The Dryline

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The Dryline

• Boundary separating two air masses warm and
  moist air east of the dryline and hot and dry air
  west of the dryline.
• Dryline most thought of as a mechanism for severe
  thunderstorm development, but can pose a
  significant concern for fire weather.
• Areas west of the dryline experience hot
  temperatures and very low relative humidities
  (single digit values), full sunshine to help dry
  fuels, and gusty winds as the atmosphere mixes
  stronger winds aloft down to the surface.
• Unique feature common to Texas, Oklahoma, and
  Kansas in the spring.

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L
High Humidities Gusty South To Southeast Winds
Hot TemperaturesSingle Digit Humidities Gusty
Southwest Winds
WichitaFalls
Fort Stockton
FortDavis
Alpine
Del Rio
Severe Thunderstorms
Alice
Dryline
McAllen
3

• Dryline moves east during the day and then
  retreats westward at night. This cycle can
  continue for days.
• Results in sudden wind shifts and sharply
  lowering relative humidities as dry line moves
  east and creates shifting winds and sharp
  humidity rises when it moves west.
• Significant impact on fires increase or
  decrease intensity, potentially re-ignite
  smoldering fuels, cause firefighter safety
  issues.
• Dry lightning also possible near dryline.