SUMMARY OF SEASONAL FORECAST DATA FOR UK AND EIRE


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Experimental summary of Climate Forecasts for the UK for this and next month - updated as new data becomes available.
Previous issue March 2018 data
Seasonal - latest issue


Summary of internationally available experimental Forecasts for current month and next month for the UK and Eire


Updated 300418. (Typically updated during Thursday/Friday). Major updates may be noted on Twitter @T2mike




Met Office regular update text for 30days


Interpreted from UKMO.
UKMO 260418 - 1st May to 25th May 2018 - Some drier spells at first but mostly a changeable start with some rain or showers. Trending drier but may be restricted to the north later as the showers becomes shoery, perhaps thundery. Cool at first in north, still with a frost risk, but near normal elsewhere. Trending near normal to warm for periods especially during drier spells.
UKMO 190418 - 24th April to 18th May 2018 - A typical changeable westerly type with rain or showers especially in the N and W with longer drier interval in the E and SE though here too some rain at times. Temperature near normal perhaps warm at times in the SE but a move to more NW rather than SW or W winds into May may bring cooler temperatures especially in the North. UKMO 110418 - 16th April to 10th May 2018 - Some rain or showers with chilly temperature near E coasts but nearer normal elsewhere to start the period but trending to drier and warmer weather though still with a shower risk in the west. Becoming more unsettled again late in April and for start of May with nearer nornal temperatures.
UKMO 030418 - 8th April to 2nd May 2018 - North some showers, wintry at times but most a good deal of dry weather but with cold temperatures. In the south rain or showers at times but milder temperatures. Chance of a drier interlude soon after mid month before returning unsettled.
UKMO 290318 - 3rd April to 27th April 2018 - Mostly colder than average although the south may see values nearer normal and later in the month some also warmer days as the risk of frost become confined to northern areas. Rain or showers with some hills snow, especially in the north. Drier spells especially in the SE with more widespread drier spells possible for a time from about mid month.


CFS2 Anomalies are with respect to 1999-2010 hindcast climatology

CFS2 Data 250418
26-2M TEMP: below normal PPN: normal locally below in N and above in S
3M-9M TEMP: below normal PPN: normal
10-16 TEMP: normal PPN: normal
17-23 TEMP: normal PPN: normal

CFS2 Data 180418
19-25 TEMP: above normal PPN: S below far N above elsewhere normal
26-2M TEMP: normal but above in Wales and most of England PPN: normal perhaos below in S.
3M-9M TEMP: below normal PPN: normal
10-16 TEMP: below normal PPN: normal

CFS2 Data 100418
11-17 TEMP: above normal PPN: normal or above but below in far N
18-24 TEMP: above normal PPN: normal but below in NW Scotland
25-1M TEMP: normal but above in N Scotland, Wales and S half England PPN: normal perhaos below in S
2M-8M TEMP: normal or above normal PPN:normal

CFS2 Data 020418
3A-9A TEMP: Below normal but above normal in S PPN: Below normal
10-16 TEMP: above normal chance of normal in N and Eire. PPN: elow normal chance of normal in N
17-23 TEMP: normal or above PPN: normal or below
24-30 TEMP: uncertain above/below PPN: normal



JMA - issued - 250418
28day mean - Temp Above normal but Eire and N Ireland below normal PPN Above normal PMSL Below normal (Weak NW).
28-4M TEMP: below normal PPN: Above normal PMSL: Below normal (NW).
5M-11 TEMP: Above normal PPN: Above normal PMSL: beow normal (Slack NW).
12-25 TEMP: Above normal PPN: S and W above normal elsewhere below PMSL: W below elsewhere above (SLACK).

JMA - issued - 180418
28day mean - Temp above normal PPN N above normal S below PMSL N below S above (W).
21-27 TEMP: above normal PPN: N above normal elsewhere below PMSL: N below elsewhere above (WNW) .
28-4M TEMP: below normal PPN: W above normal elsewhere below PMSL: N below S above (W).
5M-18 TEMP: above normal PPN: England and Wales below normal elsewhere above PMSL: above normal (SW).

JMA - issued - due 120418
28day mean - Temp above normal PPN below normal PMSL below normal (weak SW).
14-20 TEMP: above normal PPN: Eire and W of Uk above normal elsewhere below PMSL: Below in the W and to the W elsewhere above (S strong in W).
21-27 TEMP: above normal PPN: below normal PMSL: below normal (SLACK/Coll).
28-11 TEMP: above normal PPN: below normal PMSL: below normal (Weak NW)

JMA - issued - 040418
28day mean - Temp SW England below but elsewhere above normal PPN Below normal PMSL below normal (Slack W).
7A-13 TEMP: above normal except N Sea coasts PPN: England and Wales above normal elsewhere below PMSL: below especilly across SW UK and S EIre (slack SE).
14-20 TEMP: above normal PPN: Eire and SW UK above elsewhere below PMSL: Eire and SW Uk below elsewhere above (SLACK).
21-4M TEMP: below normal PPN: below normal PMSL: above normal (slack NW).



