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Verification of Experimental Seasonal Summary Forecast for UK area, January, February and March 2018 - compiled 4 April 2018
Met Office Anomaly Graphs
Met Office Monthly Anomaly Charts
CPC/UKMO MONTH TEMP and PPN anomalies
Review:
Pressure: January and March below averge February above, three month mean below average.
Temperature: Scotland, N Ireland and Eire, below average throughout, but only slightly in January, season below average. England and Wales Januarys milder but Feb and March colder. Season colder. All UK colder than average for season.
Rainfall: Generally wetter Jnauary, drier February and mostly wetter March except Scotland, N Ireland and NW Eire had drier March. UK as whole slightly below for season but this hides wetter England, Wales, Eire and N Ireland and drier Scotland.
Sunshine: near average January above in February but below in March, season above normal.
Verification will be looking for below average pressure and temperatuyre with above average rain (except in N). Some idea of milder start and colder end and drier and colder February.
Follow link to
original forecast summary for detail of forecast.
DATA available in 2017 December for 2018 January February March
Original summary "Summary - 16Dec2017 -
Strong signal for above normal. Some variations; from near normal and a minority below normal in far N to well above normal in the south. Most systems have each month above normal although anomalies in March less strong and hints that it may be colder than normal later in the month?. Rainfall signal is also for above normal for the season perhaps especially so in January and less so in March for central and southern parts. Above normal strongest signal in SW third of UK and parts of Eire transferring to northern parts later in season. March less wet espeically in S and E. Signal for below normal pressure which is required for milder wetter regime.
Hint of caution stratospheric warming is occuring over Canada and may impact on the weather patterns later inthe season. Not yet sure 1. whether reversal of stratospheric winds will occur towards UK area leading to more blocked patterns (could be anticyclonic or cyclonic in UK area) or 2. the polar stratospheric vortex will be warmed out very early or 3.votex will re-develop.
La Nina statistical relationship was not a help.
Verification will be looking for below average pressure and temperatuyre with above average rain (except in N). Some idea of milder start and colder end and drier and colder February.
CFS2 and NMME graphics gave idea of above average rainfall but did not get drier Febuary and temperature indication waas poor way to warm.
Scoring will attempt to state good, fair, poor or no signal.
No signal for any centre for less above normnal/near normal in July after warmer May/June.
Summary: Signal for stratospheric warming was correct but this led to a change to colder types much earlier than implied hence temperature forecast was poor. Rainfall some good indication for above normal in the south but no idea of drier February. Pressure signal good.
1. Russia: Temp missing . PPN missing .
2. USA - CFS2 : Temp poor . PPN fair, good in S for above (normal but not monthly deatail) .
3. UKMO Contingency: Temp poor . PPN good .
4. UKMO : Temp poor. PPN good . PMSL good .
5. USA - IRI : Temp no signal . PPN good .
6. KMA APCC : Temp poor . PPN poor .
7. JMA : Temp poor. PPN fair . PMSL good
8. NMME : Temp poor . PPN good .
9. IMME - Temp poor . PPN fair .
10. BCC - Temp poor . PPN fair .
11. NASA - Temp poor . PPN poor .
12. Brazil: Temp poor . PPN poor . PMSL good.
13. CanSips : Temp poor . PPN good got some idea of drier Feb .
14. SAWS: : Temp poor . PPN good (but poor for drier N) .
15. Copernicus Temp poor . PPN good . PMSL good
16. EC Temp poor . PPN good . PMSL good
17. MF Temp poor . PPN fair . PMSL good
18. JAMTEC: Temp poor . PPN good .
CFS2 MAX MIN TEMP
CFS2 TEMP
CFS2 PPN
NMME MAX and MIN not available
NMME Temp:
NMME PPN rate:
NMME TEMP PROBS:
NMME PPN:
UK area Plotted from 1 deg grib NMME ENS Temp and PPN rate mean anomaly
CFS2 E3 ensemble of 10 days of model runs - see graphic for data date.
DATA available in November for 2018 January February March
Only Cansips had indication of colder Feb. (BCC had colder J and F and milder M). most had above normal rainfall.
DATA available in October for 2018 January February March
BCC China had a good stab at monthly temperature and rainfall but ws too mild for March. Cansips was good with monthly rain but not good with temperature.
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