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Convective Outlook

Introduction:

Convective Outlook
Figure 1: Convective Outlook

Issuance & Validity:

  • Issued as required
  • Day 1 issued 5 times, valid first 24 hours
  • Day 2 issued 2 times, valid next 24 hours
  • Additional validity explained later
  • Data is forecasted

Information:

  • The left-hand panel is the Day 1 Convective Outlook
  • The right-hand panel is the Day 2 Convective Outlook
  • These guidance products are produced at the Storm Prediction Center (SPC) in Norman, OK.

Day 1 Convective Outlook:

  • Outlines areas where thunderstorms are forecast during the Day 1 period
  • First issuance is 0600Z and is the initial Day 1 outlook valid 1200Z that day until 1200Z the following day
  • The other issuances are 1300Z, 1630Z, 2000Z, and 0100Z, all valid until 1200Z the next day
  • Outlooks issue qualifiers for the level of risk (SLGT, MDT, HIGH - see below), as well as areas of general thunderstorms

Day 2 Convective Outlook:

  • Outlines areas where thunderstorms are forecast during the Day 1 period
  • Initially issued at 0830Z during standard time and 0730Z during daylight time
  • It is updated at 1730Z
  • Time frame covered is from 1200Z the following day to 1200Z the next day
  • Day 2 outlook also issues risk qualifiers

Levels of Risk (risk qualifiers):

NOTATION EXPLANATION
SEE TEXT Used for those situations where a SLGT risk was considered but at the time of the forecast, was not warranted
SLGT (slight risk) A high probability of 5 to 29 reports of 1 inch or larger hail, and/or 3-5 tornadoes, and/or 5 to 29 wind events, or a low/moderate probability of moderate to high risk being issued later if some conditions come together
MDT (moderate risk) A high probability of at least 30 reports of hail 1 inch or larger; or 6-19 tornadoes; or numerous wind events (30)
HIGH (high risk) A high probability of at least 20 tornadoes with at least two of them rated F3 (or higher), or an extreme derecho causing widespread (50 or more) wind events with numerous higher-end wind (80 mph or higher) and structural damage reports

Conclusion:

References: