2014-15 Winter Weather Outlook North Alabama Area
Dec 27, 2015
2014-15 Winter Weather Outlook
North Alabama Area
Record November COLD!!
Location
ActualMonday Night
Low (°F)
Record Monday Night
Low (°F)
ForecastTuesday High
(°F)
Record (Low Max)
Tuesday High (°F)
Huntsville Airport
22° 18° (1959) 32° 36° (2000)
Muscle Shoals Airport
21° 18° (1959&1914)
33° 36° (1903)
Decatur Airport 21° * 22° (2008) 33° 36° (2000)
Scottsboro 20° 18° (1959) 33° 36° (1959)
Fayetteville, TN 18° 15° (1959) 32° 32° (1959)* New Record
In An Average Year...
NOV DEC JAN FEBMA
R63.7
°53.5
°51.2
°55.9
°64.9
°
41.8°
34.4°
31.8°
35.5°
42.2°
4.94”
5.77”
4.89”
4.84”
5.21”
0 0.3” 1.1” 0.5” 0.5”Average: 2.4”
SnowSeason Record:
24.1” (’63-’64)
Calendar Day Record:15.7” (12/31/63)
Averages based on 1981-2010 data
Through November 17:* Max Temp: 59.6* Min Temp: 36.2
Recent Winters in Huntsville
Season Temp (F)
‘03-04 15
‘04-05 14
‘05-06 16
‘06-07 14
‘07-08 14
’08-09 9
’09-10 13
’10-11 8
‘11-12 19
’12-13 21
’13-14 4 **
Season
Snowfall
‘03-04 Trace
‘04-05 Trace
‘05-06 0.6”
‘06-07 1.0”
‘07-08 0.7”
’08-09 0.7”
’09-10 3.2”
’10-11 14.3”
‘11-12 Trace
’12-13 0.7”
’13-14 5.2”
Coldest Temperatures
Snowfall
Seasonal Average: 2.4”
** Coldest since Feb. 1996
NWS Winter Weather Products
• Outlooks– Hazardous Weather Outlook– Special Weather Statement
• Watch– Winter Storm Watch– Ice Storm Watch
• Warning / Advisory– Winter Storm Warning– Ice Storm Warning– Winter Weather Advisory– Freezing Rain Advisory
** Blizzard Warnings can be issued when strong winds accompany heavy snow
Product Criteria
Winter Storm Watch At least a 50/50 chance that warning criteria (>2 inches of sleet/snow and /or ice accumulations of 1/4 of an inch or greater) will be met in the next 12 to 24 hours.
Winter Weather Advisory 1" to 2" of snow and/or sleet in less than 12 hours **
Freezing Rain Advisory Ice Accumulations up to 1/4”
Wind Chill Advisory Wind chill readings between -10°F and 0°F
Winter Storm Warning Greater than 2" of snow and/or sleet in 12 hours or > than 4" of snow in 24 hours
Ice Storm Warning Ice accumulations of 1/4" or greater
Wind Chill Warning Wind chill readings at or below -10°F
Blizzard Warning Greater than 2" of snow and/or sleet in 12 hours or greater than 4" of snow in 24 hours AND sustained winds of 35 MPH or greater AND considering blowing and drifting snow reducing visibilities to 1/4 mile or less for 3 or more hours
NWS Huntsville’s Winter Weather Products
** Note: Criteria for each product is a guideline and public safety/IMPACTS are taken into consideration
Stay Informed / Be PreparedNWSChat
iNWS800MHz RadioSocial Media
PhoneWeb / Internet
Mobile
NWS Huntsville 24/7 Contact Info
• Phone:– 256.890.8503 / 8507 / 8508
• 800 MHz Radio:– 1*77*183 (base station)– 283 (Dave)
• Social Media– NWS Huntsville (FB) / @NWSHuntsville
(Twitter)• NWSChat – “hunchat”• Web: www.weather.gov/huntsville
EM Briefing Page (Internal)
Winter “tab” will also show• Wind chill forecast • Snow/Ice accums
http://www.srh.noaa.gov/hun/?n=embrief_winter
Staying Informed / Planning
NWS Huntsville webpage – http://www.weather.gov/huntsville
Winter Precipitation Types
TN Valley Winter Weather Scenarios
Coastal Low Track
Low pressure just to south – shallow cold air scenario
Northern Plains “Clipper” system
Upper level Low
Seasonal Outlooks
• Things to keep in mind…– They are probabilistic outlooks– “Equal Chances” does not mean “Near
Normal”• 33% of near normal• 33% of above normal• 33% of below normal
• Other climate patterns/variables in play– El Nino/La Nina– North Atlantic Oscillation (NAO)– Arctic Oscillation (AO)
Taken from NOAA’s Climate Prediction Center
Taken from NOAA’s Climate Prediction Center
Latest on El Niño • El Niño WATCH
– Issued when conditions are favorable for the development of El Niño conditions within the next six months.• There is a 58% chance
of El Niño during the Northern Hemisphere winter, which is favored to last into the Northern Hemisphere spring 2015.
Typical El Nino Climate Pattern
North Atlantic Oscillation
• Among the most important modes of seasonal variability in the Northern Hemisphere
• Represented by pressure changes in the North Atlantic
• Positive/Negative phase
• State of the science does not allow for reasonable predictions of either negative or positive phases of NAO beyond about 2 weeks
LH
NAO – Positive vs. Negative Phase
• The Positive Phase
• Low Pressure system near Iceland and the Azores High Pressure system are both generally strong.
• This creates an upper zonal wind flow pattern and colder air tends to stay up north in Canada and Alaska.
LH
Strong Low
Strong High
Cold AirStays North
Warm Air
Positive NAOWinter 2011-2012
Seasonal OutlooksThe North Atlantic Oscillation (NAO)
• The Negative Phase• The Icelandic Low,
and the Azores High will often weaken considerably.
• This creates a highly amplified pattern where blocking occurs upstream in the Atlantic. This causes cold air to flow southward into the United States.
L
H
Weak Low
Weak High
Cold AirPlunges
South
Warm Air
“blocking”
Negative NAOWinter 2010-2011
Arctic Oscillation (AO)• Drives temperatures during Winter
months• Involves strength of Polar Jet Stream
(Arctic Circle)• Positive / Negative phase (like NAO)
– Positive = strong jet = cold air locked up– Negative = weaker jet = cold air can shift
south
AO / NAO – where are we now?
Observed NAO & 7-14 day Forecast
Observed AO & 7-14 day Forecast
For more Climate/Outlook
information…• Visit our web page:
http://www.srh.noaa.gov/hun/?n=elnino_winter_study
Click on Temperatures/Precipitation for each specific Region
Winter Weather Awareness Many people travel across the country, throughout the winter months. It’s
important to look ahead at the weather forecast and plan accordingly, but it’s also important to equip your vehicle with the proper tools/resources in case winter
weather impacts your area.
Have one of these in your
vehicle!!