George D. PhillipsNOAA/NWS Weather Forecast Office, Topeka, Kansas

Convective wind events Usually difficult unless bow echo or long-

lived HP Supercell windstorm Mid-summer high based stuff often not

otherwise strong looking on radar Orientation of winds to radar makes for

challenges inferring strength of winds Distance from radar makes for challenges

in inferring surface wind speeds

• Non-convective wind events– Often difficult unless tied to strong

gradient winds around an intense extratropical cyclone

– Can be difficult to tie the events to a radar or satellite feature

– If precip, patterns may not stand out– Questions:–How large of an area will be affected?–How long will the strong wind threat last?–What product to issue?

• Extratropical cyclone with strong pressure gradient

• Local isallobaric enhancement to pressure gradient

• Gravity waves?• Wake lows - obviously associated with

mature or dissipating Mesoscale Convective Systems

• Heat burst – associated often with otherwise innocuous convection, or the remains of convection

• NCDWEAWSPAASLLJ

Strong synoptic system with strong LLJLate at night 0900 – 1200 UTCEast central KansasA number of observation sites with

max gusts over 45 ktsMax gust measured 60 kts at EMPEMP had gusts > 45 kts for 50 minutesTree, powerline and/or roof damage

across parts of 5 counties in TOP CWA

Strong synoptic system with strong LLJ Overnight 0500 – 0900 UTC East central Kansas A number of observation sites with max

gusts over 40 kts Max gust measured 57 kts at UKL Two rounds of strong winds for some

sites Large tree branches down and some

roof damage

Spring timeEvening or overnight eventStrong synoptic system & strong low-

level jetStrong damaging winds along or just

north of mostly stratiform precipitation area

If Strong spring extratropical system with

strong southerly low-level jet, and Mostly stratiform precipitation area to

the north of more intense or dying convection

Then Watch for strong winds along or just

north of northern edge of precipitation area

Challenging Watch 15 minute METARs and “mesonet”

obs for strong wind gusts in favored area Have a program that alerts for strong

wind gusts Near north edge of precip - Perhaps issue

High Wind Warning for an area maybe 30-50 miles north/south of northern edge of precipitation for a couple hours

Extend in time/space as necessary If weaker winds, perhaps Wind Advisory

Issued when sustained winds of 40 mph or greater are occurring or expected to persist for an hour or longer or if winds of 58 mph or greater are expected for any duration.

Look more closely at potential connection to gravity waves

Look at the “Duct Function” which may be useful for Wake Lows and Gravity Waves

If you have experienced such an event, or do in the future, let me know

George.Phillips@noaa.gov