Severe Weather Outlook
SPC Links
Update times are all UTC:
 Day 1—updated 06:00, 13:00, 16:30, 20:00, 01:00 (next UTC day)
 Day 2—updated 06:00 (during DST) or 07:00 (during Standard Time) and 17:30
 Day 3— updated 07:30 (during DST) or 08:30 (during Standard Time)
 Days 48
The Outlooks
Notes
(June 4, 2024)  NOTICE: This page may be offline (meaning no updates to the table below) at times during the first half or so of June, or possibly in July. The computer that creates the table is due for an operating system upgrade, which will be installed at a different residence, and will likely be offline for several hours at a time as it is being transported and upgraded.
(May 2, 2024)  The original PHP program that created this table for several years, then became unmaintainable (see the nowobsolete notes below), has been replaced with a Rust program that runs on a timer on a "local" computer, and its output is then synced with this website. As of May 2, 2024, that program is run every 5 minutes, but may be run lessfrequently in the near future.
Also, the selection of locations is a list of places that are (or were) places of particular importance to me, and coincidentally cover quite a bit of the geography of the contiguous United States. To see the latitude and longitude used for each site, hover the cursor over the location name (may not work on mobile devices).
The "issuance/valid time", below, is the standard issuance time for the actual forecast. For example, if the Day 2 outlook is listed as "22/06:00 UTC", it means that the Day 2 outlook shown is "valid" at 06:00 UTC on the 22nd, although the outlook is in effect from 12:00 UTC on the 23rd through 12:00 UTC on the 24th.
Old Notes
(OBSOLETE) NOTE  (Updated again June 9, 2019)  SPC file access from this page appears not to be possible anymore. Expect a "no data"type response from this page until I can find another way to get the information...if I can find another way.
(OBSOLETE) (Updated December 6, 2018)  Please note that there are frequent problems when either (1) the threat lines have short breaks in them or (2) there is more than one polygon of the same outlook type. A new Typescript version is under development that should address these issues, plus (hopefully) speed up the rendering of this page.
The Table
Updated: 20240614 19:25 UTC
Day 1 issuance/valid time: 14/16:30 UTC
Day 2 issuance/valid time: 14/17:30 UTC
Day 3 issuance/valid time: 14/07:30 UTC
Location 
Day 1 
Day 2 
Day 3 
Fri 14  Sat 15  Sun 16 
Ellsworth ME  MRGL
TORNADO: 0% 
HAIL: 5% 
WIND: 5% 

NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE

Oklahoma City OK  NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

TSTM
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE

Norman OK  NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE

Alpena MI  NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

TSTM

Moline IL  NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

TSTM
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

TSTM

Ceres CA  NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE

Bellevue NE  TSTM
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

SLGT
TORNADO: 5% 
HAIL: 15% 
WIND: 15% 

TSTM

Scott AFB IL  NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE

Canton IL  NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE
TORNADO: 0% 
HAIL: 0% 
WIND: 0% 

NONE

Legend
Example
Day 1 
Day 2 
Day 3 
Risk Category
Probability of Tornadoes 
Probability of Hail 
Probability of Wind 

Risk Category
Probability of Tornadoes 
Probability of Hail 
Probability of Wind 

Risk Category

"Probability" refers to the approximate probability of severe weather within 25 miles (about 40 km) of the point.
Risk Categories
Item  Example  Description 
No thunderstorms expected  NONE  The risk of thunderstorms at the given point is very low or zero. 
Chance of thunderstorms  TSTM  Thunderstorms possible, but organized severe storms are unlikely. 
Marginal Risk  MRGL  "Marginal Risk" of severe storms at the given point. 
Slight Risk  SLGT  "Slight Risk" of severe storms at the given point. 
Enhanced Risk  ENH  "Enhanced Slight Risk" of severe storms at the given point. 
Moderate Risk  MDT  "Moderate Risk" of severe storms at the given point. 
High Risk  HIGH  "High Risk" of severe storms at the given point. 
Probabilities
Probabilities that are used for hail and wind: 5%, 15%, 30%, 45%, and 60%.
Tornado probabilities include the above, plus 2% and 10%.
Day 3 probabilities are: 5%, 15%, 30%, and 45%.
No Severe Weather Expected
Item  Example  Description 
<2% tornado risk  TORNADO: 0%  Less than 2% chance of tornado within 25 mi. 
<5% hail risk  HAIL: 0%  Less than 5% chance of severe hail (1inch [~25 mm] or larger) within 25 mi. 
<5% wind risk  WIND: 0%  Less than 5% chance of severe wind (58 mph [~93 km/h] or more) within 25 mi. 
<5% severe risk  Svr prob: 0%  Less than 5% chance of severe weather (all kinds) within 25 mi. 
Severe Weather Expected
Item  Example  Description 
≥2% tornado risk  TORNADO: 5%  2% chance or greater of tornado within 25 mi. 
≥5% hail risk  HAIL: 15%  5% chance or greater of severe hail within 25 mi. 
≥5% wind risk  WIND: 15%  5% chance or greater of severe wind within 25 mi. 
≥5% severe risk  Svr prob: 15%  5% chance or greater of severe weather within 25 mi. 
Significant Severe Weather Expected
Item  Example  Description 
"Significant" tornado risk  TORNADO: 15%  10% chance or greater of F2 to F5 tornado within 25 mi. 
"Significant" hail risk  HAIL: 45%  10% chance or greater of 2inch (~51 mm) diameter (or larger) hail within 25 mi. 
"Significant" wind risk  WIND: 45%  10% chance or greater of 75 mph (~120 km/h) wind, or stronger, within 25 mi. 
"Significant" severe weather risk  Svr prob: 30%  15% chance of greater of one or more of the above conditions within 25 mi. 
Latest update: June 4, 2024