CMA 100 member Ensemble issued date 260418 (25th 80 members rather than 100)
26-5M TEMP: Below normal
PPN : above normal
6M-15 TEMP: near or slgihtly below normal
PPN : S 40% chance below elsewhere above
16-25 TEMP: Below normal
PPN : NW below normal elsewhere above normal
26-4J TEMP: Below normal
PPN : Below normal but W and S chance of above normal

CMA 100 member Ensemble issued date 210418
21-30 TEMP: England 60% prob above elsewhere 80% prob below
PPN : above normal
1M-10 TEMP: Below normal
PPN : above normal but the S 40% prob below normal
11-20 TEMP: normal or below
PPN : above normal but S England 40% prob of below normal
21-30 TEMP: below normal but S 60% prob normal
PPN : Eire and N Ireland 80% prob above normal, SW EnNgland 60% prob above elsewhere prob favout below normal

CMA 100 member Ensemble issued date 160418
16-25 TEMP: above normal
PPN : above normal
26-5M TEMP: below normal
PPN : England and Wales 80% prob below elsewhere above normal
6M-15 TEMP: England slightly below elsewhere above
PPN : Mostly above normal
16-25 TEMP: Mostly above normal
PPN : Mostly below normal

CMA 100 member Ensemble issued date 110418
11-20 TEMP: S above normal N 50/50 split above/below
PPN : above normal but far N Scotland below
21-30 TEMP: near or slightly above normal
PPN : N and W below England mostly above
1M-10 TEMP: near normal
PPN : S above N below
11-20 TEMP: near normal
PPN : mosly above normal

CMA 100 member Ensemble issued date 060418
6A-15 TEMP: Below normal but S 40% prob above
PPN : above normal
16-24 TEMP: 60% above 20% near normal 20% below
PPN : mostly below normal but 40% risk above in S
25-5M TEMP: mostly near normal
PPN : mostly below normal
6M-15 TEMP: below normal
PPN : above normal

CMA 100 member Ensemble issued date 010418
1A-10 TEMP: below normal
PPN : N below elsewhere above
11-20 TEMP: normal 60% below 40%
PPN : below normal 60%
21-30 TEMP: Slightly above 80%
PPN : N Scotland 60% prob abopve elsewhere 80% prob below
1M-10 TEMP: Slightly above
PPN : 60% below




April single issue forecasts issued late March.


UKMO contingency 290318 - All of UK single average figure output.
TEMP:
APRIL: Below normal is more likely than above normal. The split is roughly 60/40 between number of colder/warmer than average ensemble members. Roughtly three clusters one above normal and two below/well below normal. Interesting reduction in the probablity for near normal values.
PPN:
APRIL: Below normal more likely than above. Split is roughly 55/45% below/above. Ensemble members cover a wide spread greater than the cliamtology. Reduced number of solutions slightly above normal and increased slightly below normal.

CanSIPS - 310318
TEMP:
APR below normal
PPN :
APR Scotland below England Wales and SE Enire above elsewhere normal


Next full month May 2018 (number of runs) [running total]




UKMO contingency 300418
TEMP:
MAY Fairly even spread above or below normal but with few member clustered near normal implying uncertainty (Met O says near normal)
PPN:
MAY above normal more likely than below - districbution shifted towards above normal but there are two similar clusters one above and one below normal. More members of the ensemble well above normal.


NOAA - CFS2 - 260418 valid for May 2018
TEMP: Near or below normal in S (4/7), above (3/7). In N near normal (3/7) above (4/7)
PPN : Normal N 3/7 S 5/7. Below normal N 4/7 S 0/7

NOAA - CFS2 - 190418 valid for May 2018
TEMP: 5/8 [9/19] above normal, 7/8 [11/19] in S, otherwise normal [9/19]
PPN : NW half of UK above normal 7/8 [8/19] SW half normal 6/8 [14/19]or below 2/8 [5/19]

NOAA - CFS2 - 110418 - valid for May 2018
TEMP: Above normal 2/8 [4/11] normal 6/8 [7/11]
PPN : Above normal in N 1/8 [1/11] below normal 3/8 [3/11] normal 5/8 [8/11] (4/8 in N)

NOAA - CFS2 -030418 valid for May 2018
TEMP: above normal 2/3 normal 1/3
PPN : normal 3/3



CanSIPS - 310318
TEMP:
MAY above normal but SW England and Eire normal JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR
PPN :
MAY normal





CFS2 E3 ensemble of 10 days of model runs. Updated - see date on graphic.
TN1 TN4


Graphics ex NOAA CPC 080418
NMME T2M and PPN anomaly UK ZOOMED area plotted from 1 DEG GRIB NMME data

NMME NMME

CFS2 PPN rate and 2M temp anomaly
CFS CFS

NMME MAX and MIN not available

NMME T2M and PPN anomaly

NMME NMME

Temp and PPN rate probability NMME

NMME NMME


NOTEs: 1. NORMAL=typically the model normal based on historic runs rather than the measured normal from observation - hence trends rather than numbers are a better guide.
2. CFS2 seasonal anomalies are with respect to the lead dependent model climatology from the hindcast period (1999-2010) without any adjustment - a very warm decade!.
3. UKMET The hindcast period used for model normal is 1996 to 2009. 42-member ensemble seasonal forecast (120KM res over land) combining and bias correcting all forecast members available prior to issue.
4. CFS2 Weekly forecast anomalies are with respect to 1999-2010 hindcast climatology which was a warm period (SST 1982-2010) also mostly a wet period for Uk compared to longer period stats.
CFS2 Monthly and seasonal hind cast period 1982-2010
5. NMME data, please see the BAMS article (Kirtman et al. 2014). The NMME project and data dissemination is supported by NOAA, NSF, NASA and DOE. with the help of NCEP, IRI and NCAR personnel in creating, updating and maintaining the NMME archive.

KEY:
UKMO=UK Met Office KMA= Korea Met Agency JMA=Japan Met Agency Russia=Hydrometcentre of Russia NOAA=main US climate data model used by Climate Prediction Centre. Other N America data also used via NASA and IRI. CMA=China Meteorological Administration

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