A THE UNIVERSITY OF ALABAMA IN HUNTSVILLE Motivation • Increasing evidence that bulk microphysical schemes in mesoscale models underpredict riming within winter storms. :tor--------..,.----.----------,.------,--------,.----, ~ a) 8 MRR 7 Simulations of nine winter storms over Long Island, NY highlighted ;:10 gl b) underprediction of s 1 MDR~ 7 61 ;1.: ~ snow fallspeeds ~ ~ ~ =·~ 4 ~= during moderate riming conditions as ~ ~ ~ ~ ~ ~ ~ ~ ~ compared to MRR Fi,...,.quoncy (%1 measurements d)' . ) THOM2 SBU-YUN Molthan et al. (2016) .5 .o .5 ~-o M.,. .n Reflectivity-Weighted f'Z>II' Speed (rn s-•) Frequen.~y (% • . r>eq ueno::y (%) Some Questions • What processes led to the rapid intensification and microphysical changes of the warm frontal precipitation band (Colle et al. 2016)? • How well can current, more advanced BMPs (i.e, P3, Goddard 41CE, SBU, and Morrison) predict the warm frontal band development and riming intensity for this event? • How do cloud microphysical processes modify the environmental conditions and the subsequent warm frontal band development? Warm Frontal Band During GCPEx 18 February 2012: King City Radar Animation 1200 UTC NWS Surface Analysis ··-···-······-··---·········-·······················-.. , ................................... . rb ) ···. . s.o 10.0 ....... \Iii;- Weather Research and Forecasting Simulations NASA-Unified-WRF configuration 520N IC and 6-h RUC Analyses sooN Boundary starting 1800 UTC 17 Fe~oN Conditions (30-h run) 46°N Vertical 44°N Resolution 50 Levels PBL Physics Mellor-Yamada-Janjic ooN 4 Cloud P3 scheme for CTL run oN 38 microphysics (Morrison et al. (20 15) qfloN ~~~~~~~~~~~~~====~ Short- and Longwave Radiation RRTMG : ~ .. . ..-·;· ... -- .... .. . . .. ---.. ..... :Kihg'City·Ra.'r ...... ..... .. Horizonal :(WKR) 1 km.S"N · ·· Resolution 9km 3km ·~ Detroit, Ml Cumulus Grell Turned Turned~-~ ';rx). . .... -:· ............ · · .. · · · , ... ·. ---,· ........: . ..... · + -- scheme Freitas off ofLz.s·N . .. ---- . . · - . -- .. -~- -~- ~~b~;AYI!" -------------------------------------------------------------- 1100 UTC- Mature OBS WRF Microphysical Schemes Scheme I Acronym Moments Notes Selected References Single ice-phase category evolves freely Predicted Particle Monison et al. (2015a) 2 in time and space; lookup table for N os, As Properties I P3 Morrison et al. (2015b) based on mass and number concentration Exphcit prediction of' number Morrison I MORR 2 Morrison et al. (2009) concentration and mass for each species Snow tnapping routine for N "'lT,qJ and Goddard 4ICE I 4ICE 1 Lang et al. (2014) N og(T,qg) N os(T) by Houze et al. (1979); M-D and Lin and Colle (2011) Stony Brook I SBU 1 V-D functions of diagnosed riming factor Lin et al. (2011) Ri, T Scheme 1-ls Ps (kg m-3) rr lookup P3 predicted -6 Ps 3 table rr MORR fCMos, As) 0 100 I 400 2 11.72 I 19.3 0.41 I 0.37 - Ps 6 151.01 I 50 I 300, rr 0.24 I 0.36, 4ICE .f(T, qs) 0 3 330.22, 500 -6 Ps 544.83 0.54 SBU .f(T) 0 .f(D) .f(T, R ;) .f(T, R;) .f(T, Ri) .f(T, Ri) P::i Cl\IL llr 0 MORR Reflectivity Obs vs WRF at 1130 UTC 79~w 20120218 1154 4S'N SSM IS 150 GHz Satellite Simulator 44"N Comparisons with WRF Micro at 1130 UTC Ice Water Content Intercept Paramete ~.0-·· oJ.V 41CE +- :\irr: 4.8 - 4ICI --r: - ! I - 1.0~ 3.5 "?:to ...!...:.:. , :J: :zs ·cl;;: l . ::c 2.0 LS 1.0~ 0.5 ()_{) '10.:0 "10 19~w Hydrometeor Mu.ss Content (g m··~) ~.-,. tmm, m .i) 20120218 1154 SSMIS 4j'N 150 G Hz Satellite 44.5'N ........... Simulator Comparisons with WRF Micro at 1130 .. ···· .........' ...... ... . UTC s1·:w Ice Water Content Intercept Parameter ~.0-·· !J.O 1- :\in: 4.~ --r.: - - 41Cl ..!, I - - MOl 21S ·>··· ..... ..... : ....... . 1.0: - PJ ... .' - snu ;no 3.5 f :E L.S: ·lr; l . :I: 2.0 1.0: ....·· ·A······· ··· .. Ct. .. O.!J ().{) s1·:w 1o·- to 10' '] 0~ Hydrometeor Muss Content (g m··'..)