Moisture/Lift/Instability

925 mb Temp Advection	925 mb Frontogenesis		925-850 mb Frontogenesis	925 mb Moisture Transport

850 mb Temp Advection	850 mb Frontogenesis	850 mb Frontogenesis 800-750 mb EPV	850-700 mb Frontogenesis	850 mb Moisture Transport

700 mb Temp Advection	700 mb Frontogenesis	700 mb Frontogenesis 650-500 mb EPV	700-500 mb Frontogenesis	Mid Level Lapse Rates

Mesoscale bands of heavy snow are favored where frontogenetic circulations are embedded within an unstable thermodynamic enviroment (slantwise or vertical) .  Geostrophic Equivalent Potential Vorticity (EPVg) < 0 suggest parcels will be unstable to slantwise motions within that layer of the atmosphere. EPVg as an ingredient to mesoscale banded precipitation is best evaluated in a 50-100 mb layer directly above where frontogensis is being analyzed.  If EVPg is < 0 in this layer, the ageostrophic frontogenetic circulation will be enhanced. If elevated CAPE or steep lapse rates are also present, the parcels unstable to slantwise motion will become unstable in the vertical, resulting in upright convection.  Thermodynamics Sfc T/Td/MSLP Near Surface Freezing Temp SFC Wet Bulb Freezing Level MSLP 2hr MSLP Change Sfc Obs 3hr Temp Change 925 mb 850 mb 850 mb - Wind 700 mb 500 mb 500 mb - 12hr Hgt Chg 700-400mb Diff Vort Adv 400-250mb Pot Vort Adv 300 mb DGZ DGZ Depth DGZ RH DGZ Depth + RH Lake Effect and Snow Squall Lake Effect Snow 1 Lake Effect Snow 2 Snow Squall Low Level Lapse Rates