Northern Alabama - Decatur - Priceville

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Daily Weather Charts

Severe/Hazardous Weather, Huntsville Office, National Weather Service
Storm Prediction Center, NCEP, NWS

Weather Station at Pryor Field, Decatur, AL - Conditions - Last Three Days | Meteogram

 

Current Conditions

 250 mb Upper Air Map

Activity Chart

National Water Vapor Satellite Image

Lower Mississippi Valley Sector Radar

 

SE US Satellite Image

Gulf Coast IR image from GOES

Gulf Coast

Gulf of Mexico IR Image from GOES

Gulf of Mexico

Florida IR image from GOES

Florida

East Coast IR image from GOES

East Coast

 

Huntsville, AL, Skew-T Sounding Chart

Station KEET in Birmingham, AL


 

 

 

Sounding for Decatur, AL


 

 

Skew-T Questions

Questions concerning values displayed on the SKEW-T graphic that expand understanding of the stability of the air mass over this area, together with its potential for severe weather:

Sounding variables and indices

Y / N - L57 Lapse Rate: Greater than 5.5° C/km? greater than 6.7° C/km?
Y / N - Is the Theta-E Index greater than 5? Greater than 8?
Y / N
- Lifted Index (LI): Less than -4? Less than -8?
Y / N - Showalter Index (SI): Less than -4? Less than -8?
Y / N - Total Totals Index (TT): Greater than 53? Greater than 56?
Y / N - K Index (KI): Greater than 26? Greater than 40?
Y / N - SWEAT Index (Severe Weather Threat Index): Greater than 300? Greater than 400?
Y / N - Energy Index (EI): Less than 0? Less than -2?

Parcel Indices

Y / N - CAPE ( Convective available potential energy): Greater than 1,500? Greater than 2,500?
Y / N - CINH (Convective inhibition): Greater than 51? Greater than 200?
Y / N - CAP: (Cap strength): Greater than 2.0? Greater than 4.1?
Y / N - Super-adiabatic lapse rate – where the temperature decreases with height – at a rate of greater than 10 degrees Celsius per kilometer? (data is displayed on the NWS Skew-T Sounding Charts in the lower left corner)

 

Wind Parameters

Y / N - HEL (Storm relative helicity): Greater than 300? Greater than 400?
Y / N - EHI (Energy-Helicity Index): Greater than 1? Greater than 5?
Y / N - BRN (Bulk Richardson Number): Less than 45? In the teens?
Y / N - Upper level winds (between 500 and 300 mb level) of greater than 100 knots?
Y / N - Low level winds (850 to 700 mb) at 25 knots or greater?
Y / N - Atmospheric winds increasing at higher levels (upper level speed shear greater than 70 knots)?
Y / N - Atmospheric winds from different directions (directional shear of 60 degrees or more from the surface to 700 mb)?

 

Current Surface Conditions

Y / N - Dew Point greater than 55 degrees?
Y / N - Temperature greater than 80 degrees? In the forecast? - Y / N (High temperature and high dew point indicates high instability, increasing the threat of severe weather.)
Y / N - Relative Humidity (RH): Greater than 50%? Greater than 80%?
Y / N - Is there a 30 to 50 degree surface temperature/dew point spreads? (High microburst potential.)

 

When these values indicate the potential for severe weather, or where there is some questions about the values displayed on the graphic, I bring up the Text version of the SKEW-T and check the appropriate values.

 

PW - Moisture Content:

0.50 inches or less = Very low
0.50 to 1.25 inches = Low
1.25 to 1.75 inches = Moderate
1.75 to 2.00 inches = High
2.00 inches or above = Very high

Dew Point

Greater than 75° = Very high

65-74° = High

55-64° = Moderate

Less than 55° = Low

Low Level Jet

Greater than 70 knots = Extremely high

50-69 = Very high

30-49 = High

20-29 = Moderate

Less than 20 = Low

 

Additional Variables to Watch: Vertical Wind Shear, Veering, Mid-level Cap, Helicity.

See also SKEW-T for Birmingham, AL.

See generally "Getting to Know the SKEW-T Parameters" by meteorologist Jeff Haby.

 

 

Current Conditions-Willow Place 
Current Weather in Priceville, AL (Cumulus)
KALDECAT4 | CW7715 | PWS Weather

Pryor Field, Decatur, AL - Current Conditions | Meteogram | Text Archive

 

Mesoscale Analysis Page

Mesoscale Discussion

 

Southeast Sector - Storm Prediction Center Mesoanalysis Sectors


 

 

National Weather Hazards

National Weather Hazards

 

Thunderstorm Outlook

Atlantic Tropical Cyclone Activity

 

Thunderstorm Outlook - 16Z-20Z

16Z-20Z

Thunderstorm Outlook - 20Z-00Z

 20Z-0Z

Thunderstorm Outlook - 00Z-04Z

0Z-4Z

 

National Forecast Map

Quantitative Precipitation Forecast

National Forecast Maps

24 Hour Forecast  | 48 Hour Forecast | 3 Day | 4 Day | 5 Day | 6 Day

Quantative Precipitation Forecast-Day One

Day 2 Precipitation Forecast | Day 3 Precipitation Forecast

 

Huntsville Weather Forecast Office

 

Hazardous Weather Outlook


 

Area Forecast Discussion


 

Day One Convective Outlook


 

National Forecast Model Maps
National Weather Service

Short Range
24 hour
48 hour

Medium Range
Day 3
Day 4
Day 5
Day 6

A few of the additional weather pages on this web site:

Huntsville Weather Forecast Office, National Weather Service

Storm Prediction Center: Watches, Mesoscale Discussions, Outlooks

 

Amateur Radio Fact of the Day

 

 

 

 

SKYWARN Storm Spotter

American Radio Relay League

AF4AX

 

Amateur Radio Emergency Service