 Extreme)
For Strong to Extreme El Ninos
Precip…increases: (Dec. – Feb.)
+1.98 to 2.55 inches
Seasonal Snow increases
+ 6.2 to 13.5 inches
** 5 of 6 Strong to Extreme El Ninos exhibited
Above Normal Precip. and Snow
1983
(Extreme El Nino)
Monthly Total Snowfall for Lubbock Area, TX
Year Jan Feb Mar Apr May Jun
1982 0.5 2.7
1983 25.3 3.4
T
T
0.0
5.3
0.0
0.0
0.0
0.0
Jul Aug Sep Oct Nov Dec
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.4
0.0
Seasonal Total was 41.2 inches
25+ inches coming in January
5+ inches fell in April!
6.8
2.3
Ann
ual
10.4
36.3
1983
(Extreme El Nino)
Monthly Total Snowfall for Lubbock Area, TX
Year Jan Feb Mar Apr May Jun
1982 0.5 2.7
1983 25.3 3.4
T
T
0.0
5.3
0.0
0.0
0.0
0.0
Jul Aug Sep Oct Nov Dec
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.4
0.0
6.8
2.3
Ann
ual
10.4
36.3
Biggest Single Snowstorm - January 20-21st - 16.7”
Largest 24 Hour Snowfall – January 20-21st – 16.2”
Most snow in January – 32.1”
One Day total was not broken – 12.1, Feb. 20, 1961
El Nino Notes/Stats…
(Stats for Lubbock, TX)
More Extreme Events?
Big Snows 8-12+ inches?
Flooding Rains??
Icing??
Photo courtesy of Lubbock Avalanche Journal
The latest weekly SST
departures are:
Niño
Niño
Niño
Niño
4
3.4
3
1+2
1.0ºC
2.3ºC
2.6ºC
2.0ºC
EL Nino is likely to be strong to extreme, and may
peak at extreme levels this fall and Winter
Average
is 19.12”
Official Lubbock Precipitation
(through Aug. 13)
Total for Year – 22.05” (11.95” Avg.)
CPC Upcoming Winter Weather Outlook – Dec. – Feb. 2015-16
Jody James
Warning Coordination
Meteorologist
National Weather Service
2579 South Loop 289, Suite 100
Lubbock, TX 79423
Phone (Office) 806-745-3916 x223
Website weather.gov/lubbock
Facebook
US.NationalWeatherService.Lubbock.gov
Twitter twitter.com/NWSLubbock
My Twitter @JLJ63