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This weather forecast discusses the development of a storm in Eastern Canada, invasion of colder surface air in Northern Alberta, and the impact on the West Coast and Prairie regions. The forecast includes information on precipitation, snowfall, storm force winds, and the movement of weather systems.
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12Z Wed (analysis) Lecture 26: Map discussion CMC prog from 12Z Wednesday Here is the 0h (analysis) …what development was forecast?
12Z Thu • analysis 12Z Thu 522 • invasion of colder sfc air in N. Ab • storm in E. Canada
00Z Fri For 5 pm MST Thursday… • high in N. Alberta 1032 mb • develop strong Gulf of Alaska low • eastern storm below 984 mb
Thu Nov 09 22:10:15 2006 GMT… W COAST: GLFALSK LO WILL REMAIN NRLY STNRY … BULK OF PCPN WILL HIT THE COAST BY BTWN T+12 AND T+36H WITH MAX AMNTS FOR WRN VRILS. LIQUID PCPN WILL TAPER DOWN BYND T+36H, SHIFTG TO NWRN US COAST. BUT SNOW WILL INCRSD BYND MID PD ALNG SRN PAC RANGE, THEN INTNSFYG ALNG THE SRN FOOTHILLS LATER IN THE PD. UP TO 15CM IS FCST BY MODEL FOR THE FOOTHILLS. STORM FORCE WINDS WILL AFFECT BC COAST ON D1 BUT WILL RPDLY WKN AS UPR TROF MVS INLAND ON D2. PRAIRIES : SIG LO FCST TO DVLP OVR SRN AB LATE IN THE PD WILL BRING LGT SNOW TO THE SRN PRAIRIES, BUT WITH MXD OR LIQUID PCPN OVR XTRM AB WITH WRM OVRNNG . 5 am + 12 5 pm Thurs ?
ISSUED BY THE PRAIRIE AND ARCTIC STORM PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CST THURSDAY NOVEMBER 9 2006. PRAIRIE DISCUSSION...ARCTIC HIGH ESTABLISHED OVER CENTRAL AB/SK. EAST OF HIGH WIDESPREAD BOUNDARY LAYER CLOUD. PBL IS VERY UNSTABLE AND WIDESPREAD FLURRIES ARE PRESENT. COLD AIR ADVECTION OVER LARGER LAKES CONTRIBUTING TO BL MOISTURE. PRECIPITATION IS MORE ENHANCED IN OFFSHORE FLOW FOR LARGER LAKES. WEST OF THE HIGH...NELY LO LVL FLO IN COMBINATION WITH OVERRUNNING MID TO UPPER LVL FLOW PRODUCING SOME PRECIPITATION IN UPLOPE AREAS OF SW SK AND WRN AB. THIS WILL CONTINUE AS THE SFC HIGH SLOWLY DRIFTS SOUTHEASTWARD.
How did the prog do? - main features were captured • arctic high in N. Alberta 1027 mb • Gulf of Alaska low trowal CMC “complete” surface analysis 18Z Thurs 9 Nov., 2006
arctic high 1028 mb and rising faster on its east flank – ie. moving eastward • light sfc winds CMC “preliminary” surface analysis 18Z Thurs 9 Nov., 2006
surface warming occurred • may be related to sink in lee of Rockies
Sea surface winds from Quikscat polar-orbiting satellite • derived from radar backscatter reveals the Gulf of Alaska low
… zooming in … Quikscat winds … 22Z Thurs 9 Nov. 2006 • strongest winds on W flank – consistent with isobar packing on CMC analysis?
http://ursus-marinus.ncep.noaa.gov/sst/oper/global_anomaly_oper0.pnghttp://ursus-marinus.ncep.noaa.gov/sst/oper/global_anomaly_oper0.png • Note the El Nino pattern
850 mb lee trowal in west central Ab • weak lee trough visible at 850, 700 • causal SW current at 700 mb evident • lee downslope adiabatic warming – larger T-Td in lee • the coastal low obviously responsible for our slightly milder conditions • weak flow aloft – slow evolution today? CMC 850 mb and 700 mb analyses 12Z Fri 10 Nov., 2006
arctic high now centred over Saskatchewan (has moved east as anticipated) • weak irregular sfc lee trough (hard to see due to “noisy” in isobars) is deepening • cyclogenesis expected – new lee storm by 12Z Sat and moves to Sask by 00Z Sun
PRAIRIE AND ARCTIC STORM PREDICTION CENTRE 7:00 AM CST FRIDAY NOVEMBER 10 2006. UPPER DISTURBANCE WILL CROSS MOUNTAINS OVERNIGHT BRINGING WARMER AIR IN ALOFT. LOW DEVELOPS IN CENTRAL ALBERTA AND TRACKS ACROSS CENTRAL SASKATCHEWAN WITH AREA OF SNOW TO THE NORTH OF LOW. WARMER AIR RETURNS TO THE SOUTHERN PRAIRIES FOR THE WEEKEND. STRONG SOUTHERLY WINDS ARE EXPECTED FOR LATE IN THE DAY SATURDAY
moist lower tropos. • weak winds • not much change likely during the day