tulsa, ok heavy rain event

Tulsa, OK Heavy Rain Event

May 5 – May 6, 2000

John LaGue & Mike Boehmke

Pre-Event Conditions

• Weak mid- to upper-level cyclonic circulation• Ongoing convection near area of interest• Lack of well-defined surface boundary, but plenty of

available low-level moisture and outflow boundaries

• Mid-60s dewpoints over event area; low-70s dewpoints in southern Oklahoma

• Somewhat increased afternoon surface heating in area of interest helped lead to initial evening

development in Tulsa area.

May 5 @ 2100 UTC Surface Plot

Weak Isentropic Lift Present Over Event Area

Theta-E Ridge to S; Moisture Advection into TUL Area

Forcast Precipitable Water

More Favorable Conditions by 0600 UTC

• Increase in strength of low-level jet

• Continued advection of warmer air and higher

Theta-E air into TUL area as shown by RUCinitializations

• Continued thunderstorm development near center of mid- to upper-level circulation

• Rainfall coverage and intensity rapidly increases after 0800 UTC

• Note the area of regeneration just NW of TUL

Continued Isentropic Lift Forecast @ 0600 UTC

1200 UTC Conditions

• Increased low-level jet• Low-level jet veers from 0600 UTC• Mid- to upper-level circulation begins to move

northeast• Mid-level dry intrusion evident on OUN sounding

OUN sounding 1200 UTC 5/6/2000

12Z 24-hour rainfall ending 5/6/2000

Tulsa Area 24-Hour Gage Totals( > 4.5”)

• TULSA 9WNW - 6.81

• TULSA 16SW - 6.26

• HEYBURN DAM - 6.32

• TULSA 7SSE - 5.71

• TULSA 6SSW - 5.55

• TULSA 5SSW - 5.48

• TULSA 11SW - 5.20

• TULSA 9SSE - 5.08

• TULSA 4SW - 4.61

• MANNFORD 6NW - 4.60