For evaluation of the outcome, see: 202101 - Snowfall - Sweden


For "Known Forecast Issues", see: Known IFS forecasting issues


Analyses from DWD (11 January every 6th hour)


Analyses from SMHI

Observations from Stockholm Arlanda (left) and Sundsvall () (from ogimet.com)



Short visibility forecast

(See issue M9)

Forecasts from 11 January 12UTC+12 for visibility (left), snowfall rate (middle) and total precipitation rate (right)


Forecasts from 11 January 12UTC+12 for visibility for operational forecast (left, same as above) and for 47r3 experiment (right).


Metars from 3 airports along the Swedish east-coast:


METAR/TAF for ESNN at 23:20 11/01/2021 UTCSundsvall-Harnosand Flygplats
METAR ESNN 112320Z AUTO 10020G33KT 0500
           R16/P2000N R34/P2000N SN
           VV007 M00/M00 Q0988=


METAR/TAF for ESNK at 23:20 11/01/2021 UTCKramfors Flygplats
METAR ESNK 112320Z AUTO 11016KT 070V130
           0350 R17/1200D R35/1400D +SN
           VV006 M00/M00 Q0992=


METAR/TAF for ESNO at 23:20 11/01/2021 UTCOrnskoldsvik Airport
METAR ESNO 112320Z AUTO 09021G31KT 1000
           R12/P2000N R30/P2000N -SN
           FEW002/// SCT005///
           BKN010/// M01/M02 Q0997=

ecPoint

Probability for >20 mm/12h in raw ensemble (left) and ecPoint (right).

CDF for precipitation for Stockholm (left) and northern point (right)

Snow accumulation

Known Forecast Issues S2 and S3.

The plot below shows time-series of various parameters for a point in Southern Sweden in the forecast from 11 January 12UTC and the map for precipitation type for step 12.

2-metre temperature

To evaluate the forecasts for the cold spell that followed after the cyclone, the plot below evaluates the forecasts for 2-metre temperature over southern Sweden 14-16 January, for the region outline in the 1-3 day EFI plot for the same period below. The cold signal started to appear on 28 December.


Seasonal anomalies

Time-series of daily mean 2-metre temperature in Stockholm from 1 November to 1 April (x-value is 0 on 1 January 2021). The thin line is daily mean, think solid is 7-day running mean and dashed line is ERA Interim daily climatology.