400 likes | 558 Views
TURBULENCE BASICS FORECASTING TOOLS RECENT CASE STUDIES TODAY’S TURBULENCE. TURBULENCE: “NOT” A FUNCTION OF STRENGTH OF JET STREAM, BUT RATHER A FUNCTION OF THE STRENGTH OF THE SPEED AND DIRECTIONAL SHEARS ASSOCIATED. TURBULENCE: LOOKING AT LAYER SPEED SHEARS AND
E N D
TURBULENCE BASICS • FORECASTING TOOLS • RECENT CASE STUDIES • TODAY’S TURBULENCE
TURBULENCE: “NOT” A FUNCTION OF STRENGTH OF JET STREAM, BUT RATHER A FUNCTION OF THE STRENGTH OF THE SPEED AND DIRECTIONAL SHEARS ASSOCIATED.
TURBULENCE: LOOKING AT LAYER SPEED SHEARS AND TRYING TO BETTER QUANTIFY THE FORECAST MODELS.
EXAMPLE 1) MODERATE-STRONG JET – MINIMAL TURB (NOVEMBER 2009) UPPER JET 100-130KT COVERED MANY ALTITUDES W/ LITTLE IN WAY OF LAYER SPEED OR DIRECTIONAL SHEAR.
FL370 ~100KT GENERALLY SMOOTH FLIGHT ALTITUDES KORD SOUNDING 0000Z INDICATING FAIRLY UNIFORM WINDS FL370 DOWN TO FL180 FL180 ~95KT
STILL NEED TO USE FORECAST MODELS WITH CAUTION… EXAMPLE 2) POORLY FORECAST JETSTREAM WHICH WAS INDUCED BY THUNDERSTORM UPPER LEVEL OUTFLOW
May 23, 2011 • Initially weak jet stream pattern – little turbulence expectations. • Forecast models of Jet and Turb were well under-forecast. • An area of thunderstorms Missouri and S. ILL and associated upper outflow induced a strongly sheared jet over IL-MI. • Details: forecast models predicted ~70kt jet FL340-FL360 over IL-IND-MICH, while in actuality ~100-115kt jet developed. • By early-mid afternoon a significant turbulence situation developed with frequent MOD TURB FL270-FL400 and local SEVERE FL270-FL320.
SYNOPTIC PATTERN AND VISIBLE SATELLITE CLUES….
ACTUAL JET LEVEL WINDS 2100-0000Z AT FL330-FL360 @ 100-115KT
ACTUAL VS. MODEL COMPARISON. 2100-0000Z 12HR FCST.. VALID 0000Z
SEVERE TURB @ ~FL290 VCNTY DBQ
MOD-SEV FL270-FL320 VCNTY MSN
EXAMPLE 3) WELL MODELED STRONGLY SHEARED JET NORTH OF STRONG BAROCLINIC ZONE. SEPTEMBER 5, 2011 ...SEVERAL SEVERE REPORTS OVER NORTH IND-SOUTH MICH.
EXAMPLE 3) WELL MODELED STRONGLY SHEARED JET NORTH OF STRONG BAROCLINIC ZONE. SEPTEMBER 5, 2011 ...SEVERAL SEVERE TURB REPORTS OVER NORTH IND-SOUTH MICH.
SYNOPTIC PATTERN: STRONG BAROCLINIC ZONE BETWEEN SURFACE HIGH GREAT LAKES AND REMNANTS OF TROPICAL STORM “LEE”
SEV TURB FL285-290 VCNTY GIJ (north of SBN)
31,700’ NUMEROUS AC MOD SEVERE TURB FL250-FL330 VCNTY GIJ (north of SBN) 26,300’
TODAY’S TURBULENCE ? SATELLITE: http://aviationweather.gov/adds/satellite/displaySat.php?region=US&isingle=mult_big&itype=wv AMDAR: http://amdar.noaa.gov/java/ AIRMETS: http://aviationweather.gov/products/gairmet/ FORECAST GUIDANCE: AWC ELROD: http://aviationweather.gov/exp/ellrod/ruc/ AWC GTG: http://aviationweather.gov/adds/turbulence/turb_nav.php