Practical Exercise et simulated assessment : Thunderstorm, icing, turbulence
1. Your team need to produce a TS SIGMET, a ICING SIGMET and a TURBULENCE SIGMET.
Info needed:
TS SIGMET - CB max top - CB qualifiers : FRQ TS (TSGR or TSGR PSLB +FC) SQLN TS (TSGR or TSGR PSLB +FC) - Direction and speed - Trend :Intensifying/weakening/no change ICING SIGMET - Base FL, Top FL - Direction and speed - Trend :Intensifying/weakening/no change TURBULENCE SIGMET - Base FL, Top FL - Direction and speed - Trend :Intensifying/weakening/no change
2. Would you need to include these infos (severe TS, ICING or TURB) into another forecast product?
3. AMF assessment :Appropriate techniques 3.1a Forecasting severe thunderstorms Demonstrates ability to forecast the intensity, extent, movement and tops: o Verifies upstream data for intensity and visibilities in thunderstorms; o Uses satellite imagery to determine extent, evolution and movement; o Compares IR cloud-top temperature to soundings to determine tops; o Determines thunderstorm tops using radar; o Uses different NWP models and compares to reality; o Considers synoptic patterns (warm front vs. cold front thunderstorms); o Verifies different convective indices (K, LI, SWEAT, etc.); o Coordinates with other weather offices; o Determines the 0-6km mean wind for thunderstorm movement.
Demonstrates ability to forecast wind gust strength and wind shear: o Verifies upstream data; o Verifies upper-level winds using soundings (model and actual); o Uses the Doppler radar to locate possible mesocyclones and potential gusts; o Uses satellite imagery to determine whether gust fronts are present; o Coordinates with other weather offices for wind warnings.
Demonstrates ability to forecast thunderstorms: o Knows the necessary ingredients for thunderstorm formation (moisture, instability and trigger); o Uses water vapour imagery to locate jet streams (right-entrance and left-exit regions) and shortwaves; o Uses radar extrapolation tool to determine arrival time and duration; o Enumerates different indices/clues that indicate a thunderstorm might be severe (overshooting tops, hail, meso, strong winds, etc.).
3.1b Forecasting turbulence Demonstrates ability to forecast type: MECH, CAT, LEE WV o Knows the formation criteria for different types of turbulence; o Considers local effects; o Uses different types of satellite imagery for clues of turbulence (transverse bands, mountain waves, etc.); o Uses NWP models to determine levels and hence the type; o Determines surface stability (MECH vs. LLWS); o Verifies the Outgoing Flux field to locate lee waves (vertically-propagating); o Compares NWP model soundings to actual soundings; o Knows the moderate and severe MECH wind criteria; o Verifies soundings to determine moderate-to-severe wind shear levels.
Demonstrates ability to forecast severity: o Uses different tools; o Knows the difference between moderate and severe mechanical turbulence (wind force); o Uses water vapour imagery (strong moisture contrasts, well-defined transverse bands, etc.); o Considers synoptic patterns (deformation zones, etc.); o Monitors PIREPs.
Demonstrates ability to forecast base, top, onset, duration and dissipation time for the phenomenon: o Uses different tools; o Verifies IR cloud-top temperature and compares to soundings to determine level of tropopause and tops of lee wave turbulence; o Verifies soundings to determine levels of moderate-to-severe wind shear.
3.1d Forecasting icing Demonstrate ability to forecast type: CLR, MXD, RIME o Considers synoptic patterns; o Knows which type of icing is most dangerous and why; o Accurately explains what each type of icing is associated to; o Uses NWP soundings for profiles (warm nose) and cloud type and compares to actual soundings; o Uses satellite imagery to determine cloud type and therefore icing type; o Monitors PIREPs.
Demonstrates ability to forecast severity: LGT, MDT, SEV o Considers synoptic patterns; o Uses NWP soundings for profiles and cloud type and compares to actual soundings; o Uses satellite imagery to determine cloud type; o Monitors PIREPs;
Demonstrates ability to forecast base/top, onset, duration and dissipation time: o Uses NWP models and compares to reality; o Uses satellite imagery and extrapolates clouds; o Uses model soundings to forecast base and top; o Monitors PIREPs.
4. Decode a TS, ICING and TURBULENCE SIGMET SIGA0E KZNY SIGMET ECHO 2 VALID 201330/201730 KKCI- NEW YORK OCEANIC FIR FRQ TS OBS AT 1330Z WI N3200 W05645 - N2645 W05700 - N2645 W06845 - N3045 W06915 - N3200 W05645. TOP FL450. MOV ESE 15KT. NC.
ENOB SIGMET E02 VALID 201401/201801 ENVN- ENOB BODO OCEANIC FIR OCNL SEV TURB FCST WI 30 NM FM LINE N7620 - E01000 AND N7720 - E03000 FL200/290 MOV SE NC=
NZZO SIGMET 27 VALID 201424/201824 NZKL- NZZO AUCKLAND OCEANIC FIR SEV ICE FCST WI S3820 W14030 - S3800 W13700 - S4110 W13830 - S4750 W13450 - S4620 W14000 - S4120 W14300 - S3820 W14030 3000FT/FL160 STNR NC=
Find the following info for TS : - CB max tops - CB qualifier - Direction and speed - Intensifying/weakening/no change
Find the following info for ICING : - FL base and top - Direction and speed - Intensifying/weakening/no change Find the following info for TURBULENCE : - FL base and top - Direction and speed - Intensifying/weakening/no change